"""
读档功能模块
"""
import json
from pathlib import Path
from typing import Tuple, List, Optional

from src.classes.world import World
from src.classes.map import Map
from src.classes.calendar import MonthStamp
from src.classes.avatar import Avatar
from src.classes.event import Event
from src.classes.sect import sects_by_id, Sect
from src.classes.relation import Relation
from src.sim.simulator import Simulator
from src.run.load_map import load_cultivation_world_map
from src.utils.config import CONFIG


def get_events_db_path(save_path: Path) -> Path:
    """
    根据存档路径计算事件数据库路径。

    例如：save_20260105_1423.json -> save_20260105_1423_events.db
    """
    return save_path.with_suffix("").with_name(save_path.stem + "_events.db")


def load_game(save_path: Optional[Path] = None) -> Tuple[World, Simulator, List[Sect]]:
    """
    从文件加载游戏状态
    
    Args:
        save_path: 存档路径，默认为saves/save.json
        
    Returns:
        (world, simulator, existed_sects)
        
    Raises:
        FileNotFoundError: 如果存档文件不存在
        Exception: 如果加载失败
    """
    # 确定加载路径
    if save_path is None:
        saves_dir = CONFIG.paths.saves
        save_path = saves_dir / "save.json"
    else:
        save_path = Path(save_path)
    
    if not save_path.exists():
        raise FileNotFoundError(f"存档文件不存在: {save_path}")
    
    try:
        # 读取存档文件
        with open(save_path, "r", encoding="utf-8") as f:
            save_data = json.load(f)
        
        # 读取元信息
        meta = save_data.get("meta", {})
        print(f"正在加载存档 (版本: {meta.get('version', 'unknown')}, "
              f"游戏时间: {meta.get('game_time', 'unknown')})")
        
        # 重建地图（地图本身不变，只需重建宗门总部位置）
        game_map = load_cultivation_world_map()

        # 读取世界数据
        world_data = save_data.get("world", {})
        month_stamp = MonthStamp(world_data["month_stamp"])

        # 计算事件数据库路径
        events_db_path = get_events_db_path(save_path)

        # 重建World对象（使用 SQLite 事件存储）
        world = World.create_with_db(
            map=game_map,
            month_stamp=month_stamp,
            events_db_path=events_db_path,
        )
        
        # 获取本局启用的宗门
        existed_sect_ids = world_data.get("existed_sect_ids", [])
        existed_sects = [sects_by_id[sid] for sid in existed_sect_ids if sid in sects_by_id]
        
        # 第一阶段：重建所有Avatar（不含relations）
        avatars_data = save_data.get("avatars", [])
        all_avatars = {}
        for avatar_data in avatars_data:
            avatar = Avatar.from_save_dict(avatar_data, world)
            all_avatars[avatar.id] = avatar
        
        # 第二阶段：重建relations（需要所有avatar都已加载）
        for avatar_data in avatars_data:
            avatar_id = avatar_data["id"]
            avatar = all_avatars[avatar_id]
            relations_dict = avatar_data.get("relations", {})
            
            for other_id, relation_value in relations_dict.items():
                if other_id in all_avatars:
                    other_avatar = all_avatars[other_id]
                    relation = Relation(relation_value)
                    avatar.relations[other_avatar] = relation
        
        # 将所有avatar添加到world
        world.avatar_manager.avatars = all_avatars

        # 检查是否需要从 JSON 迁移事件（向后兼容）
        db_event_count = world.event_manager.count()
        events_data = save_data.get("events", [])

        if db_event_count == 0 and len(events_data) > 0:
            # SQLite 数据库是空的，但 JSON 中有事件，执行迁移
            print(f"正在从 JSON 迁移 {len(events_data)} 条事件到 SQLite...")
            for event_data in events_data:
                event = Event.from_dict(event_data)
                world.event_manager.add_event(event)
            print("事件迁移完成")
        else:
            print(f"已从 SQLite 加载 {db_event_count} 条事件")

        # 重建Simulator
        simulator_data = save_data.get("simulator", {})
        simulator = Simulator(world)
        simulator.awakening_rate = simulator_data.get("awakening_rate", simulator_data.get("birth_rate", CONFIG.game.npc_awakening_rate_per_month))

        print(f"存档加载成功！共加载 {len(all_avatars)} 个角色")
        return world, simulator, existed_sects
        
    except Exception as e:
        print(f"加载游戏失败: {e}")
        import traceback
        traceback.print_exc()
        raise


def check_save_compatibility(save_path: Path) -> Tuple[bool, str]:
    """
    检查存档兼容性
    
    Args:
        save_path: 存档路径
        
    Returns:
        (是否兼容, 错误信息)
    """
    try:
        with open(save_path, "r", encoding="utf-8") as f:
            save_data = json.load(f)
        
        meta = save_data.get("meta", {})
        save_version = meta.get("version", "unknown")
        current_version = CONFIG.meta.version
        
        # 当前不做版本兼容性检查，直接返回兼容
        # 未来可以在这里添加版本比较逻辑
        return True, ""
        
    except Exception as e:
        return False, f"无法读取存档文件: {e}"