"""
FileSystem Trace Store - 文件系统存储实现

用于跨进程数据共享，数据持久化到 .trace/ 目录

目录结构：
.trace/{trace_id}/
├── meta.json           # Trace 元数据
├── goal.json           # GoalTree（扁平 JSON，通过 parent_id 构建层级）
├── messages/           # Messages（每条独立文件）
│   ├── {message_id}.json
│   └── ...
└── events.jsonl        # 事件流（WebSocket 续传）

Sub-Trace 是完全独立的 Trace，有自己的目录：
.trace/{parent_id}@{mode}-{timestamp}-{seq}/
├── meta.json           # parent_trace_id 指向父 Trace
├── goal.json
├── messages/
└── events.jsonl
"""

import json
import os
import logging
from pathlib import Path
from typing import Dict, List, Optional, Any
from datetime import datetime

from .models import Trace, Message
from .goal_models import GoalTree, Goal, GoalStats

logger = logging.getLogger(__name__)


class FileSystemTraceStore:
    """文件系统 Trace 存储"""

    def __init__(self, base_path: str = ".trace"):
        self.base_path = Path(base_path)
        self.base_path.mkdir(exist_ok=True)

    def _get_trace_dir(self, trace_id: str) -> Path:
        """获取 trace 目录"""
        return self.base_path / trace_id

    def _get_meta_file(self, trace_id: str) -> Path:
        """获取 meta.json 文件路径"""
        return self._get_trace_dir(trace_id) / "meta.json"

    def _get_goal_file(self, trace_id: str) -> Path:
        """获取 goal.json 文件路径"""
        return self._get_trace_dir(trace_id) / "goal.json"

    def _get_messages_dir(self, trace_id: str) -> Path:
        """获取 messages 目录"""
        return self._get_trace_dir(trace_id) / "messages"

    def _get_message_file(self, trace_id: str, message_id: str) -> Path:
        """获取 message 文件路径"""
        return self._get_messages_dir(trace_id) / f"{message_id}.json"

    def _get_events_file(self, trace_id: str) -> Path:
        """获取 events.jsonl 文件路径"""
        return self._get_trace_dir(trace_id) / "events.jsonl"

    def _get_model_usage_file(self, trace_id: str) -> Path:
        """获取 model_usage.json 文件路径"""
        return self._get_trace_dir(trace_id) / "model_usage.json"

    # ===== Trace 操作 =====

    async def create_trace(self, trace: Trace) -> str:
        """创建新的 Trace"""
        trace_dir = self._get_trace_dir(trace.trace_id)
        trace_dir.mkdir(exist_ok=True)

        # 创建 messages 目录
        messages_dir = self._get_messages_dir(trace.trace_id)
        messages_dir.mkdir(exist_ok=True)

        # 写入 meta.json
        meta_file = self._get_meta_file(trace.trace_id)
        meta_file.write_text(json.dumps(trace.to_dict(), indent=2, ensure_ascii=False), encoding="utf-8")

        # 创建空的 events.jsonl
        events_file = self._get_events_file(trace.trace_id)
        events_file.touch()

        return trace.trace_id

    async def get_trace(self, trace_id: str) -> Optional[Trace]:
        """获取 Trace"""
        meta_file = self._get_meta_file(trace_id)
        if not meta_file.exists():
            return None

        data = json.loads(meta_file.read_text(encoding="utf-8"))

        # 解析 datetime 字段
        if data.get("created_at"):
            data["created_at"] = datetime.fromisoformat(data["created_at"])
        if data.get("completed_at"):
            data["completed_at"] = datetime.fromisoformat(data["completed_at"])

        return Trace.from_dict(data)

    async def update_trace(self, trace_id: str, **updates) -> None:
        """更新 Trace"""
        trace = await self.get_trace(trace_id)
        if not trace:
            return

        # 更新字段
        for key, value in updates.items():
            if hasattr(trace, key):
                setattr(trace, key, value)

        # 写回文件
        meta_file = self._get_meta_file(trace_id)
        meta_file.write_text(json.dumps(trace.to_dict(), indent=2, ensure_ascii=False), encoding="utf-8")

    async def list_traces(
        self,
        mode: Optional[str] = None,
        agent_type: Optional[str] = None,
        uid: Optional[str] = None,
        status: Optional[str] = None,
        limit: int = 50
    ) -> List[Trace]:
        """列出 Traces"""
        traces = []

        if not self.base_path.exists():
            return []

        for trace_dir in self.base_path.iterdir():
            if not trace_dir.is_dir():
                continue

            meta_file = trace_dir / "meta.json"
            if not meta_file.exists():
                continue

            try:
                data = json.loads(meta_file.read_text(encoding="utf-8"))

                # 过滤
                if mode and data.get("mode") != mode:
                    continue
                if agent_type and data.get("agent_type") != agent_type:
                    continue
                if uid and data.get("uid") != uid:
                    continue
                if status and data.get("status") != status:
                    continue

                # 解析 datetime
                if data.get("created_at"):
                    data["created_at"] = datetime.fromisoformat(data["created_at"])
                if data.get("completed_at"):
                    data["completed_at"] = datetime.fromisoformat(data["completed_at"])

                traces.append(Trace.from_dict(data))
            except Exception:
                continue

        # 排序（最新的在前）
        traces.sort(key=lambda t: t.created_at, reverse=True)

        return traces[:limit]

    # ===== GoalTree 操作 =====

    async def get_goal_tree(self, trace_id: str) -> Optional[GoalTree]:
        """获取 GoalTree"""
        goal_file = self._get_goal_file(trace_id)
        if not goal_file.exists():
            return None

        try:
            data = json.loads(goal_file.read_text(encoding="utf-8"))
            return GoalTree.from_dict(data)
        except Exception:
            return None

    async def update_goal_tree(self, trace_id: str, tree: GoalTree) -> None:
        """更新完整 GoalTree"""
        goal_file = self._get_goal_file(trace_id)
        goal_file.write_text(json.dumps(tree.to_dict(), indent=2, ensure_ascii=False), encoding="utf-8")

    async def add_goal(self, trace_id: str, goal: Goal) -> None:
        """添加 Goal 到 GoalTree"""
        tree = await self.get_goal_tree(trace_id)
        if not tree:
            return

        tree.goals.append(goal)
        await self.update_goal_tree(trace_id, tree)

        # 推送 goal_added 事件
        event_data = {
            "goal": goal.to_dict(),
            "parent_id": goal.parent_id
        }
        await self.append_event(trace_id, "goal_added", event_data)

        # 打印详细的 goal 信息
        desc_preview = goal.description[:80] + "..." if len(goal.description) > 80 else goal.description
        print(f"[Goal Added] ID={goal.id}, Parent={goal.parent_id or 'root'}")
        print(f"  📝 {desc_preview}")
        if goal.reason:
            reason_preview = goal.reason[:60] + "..." if len(goal.reason) > 60 else goal.reason
            print(f"  💡 {reason_preview}")

    async def update_goal(self, trace_id: str, goal_id: str, **updates) -> None:
        """更新 Goal 字段"""
        tree = await self.get_goal_tree(trace_id)
        if not tree:
            return

        goal = tree.find(goal_id)
        if not goal:
            return

        # 更新字段
        for key, value in updates.items():
            if hasattr(goal, key):
                # 特殊处理 stats 字段（可能是 dict）
                if key in ["self_stats", "cumulative_stats"] and isinstance(value, dict):
                    value = GoalStats.from_dict(value)
                setattr(goal, key, value)

        await self.update_goal_tree(trace_id, tree)

        # 推送 goal_updated 事件
        # 如果状态变为 completed，检查是否需要级联完成父 Goal
        affected_goals = [{"goal_id": goal_id, "updates": updates}]

        if updates.get("status") == "completed":
            # 检查级联完成：如果所有兄弟 Goal 都完成，父 Goal 也完成
            cascade_completed = await self._check_cascade_completion(trace_id, goal)
            affected_goals.extend(cascade_completed)

        await self.append_event(trace_id, "goal_updated", {
            "goal_id": goal_id,
            "updates": updates,
            "affected_goals": affected_goals
        })
        print(f"[DEBUG] Pushed goal_updated event: goal_id={goal_id}, updates={updates}, affected={len(affected_goals)}")

    async def _check_cascade_completion(
        self,
        trace_id: str,
        completed_goal: Goal
    ) -> List[Dict[str, Any]]:
        """
        检查级联完成：如果一个 Goal 的所有子 Goal 都完成，则自动完成父 Goal

        Args:
            trace_id: Trace ID
            completed_goal: 刚完成的 Goal

        Returns:
            受影响的父 Goals 列表（自动完成的）
        """
        if not completed_goal.parent_id:
            return []

        tree = await self.get_goal_tree(trace_id)
        if not tree:
            return []

        affected = []
        parent = tree.find(completed_goal.parent_id)

        if not parent:
            return []

        # 获取父 Goal 的所有子 Goal
        children = tree.get_children(parent.id)

        # 检查是否所有子 Goal 都已完成（排除 abandoned）
        all_completed = all(
            child.status in ["completed", "abandoned"]
            for child in children
        )

        if all_completed and parent.status != "completed":
            # 自动完成父 Goal
            parent.status = "completed"
            if not parent.summary:
                # 生成自动摘要
                completed_count = sum(1 for c in children if c.status == "completed")
                parent.summary = f"所有子目标已完成 ({completed_count}/{len(children)})"

            await self.update_goal_tree(trace_id, tree)

            affected.append({
                "goal_id": parent.id,
                "status": "completed",
                "summary": parent.summary,
                "cumulative_stats": parent.cumulative_stats.to_dict()
            })

            # 递归检查祖父 Goal
            grandparent_affected = await self._check_cascade_completion(trace_id, parent)
            affected.extend(grandparent_affected)

        return affected

    # ===== Message 操作 =====

    async def add_message(self, message: Message) -> str:
        """
        添加 Message

        自动更新关联 Goal 的 stats（self_stats 和祖先的 cumulative_stats）
        """
        trace_id = message.trace_id

        # 1. 写入 message 文件
        messages_dir = self._get_messages_dir(trace_id)
        message_file = messages_dir / f"{message.message_id}.json"
        message_file.write_text(json.dumps(message.to_dict(), indent=2, ensure_ascii=False), encoding="utf-8")

        # 2. 更新 trace 统计
        trace = await self.get_trace(trace_id)
        if trace:
            trace.total_messages += 1
            trace.last_sequence = max(trace.last_sequence, message.sequence)

            # 累计 tokens（完整版）
            if message.prompt_tokens:
                trace.total_prompt_tokens += message.prompt_tokens
            if message.completion_tokens:
                trace.total_completion_tokens += message.completion_tokens
            if message.reasoning_tokens:
                trace.total_reasoning_tokens += message.reasoning_tokens
            if message.cache_creation_tokens:
                trace.total_cache_creation_tokens += message.cache_creation_tokens
            if message.cache_read_tokens:
                trace.total_cache_read_tokens += message.cache_read_tokens

            # 向后兼容：也更新 total_tokens
            if message.tokens:
                trace.total_tokens += message.tokens
            elif message.prompt_tokens or message.completion_tokens:
                trace.total_tokens += (message.prompt_tokens or 0) + (message.completion_tokens or 0)

            if message.cost:
                trace.total_cost += message.cost
            if message.duration_ms:
                trace.total_duration_ms += message.duration_ms

            # 更新 Trace
            await self.update_trace(
                trace_id,
                total_messages=trace.total_messages,
                last_sequence=trace.last_sequence,
                total_tokens=trace.total_tokens,
                total_prompt_tokens=trace.total_prompt_tokens,
                total_completion_tokens=trace.total_completion_tokens,
                total_reasoning_tokens=trace.total_reasoning_tokens,
                total_cache_creation_tokens=trace.total_cache_creation_tokens,
                total_cache_read_tokens=trace.total_cache_read_tokens,
                total_cost=trace.total_cost,
                total_duration_ms=trace.total_duration_ms
            )

        # 3. 更新 Goal stats
        await self._update_goal_stats(trace_id, message)

        # 4. 追加 message_added 事件
        affected_goals = await self._get_affected_goals(trace_id, message)
        event_id = await self.append_event(trace_id, "message_added", {
            "message": message.to_dict(),
            "affected_goals": affected_goals
        })
        if event_id:
            try:
                from . import websocket as trace_ws

                await trace_ws.broadcast_message_added(
                    trace_id=trace_id,
                    event_id=event_id,
                    message_dict=message.to_dict(),
                    affected_goals=affected_goals,
                )
            except Exception:
                logger.exception("Failed to broadcast message_added (trace_id=%s, event_id=%s)", trace_id, event_id)

        return message.message_id

    async def _update_goal_stats(self, trace_id: str, message: Message) -> None:
        """更新 Goal 的 self_stats 和祖先的 cumulative_stats"""
        tree = await self.get_goal_tree(trace_id)

        if not tree:
            return

        # 找到关联的 Goal
        goal = tree.find(message.goal_id)
        if not goal:
            return

        # 更新自身 self_stats
        goal.self_stats.message_count += 1
        if message.tokens:
            goal.self_stats.total_tokens += message.tokens
        if message.cost:
            goal.self_stats.total_cost += message.cost
        # TODO: 更新 preview（工具调用摘要）

        # 更新自身 cumulative_stats
        goal.cumulative_stats.message_count += 1
        if message.tokens:
            goal.cumulative_stats.total_tokens += message.tokens
        if message.cost:
            goal.cumulative_stats.total_cost += message.cost

        # 沿祖先链向上更新 cumulative_stats
        current_goal = goal
        while current_goal.parent_id:
            parent = tree.find(current_goal.parent_id)
            if not parent:
                break

            parent.cumulative_stats.message_count += 1
            if message.tokens:
                parent.cumulative_stats.total_tokens += message.tokens
            if message.cost:
                parent.cumulative_stats.total_cost += message.cost

            current_goal = parent

        # 保存更新后的 tree
        await self.update_goal_tree(trace_id, tree)

    async def _get_affected_goals(self, trace_id: str, message: Message) -> List[Dict[str, Any]]:
        """获取受影响的 Goals（自身 + 所有祖先）"""
        tree = await self.get_goal_tree(trace_id)

        if not tree:
            return []

        goal = tree.find(message.goal_id)
        if not goal:
            return []

        affected = []

        # 添加自身（包含 self_stats 和 cumulative_stats）
        affected.append({
            "goal_id": goal.id,
            "self_stats": goal.self_stats.to_dict(),
            "cumulative_stats": goal.cumulative_stats.to_dict()
        })

        # 添加所有祖先（仅 cumulative_stats）
        current_goal = goal
        while current_goal.parent_id:
            parent = tree.find(current_goal.parent_id)
            if not parent:
                break

            affected.append({
                "goal_id": parent.id,
                "cumulative_stats": parent.cumulative_stats.to_dict()
            })

            current_goal = parent

        return affected

        return affected

    async def get_message(self, message_id: str) -> Optional[Message]:
        """获取 Message（扫描所有 trace）"""
        for trace_dir in self.base_path.iterdir():
            if not trace_dir.is_dir():
                continue

            # 检查 messages 目录
            message_file = trace_dir / "messages" / f"{message_id}.json"
            if message_file.exists():
                try:
                    data = json.loads(message_file.read_text(encoding="utf-8"))
                    return Message.from_dict(data)
                except Exception:
                    pass

        return None

    async def get_trace_messages(
        self,
        trace_id: str,
    ) -> List[Message]:
        """获取 Trace 的所有 Messages（包含所有分支，按 sequence 排序）"""
        messages_dir = self._get_messages_dir(trace_id)

        if not messages_dir.exists():
            return []

        messages = []
        for message_file in messages_dir.glob("*.json"):
            try:
                data = json.loads(message_file.read_text(encoding="utf-8"))
                msg = Message.from_dict(data)
                messages.append(msg)
            except Exception:
                continue

        # 按 sequence 排序
        messages.sort(key=lambda m: m.sequence)
        return messages

    async def get_main_path_messages(
        self,
        trace_id: str,
        head_sequence: int
    ) -> List[Message]:
        """
        获取从 head_sequence 沿 parent_sequence 链回溯到 root 的完整路径

        此函数是通用的路径追溯函数，返回从指定 head 到 root 的完整消息链。
        只要 trace.head_sequence 管理正确（指向主路径），此函数自然返回主路径消息。
        侧分支消息通过 parent_sequence 链自然被跳过（因为主路径的 parent 不指向侧分支）。

        Returns:
            按 sequence 正序排列的路径 Message 列表
        """
        # 加载所有消息，建立 sequence -> Message 索引
        all_messages = await self.get_trace_messages(trace_id)
        messages_by_seq = {m.sequence: m for m in all_messages}

        # 从 head 沿 parent chain 回溯
        path = []
        seq = head_sequence
        while seq is not None:
            msg = messages_by_seq.get(seq)
            if not msg:
                break
            path.append(msg)
            seq = msg.parent_sequence

        # 反转为正序（root → head）
        path.reverse()
        return path

    async def get_messages_by_goal(
        self,
        trace_id: str,
        goal_id: str
    ) -> List[Message]:
        """获取指定 Goal 关联的所有 Messages"""
        all_messages = await self.get_trace_messages(trace_id)
        return [m for m in all_messages if m.goal_id == goal_id]

    async def update_message(self, message_id: str, **updates) -> None:
        """更新 Message 字段"""
        message = await self.get_message(message_id)
        if not message:
            return

        # 更新字段
        for key, value in updates.items():
            if hasattr(message, key):
                setattr(message, key, value)

        # 确定文件路径
        messages_dir = self._get_messages_dir(message.trace_id)
        message_file = messages_dir / f"{message_id}.json"
        message_file.write_text(json.dumps(message.to_dict(), indent=2, ensure_ascii=False), encoding="utf-8")

    async def abandon_messages_after(self, trace_id: str, cutoff_sequence: int) -> List[str]:
        """
        将 sequence > cutoff_sequence 的 active messages 标记为 abandoned。
        返回被 abandon 的 message_id 列表。
        """
        all_messages = await self.get_trace_messages(trace_id)
        abandoned_ids = []
        now = datetime.now()

        for msg in all_messages:
            if msg.sequence > cutoff_sequence and msg.status == "active":
                msg.status = "abandoned"
                msg.abandoned_at = now
                # 直接写回文件
                message_file = self._get_messages_dir(trace_id) / f"{msg.message_id}.json"
                message_file.write_text(
                    json.dumps(msg.to_dict(), indent=2, ensure_ascii=False),
                    encoding="utf-8"
                )
                abandoned_ids.append(msg.message_id)

        return abandoned_ids

    # ===== 模型使用追踪 =====

    async def record_model_usage(
        self,
        trace_id: str,
        sequence: int,
        role: str,
        model: str,
        prompt_tokens: int,
        completion_tokens: int,
        cache_read_tokens: int = 0,
        tool_name: Optional[str] = None,
    ) -> None:
        """
        记录模型使用情况到 model_usage.json

        Args:
            trace_id: Trace ID
            sequence: 消息序号
            role: 角色（assistant/tool）
            model: 模型名称
            prompt_tokens: 输入tokens
            completion_tokens: 输出tokens
            cache_read_tokens: 缓存读取tokens
            tool_name: 工具名称（role=tool时）
        """
        usage_file = self._get_model_usage_file(trace_id)

        # 读取现有数据
        if usage_file.exists():
            data = json.loads(usage_file.read_text(encoding="utf-8"))
        else:
            data = {
                "summary": {
                    "total_models": 0,
                    "total_tokens": 0,
                    "total_cache_read_tokens": 0,
                    "agent_tokens": 0,
                    "tool_tokens": 0,
                },
                "models": [],
                "timeline": [],
            }

        # 更新summary
        total_tokens = prompt_tokens + completion_tokens
        data["summary"]["total_tokens"] += total_tokens
        data["summary"]["total_cache_read_tokens"] += cache_read_tokens

        if role == "assistant":
            data["summary"]["agent_tokens"] += total_tokens
            source = "agent"
        else:
            data["summary"]["tool_tokens"] += total_tokens
            source = f"tool:{tool_name}" if tool_name else "tool"

        # 更新models列表
        model_entry = None
        for m in data["models"]:
            if m["model"] == model and m["source"] == source:
                model_entry = m
                break

        if model_entry:
            model_entry["prompt_tokens"] += prompt_tokens
            model_entry["completion_tokens"] += completion_tokens
            model_entry["total_tokens"] += total_tokens
            model_entry["cache_read_tokens"] += cache_read_tokens
            model_entry["call_count"] += 1
        else:
            data["models"].append({
                "model": model,
                "source": source,
                "prompt_tokens": prompt_tokens,
                "completion_tokens": completion_tokens,
                "total_tokens": total_tokens,
                "cache_read_tokens": cache_read_tokens,
                "call_count": 1,
            })
            data["summary"]["total_models"] = len(data["models"])

        # 添加到timeline
        timeline_entry = {
            "sequence": sequence,
            "role": role,
            "model": model,
            "prompt_tokens": prompt_tokens,
            "completion_tokens": completion_tokens,
        }
        if cache_read_tokens > 0:
            timeline_entry["cache_read_tokens"] = cache_read_tokens
        if tool_name:
            timeline_entry["tool_name"] = tool_name
        data["timeline"].append(timeline_entry)

        # 写回文件
        usage_file.write_text(json.dumps(data, indent=2, ensure_ascii=False), encoding="utf-8")

    # ===== 事件流操作（用于 WebSocket 断线续传）=====

    async def get_events(
        self,
        trace_id: str,
        since_event_id: int = 0
    ) -> List[Dict[str, Any]]:
        """获取事件流"""
        events_file = self._get_events_file(trace_id)
        if not events_file.exists():
            return []

        events = []
        with events_file.open('r', encoding='utf-8') as f:
            for line in f:
                try:
                    event = json.loads(line.strip())
                    if event.get("event_id", 0) > since_event_id:
                        events.append(event)
                except Exception:
                    continue

        return events

    async def append_event(
        self,
        trace_id: str,
        event_type: str,
        payload: Dict[str, Any]
    ) -> int:
        """追加事件，返回 event_id"""
        # 获取 trace 并递增 event_id
        trace = await self.get_trace(trace_id)
        if not trace:
            return 0

        trace.last_event_id += 1
        event_id = trace.last_event_id

        # 更新 trace 的 last_event_id
        await self.update_trace(trace_id, last_event_id=event_id)

        # 创建事件
        event = {
            "event_id": event_id,
            "event": event_type,
            "ts": datetime.now().isoformat(),
            **payload
        }

        # 追加到 events.jsonl
        events_file = self._get_events_file(trace_id)
        with events_file.open('a', encoding='utf-8') as f:
            f.write(json.dumps(event, ensure_ascii=False) + '\n')

        return event_id