import asyncio
from typing import Dict, List, Optional, Tuple

import httpx
from sqlalchemy import text
from sqlalchemy.ext.asyncio import AsyncSession


SOLVED_SHOW_URL = "https://solved.ac/api/v3/problem/show"


async def solved_problem_show(client: httpx.AsyncClient, problem_id: int) -> Tuple[Optional[str], Optional[str], Optional[int], Optional[List[str]]]:
    """
    solved.ac problem/show 호출해서 메타 가져오기
    반환: (title_ko, title_en, level, tags_keys)
    """
    r = await client.get(SOLVED_SHOW_URL, params={"problemId": problem_id})
    if r.status_code != 200:
        return None, None, None, None

    data = r.json()
    title_ko = data.get("titleKo")
    title_en = data.get("titleEn")
    level = data.get("level")

    # tags: [{"key": "...", "isMeta": ..., "bojTagId": ..., "problemCount": ...}, ...]
    tags = data.get("tags") or []
    tag_keys = [t.get("key") for t in tags if t.get("key")]

    return title_ko, title_en, level, tag_keys


async def enrich_workbook(
    db: AsyncSession,
    workbook_id: int,
    only_missing: bool = True,     # True면 NULL인 것만 채움, False면 덮어씀
    commit_every: int = 50,        # 몇 개마다 커밋할지
    sleep_sec: float = 0.12,       # solved.ac 부하 줄이려고 약간 쉬기
    timeout: float = 10.0,
) -> Dict:
    """
    전제: workbook_problems에 (workbook_id, problem_id)는 이미 채워져 있음
    목표: solved.ac problem/show로 title_ko/title_en/level/tags를 채움
    """

    # 1) 대상 problem_id 목록 뽑기 (missing만 or 전체)
    if only_missing:
        rows = (await db.execute(
            text("""
                SELECT problem_id
                FROM workbook_problems
                WHERE workbook_id = :wid
                  AND (
                        title_ko IS NULL
                     OR title_en IS NULL
                     OR level IS NULL
                     OR tags IS NULL
                  )
                ORDER BY problem_id
            """),
            {"wid": workbook_id},
        )).all()
    else:
        rows = (await db.execute(
            text("""
                SELECT problem_id
                FROM workbook_problems
                WHERE workbook_id = :wid
                ORDER BY problem_id
            """),
            {"wid": workbook_id},
        )).all()

    problem_ids = [int(r[0]) for r in rows]

    if not problem_ids:
        return {
            "workbook_id": workbook_id,
            "target_count": 0,
            "updated": 0,
            "skipped": 0,
            "failed": 0,
            "message": "nothing to enrich (already filled)",
        }

    updated = 0
    skipped = 0
    failed = 0

    # 2) solved.ac 호출 + 업데이트
    async with httpx.AsyncClient(timeout=timeout, headers={"User-Agent": "baekjoon-n8n-bot/1.0"}) as client:
        for i, pid in enumerate(problem_ids, start=1):
            try:
                title_ko, title_en, level, tag_keys = await solved_problem_show(client, pid)

                # 응답이 다 비었으면 스킵
                if title_ko is None and title_en is None and level is None and (not tag_keys):
                    skipped += 1
                    continue

                # tags 저장: TEXT[] (Postgres) -> 파라미터에 list 넘기면 asyncpg가 배열로 처리해줌
                # only_missing=True면 COALESCE로 NULL만 채우고, False면 그냥 덮어씀
                if only_missing:
                    await db.execute(
                        text("""
                            UPDATE workbook_problems
                               SET title_ko = COALESCE(:tko, title_ko),
                                   title_en = COALESCE(:ten, title_en),
                                   level    = COALESCE(:lvl, level),
                                   tags     = COALESCE(:tags, tags)
                             WHERE workbook_id = :wid
                               AND problem_id = :pid
                        """),
                        {"tko": title_ko, "ten": title_en, "lvl": level, "tags": tag_keys if tag_keys else None, "wid": workbook_id, "pid": pid},
                    )
                else:
                    await db.execute(
                        text("""
                            UPDATE workbook_problems
                               SET title_ko = :tko,
                                   title_en = :ten,
                                   level    = :lvl,
                                   tags     = :tags
                             WHERE workbook_id = :wid
                               AND problem_id = :pid
                        """),
                        {"tko": title_ko, "ten": title_en, "lvl": level, "tags": tag_keys if tag_keys else None, "wid": workbook_id, "pid": pid},
                    )

                updated += 1

                # 커밋 배치
                if i % commit_every == 0:
                    await db.commit()

                # rate limit
                if sleep_sec > 0:
                    await asyncio.sleep(sleep_sec)

            except Exception:
                failed += 1
                # 실패해도 다음 문제로 계속 진행

    await db.commit()

    return {
        "workbook_id": workbook_id,
        "target_count": len(problem_ids),
        "updated": updated,
        "skipped": skipped,
        "failed": failed,
        "only_missing": only_missing,
        "commit_every": commit_every,
        "sleep_sec": sleep_sec,
        "message": "enrich done",
    }