"""
Trace Upload API

提供 Trace 压缩包上传和导入功能
"""

import os
import shutil
import tempfile
import zipfile
from typing import List, Dict, Any
from fastapi import APIRouter, UploadFile, File, HTTPException
from pydantic import BaseModel

from .protocols import TraceStore


router = APIRouter(prefix="/api/traces", tags=["traces"])


# ===== Response 模型 =====


class UploadResponse(BaseModel):
    """上传响应"""
    success: bool
    message: str
    imported_traces: List[str]
    failed_traces: List[Dict[str, str]]


# ===== 全局 TraceStore =====


_trace_store: TraceStore | None = None


def set_trace_store(store: TraceStore):
    """设置 TraceStore 实例"""
    global _trace_store
    _trace_store = store


def get_trace_store() -> TraceStore:
    """获取 TraceStore 实例"""
    if _trace_store is None:
        raise RuntimeError("TraceStore not initialized")
    return _trace_store


# ===== 辅助函数 =====


def is_valid_trace_folder(folder_path: str) -> bool:
    """
    验证是否是有效的 trace 文件夹

    有效的 trace 文件夹应该包含：
    - meta.json 文件
    """
    return os.path.isfile(os.path.join(folder_path, "meta.json"))


def extract_and_import_traces(zip_path: str, base_trace_path: str) -> tuple[List[str], List[Dict[str, str]]]:
    """
    解压并导入 traces

    Returns:
        (imported_traces, failed_traces)
    """
    import logging
    logger = logging.getLogger(__name__)

    imported = []
    failed = []

    # 创建临时目录
    with tempfile.TemporaryDirectory() as temp_dir:
        try:
            # 解压文件
            with zipfile.ZipFile(zip_path, 'r') as zip_ref:
                zip_ref.extractall(temp_dir)

            logger.info(f"Extracted to temp dir: {temp_dir}")

            # 收集所有有效的 trace 文件夹
            valid_traces = []

            # 遍历解压后的内容
            for root, dirs, files in os.walk(temp_dir):
                # 检查当前目录是否是 trace 文件夹
                if is_valid_trace_folder(root):
                    valid_traces.append(root)
                    logger.info(f"Found valid trace folder: {root}")

            if not valid_traces:
                logger.warning(f"No valid traces found in {temp_dir}")
                # 列出临时目录的内容用于调试
                for root, dirs, files in os.walk(temp_dir):
                    logger.info(f"Dir: {root}, Files: {files[:5]}")  # 只显示前5个文件

            # 导入找到的 trace 文件夹
            for trace_folder in valid_traces:
                trace_folder_name = os.path.basename(trace_folder)
                target_path = os.path.join(base_trace_path, trace_folder_name)

                try:
                    # 如果目标已存在，跳过
                    if os.path.exists(target_path):
                        failed.append({
                            "trace_id": trace_folder_name,
                            "reason": "Trace already exists"
                        })
                        logger.warning(f"Trace already exists: {trace_folder_name}")
                        continue

                    # 复制到目标目录
                    shutil.copytree(trace_folder, target_path)
                    imported.append(trace_folder_name)
                    logger.info(f"Imported trace: {trace_folder_name}")

                except Exception as e:
                    failed.append({
                        "trace_id": trace_folder_name,
                        "reason": str(e)
                    })
                    logger.error(f"Failed to import {trace_folder_name}: {e}")

        except zipfile.BadZipFile:
            raise HTTPException(status_code=400, detail="Invalid zip file")
        except Exception as e:
            logger.error(f"Failed to extract zip: {e}")
            raise HTTPException(status_code=500, detail=f"Failed to extract zip: {str(e)}")

    return imported, failed


# ===== 路由 =====


@router.post("/upload", response_model=UploadResponse)
async def upload_traces(file: UploadFile = File(...)):
    """
    上传 trace 压缩包并导入

    支持的格式：.zip
    压缩包可以包含：
    - 单个 trace 文件夹
    - 多个 trace 文件夹
    - 嵌套的 trace 文件夹

    Args:
        file: 上传的压缩包文件
    """
    # 验证文件类型
    if not file.filename or not file.filename.endswith('.zip'):
        raise HTTPException(status_code=400, detail="Only .zip files are supported")

    # 获取 trace 存储路径
    store = get_trace_store()
    # 假设 FileSystemTraceStore 有 base_path 属性
    if not hasattr(store, 'base_path'):
        raise HTTPException(status_code=500, detail="TraceStore does not support file system operations")

    base_trace_path = store.base_path

    # 保存上传的文件到临时位置
    with tempfile.NamedTemporaryFile(delete=False, suffix='.zip') as temp_file:
        temp_file_path = temp_file.name
        content = await file.read()
        temp_file.write(content)

    try:
        # 解压并导入
        imported, failed = extract_and_import_traces(temp_file_path, base_trace_path)

        # 构建响应消息
        if imported and not failed:
            message = f"Successfully imported {len(imported)} trace(s)"
        elif imported and failed:
            message = f"Imported {len(imported)} trace(s), {len(failed)} failed"
        elif not imported and failed:
            message = f"Failed to import all traces"
        else:
            message = "No valid traces found in the zip file"

        return UploadResponse(
            success=len(imported) > 0,
            message=message,
            imported_traces=imported,
            failed_traces=failed
        )

    finally:
        # 清理临时文件
        if os.path.exists(temp_file_path):
            os.unlink(temp_file_path)