# -*- coding: utf-8 -*-
"""本地 HTTP 引擎服务: 云库优先, 皮卡鱼兜底。供油猴脚本调用。"""
import argparse
import logging

from aiohttp import web

from .cloud import CloudBook
from .coords import fen_from_moves, site_to_ucci, ucci_to_site
from .pikafish import Pikafish

logging.basicConfig(level=logging.INFO, format='%(asctime)s %(name)s %(message)s')
log = logging.getLogger('xiangqi.server')


class Service:
    def __init__(self, args):
        self.args = args
        self.cloud = CloudBook(min_score=args.cloud_min_score)
        self.engine = None  # 惰性启动(首个请求前/启动时)

    async def startup(self, app):
        self.engine = await Pikafish(
            threads=self.args.threads, hash_mb=self.args.hash,
            movetime=self.args.movetime,
            log=(lambda m: log.debug(m)) if self.args.quiet else (lambda m: log.info(m)),
        ).start()

    async def shutdown(self, app):
        if self.engine:
            await self.engine.quit()
        await self.cloud.close()

    async def bestmove(self, moves_site, fen=None, movetime=None, depth=None):
        moves_ucci = [site_to_ucci(m) for m in moves_site]
        fen = fen or fen_from_moves(moves_ucci)

        # 1. 云库优先
        try:
            cloud_hit = await self.cloud.best(fen, moves_count=len(moves_ucci))
        except Exception as e:
            log.warning('cloud error: %s', e)
            cloud_hit = None
        if cloud_hit and not depth:
            mv, score, note = cloud_hit
            return {'ok': True, 'source': 'cloud', 'move': ucci_to_site(mv),
                    'score': f'cp {score}', 'note': note, 'ms': 0}

        # 2. 皮卡鱼兜底
        try:
            mv, score = await self.engine.bestmove(moves=moves_ucci, fen=fen,
                                                   movetime=movetime, depth=depth)
        except Exception:
            log.exception('engine crashed, restarting')
            await self.engine.restart()
            raise
        return {'ok': True, 'source': 'engine', 'move': ucci_to_site(mv),
                'score': score, 'note': None}


@web.middleware
async def cors_middleware(request, handler):
    """油猴脚本从 https 页面跨域调用本服务: 处理 OPTIONS 预检并补 CORS 头。"""
    if request.method == 'OPTIONS':
        resp = web.Response(status=204)
    else:
        resp = await handler(request)
    resp.headers['Access-Control-Allow-Origin'] = '*'
    resp.headers['Access-Control-Allow-Methods'] = 'GET, POST, OPTIONS'
    resp.headers['Access-Control-Allow-Headers'] = 'Content-Type'
    return resp


def make_app(args):
    svc = Service(args)

    async def health(_):
        return web.json_response({
            'ok': True,
            'engine': svc.engine.path if svc.engine else None,
            'cloud': {'min_score': svc.cloud.min_score,
                      'hit': svc.cloud.ok_count, 'miss': svc.cloud.miss_count},
        })

    async def bestmove(request):
        try:
            req = await request.json()
        except Exception:
            return web.json_response({'ok': False, 'error': 'bad json'}, status=400)
        moves = req.get('moves', [])
        if not isinstance(moves, list) or not all(isinstance(m, str) for m in moves):
            return web.json_response({'ok': False, 'error': 'moves 格式错误'}, status=400)
        try:
            out = await svc.bestmove(
                moves,
                fen=req.get('fen'),
                movetime=req.get('movetime'),
                depth=req.get('depth'),
            )
            return web.json_response(out)
        except Exception as e:
            return web.json_response({'ok': False, 'error': str(e)}, status=500)

    app = web.Application(middlewares=[cors_middleware])
    app.router.add_get('/health', health)
    app.router.add_post('/bestmove', bestmove)
    app.on_startup.append(svc.startup)
    app.on_cleanup.append(svc.shutdown)
    return app


def main():
    p = argparse.ArgumentParser(description='皮卡鱼 + 云库本地服务')
    p.add_argument('--port', type=int, default=9377)
    p.add_argument('--movetime', type=int, default=800, help='每步思考毫秒(深度未指定时)')
    p.add_argument('--depth', type=int, default=None, help='固定深度(优先于 movetime)')
    p.add_argument('--threads', type=int, default=None, help='线程数(默认=CPU核心数)')
    p.add_argument('--hash', type=int, default=256, help='哈希表 MB')
    p.add_argument('--cloud-min-score', type=int, default=15,
                   help='云库着法采纳阈值(厘兵, 红方视角)')
    p.add_argument('--quiet', action='store_true', help='不打印引擎 info')
    args = p.parse_args()

    app = make_app(args)
    mode = f'depth={args.depth}' if args.depth else f'movetime={args.movetime}ms'
    print(f'[server] http://127.0.0.1:{args.port} ({mode}, '
          f'threads={args.threads or "max"}, hash={args.hash}MB, '
          f'cloud_min_score={args.cloud_min_score})', flush=True)
    web.run_app(app, host='127.0.0.1', port=args.port, print=None)


if __name__ == '__main__':
    main()