From 98b086f746fdc519cf0d51b86a777a265c359552 Mon Sep 17 00:00:00 2001
From: seanbreckenridge <seanbrecke@gmail.com>
Date: Mon, 27 Feb 2023 20:30:06 -0800
Subject: [PATCH] location fallback (#263)

see https://github.com/karlicoss/HPI/issues/262

* move home to fallback/via_home.py
* move via_ip to fallback
* add fallback model
* add stub via_ip file
* add fallback_locations for via_ip
* use protocol for locations
* estimate_from helper, via_home estimator, all.py
* via_home: add accuracy, cache history
* add datasources to gpslogger/google_takeout
* tz/via_location.py: update import to fallback
* denylist docs/installation instructions
* tz.via_location: let user customize cachew refresh time
* add via_ip.estimate_location using binary search
* use estimate_location in via_home.get_location
* tests: add gpslogger to location config stub
* tests: install tz related libs in test env
* tz: add regression test for broken windows dates

* vendorize bisect_left from python src
doesnt have a 'key' parameter till python3.10
---
 doc/DENYLIST.md                  | 130 ++++++++++++++++++++++
 doc/MODULE_DESIGN.org            |   3 +-
 my/config.py                     |   4 +-
 my/core/compat.py                |  32 ++++++
 my/core/denylist.py              | 178 +++++++++++++++++++++++++++++++
 my/ip/all.py                     |   2 +-
 my/ip/common.py                  |   8 +-
 my/location/all.py               |   1 +
 my/location/common.py            |  23 +++-
 my/location/fallback/all.py      |  53 +++++++++
 my/location/fallback/common.py   | 120 +++++++++++++++++++++
 my/location/fallback/via_home.py | 104 ++++++++++++++++++
 my/location/fallback/via_ip.py   |  99 +++++++++++++++++
 my/location/google_takeout.py    |   7 +-
 my/location/gpslogger.py         |  10 +-
 my/location/home.py              |  74 +------------
 my/location/via_ip.py            |  38 +------
 my/time/tz/via_location.py       |  95 ++++++++++++-----
 setup.py                         |   1 +
 tests/core/test_denylist.py      | 106 ++++++++++++++++++
 tests/location.py                |  23 +---
 tests/location_fallback.py       | 125 ++++++++++++++++++++++
 tests/shared_config.py           |  65 +++++++++++
 tests/tz.py                      |  47 +++-----
 tox.ini                          |   8 +-
 25 files changed, 1166 insertions(+), 190 deletions(-)
 create mode 100644 doc/DENYLIST.md
 create mode 100644 my/core/denylist.py
 create mode 100644 my/location/fallback/all.py
 create mode 100644 my/location/fallback/common.py
 create mode 100644 my/location/fallback/via_home.py
 create mode 100644 my/location/fallback/via_ip.py
 create mode 100644 tests/core/test_denylist.py
 create mode 100644 tests/location_fallback.py
 create mode 100644 tests/shared_config.py

diff --git a/doc/DENYLIST.md b/doc/DENYLIST.md
new file mode 100644
index 0000000..d57b8b1
--- /dev/null
+++ b/doc/DENYLIST.md
@@ -0,0 +1,130 @@
+For code reference, see: [`my.core.denylist.py`](../my/core/denylist.py)
+
+A helper module for defining denylists for sources programmatically (in layman's terms, this lets you remove some particular output from a module you don't want)
+
+Lets you specify a class, an attribute to match on,
+and a JSON file containing a list of values to deny/filter out
+
+As an example, this will use the `my.ip` module, as filtering incorrect IPs was the original use case for this module:
+
+```python
+class IP(NamedTuple):
+    addr: str
+    dt: datetime
+```
+
+A possible denylist file would contain:
+
+```json
+[
+    {
+        "addr": "192.168.1.1",
+    },
+    {
+        "dt": "2020-06-02T03:12:00+00:00",
+    }
+]
+```
+
+Note that if the value being compared to is not a single (non-array/object) JSON primitive
+(str, int, float, bool, None), it will be converted to a string before comparison
+
+To use this in code:
+
+```python
+from my.ip.all import ips
+filtered = DenyList("~/data/ip_denylist.json").filter(ips())
+```
+
+To add items to the denylist, in python (in a one-off script):
+
+```python
+from my.ip.all import ips
+from my.core.denylist import DenyList
+
+d = DenyList("~/data/ip_denylist.json")
+
+for ip in ips():
+    # some custom code you define
+    if ip.addr == ...:
+        d.deny(key="ip", value=ip.ip)
+    d.write()
+```
+
+... or interactively, which requires [`fzf`](https://github.com/junegunn/fzf) and [`pyfzf-iter`](https://pypi.org/project/pyfzf-iter/) (`python3 -m pip install pyfzf-iter`) to be installed:
+
+```python
+from my.ip.all import ips
+from my.core.denylist import DenyList
+
+d = DenyList("~/data/ip_denylist.json")
+d.deny_cli(ips())  # automatically writes after each selection
+```
+
+That will open up an interactive `fzf` prompt, where you can select an item to add to the denylist
+
+This is meant for relatively simple filters, where you want to filter items out
+based on a single attribute of a namedtuple/dataclass. If you want to do something
+more complex, I would recommend overriding the `all.py` file for that source and
+writing your own filter function there.
+
+For more info on all.py:
+
+https://github.com/karlicoss/HPI/blob/master/doc/MODULE_DESIGN.org#allpy
+
+This would typically be used in an overridden `all.py` file, or in a one-off script
+which you may want to filter out some items from a source, progressively adding more
+items to the denylist as you go.
+
+A potential `my/ip/all.py` file might look like (Sidenote: `discord` module from [here](https://github.com/seanbreckenridge/HPI)):
+
+```python
+from typing import Iterator
+
+from my.ip.common import IP
+from my.core.denylist import DenyList
+
+deny = DenyList("~/data/ip_denylist.json")
+
+# all possible data from the source
+def _ips() -> Iterator[IP]:
+    from my.ip import discord
+    # could add other imports here
+
+    yield from discord.ips()
+
+
+# filtered data
+def ips() -> Iterator[IP]:
+    yield from deny.filter(_ips())
+```
+
+To add items to the denylist, you could create a `__main__.py` in your namespace package (in this case, `my/ip/__main__.py`), with contents like:
+
+```python
+from my.ip import all
+
+if __name__ == "__main__":
+    all.deny.deny_cli(all.ips())
+```
+
+Which could then be called like: `python3 -m my.ip`
+
+Or, you could just run it from the command line:
+
+```
+python3 -c 'from my.ip import all; all.deny.deny_cli(all.ips())'
+```
+
+To edit the `all.py`, you could either:
+
+- install it as editable (`python3 -m pip install --user -e ./HPI`), and then edit the file directly
+- or, create a namespace package, which splits the package across multiple directories. For info on that see [`MODULE_DESIGN`](https://github.com/karlicoss/HPI/blob/master/doc/MODULE_DESIGN.org#namespace-packages), [`reorder_editable`](https://github.com/seanbreckenridge/reorder_editable), and possibly the [`HPI-template`](https://github.com/seanbreckenridge/HPI-template) to create your own HPI namespace package to create your own `all.py` file.
+
+TODO: link to seanbreckenridge/HPI-personal for an example of this once this is merged/settled
+
+Sidenote: the reason why we want to specifically override
+the all.py and not just create a script that filters out the items you're
+not interested in is because we want to be able to import from `my.ip.all`
+or `my.location.all` from other modules and get the filtered results, without
+having to mix data filtering logic with parsing/loading/caching (the stuff HPI does)
diff --git a/doc/MODULE_DESIGN.org b/doc/MODULE_DESIGN.org
index b17526d..691dd1c 100644
--- a/doc/MODULE_DESIGN.org
+++ b/doc/MODULE_DESIGN.org
@@ -226,8 +226,7 @@ The main goals are:
  - doesn't require you to maintain a fork of this repository, though you can maintain a separate HPI repository (so no patching/merge conflicts)
  - allows you to easily add/remove sources to the ~all.py~ module, either by:
     - overriding an ~all.py~ in your own repository
-    - just commenting out the source/adding 2 lines to import and ~yield
-      from~ your new source
+    - just commenting out the source/adding 2 lines to import and ~yield from~ your new source
     - doing nothing! (~import_source~ will catch the error and just warn you
       and continue to work without changing any code)
 
diff --git a/my/config.py b/my/config.py
index e9eafec..7075d1d 100644
--- a/my/config.py
+++ b/my/config.py
@@ -72,16 +72,18 @@ class google:
 
 
 from typing import Sequence, Union, Tuple
-from datetime import datetime, date
+from datetime import datetime, date, timedelta
 DateIsh = Union[datetime, date, str]
 LatLon = Tuple[float, float]
 class location:
     # todo ugh, need to think about it... mypy wants the type here to be general, otherwise it can't deduce
     # and we can't import the types from the module itself, otherwise would be circular. common module?
     home: Union[LatLon, Sequence[Tuple[DateIsh, LatLon]]] = (1.0, -1.0)
+    home_accuracy = 30_000.0
 
     class via_ip:
         accuracy: float
+        for_duration: timedelta
 
     class gpslogger:
         export_path: Paths = ''
diff --git a/my/core/compat.py b/my/core/compat.py
index 3c825f2..dcf97cc 100644
--- a/my/core/compat.py
+++ b/my/core/compat.py
@@ -125,3 +125,35 @@ else:
     else:
         from typing import Dict
         TypedDict = Dict
+
+
+# bisect_left doesnt have a 'key' parameter (which we use)
+# till python3.10
+if sys.version_info[:2] <= (3, 9):
+    from typing import List, TypeVar, Any, Optional, Callable
+    X = TypeVar('X')
+    # copied from python src
+    def bisect_left(a: List[Any], x: Any, lo: int=0, hi: Optional[int]=None, *, key: Optional[Callable[..., Any]]=None) -> int:
+        if lo < 0:
+            raise ValueError('lo must be non-negative')
+        if hi is None:
+            hi = len(a)
+        # Note, the comparison uses "<" to match the
+        # __lt__() logic in list.sort() and in heapq.
+        if key is None:
+            while lo < hi:
+                mid = (lo + hi) // 2
+                if a[mid] < x:
+                    lo = mid + 1
+                else:
+                    hi = mid
+        else:
+            while lo < hi:
+                mid = (lo + hi) // 2
+                if key(a[mid]) < x:
+                    lo = mid + 1
+                else:
+                    hi = mid
+        return lo
+else:
+    from bisect import bisect_left  # type: ignore[misc]
diff --git a/my/core/denylist.py b/my/core/denylist.py
new file mode 100644
index 0000000..fcf3e2b
--- /dev/null
+++ b/my/core/denylist.py
@@ -0,0 +1,178 @@
+"""
+A helper module for defining denylists for sources programatically
+(in lamens terms, this lets you remove some output from a module you don't want)
+
+For docs, see doc/DENYLIST.md
+"""
+
+import sys
+import json
+import functools
+from collections import defaultdict
+from typing import TypeVar, Set, Any, Mapping, Iterator, Dict, List
+from pathlib import Path
+
+import click
+from more_itertools import seekable
+from my.core.serialize import dumps
+from my.core.common import PathIsh
+from my.core.warnings import medium
+
+
+T = TypeVar("T")
+
+DenyMap = Mapping[str, Set[Any]]
+
+
+def _default_key_func(obj: T) -> str:
+    return str(obj)
+
+
+class DenyList:
+    def __init__(self, denylist_file: PathIsh):
+        self.file = Path(denylist_file).expanduser().absolute()
+        self._deny_raw_list: List[Dict[str, Any]] = []
+        self._deny_map: DenyMap = defaultdict(set)
+
+        # deny cli, user can override these
+        self.fzf_path = None
+        self._fzf_options = ()
+        self._deny_cli_key_func = None
+
+    def _load(self) -> None:
+        if not self.file.exists():
+            medium(f"denylist file {self.file} does not exist")
+            return
+
+        deny_map: DenyMap = defaultdict(set)
+        data: List[Dict[str, Any]]= json.loads(self.file.read_text())
+        self._deny_raw_list = data
+
+        for ignore in data:
+            for k, v in ignore.items():
+                deny_map[k].add(v)
+
+        self._deny_map = deny_map
+
+    def load(self) -> DenyMap:
+        self._load()
+        return self._deny_map
+
+    def write(self) -> None:
+        if not self._deny_raw_list:
+            medium("no denylist data to write")
+            return
+        self.file.write_text(json.dumps(self._deny_raw_list))
+
+    @classmethod
+    def _is_json_primitive(cls, val: Any) -> bool:
+        return isinstance(val, (str, int, float, bool, type(None)))
+
+    @classmethod
+    def _stringify_value(cls, val: Any) -> Any:
+        # if it's a primitive, just return it
+        if cls._is_json_primitive(val):
+            return val
+        # otherwise, stringify-and-back so we can compare to
+        # json data loaded from the denylist file
+        return json.loads(dumps(val))
+
+    @classmethod
+    def _allow(cls, obj: T, deny_map: DenyMap) -> bool:
+        for deny_key, deny_set in deny_map.items():
+            # this should be done separately and not as part of the getattr
+            # because 'null'/None could actually be a value in the denylist,
+            # and the user may define behavior to filter that out
+            if not hasattr(obj, deny_key):
+                return False
+            val = cls._stringify_value(getattr(obj, deny_key))
+            # this object doesn't have have the attribute in the denylist
+            if val in deny_set:
+                return False
+        # if we tried all the denylist keys and didn't return False,
+        # then this object is allowed
+        return True
+
+    def filter(
+        self,
+        itr: Iterator[T],
+        invert: bool = False,
+    ) -> Iterator[T]:
+        denyf = functools.partial(self._allow, deny_map=self.load())
+        if invert:
+            return filter(lambda x: not denyf(x), itr)
+        return filter(denyf, itr)
+
+    def deny(self, key: str, value: Any, write: bool = False) -> None:
+        '''
+        add a key/value pair to the denylist
+        '''
+        if not self._deny_raw_list:
+            self._load()
+        self._deny_raw({key: self._stringify_value(value)}, write=write)
+
+    def _deny_raw(self, data: Dict[str, Any], write: bool = False) -> None:
+        self._deny_raw_list.append(data)
+        if write:
+            self.write()
+
+    def _prompt_keys(self, item: T) -> str:
+        import pprint
+
+        click.echo(pprint.pformat(item))
+        # TODO: extract keys from item by checking if its dataclass/NT etc.?
+        resp = click.prompt("Key to deny on").strip()
+        if not hasattr(item, resp):
+            click.echo(f"Could not find key '{resp}' on item", err=True)
+            return self._prompt_keys(item)
+        return resp
+
+    def _deny_cli_remember(
+        self,
+        items: Iterator[T],
+        mem: Dict[str, T],
+    ) -> Iterator[str]:
+        keyf = self._deny_cli_key_func or _default_key_func
+        # i.e., convert each item to a string, and map str -> item
+        for item in items:
+            key = keyf(item)
+            mem[key] = item
+            yield key
+
+    def deny_cli(self, itr: Iterator[T]) -> None:
+        try:
+            from pyfzf import FzfPrompt
+        except ImportError:
+            click.echo("pyfzf is required to use the denylist cli, run 'python3 -m pip install pyfzf_iter'", err=True)
+            sys.exit(1)
+
+        # wrap in seekable so we can use it multiple times
+        # progressively caches the items as we iterate over them
+        sit = seekable(itr)
+
+        prompt_continue = True
+
+        while prompt_continue:
+            # reset the iterator
+            sit.seek(0)
+            # so we can map the selected string from fzf back to the original objects
+            memory_map: Dict[str, T] = {}
+            picker = FzfPrompt(
+                executable_path=self.fzf_path, default_options="--no-multi"
+            )
+            picked_l = picker.prompt(
+                self._deny_cli_remember(itr, memory_map),
+                "--read0",
+                *self._fzf_options,
+                delimiter="\0",
+            )
+            assert isinstance(picked_l, list)
+            if picked_l:
+                picked: T = memory_map[picked_l[0]]
+                key = self._prompt_keys(picked)
+                self.deny(key, getattr(picked, key), write=True)
+                click.echo(f"Added {self._deny_raw_list[-1]} to denylist", err=True)
+            else:
+                click.echo("No item selected", err=True)
+
+            prompt_continue = click.confirm("Continue?")
diff --git a/my/ip/all.py b/my/ip/all.py
index b21b543..f4cdb37 100644
--- a/my/ip/all.py
+++ b/my/ip/all.py
@@ -13,7 +13,7 @@ from typing import Iterator
 
 from my.core.common import Stats, warn_if_empty
 
-from .common import IP
+from my.ip.common import IP
 
 
 @warn_if_empty
diff --git a/my/ip/common.py b/my/ip/common.py
index 82008e2..b4bfc8e 100644
--- a/my/ip/common.py
+++ b/my/ip/common.py
@@ -7,7 +7,7 @@ REQUIRES = ["git+https://github.com/seanbreckenridge/ipgeocache"]
 from my.core import __NOT_HPI_MODULE__
 
 import ipaddress
-from typing import NamedTuple, Iterator
+from typing import NamedTuple, Iterator, Tuple
 from datetime import datetime
 
 import ipgeocache
@@ -23,6 +23,12 @@ class IP(NamedTuple):
     def ipgeocache(self) -> Json:
         return ipgeocache.get(self.addr)
 
+    @property
+    def latlon(self) -> Tuple[float, float]:
+        loc: str = self.ipgeocache()["loc"]
+        lat, _, lon = loc.partition(",")
+        return float(lat), float(lon)
+
     @property
     def tzname(self) -> str:
         tz: str = self.ipgeocache()["timezone"]
diff --git a/my/location/all.py b/my/location/all.py
index eec4bcc..8d51a82 100644
--- a/my/location/all.py
+++ b/my/location/all.py
@@ -32,6 +32,7 @@ def _gpslogger_locations() -> Iterator[Location]:
     yield from gpslogger.locations()
 
 
+# TODO: remove, user should use fallback.estimate_location or fallback.fallback_locations instead
 @import_source(module_name="my.location.via_ip")
 def _ip_locations() -> Iterator[Location]:
     from . import via_ip
diff --git a/my/location/common.py b/my/location/common.py
index b0676ec..fa8bdad 100644
--- a/my/location/common.py
+++ b/my/location/common.py
@@ -1,17 +1,34 @@
 from datetime import date, datetime
-from typing import Union, Tuple, NamedTuple, Optional
+from typing import Union, Tuple, Optional
+from dataclasses import dataclass
 
 from my.core import __NOT_HPI_MODULE__
+from my.core.compat import Protocol
 
 DateIsh = Union[datetime, date, str]
 
 LatLon = Tuple[float, float]
 
 
-# TODO: add timezone to this? can use timezonefinder in tz provider instead though
-class Location(NamedTuple):
+class LocationProtocol(Protocol):
     lat: float
     lon: float
     dt: datetime
     accuracy: Optional[float]
     elevation: Optional[float]
+    datasource: Optional[str] = None  # which module provided this, useful for debugging
+
+
+# TODO: add timezone to this? can use timezonefinder in tz provider instead though
+
+
+# converted from namedtuple to a dataclass so datasource field can be added optionally
+# if we want, can eventually be converted back to a namedtuple when all datasources are compliant
+@dataclass(frozen=True, eq=True)
+class Location(LocationProtocol):
+    lat: float
+    lon: float
+    dt: datetime
+    accuracy: Optional[float]
+    elevation: Optional[float]
+    datasource: Optional[str] = None  # which module provided this, useful for debugging
diff --git a/my/location/fallback/all.py b/my/location/fallback/all.py
new file mode 100644
index 0000000..0c7b8cd
--- /dev/null
+++ b/my/location/fallback/all.py
@@ -0,0 +1,53 @@
+# TODO: add config here which passes kwargs to estimate_from (under_accuracy)
+# overwritable by passing the kwarg name here to the top-level estimate_location
+
+from typing import Iterator, Optional
+
+from my.core.source import import_source
+from my.location.fallback.common import (
+    estimate_from,
+    FallbackLocation,
+    DateExact,
+    LocationEstimator,
+)
+
+
+def fallback_locations() -> Iterator[FallbackLocation]:
+    # can comment/uncomment sources here to enable/disable them
+    yield from _ip_fallback_locations()
+
+
+def fallback_estimators() -> Iterator[LocationEstimator]:
+    # can comment/uncomment estimators here to enable/disable them
+    # the order of the estimators determines priority if location accuries are equal/unavailable
+    yield _ip_estimate
+    yield _home_estimate
+
+
+def estimate_location(dt: DateExact, first_match: bool=False, under_accuracy: Optional[int] = None) -> FallbackLocation:
+    loc = estimate_from(dt, estimators=list(fallback_estimators()), first_match=first_match, under_accuracy=under_accuracy)
+    # should never happen if the user has home configured
+    if loc is None:
+        raise ValueError("Could not estimate location")
+    return loc
+
+
+@import_source(module_name="my.location.fallback.via_home")
+def _home_estimate(dt: DateExact) -> Iterator[FallbackLocation]:
+    from my.location.fallback.via_home import estimate_location as via_home_estimate
+
+    yield from via_home_estimate(dt)
+
+
+@import_source(module_name="my.location.fallback.via_ip")
+def _ip_estimate(dt: DateExact) -> Iterator[FallbackLocation]:
+    from my.location.fallback.via_ip import estimate_location as via_ip_estimate
+
+    yield from via_ip_estimate(dt)
+
+
+@import_source(module_name="my.location.fallback.via_ip")
+def _ip_fallback_locations() -> Iterator[FallbackLocation]:
+    from my.location.fallback.via_ip import fallback_locations as via_ip_fallback
+
+    yield from via_ip_fallback()
diff --git a/my/location/fallback/common.py b/my/location/fallback/common.py
new file mode 100644
index 0000000..fa1d4c5
--- /dev/null
+++ b/my/location/fallback/common.py
@@ -0,0 +1,120 @@
+from __future__ import annotations
+from dataclasses import dataclass
+from typing import Optional, Callable, Sequence, Iterator, List, Union
+from datetime import datetime, timedelta, timezone
+
+from ..common import LocationProtocol, Location
+DateExact = Union[datetime, float, int]  # float/int as epoch timestamps
+
+Second = float
+
+@dataclass
+class FallbackLocation(LocationProtocol):
+    lat: float
+    lon: float
+    dt: datetime
+    duration: Optional[Second] = None
+    accuracy: Optional[float] = None
+    elevation: Optional[float] = None
+    datasource: Optional[str] = None  # which module provided this, useful for debugging
+
+    def to_location(self, end: bool = False) -> Location:
+        '''
+        by default the start date is used for the location
+        If end is True, the start date + duration is used
+        '''
+        dt: datetime = self.dt
+        if end and self.duration is not None:
+            dt += timedelta(self.duration)
+        return Location(
+            lat=self.lat,
+            lon=self.lon,
+            dt=dt,
+            accuracy=self.accuracy,
+            elevation=self.elevation,
+            datasource=self.datasource,
+        )
+
+    @classmethod
+    def from_end_date(
+        cls,
+        *,
+        lat: float,
+        lon: float,
+        dt: datetime,
+        end_dt: datetime,
+        accuracy: Optional[float] = None,
+        elevation: Optional[float] = None,
+        datasource: Optional[str] = None,
+    ) -> FallbackLocation:
+        '''
+        Create FallbackLocation from a start date and an end date
+        '''
+        if end_dt < dt:
+            raise ValueError("end_date must be after dt")
+        duration = (end_dt - dt).total_seconds()
+        return cls(
+            lat=lat,
+            lon=lon,
+            dt=dt,
+            duration=duration,
+            accuracy=accuracy,
+            elevation=elevation,
+            datasource=datasource,
+        )
+
+
+# a location estimator can return multiple fallbacks, incase there are
+# differing accuracies/to allow for possible matches to be computed
+# iteratively
+LocationEstimator = Callable[[DateExact], Iterator[FallbackLocation]]
+LocationEstimators = Sequence[LocationEstimator]
+
+# helper function, instead of dealing with datetimes while comparing, just use epoch timestamps
+def _datetime_timestamp(dt: DateExact) -> float:
+    if isinstance(dt, datetime):
+        try:
+            return dt.timestamp()
+        except ValueError:
+            # https://github.com/python/cpython/issues/75395
+            return dt.replace(tzinfo=timezone.utc).timestamp()
+    return float(dt)
+
+def _iter_estimate_from(
+    dt: DateExact,
+    estimators: LocationEstimators,
+) -> Iterator[FallbackLocation]:
+    for est in estimators:
+        yield from est(dt)
+
+
+def estimate_from(
+    dt: DateExact,
+    estimators: LocationEstimators,
+    *,
+    first_match: bool = False,
+    under_accuracy: Optional[int] = None,
+) -> Optional[FallbackLocation]:
+    '''
+    first_match: if True, return the first location found
+    under_accuracy: if set, only return locations with accuracy under this value
+    '''
+    found: List[FallbackLocation] = []
+    for loc in _iter_estimate_from(dt, estimators):
+        if under_accuracy is not None and loc.accuracy is not None and loc.accuracy > under_accuracy:
+            continue
+        if first_match:
+            return loc
+        found.append(loc)
+
+    if not found:
+        return None
+
+    # if all items have accuracy, return the one with the lowest accuracy
+    # otherwise, we should prefer the order that the estimators are passed in as
+    if all(loc.accuracy is not None for loc in found):
+        # return the location with the lowest accuracy
+        return min(found, key=lambda loc: loc.accuracy)  # type: ignore[return-value, arg-type]
+    else:
+        # return the first location
+        return found[0]
diff --git a/my/location/fallback/via_home.py b/my/location/fallback/via_home.py
new file mode 100644
index 0000000..240da84
--- /dev/null
+++ b/my/location/fallback/via_home.py
@@ -0,0 +1,104 @@
+'''
+Simple location provider, serving as a fallback when more detailed data isn't available
+'''
+
+from dataclasses import dataclass
+from datetime import datetime, time, timezone
+from functools import lru_cache
+from typing import Sequence, Tuple, Union, cast, List, Iterator
+
+from my.config import location as user_config
+
+from my.location.common import LatLon, DateIsh
+from my.location.fallback.common import FallbackLocation, DateExact
+
+@dataclass
+class Config(user_config):
+    home: Union[
+        LatLon,         # either single, 'current' location
+        Sequence[Tuple[ # or, a sequence of location history
+            DateIsh,    # date when you moved to
+            LatLon,     # the location
+        ]]
+    ]
+
+    # default ~30km accuracy
+    # this is called 'home_accuracy' since it lives on the base location.config object,
+    # to differentiate it from accuracy for other providers
+    home_accuracy: float = 30_000
+
+    # TODO could make current Optional and somehow determine from system settings?
+    @property
+    def _history(self) -> Sequence[Tuple[datetime, LatLon]]:
+        home1 = self.home
+        # todo ugh, can't test for isnstance LatLon, it's a tuple itself
+        home2: Sequence[Tuple[DateIsh, LatLon]]
+        if isinstance(home1[0], tuple):
+            # already a sequence
+            home2 = cast(Sequence[Tuple[DateIsh, LatLon]], home1)
+        else:
+            # must be a pair of coordinates. also doesn't really matter which date to pick?
+            loc = cast(LatLon, home1)
+            home2 = [(datetime.min, loc)]
+
+        # todo cache?
+        res = []
+        for x, loc in home2:
+            dt: datetime
+            if isinstance(x, str):
+                dt = datetime.fromisoformat(x)
+            elif isinstance(x, datetime):
+                dt = x
+            else:
+                dt = datetime.combine(x, time.min)
+            # todo not sure about doing it here, but makes it easier to compare..
+            if dt.tzinfo is None:
+                dt = dt.replace(tzinfo=timezone.utc)
+            res.append((dt, loc))
+        res = list(sorted(res, key=lambda p: p[0]))
+        return res
+
+
+from ...core.cfg import make_config
+config = make_config(Config)
+
+
+@lru_cache(maxsize=None)
+def get_location(dt: datetime) -> LatLon:
+    '''
+    Interpolates the location at dt
+    '''
+    loc = list(estimate_location(dt))
+    assert len(loc) == 1
+    return loc[0].lat, loc[0].lon
+
+
+# TODO: in python3.9, use functools.cached_property instead?
+@lru_cache(maxsize=None)
+def homes_cached() -> List[Tuple[datetime, LatLon]]:
+    return list(config._history)
+
+
+def estimate_location(dt: DateExact) -> Iterator[FallbackLocation]:
+    from my.location.fallback.common import _datetime_timestamp
+    d: float = _datetime_timestamp(dt)
+    hist = list(reversed(homes_cached()))
+    for pdt, (lat, lon) in hist:
+        if d >= pdt.timestamp():
+            yield FallbackLocation(
+                lat=lat,
+                lon=lon,
+                accuracy=config.home_accuracy,
+                dt=datetime.fromtimestamp(d, timezone.utc),
+                datasource='via_home')
+            return
+    else:
+        # I guess the most reasonable is to fallback on the first location
+        lat, lon = hist[-1][1]
+        yield FallbackLocation(
+            lat=lat,
+            lon=lon,
+            accuracy=config.home_accuracy,
+            dt=datetime.fromtimestamp(d, timezone.utc),
+            datasource='via_home')
+        return
diff --git a/my/location/fallback/via_ip.py b/my/location/fallback/via_ip.py
new file mode 100644
index 0000000..1da2315
--- /dev/null
+++ b/my/location/fallback/via_ip.py
@@ -0,0 +1,99 @@
+"""
+Converts IP addresses provided by my.location.ip to estimated locations
+"""
+
+REQUIRES = ["git+https://github.com/seanbreckenridge/ipgeocache"]
+
+from datetime import timedelta
+
+from my.core import dataclass, Stats, make_config
+from my.config import location
+from my.core.warnings import medium
+
+
+@dataclass
+class ip_config(location.via_ip):
+    # no real science to this, just a guess of ~15km accuracy for IP addresses
+    accuracy: float = 15_000.0
+    # default to being accurate for a day
+    for_duration: timedelta = timedelta(hours=24)
+
+
+# TODO: move config to location.fallback.via_location instead and add migration
+config = make_config(ip_config)
+
+
+from functools import lru_cache
+from typing import Iterator, List
+
+from my.core.common import LazyLogger
+from my.core.compat import bisect_left
+from my.ip.all import ips
+from my.location.common import Location
+from my.location.fallback.common import FallbackLocation, DateExact, _datetime_timestamp
+
+logger = LazyLogger(__name__, level="warning")
+
+
+def fallback_locations() -> Iterator[FallbackLocation]:
+    dur = config.for_duration.total_seconds()
+    for ip in ips():
+        lat, lon = ip.latlon
+        yield FallbackLocation(
+            lat=lat,
+            lon=lon,
+            dt=ip.dt,
+            accuracy=config.accuracy,
+            duration=dur,
+            elevation=None,
+            datasource="via_ip",
+        )
+
+
+# for compatibility with my.location.via_ip, this shouldnt be used by other modules
+def locations() -> Iterator[Location]:
+    medium("locations is deprecated, should use fallback_locations or estimate_location")
+    yield from map(FallbackLocation.to_location, fallback_locations())
+
+
+@lru_cache(1)
+def _sorted_fallback_locations() -> List[FallbackLocation]:
+    fl = list(filter(lambda l: l.duration is not None, fallback_locations()))
+    logger.debug(f"Fallback locations: {len(fl)}, sorting...:")
+    fl.sort(key=lambda l: l.dt.timestamp())
+    return fl
+
+
+def estimate_location(dt: DateExact) -> Iterator[FallbackLocation]:
+    # logger.debug(f"Estimating location for: {dt}")
+    fl = _sorted_fallback_locations()
+    dt_ts = _datetime_timestamp(dt)
+
+    # search to find the first possible location which contains dt (something that started up to
+    # config.for_duration ago, and ends after dt)
+    idx = bisect_left(fl, dt_ts - config.for_duration.total_seconds(), key=lambda l: l.dt.timestamp())  # type: ignore[operator,call-arg,type-var]
+
+    # all items are before the given dt
+    if idx == len(fl):
+        return
+
+    # iterate through in sorted order, until we find a location that is after the given dt
+    while idx < len(fl):
+        loc = fl[idx]
+        start_time = loc.dt.timestamp()
+        # loc.duration is filtered for in _sorted_fallback_locations
+        end_time = start_time + loc.duration  # type: ignore[operator]
+        if start_time <= dt_ts <= end_time:
+            # logger.debug(f"Found location for {dt}: {loc}")
+            yield loc
+        # no more locations could possibly contain dt
+        if start_time > dt_ts:
+            # logger.debug(f"Passed start time: {end_time} > {dt_ts} ({datetime.fromtimestamp(end_time)} > {datetime.fromtimestamp(dt_ts)})")
+            break
+        idx += 1
+
+
+def stats() -> Stats:
+    from my.core import stat
+
+    return {**stat(locations)}
diff --git a/my/location/google_takeout.py b/my/location/google_takeout.py
index 80b31cb..a1c1403 100644
--- a/my/location/google_takeout.py
+++ b/my/location/google_takeout.py
@@ -23,7 +23,12 @@ def locations() -> Iterator[Location]:
     for g in events():
         if isinstance(g, GoogleLocation):
             yield Location(
-                lon=g.lng, lat=g.lat, dt=g.dt, accuracy=g.accuracy, elevation=None
+                lon=g.lng,
+                lat=g.lat,
+                dt=g.dt,
+                accuracy=g.accuracy,
+                elevation=None,
+                datasource="google_takeout",
             )
 
 
diff --git a/my/location/gpslogger.py b/my/location/gpslogger.py
index 95f4474..46fc381 100644
--- a/my/location/gpslogger.py
+++ b/my/location/gpslogger.py
@@ -32,9 +32,16 @@ from .common import Location
 
 logger = LazyLogger(__name__, level="warning")
 
+def _input_sort_key(path: Path) -> str:
+    if "_" in path.name:
+        return path.name.split("_", maxsplit=1)[1]
+    return path.name
+
 
 def inputs() -> Sequence[Path]:
-    return get_files(config.export_path, glob="*.gpx")
+    # gpslogger files can optionally be prefixed by a device id,
+    # like b5760c66102a5269_20211214142156.gpx
+    return sorted(get_files(config.export_path, glob="*.gpx", sort=False), key=_input_sort_key)
 
 
 def _cachew_depends_on() -> List[float]:
@@ -65,6 +72,7 @@ def _extract_locations(path: Path) -> Iterator[Location]:
                         accuracy=config.accuracy,
                         elevation=point.elevation,
                         dt=datetime.replace(point.time, tzinfo=timezone.utc),
+                        datasource="gpslogger",
                     )
 
 
diff --git a/my/location/home.py b/my/location/home.py
index ac0fcb8..f6e6978 100644
--- a/my/location/home.py
+++ b/my/location/home.py
@@ -1,71 +1,7 @@
-'''
-Simple location provider, serving as a fallback when more detailed data isn't available
-'''
-from dataclasses import dataclass
-from datetime import datetime, time, timezone
-from functools import lru_cache
-from typing import Sequence, Tuple, Union, cast
+from .fallback.via_home import *
 
-from my.config import location as user_config
+from my.core.warnings import high
 
-from my.location.common import LatLon, DateIsh
-
-@dataclass
-class Config(user_config):
-    home: Union[
-        LatLon,         # either single, 'current' location
-        Sequence[Tuple[ # or, a sequence of location history
-            DateIsh,    # date when you moved to
-            LatLon,     # the location
-        ]]
-    ]
-    # TODO could make current Optional and somehow determine from system settings?
-    @property
-    def _history(self) -> Sequence[Tuple[datetime, LatLon]]:
-        home1 = self.home
-        # todo ugh, can't test for isnstance LatLon, it's a tuple itself
-        home2: Sequence[Tuple[DateIsh, LatLon]]
-        if isinstance(home1[0], tuple):
-            # already a sequence
-            home2 = cast(Sequence[Tuple[DateIsh, LatLon]], home1)
-        else:
-            # must be a pair of coordinates. also doesn't really matter which date to pick?
-            loc = cast(LatLon, home1)
-            home2 = [(datetime.min, loc)]
-
-        # todo cache?
-        res = []
-        for x, loc in home2:
-            dt: datetime
-            if isinstance(x, str):
-                dt = datetime.fromisoformat(x)
-            elif isinstance(x, datetime):
-                dt = x
-            else:
-                dt = datetime.combine(x, time.min)
-            # todo not sure about doing it here, but makes it easier to compare..
-            if dt.tzinfo is None:
-                dt = dt.replace(tzinfo=timezone.utc)
-            res.append((dt, loc))
-        res = list(sorted(res, key=lambda p: p[0]))
-        return res
-
-
-from ..core.cfg import make_config
-config = make_config(Config)
-
-
-@lru_cache(maxsize=None)
-def get_location(dt: datetime) -> LatLon:
-    '''
-    Interpolates the location at dt
-    '''
-    if dt.tzinfo is None:
-        dt = dt.replace(tzinfo=timezone.utc)
-    hist = list(reversed(config._history))
-    for pdt, loc in hist:
-        if dt >= pdt:
-            return loc
-    else:
-        # I guess the most reasonable is to fallback on the first location
-        return hist[-1][1]
+high(
+    "my.location.home is deprecated, use my.location.fallback.via_home instead, or estimate locations using the higher-level my.location.fallback.all.estimate_location"
+)
diff --git a/my/location/via_ip.py b/my/location/via_ip.py
index e882cdb..df48f8b 100644
--- a/my/location/via_ip.py
+++ b/my/location/via_ip.py
@@ -1,39 +1,7 @@
-"""
-Converts IP addresses provided by my.location.ip to estimated locations
-"""
-
 REQUIRES = ["git+https://github.com/seanbreckenridge/ipgeocache"]
 
-from my.core import dataclass, Stats
-from my.config import location
+from .fallback.via_ip import *
 
+from my.core.warnings import high
 
-@dataclass
-class config(location.via_ip):
-    # no real science to this, just a guess of ~15km accuracy for IP addresses
-    accuracy: float = 15_000.0
-
-
-from typing import Iterator
-
-from .common import Location
-from my.ip.all import ips
-
-
-def locations() -> Iterator[Location]:
-    for ip in ips():
-        loc: str = ip.ipgeocache()["loc"]
-        lat, _, lon = loc.partition(",")
-        yield Location(
-            lat=float(lat),
-            lon=float(lon),
-            dt=ip.dt,
-            accuracy=config.accuracy,
-            elevation=None,
-        )
-
-
-def stats() -> Stats:
-    from my.core import stat
-
-    return {**stat(locations)}
+high("my.location.via_ip is deprecated, use my.location.fallback.via_ip instead")
diff --git a/my/time/tz/via_location.py b/my/time/tz/via_location.py
index 6b8e835..e111a4a 100644
--- a/my/time/tz/via_location.py
+++ b/my/time/tz/via_location.py
@@ -41,17 +41,23 @@ class config(user_config):
     # if the accuracy for the location is more than 5km, don't use
     require_accuracy: float = 5_000
 
+    # how often (hours) to refresh the cachew timezone cache
+    # this may be removed in the future if we opt for dict-based caching
+    _iter_tz_refresh_time: int = 6
+
 
 from collections import Counter
 from datetime import date, datetime
 from functools import lru_cache
 from itertools import groupby
-from typing import Iterator, NamedTuple, Optional, Tuple, Any, List, Iterable
+from typing import Iterator, NamedTuple, Optional, Tuple, Any, List, Iterable, Set
 
-from more_itertools import seekable
+import heapq
 import pytz
+from more_itertools import seekable
 
 from my.core.common import LazyLogger, mcachew, tzdatetime
+from my.core.source import import_source
 
 logger = LazyLogger(__name__, level='warning')
 
@@ -102,23 +108,13 @@ def _sorted_locations() -> List[Tuple[LatLon, datetime]]:
     return list(sorted(_locations(), key=lambda x: x[1]))
 
 
-# Note: this takes a while, as the upstream since _locations isn't sorted, so this
-# has to do an iterative sort of the entire my.locations.all list
-def _iter_local_dates() -> Iterator[DayWithZone]:
-    finder = _timezone_finder(fast=config.fast) # rely on the default
-    #pdt = None
-    # TODO: warnings doesnt actually warn?
-    warnings = []
-
-    locs: Iterable[Tuple[LatLon, datetime]]
-    locs = _sorted_locations() if config.sort_locations else _locations()
-
-    # todo allow to skip if not noo many errors in row?
+def _find_tz_for_locs(finder: Any, locs: Iterable[Tuple[LatLon, datetime]]) -> Iterator[DayWithZone]:
     for (lat, lon), dt in locs:
         # TODO right. its _very_ slow...
         zone = finder.timezone_at(lat=lat, lng=lon)
+        # todo allow to skip if not noo many errors in row?
         if zone is None:
-            warnings.append(f"Couldn't figure out tz for {lat}, {lon}")
+            # warnings.append(f"Couldn't figure out tz for {lat}, {lon}")
             continue
         tz = pytz.timezone(zone)
         # TODO this is probably a bit expensive... test & benchmark
@@ -133,6 +129,33 @@ def _iter_local_dates() -> Iterator[DayWithZone]:
         z = tz.zone; assert z is not None
         yield DayWithZone(day=ndate, zone=z)
 
+# Note: this takes a while, as the upstream since _locations isn't sorted, so this
+# has to do an iterative sort of the entire my.locations.all list
+def _iter_local_dates() -> Iterator[DayWithZone]:
+    finder = _timezone_finder(fast=config.fast) # rely on the default
+    #pdt = None
+    # TODO: warnings doesnt actually warn?
+    # warnings = []
+
+    locs: Iterable[Tuple[LatLon, datetime]]
+    locs = _sorted_locations() if config.sort_locations else _locations()
+
+    yield from _find_tz_for_locs(finder, locs)
+
+
+# my.location.fallback.estimate_location could be used here
+# but iterating through all the locations is faster since this
+# is saved behind cachew
+@import_source(module_name="my.location.fallback.all")
+def _iter_local_dates_fallback() -> Iterator[DayWithZone]:
+    from my.location.fallback.all import fallback_locations as flocs
+
+    def _fallback_locations() -> Iterator[Tuple[LatLon, datetime]]:
+        for loc in sorted(flocs(), key=lambda x: x.dt):
+            yield ((loc.lat, loc.lon), loc.dt)
+
+    yield from _find_tz_for_locs(_timezone_finder(fast=config.fast), _fallback_locations())
+
 
 def most_common(lst: List[DayWithZone]) -> DayWithZone:
     res, _ = Counter(lst).most_common(1)[0]  # type: ignore[var-annotated]
@@ -142,27 +165,43 @@ def most_common(lst: List[DayWithZone]) -> DayWithZone:
 def _iter_tz_depends_on() -> str:
     """
     Since you might get new data which specifies a new timezone sometime
-    in the day, this causes _iter_tzs to refresh every 6 hours, like:
+    in the day, this causes _iter_tzs to refresh every _iter_tz_refresh_time hours
+    (default 6), like:
     2022-04-26_00
     2022-04-26_06
     2022-04-26_12
     2022-04-26_18
     """
+    mod = config._iter_tz_refresh_time
+    assert mod >= 1
     day = str(date.today())
     hr = datetime.now().hour
-    hr_truncated = hr // 6 * 6
+    hr_truncated = hr // mod * mod
     return "{}_{}".format(day, hr_truncated)
 
 
-# refresh _iter_tzs every 6 hours -- don't think a better depends_on is possible dynamically
+# refresh _iter_tzs every few hours -- don't think a better depends_on is possible dynamically
 @mcachew(logger=logger, depends_on=_iter_tz_depends_on)
 def _iter_tzs() -> Iterator[DayWithZone]:
     # since we have no control over what order the locations are returned,
     # we need to sort them first before we can do a groupby
     local_dates: List[DayWithZone] = list(_iter_local_dates())
     local_dates.sort(key=lambda p: p.day)
-    for d, gr in groupby(local_dates, key=lambda p: p.day):
-        logger.info('processed %s', d)
+    logger.debug(f"no. of items using exact locations: {len(local_dates)}")
+
+    local_dates_fallback: List[DayWithZone] = list(_iter_local_dates_fallback())
+    local_dates_fallback.sort(key=lambda p: p.day)
+
+    # find days that are in fallback but not in local_dates (i.e., missing days)
+    local_dates_set: Set[date] = set(d.day for d in local_dates)
+    use_fallback_days: List[DayWithZone] = [d for d in local_dates_fallback if d.day not in local_dates_set]
+    logger.debug(f"no. of items being used from fallback locations: {len(use_fallback_days)}")
+
+    # combine local_dates and missing days from fallback into a sorted list
+    all_dates = heapq.merge(local_dates, use_fallback_days, key=lambda p: p.day)
+
+    for d, gr in groupby(all_dates, key=lambda p: p.day):
+        logger.info(f"processed {d}{', using fallback' if d in local_dates_set else ''}")
         zone = most_common(list(gr)).zone
         yield DayWithZone(day=d, zone=zone)
 
@@ -192,7 +231,7 @@ def _get_day_tz(d: date) -> Optional[pytz.BaseTzInfo]:
 
 # ok to cache, there are only a few home locations?
 @lru_cache(maxsize=None)
-def _get_home_tz(loc) -> Optional[pytz.BaseTzInfo]:
+def _get_home_tz(loc: LatLon) -> Optional[pytz.BaseTzInfo]:
     (lat, lng) = loc
     finder = _timezone_finder(fast=False) # ok to use slow here for better precision
     zone = finder.timezone_at(lat=lat, lng=lng)
@@ -211,9 +250,17 @@ def _get_tz(dt: datetime) -> Optional[pytz.BaseTzInfo]:
     if res is not None:
         return res
     # fallback to home tz
-    from ...location import home
-    loc = home.get_location(dt)
-    return _get_home_tz(loc=loc)
+    # note: the fallback to fallback.via_home.estimate_location is still needed, since
+    # _iter_local_dates_fallback only returns days which we actually have a datetime for
+    # (e.g. there was an IP address within a day of that datetime)
+    #
+    # given a datetime, fallback.via_home.estimate_location will find which home location
+    # that datetime is between, else fallback on your first home location, so it acts
+    # as a last resort
+    from my.location.fallback import via_home as home
+    loc = list(home.estimate_location(dt))
+    assert len(loc) == 1, f"should only have one home location, received {loc}"
+    return _get_home_tz(loc=(loc[0].lat, loc[0].lon))
 
 # expose as 'public' function
 get_tz = _get_tz
diff --git a/setup.py b/setup.py
index 31fc393..b0f4ab6 100644
--- a/setup.py
+++ b/setup.py
@@ -57,6 +57,7 @@ def main() -> None:
                 # todo document these?
                 'logzero',
                 'orjson',  # for my.core.serialize
+                'pyfzf_iter',  # for my.core.denylist
                 'cachew>=0.8.0',
                 'mypy', # used for config checks
             ],
diff --git a/tests/core/test_denylist.py b/tests/core/test_denylist.py
new file mode 100644
index 0000000..d6f4c49
--- /dev/null
+++ b/tests/core/test_denylist.py
@@ -0,0 +1,106 @@
+import warnings
+
+import json
+from pathlib import Path
+from datetime import datetime
+from typing import NamedTuple, Iterator
+
+from my.core.denylist import DenyList
+
+
+class IP(NamedTuple):
+    addr: str
+    dt: datetime
+
+
+def data() -> Iterator[IP]:
+    # random IP addresses
+    yield IP(addr="67.98.113.0", dt=datetime(2020, 1, 1))
+    yield IP(addr="59.40.113.87", dt=datetime(2020, 2, 1))
+    yield IP(addr="161.235.192.228", dt=datetime(2020, 3, 1))
+    yield IP(addr="165.243.139.87", dt=datetime(2020, 4, 1))
+    yield IP(addr="69.69.141.154", dt=datetime(2020, 5, 1))
+    yield IP(addr="50.72.224.80", dt=datetime(2020, 6, 1))
+    yield IP(addr="221.67.89.168", dt=datetime(2020, 7, 1))
+    yield IP(addr="177.113.119.251", dt=datetime(2020, 8, 1))
+    yield IP(addr="93.200.246.215", dt=datetime(2020, 9, 1))
+    yield IP(addr="127.105.171.61", dt=datetime(2020, 10, 1))
+
+
+def test_denylist(tmp_path: Path) -> None:
+    tf = (tmp_path / "denylist.json").absolute()
+    with warnings.catch_warnings(record=True):
+
+        # create empty denylist (though file does not have to exist for denylist to work)
+        tf.write_text("[]")
+
+        d = DenyList(tf)
+
+        d.load()
+        assert dict(d._deny_map) == {}
+        assert d._deny_raw_list == []
+
+        assert list(d.filter(data())) == list(data())
+        # no data in denylist yet
+        assert len(d._deny_map) == 0
+        assert len(d._deny_raw_list) == 0
+
+        # add some data
+        d.deny(key="addr", value="67.98.113.0")
+        # write and reload to update _deny_map, _deny_raw_list
+        d.write()
+        d.load()
+
+        assert len(d._deny_map) == 1
+        assert len(d._deny_raw_list) == 1
+
+        assert d._deny_raw_list == [{"addr": "67.98.113.0"}]
+
+        filtered = list(d.filter(data()))
+        assert len(filtered) == 9
+        assert "67.98.113.0" not in [i.addr for i in filtered]
+
+        assert dict(d._deny_map) == {"addr": {"67.98.113.0"}}
+
+        denied = list(d.filter(data(), invert=True))
+        assert len(denied) == 1
+
+        assert denied[0] == IP(addr="67.98.113.0", dt=datetime(2020, 1, 1))
+
+        # add some non-JSON primitive data
+
+        d.deny(key="dt", value=datetime(2020, 2, 1))
+
+        # test internal behavior, _deny_raw_list should have been updated,
+        # but _deny_map doesnt get updated by a call to .deny
+        #
+        # if we change this just update the test, is just here to ensure
+        # this is the behaviour
+
+        assert len(d._deny_map) == 1
+
+        # write and load to update _deny_map
+        d.write()
+        d.load()
+
+        assert len(d._deny_map) == 2
+        assert len(d._deny_raw_list) == 2
+
+        assert d._deny_raw_list[-1] == {"dt": "2020-02-01T00:00:00"}
+
+        filtered = list(d.filter(data()))
+        assert len(filtered) == 8
+
+        assert "59.40.113.87" not in [i.addr for i in filtered]
+
+        with open(tf, "r") as f:
+            data_json = json.loads(f.read())
+
+        assert data_json == [
+            {
+                "addr": "67.98.113.0",
+            },
+            {
+                "dt": "2020-02-01T00:00:00",
+            },
+        ]
diff --git a/tests/location.py b/tests/location.py
index 298b7ba..c47849e 100644
--- a/tests/location.py
+++ b/tests/location.py
@@ -1,7 +1,5 @@
 from pathlib import Path
 
-from more_itertools import one
-
 import pytest # type: ignore
 
 
@@ -20,26 +18,11 @@ def test() -> None:
 
 @pytest.fixture(autouse=True)
 def prepare(tmp_path: Path):
-    from .common import reset_modules
-    reset_modules()
-
-    user_config = _prepare_google_config(tmp_path)
+    from .shared_config import temp_config
+    user_config = temp_config(tmp_path)
 
     import my.core.cfg as C
     with C.tmp_config() as config:
-        config.google = user_config # type: ignore
+        config.google = user_config.google
         yield
 
-
-def _prepare_google_config(tmp_path: Path):
-    from .common import testdata
-    track = one(testdata().rglob('italy-slovenia-2017-07-29.json'))
-
-    # todo ugh. unnecessary zipping, but at the moment takeout provider doesn't support plain dirs
-    import zipfile
-    with zipfile.ZipFile(tmp_path / 'takeout.zip', 'w') as zf:
-        zf.writestr('Takeout/Location History/Location History.json', track.read_bytes())
-
-    class google_config:
-        takeout_path = tmp_path
-    return google_config
diff --git a/tests/location_fallback.py b/tests/location_fallback.py
new file mode 100644
index 0000000..aad33ee
--- /dev/null
+++ b/tests/location_fallback.py
@@ -0,0 +1,125 @@
+"""
+To test my.location.fallback_location.all
+"""
+
+from typing import Iterator
+from datetime import datetime, timezone, timedelta
+
+from more_itertools import ilen
+
+from my.ip.common import IP
+
+def data() -> Iterator[IP]:
+    # random IP addresses
+    yield IP(addr="67.98.113.0", dt=datetime(2020, 1, 1, 12, 0, 0, tzinfo=timezone.utc))
+    yield IP(addr="67.98.112.0", dt=datetime(2020, 1, 15, 12, 0, 0, tzinfo=timezone.utc))
+    yield IP(addr="59.40.113.87", dt=datetime(2020, 2, 1, 12, 0, 0, tzinfo=timezone.utc))
+    yield IP(addr="59.40.139.87", dt=datetime(2020, 2, 1, 16, 0, 0, tzinfo=timezone.utc))
+    yield IP(addr="161.235.192.228", dt=datetime(2020, 3, 1, 12, 0, 0, tzinfo=timezone.utc))
+
+# redefine the my.ip.all function using data for testing
+import my.ip.all as ip_module
+ip_module.ips = data
+
+from my.location.fallback import via_ip
+
+# these are all tests for the bisect algorithm defined in via_ip.py
+# to make sure we can correctly find IPs that are within the 'for_duration' of a given datetime
+
+def test_ip_fallback() -> None:
+    # make sure that the data override works
+    assert ilen(ip_module.ips()) == ilen(data())
+    assert ilen(ip_module.ips()) == ilen(via_ip.fallback_locations())
+    assert ilen(via_ip.fallback_locations()) == 5
+    assert ilen(via_ip._sorted_fallback_locations()) == 5
+
+    # confirm duration from via_ip since that is used for bisect
+    assert via_ip.config.for_duration == timedelta(hours=24)
+
+    # basic tests
+
+    # try estimating slightly before the first IP
+    est = list(via_ip.estimate_location(datetime(2020, 1, 1, 11, 59, 59, tzinfo=timezone.utc)))
+    assert len(est) == 0
+
+    # during the duration for the first IP
+    est = list(via_ip.estimate_location(datetime(2020, 1, 1, 12, 30, 0, tzinfo=timezone.utc)))
+    assert len(est) == 1
+
+    # right after the 'for_duration' for an IP
+    est = list(via_ip.estimate_location(datetime(2020, 1, 1, 12, 0, 0, tzinfo=timezone.utc) + via_ip.config.for_duration + timedelta(seconds=1)))
+    assert len(est) == 0
+
+    # on 2/1/2020, threes one IP if before 16:30
+    est = list(via_ip.estimate_location(datetime(2020, 2, 1, 12, 30, 0, tzinfo=timezone.utc)))
+    assert len(est) == 1
+
+    # and two if after 16:30
+    est = list(via_ip.estimate_location(datetime(2020, 2, 1, 17, 00, 0, tzinfo=timezone.utc)))
+    assert len(est) == 2
+
+    # the 12:30 IP should 'expire' before the 16:30 IP, use 3:30PM on the next day
+    est = list(via_ip.estimate_location(datetime(2020, 2, 2, 15, 30, 0, tzinfo=timezone.utc)))
+    assert len(est) == 1
+
+    use_dt = datetime(2020, 3, 1, 12, 15, 0, tzinfo=timezone.utc)
+
+    # test last IP
+    est = list(via_ip.estimate_location(use_dt))
+    assert len(est) == 1
+
+    # datetime should be the IPs, not the passed IP (if via_home, it uses the passed dt)
+    assert est[0].dt != use_dt
+
+    # test interop with other fallback estimators/all.py
+    #
+    # redefine fallback_estimators to prevent possible namespace packages the user
+    # may have installed from having side effects testing this
+    from my.location.fallback import all
+    from my.location.fallback import via_home
+    def _fe() -> Iterator[all.LocationEstimator]:
+        yield via_ip.estimate_location
+        yield via_home.estimate_location
+
+    all.fallback_estimators = _fe
+    assert ilen(all.fallback_estimators()) == 2
+
+    # test that all.estimate_location has access to both IPs
+    #
+    # just passing via_ip should give one IP
+    from my.location.fallback.common import _iter_estimate_from
+    raw_est = list(_iter_estimate_from(use_dt, (via_ip.estimate_location,)))
+    assert len(raw_est) == 1
+    assert raw_est[0].datasource == "via_ip"
+    assert raw_est[0].accuracy == 15_000
+
+    # passing home should give one
+    home_est = list(_iter_estimate_from(use_dt, (via_home.estimate_location,)))
+    assert len(home_est) == 1
+    assert home_est[0].accuracy == 30_000
+
+    # make sure ip accuracy is more accurate
+    assert raw_est[0].accuracy < home_est[0].accuracy
+
+    # passing both should give two
+    raw_est = list(_iter_estimate_from(use_dt, (via_ip.estimate_location, via_home.estimate_location)))
+    assert len(raw_est) == 2
+
+    # shouldn't raise value error
+    all_est = all.estimate_location(use_dt)
+    # should have used the IP from via_ip since it was more accurate
+    assert all_est.datasource == "via_ip"
+
+    # test that a home defined in shared_config.py is used if no IP is found
+    loc = all.estimate_location(datetime(2021, 1, 1, 12, 30, 0, tzinfo=timezone.utc))
+    assert loc.datasource == "via_home"
+
+    # test a different home using location.fallback.all
+    bulgaria = all.estimate_location(datetime(2006, 1, 1, 12, 30, 0, tzinfo=timezone.utc))
+    assert bulgaria.datasource == "via_home"
+    assert (bulgaria.lat, bulgaria.lon) == (42.697842, 23.325973)
+    assert (loc.lat, loc.lon) != (bulgaria.lat, bulgaria.lon)
+
+
+# re-use prepare fixture for overriding config from shared_config.py
+from .tz import prepare
diff --git a/tests/shared_config.py b/tests/shared_config.py
new file mode 100644
index 0000000..6b83a5a
--- /dev/null
+++ b/tests/shared_config.py
@@ -0,0 +1,65 @@
+# Defines some shared config for tests
+
+from datetime import datetime, date, timezone
+from pathlib import Path
+
+from typing import Any, NamedTuple
+import my.time.tz.via_location as LTZ
+from more_itertools import one
+
+
+class SharedConfig(NamedTuple):
+    google: Any
+    location: Any
+    time: Any
+
+
+def _prepare_google_config(tmp_path: Path):
+    from .common import testdata
+    try:
+        track = one(testdata().rglob('italy-slovenia-2017-07-29.json'))
+    except ValueError:
+        raise RuntimeError('testdata not found, setup git submodules?')
+
+
+    # todo ugh. unnecessary zipping, but at the moment takeout provider doesn't support plain dirs
+    import zipfile
+    with zipfile.ZipFile(tmp_path / 'takeout.zip', 'w') as zf:
+        zf.writestr('Takeout/Location History/Location History.json', track.read_bytes())
+
+    class google_config:
+        takeout_path = tmp_path
+    return google_config
+
+
+# pass tmp_path from pytest to this helper function
+# see tests/tz.py as an example
+def temp_config(temp_path: Path) -> Any:
+    from .common import reset_modules
+    reset_modules()
+
+    LTZ.config.fast = True
+
+    class location:
+        home_accuracy = 30_000
+        home = (
+            # supports ISO strings
+            ('2005-12-04'                                       , (42.697842, 23.325973)), # Bulgaria, Sofia
+            # supports date/datetime objects
+            (date(year=1980, month=2, day=15)                   , (40.7128  , -74.0060 )), # NY
+            # check tz handling..
+            (datetime.fromtimestamp(1600000000, tz=timezone.utc), (55.7558  , 37.6173  )), # Moscow, Russia
+        )
+        # note: order doesn't matter, will be sorted in the data provider
+        class via_ip:
+            accuracy = 15_000
+        class gpslogger:
+            pass
+
+    class time:
+        class tz:
+            class via_location:
+                pass # just rely on the defaults...
+
+
+    return SharedConfig(google=_prepare_google_config(temp_path), location=location, time=time)
diff --git a/tests/tz.py b/tests/tz.py
index 0ea2b40..8f80800 100644
--- a/tests/tz.py
+++ b/tests/tz.py
@@ -1,4 +1,5 @@
-from datetime import datetime, timedelta, date, timezone
+import sys
+from datetime import datetime, timedelta
 from pathlib import Path
 
 import pytest # type: ignore
@@ -46,8 +47,15 @@ def test_tz() -> None:
     tz = LTZ._get_tz(D('20201001 14:15:16'))
     assert tz is not None
 
-    tz = LTZ._get_tz(datetime.min)
-    assert tz is not None
+    on_windows = sys.platform == 'win32'
+    if not on_windows:
+        tz = LTZ._get_tz(datetime.min)
+        assert tz is not None
+    else:
+        # seems this fails because windows doesnt support same date ranges
+        # https://stackoverflow.com/a/41400321/
+        with pytest.raises(OSError):
+            LTZ._get_tz(datetime.min)
 
 
 def test_policies() -> None:
@@ -73,36 +81,15 @@ def D(dstr: str) -> datetime:
     return datetime.strptime(dstr, '%Y%m%d %H:%M:%S')
 
 
-# TODO copy pasted from location.py, need to extract some common provider
+
 @pytest.fixture(autouse=True)
 def prepare(tmp_path: Path):
-    from .common import reset_modules
-    reset_modules()
-
-    LTZ.config.fast = True
-
-    from .location import _prepare_google_config
-    google = _prepare_google_config(tmp_path)
-
-    class location:
-        home = (
-            # supports ISO strings
-            ('2005-12-04'                                       , (42.697842, 23.325973)), # Bulgaria, Sofia
-            # supports date/datetime objects
-            (date(year=1980, month=2, day=15)                   , (40.7128  , -74.0060 )), # NY
-            # check tz handling..
-            (datetime.fromtimestamp(1600000000, tz=timezone.utc), (55.7558  , 37.6173  )), # Moscow, Russia
-        )
-        # note: order doesn't matter, will be sorted in the data provider
-
-    class time:
-        class tz:
-            class via_location:
-                pass # just rely on the defaults...
+    from .shared_config import temp_config
+    conf = temp_config(tmp_path)
 
     import my.core.cfg as C
     with C.tmp_config() as config:
-        config.google   = google
-        config.time     = time
-        config.location = location
+        config.google   = conf.google
+        config.time     = conf.time
+        config.location = conf.location
         yield
diff --git a/tox.ini b/tox.ini
index 6e7ca23..efe6069 100644
--- a/tox.ini
+++ b/tox.ini
@@ -47,7 +47,12 @@ commands =
     hpi module install my.location.google
     pip install ijson # optional dependency
 
+    # tz/location
     hpi module install my.time.tz.via_location
+    hpi module install my.ip.all
+    hpi module install my.location.gpslogger
+    hpi module install my.location.fallback.via_ip
+    hpi module install my.google.takeout.parser
 
     hpi module install my.calendar.holidays
 
@@ -125,8 +130,7 @@ commands =
         my.rescuetime             \
         my.runnerup               \
         my.stackexchange.stexport \
-        my.smscalls               \
-        my.tinder.android
+        my.smscalls
 
 
     {envpython} -m mypy --install-types --non-interactive \