#!/usr/bin/python3

"""Download Wikidata recent changes and update items in local database."""

import json
import os
import sys
import typing
from time import sleep

from matcher import database, model, utils, wikidata, wikidata_api

DB_URL = "postgresql:///matcher"
database.init_db(DB_URL)

previous_max_lastrevid = 1888214110  # Q118129609

entity_keys = {"labels", "sitelinks", "aliases", "claims", "descriptions", "lastrevid"}


def read_changes() -> None:
    qids: set[str] = set()
    max_lastrevid = 0
    for f in sorted(os.listdir("changes"), key=lambda f: int(f.partition(".")[0])):
        reply = json.load(open("changes/" + f))
        print(f, len(qids))
        for change in reply["query"]["recentchanges"]:
            # rctype = change["type"]
            title = change["title"]
            revid = change["revid"]
            if revid and revid > max_lastrevid:
                max_lastrevid = revid
            assert title.startswith("Q")
            qids.add(title)
    print(len(qids))
    print(max_lastrevid)

    return

    for cur in utils.chunk(qids, 50):
        print(cur)
        for qid, entity in wikidata_api.get_entities(cur):
            with open(f"items/{qid}.json", "w") as out:
                json.dump(entity, out)


def get_changes() -> None:
    """Get recent changes."""
    start = "2021-03-24T11:56:11"
    rccontinue = None
    i = 0
    while True:
        i += 1
        r = wikidata_api.query_wd_api(rcstart=start, rccontinue=rccontinue)
        with open(f"changes/{i:06d}.json", "w") as out:
            out.write(r.text)

        reply = r.json()
        try:
            print(reply["query"]["recentchanges"][0]["timestamp"])
        except KeyError:
            print("KeyError")

        if False:
            for change in reply["query"]["recentchanges"]:
                # rctype = change["type"]
                # if change["revid"] == 0 and change["old_revid"] == 0:
                #     continue

                if change["logtype"] == "delete" and change["logaction"] in {
                    "revision",
                    "delete",
                    "restore",
                }:
                    continue

                if change["logtype"] == "protect" and change["logaction"] in {
                    "unprotect",
                    "protect",
                }:
                    continue

                print(json.dumps(change, indent=2))
                sys.exit(0)

                continue

                if not change["title"].startswith("Q"):
                    continue  # not an item

                qid = change["title"]
                assert qid[1:].isdigit()
                item_id = int(qid[1:])
                revid = change["revid"]

                item = model.Item.query.get(item_id)
                if change["type"] == "edit" and not item:
                    continue

                if change["type"] == "new" and not item:
                    print(("new", qid))
                    continue

                if not item:
                    print(qid)
                    print(json.dumps(change, indent=2))
                print((change["type"], qid, item.lastrevid, revid))

            # print(json.dumps(reply, indent=2))

        if "continue" not in reply:
            break

        rccontinue = reply["continue"]["rccontinue"]
        print(rccontinue)
        sleep(1)


def get_timestamp():
    ts = wikidata_api.get_revision_timestamp(previous_max_lastrevid)
    print(ts)


def handle_new(change):
    qid = change["title"]
    ts = change["timestamp"]
    if change["redirect"]:
        print(f"{ts}: new item {qid}, since replaced with redirect")
        return
    item = model.Item.query.get(qid[1:])  # check if item is already loaded
    if item:
        return handle_edit(change)

    entity = wikidata_api.get_entity(qid)
    if entity["id"] != qid:
        print(f'redirect {qid} -> {entity["id"]}')
        return

    if "claims" not in entity:
        print(qid)
        print(entity)
    coords = wikidata.get_entity_coords(entity["claims"])
    if not coords:
        print(f"{ts}: new item {qid} without coordinates")
        return

    print(f"{ts}: new item {qid} with coordinates")

    item_id = int(qid[1:])
    obj = {k: v for k, v in entity.items() if k in entity_keys}
    try:
        item = model.Item(item_id=item_id, **obj)
    except TypeError:
        print(qid)
        print(f'{entity["pageid"]=} {entity["ns"]=} {entity["type"]=}')
        print(entity.keys())
        raise
    item.locations = model.location_objects(coords)
    database.session.add(item)


def coords_equal(a: dict[str, typing.Any], b: dict[str, typing.Any]) -> bool:
    """Deep equality comparison of nested dicts."""
    return json.dumps(a, sort_keys=True) == json.dumps(b, sort_keys=True)


def handle_edit(change):
    qid = change["title"]
    item = model.Item.query.get(qid[1:])
    if not item:
        return  # item isn't in our database so it probably has no coordinates

    ts = change["timestamp"]

    if item.lastrevid >= change["revid"]:
        print(f"{ts}: no need to update {qid}")
        return

    entity = wikidata_api.get_entity(qid)
    entity_qid = entity.pop("id")
    if entity_qid != qid:
        print(f"{ts}: item {qid} replaced with redirect")
        database.session.delete(item)
        database.session.commit()
        return

    assert entity_qid == qid
    existing_coords = wikidata.get_entity_coords(item.claims)
    if "claims" not in entity:
        return
    coords = wikidata.get_entity_coords(entity["claims"])

    if not coords_equal(existing_coords, coords):
        print(f"{ts}: update item {qid}, including coordinates")
        item.locations = model.location_objects(coords)
    else:
        print(f"{ts}: update item {qid}, no change to coordinates")

    for key in entity_keys:
        setattr(item, key, entity[key])


def update_timestamp(timestamp: str) -> None:
    """Save timestamp to rc_timestamp."""
    out = open("rc_timestamp", "w")
    print(timestamp, file=out)
    out.close()


def update_database() -> None:
    with open("rc_timestamp") as f:
        start = f.read().strip()

    rccontinue = None
    seen = set()
    while True:
        r = wikidata_api.get_recent_changes(rcstart=start, rccontinue=rccontinue)

        reply = r.json()
        for change in reply["query"]["recentchanges"]:
            rctype = change["type"]
            timestamp = change["timestamp"]
            qid = change["title"]
            if qid in seen:
                continue

            if rctype == "new":
                handle_new(change)
                seen.add(qid)
            if rctype == "edit":
                handle_edit(change)
                seen.add(qid)

        update_timestamp(timestamp)
        print("commit")
        database.session.commit()

        if "continue" not in reply:
            break

        rccontinue = reply["continue"]["rccontinue"]
    database.session.commit()
    print("finished")


# read_changes()
# get_timestamp()
# get_changes()

while True:
    update_database()
    sleep(60)