import hashlib
import json
import logging
import os
from datetime import datetime
from typing import Dict, List, Optional

logger = logging.getLogger(__name__)


def _item_id(task: str, assignee: str) -> str:
    raw = f"{task}|{assignee}"
    return hashlib.md5(raw.encode("utf-8")).hexdigest()[:8]


def _metric_id(metric_name: str, owner: str) -> str:
    raw = f"{metric_name}|{owner}"
    return hashlib.md5(raw.encode("utf-8")).hexdigest()[:8]


class MeetingStateStore:
    def __init__(self, state_path: str):
        self.state_path = state_path
        self._state = self._load()

    def _load(self) -> dict:
        if os.path.exists(self.state_path):
            try:
                with open(self.state_path, "r", encoding="utf-8") as f:
                    return json.load(f)
            except Exception as e:
                logger.warning(f"加载状态文件失败，将创建新状态: {e}")
        return {
            "action_items": {},
            "metrics": {},
            "meeting_series": {},
            "content_hashes": {},
        }

    def save(self):
        os.makedirs(os.path.dirname(self.state_path), exist_ok=True)
        with open(self.state_path, "w", encoding="utf-8") as f:
            json.dump(self._state, f, ensure_ascii=False, indent=2)

    def _ensure_series(self, meeting_title: str, meeting_date: str) -> str:
        series_name = self._detect_series(meeting_title)
        series = self._state["meeting_series"].get(series_name)
        if not series:
            series = {"latest_date": meeting_date, "processed_titles": []}
            self._state["meeting_series"][series_name] = series
        if meeting_date > series.get("latest_date", ""):
            series["latest_date"] = meeting_date
        if meeting_title not in series["processed_titles"]:
            series["processed_titles"].append(meeting_title)
        return series_name

    def _detect_series(self, title: str) -> str:
        import re
        cleaned = re.sub(r"（\d{4}第\w+期）", "", title)
        cleaned = re.sub(r"\(\d{4}第\w+期\)", "", cleaned)
        cleaned = re.sub(r"\d{4}第\w+期", "", cleaned)
        cleaned = re.sub(r"\d{4}年第\w+次", "", cleaned)
        cleaned = cleaned.strip("-_ ")
        return cleaned or title

    def merge_action_items(
        self,
        new_items: List[dict],
        meeting_title: str,
        meeting_date: str,
        meeting_filename: str,
    ) -> List[dict]:
        series_name = self._ensure_series(meeting_title, meeting_date)
        merged = []

        for item in new_items:
            task = item.get("task", "")
            assignee = item.get("assignee", "")
            iid = _item_id(task, assignee)

            history_entry = {
                "date": meeting_date,
                "meeting": meeting_filename,
                "status": item.get("status", "待办"),
                "priority": item.get("priority", "中"),
                "deadline": item.get("deadline", ""),
            }

            existing = self._state["action_items"].get(iid)
            if existing:
                existing["history"].append(history_entry)
                existing["latest"] = history_entry
                latest = existing["history"][-1]
                item["_item_id"] = iid
                item["_history"] = list(existing["history"])
                item["status"] = latest["status"]
                item["priority"] = latest["priority"]
                item["deadline"] = latest["deadline"]
            else:
                self._state["action_items"][iid] = {
                    "item_id": iid,
                    "task": task,
                    "assignee": assignee,
                    "series": series_name,
                    "created_meeting": meeting_filename,
                    "history": [history_entry],
                    "latest": history_entry,
                }
                item["_item_id"] = iid
                item["_history"] = [history_entry]

            merged.append(item)

        return merged

    def merge_metrics(
        self,
        new_metrics: List[dict],
        meeting_title: str,
        meeting_date: str,
        meeting_filename: str,
    ) -> List[dict]:
        merged = []

        for m in new_metrics:
            metric_name = m.get("metric_name", "")
            owner = m.get("owner", "")
            mid = _metric_id(metric_name, owner)

            history_entry = {
                "date": meeting_date,
                "meeting": meeting_filename,
                "value": m.get("value", ""),
                "target": m.get("target", ""),
                "trend": m.get("trend", ""),
            }

            existing = self._state["metrics"].get(mid)
            if existing:
                existing["history"].append(history_entry)
                existing["latest"] = history_entry
                item = m
                item["_metric_id"] = mid
                item["_history"] = list(existing["history"])
            else:
                self._state["metrics"][mid] = {
                    "metric_id": mid,
                    "metric_name": metric_name,
                    "owner": owner,
                    "history": [history_entry],
                    "latest": history_entry,
                }
                m["_metric_id"] = mid
                m["_history"] = [history_entry]

            merged.append(m)

        return merged

    def get_action_item_history(self, item_id: str) -> Optional[dict]:
        return self._state["action_items"].get(item_id)

    def get_metric_history(self, metric_id: str) -> Optional[dict]:
        return self._state["metrics"].get(metric_id)

    def get_series_info(self, title: str) -> Optional[dict]:
        series_name = self._detect_series(title)
        return self._state["meeting_series"].get(series_name)

    def has_content_hash(self, content_hash: str) -> bool:
        return content_hash in self._state["content_hashes"]

    def add_content_hash(self, content_hash: str, title: str, date: str, filename: str):
        self._state["content_hashes"][content_hash] = {
            "title": title,
            "date": date,
            "filename": filename,
        }

    def remove_content_hash(self, content_hash: str):
        self._state["content_hashes"].pop(content_hash, None)

    def get_stats(self) -> dict:
        return {
            "action_items_tracked": len(self._state["action_items"]),
            "metrics_tracked": len(self._state["metrics"]),
            "meeting_series": len(self._state["meeting_series"]),
            "content_hashes": len(self._state["content_hashes"]),
        }