#!/usr/bin/env python3
from __future__ import annotations

import json
import urllib.error
import urllib.request
from datetime import date, timedelta

ANILIST_URL = "https://graphql.anilist.co"


def yyyymmdd(value: date) -> int:
    return value.year * 10000 + value.month * 100 + value.day


def post_graphql(query: str, variables: dict) -> dict:
    payload = json.dumps({"query": query, "variables": variables}).encode("utf-8")
    headers = {
        "Content-Type": "application/json",
        "Accept": "application/json",
        "User-Agent": "anime-movies-script/1.0",
    }
    req = urllib.request.Request(ANILIST_URL, data=payload, headers=headers)
    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return json.loads(resp.read().decode("utf-8"))
    except urllib.error.HTTPError as exc:
        body = exc.read().decode("utf-8", "replace")
        raise RuntimeError(f"HTTP {exc.code}: {body}") from exc


def map_anilist_movie(media: dict | None) -> dict:
    media = media or {}
    title = media.get("title") or {}
    start_date = media.get("startDate") or {}
    studios = ((media.get("studios") or {}).get("nodes") or [])

    studio_names = []
    for node in studios:
        name = ((node or {}).get("name") or "").strip()
        if name:
            studio_names.append(name)

    genres = []
    for entry in media.get("genres") or []:
        text = str(entry or "").strip()
        if text:
            genres.append(text)

    tags = []
    for tag in media.get("tags") or []:
        if not isinstance(tag, dict):
            continue
        name = (tag.get("name") or "").strip()
        rank = int(tag.get("rank") or 0)
        if name and rank >= 70:
            tags.append(name)

    return {
        "anilist_id": int(media.get("id") or 0),
        "title_english": (title.get("english") or "").strip(),
        "title_romaji": (title.get("romaji") or "").strip(),
        "title_native": (title.get("native") or "").strip(),
        "cover_image": (((media.get("coverImage") or {}).get("large")) or "").strip(),
        "anilist_url": (media.get("siteUrl") or "").strip(),
        "start_year": int(start_date.get("year") or 0),
        "format": (media.get("format") or "").strip() or "MOVIE",
        "description": (media.get("description") or "").strip(),
        "genres_text": ", ".join(genres),
        "tags_text": ", ".join(tags),
        "studio_text": ", ".join(studio_names),
    }


def fetch_anilist_movie_candidates(today: date, years_window: int = 1) -> list[dict]:
    start_date = today - timedelta(days=365 * years_window)
    end_date = today + timedelta(days=365 * years_window)

    query = """
    query ($page: Int, $perPage: Int, $start: FuzzyDateInt, $end: FuzzyDateInt) {
      Page(page: $page, perPage: $perPage) {
        pageInfo { hasNextPage }
        media(
          type: ANIME
          format: MOVIE
          countryOfOrigin: JP
          sort: [POPULARITY_DESC, START_DATE_DESC]
          startDate_greater: $start
          startDate_lesser: $end
        ) {
          id
          title { english romaji native }
          startDate { year }
          format
          description(asHtml: false)
          genres
          tags { name rank }
          coverImage { large }
          studios { nodes { name } }
          siteUrl
        }
      }
    }
    """

    page = 1
    results = []
    seen_ids = set()

    while True:
        payload = post_graphql(
            query,
            {
                "page": page,
                "perPage": 50,
                "start": yyyymmdd(start_date) - 1,
                "end": yyyymmdd(end_date) + 1,
            },
        )

        if "errors" in payload:
            raise RuntimeError(payload["errors"])

        page_data = payload.get("data", {}).get("Page", {})
        for media in page_data.get("media", []):
            mapped = map_anilist_movie(media)
            anilist_id = mapped.get("anilist_id") or 0
            if anilist_id <= 0 or anilist_id in seen_ids:
                continue
            seen_ids.add(anilist_id)

            if not mapped.get("title_english") and not mapped.get("title_romaji") and not mapped.get("title_native"):
                continue

            results.append(mapped)

        if not page_data.get("pageInfo", {}).get("hasNextPage"):
            break
        page += 1

    return results