#!/usr/bin/python3
"""Reverse geocode: convert lat/lon to Wikidata item & Wikimedia Commons category."""

import inspect
import random
import socket
import sys
import traceback
import typing
from time import time

import sqlalchemy
import sqlalchemy.exc
import werkzeug.debug.tbtools
from flask import Flask, jsonify, redirect, render_template, request, url_for
from sqlalchemy.orm.query import Query
from werkzeug.wrappers import Response

import geocode
from geocode import database, model, scotland, wikidata
from geocode.error_mail import setup_error_mail

city_of_london_qid = "Q23311"
app = Flask(__name__)
app.config.from_object("config.default")
database.init_app(app)
setup_error_mail(app)

Tags = typing.Mapping[str, str]
logging_enabled = True


@app.errorhandler(werkzeug.exceptions.InternalServerError)
def exception_handler(e: werkzeug.exceptions.InternalServerError) -> tuple[str, int]:
    """Handle exception."""
    exec_type, exc_value, current_traceback = sys.exc_info()
    assert exc_value
    tb = werkzeug.debug.tbtools.DebugTraceback(exc_value)

    summary = tb.render_traceback_html(include_title=False)
    exc_lines = "".join(tb._te.format_exception_only())

    last_frame = list(traceback.walk_tb(current_traceback))[-1][0]
    last_frame_args = inspect.getargs(last_frame.f_code)

    return (
        render_template(
            "show_error.html",
            plaintext=tb.render_traceback_text(),
            exception=exc_lines,
            exception_type=tb._te.exc_type.__name__,
            summary=summary,
            last_frame=last_frame,
            last_frame_args=last_frame_args,
        ),
        500,
    )


def get_random_lat_lon() -> tuple[float, float]:
    """Select random lat/lon within the UK."""
    south, east = 50.8520, 0.3536
    north, west = 53.7984, -2.7296

    mul = 10000
    lat = random.randrange(int(south * mul), int(north * mul)) / mul
    lon = random.randrange(int(west * mul), int(east * mul)) / mul

    return lat, lon


def do_lookup(
    elements: "Query[model.Polygon]", lat: str | float, lon: str | float
) -> wikidata.WikidataDict:
    """Do lookup."""
    try:
        hit = osm_lookup(elements, lat, lon)
    except wikidata.QueryError as e:
        return {
            "query": e.query,
            "error": e.r.text,
            "query_url": "https://query.wikidata.org/#" + e.query,
        }

    return wikidata.build_dict(hit, lat, lon)


def lat_lon_to_wikidata(lat: float, lon: float) -> dict[str, typing.Any]:
    """Lookup lat/lon and find most appropriate Wikidata item."""
    scotland_code = scotland.get_scotland_code(lat, lon)

    elements: typing.Any
    if scotland_code:
        rows = wikidata.lookup_scottish_parish_in_wikidata(scotland_code)
        hit = wikidata.commons_from_rows(rows)
        elements = []
        result = wikidata.build_dict(hit, lat, lon)

        return {"elements": elements, "result": result}

    elements = model.Polygon.coords_within(lat, lon)
    result = do_lookup(elements, lat, lon)

    # special case because the City of London is admin_level=6 in OSM
    if result.get("wikidata") == city_of_london_qid:
        return {"elements": elements, "result": result}

    admin_level = result.get("admin_level")
    if not admin_level:
        return {"elements": elements, "result": result}

    assert isinstance(admin_level, int)
    if admin_level >= 7:
        return {"elements": elements, "result": result}

    row = wikidata.geosearch(lat, lon)
    if row:
        hit = wikidata.commons_from_rows([row])
        elements = []
        result = wikidata.build_dict(hit, lat, lon)

    return {"elements": elements, "result": result}


def get_admin_level(tags: Tags) -> int | None:
    """Read admin_level from tags."""
    admin_level_tag = tags.get("admin_level")
    return (
        int(admin_level_tag) if admin_level_tag and admin_level_tag.isdigit() else None
    )


def hit_from_wikidata_tag(tags: Tags) -> wikidata.Hit | None:
    """Check element for a wikidata tag."""
    return (
        {
            "wikidata": qid,
            "commons_cat": commons,
        }
        if "wikidata" in tags
        and (commons := wikidata.qid_to_commons_category(qid := tags["wikidata"]))
        else None
    )


def hit_from_ref_gss_tag(tags: Tags) -> wikidata.Hit | None:
    """Check element for rss:gss tag."""
    gss = tags.get("ref:gss")
    return wikidata.get_commons_cat_from_gss(gss) if gss else None


def hit_from_name(
    tags: Tags, lat: str | float, lon: str | float
) -> wikidata.Hit | None:
    """Use name to look for hit."""
    if not (name := tags.get("name")):
        return None
    if name.endswith(" CP"):  # civil parish
        name = name[:-3]

    rows = wikidata.lookup_wikidata_by_name(name, lat, lon)
    return wikidata.commons_from_rows(rows) if len(rows) == 1 else None


def osm_lookup(
    elements: "Query[model.Polygon]", lat: str | float, lon: str | float
) -> wikidata.Hit | None:
    """OSM lookup."""
    ret: wikidata.Hit | None
    for e in elements:
        assert isinstance(e, model.Polygon)
        assert e.tags
        tags: typing.Mapping[str, str] = e.tags
        admin_level: int | None = get_admin_level(tags)
        if not admin_level and tags.get("boundary") not in ("political", "place"):
            continue
        if not (
            (hit := hit_from_wikidata_tag(tags))
            or (hit := hit_from_ref_gss_tag(tags))
            or (hit := hit_from_name(tags, lat, lon))
        ):
            continue
        hit["admin_level"] = admin_level
        hit["element"] = e.osm_id
        hit["geojson"] = typing.cast(str, e.geojson_str)
        return hit

    has_wikidata_tag = [e for e in elements if e.tags.get("wikidata")]
    if len(has_wikidata_tag) != 1:
        return None

    e = has_wikidata_tag[0]
    assert e.tags
    qid = e.tags["wikidata"]
    return {
        "wikidata": qid,
        "element": e.osm_id,
        "geojson": typing.cast(str, e.geojson_str),
        "commons_cat": wikidata.qid_to_commons_category(qid),
        "admin_level": admin_level,
    }


def redirect_to_detail(q: str) -> Response:
    """Redirect to detail page."""
    lat, lon = [v.strip() for v in q.split(",", 1)]
    return redirect(url_for("detail_page", lat=lat, lon=lon))


@app.errorhandler(sqlalchemy.exc.OperationalError)
def handle_database_error(error: Exception) -> tuple[str, int]:
    """Show error screen on database error."""
    return render_template("database_error.html"), 500


@app.route("/")
def index() -> str | Response:
    """Index page."""
    t0 = time()
    database.session.execute("SELECT 1")
    q = request.args.get("q")
    if q and q.strip():
        return redirect_to_detail(q)

    lat_str, lon_str = request.args.get("lat"), request.args.get("lon")

    if lat_str is None or lon_str is None:
        samples = sorted(geocode.samples, key=lambda row: row[2])
        return render_template("index.html", samples=samples)

    lat, lon = float(lat_str), float(lon_str)

    if lat < -90 or lat > 90 or lon < -180 or lon > 180:
        return jsonify(
            coords={"lat": lat, "lon": lon},
            error="lat must be between -90 and 90, "
            + "and lon must be between -180 and 180",
        )

    result = lat_lon_to_wikidata(lat, lon)["result"]
    result.pop("element", None)
    result.pop("geojson", None)
    if logging_enabled:
        remote_addr = request.headers.get("X-Forwarded-For", request.remote_addr)
        log = model.LookupLog(
            lat=lat,
            lon=lon,
            remote_addr=remote_addr,
            fqdn=socket.getfqdn(remote_addr) if remote_addr else None,
            result=result,
            response_time_ms=int((time() - t0) * 1000),
        )
        database.session.add(log)
        database.session.commit()
    return jsonify(result)


@app.route("/random")
def random_location() -> str | Response:
    """Return detail page for random lat/lon."""
    lat, lon = get_random_lat_lon()
    return build_detail_page(lat, lon)


@app.route("/wikidata_tag")
def wikidata_tag() -> str:
    """Lookup Wikidata tag for lat/lon."""
    lat_str, lon_str = request.args["lat"], request.args["lon"]
    lat, lon = float(lat_str), float(lon_str)

    scotland_code = scotland.get_scotland_code(lat, lon)

    elements: typing.Any
    if scotland_code:
        rows = wikidata.lookup_scottish_parish_in_wikidata(scotland_code)
        hit = wikidata.commons_from_rows(rows)
        elements = []
        result = wikidata.build_dict(hit, lat, lon)
    else:
        elements = model.Polygon.coords_within(lat, lon)
        result = do_lookup(elements, lat, lon)

    return render_template(
        "wikidata_tag.html", lat=lat, lon=lon, result=result, elements=elements
    )


def build_detail_page(lat: float, lon: float) -> str:
    """Run lookup and build detail page."""
    if lat < -90 or lat > 90 or lon < -180 or lon > 180:
        error = (
            "latitude must be between -90 and 90, "
            + "and longitude must be between -180 and 180"
        )
        return render_template("query_error.html", lat=lat, lon=lon, error=error)

    try:
        reply = lat_lon_to_wikidata(lat, lon)
    except wikidata.QueryError as e:
        query, r = e.args
        return render_template("query_error.html", lat=lat, lon=lon, query=query, r=r)

    element = reply["result"].pop("element", None)
    geojson = reply["result"].pop("geojson", None)

    return render_template(
        "detail.html",
        lat=lat,
        lon=lon,
        str=str,
        element_id=element,
        geojson=geojson,
        **reply,
    )


@app.route("/detail")
def detail_page() -> Response | str:
    """Detail page."""
    database.session.execute("SELECT 1")
    try:
        lat_str, lon_str = request.args["lat"], request.args["lon"]
        lat, lon = float(lat_str), float(lon_str)
    except TypeError:
        return redirect(url_for("index"))

    return build_detail_page(lat, lon)


@app.route("/reports")
def reports() -> str:
    """Reports page with various statistics."""
    log_count = model.LookupLog.query.count()

    log_start_time = database.session.query(
        sqlalchemy.func.min(model.LookupLog.dt)
    ).scalar()

    return render_template(
        "reports.html", log_count=log_count, log_start_time=log_start_time
    )


if __name__ == "__main__":
    app.run(host="0.0.0.0")