#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
皮肤分析 API 接口服务
"""

import sys
import os
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

from fastapi import FastAPI, HTTPException, Query
from contextlib import asynccontextmanager
import asyncio
from pydantic import BaseModel, Field
import uvicorn
import logging
from datetime import datetime
from typing import Optional
from pathlib import Path
from config.settings import (API_HOST, API_CALLBACK, TASK_DB_PATH,
                             MAX_CONCURRENT_TASKS, MAX_PENDING_TASKS, MODEL_PATH, IMAGE_WORKERS)
from task_queue import TaskQueue, QueueFull
from resident_worker import ResidentPool

# ==================== 日志配置 ====================
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s.%(msecs)03d | %(levelname)s | %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S'
)
logger = logging.getLogger(__name__)

# ==================== 服务生命周期 ====================
@asynccontextmanager
async def lifespan(app):
    await asyncio.to_thread(task_queue.start)
    try:
        yield
    finally:
        await asyncio.to_thread(task_queue.stop)


app = FastAPI(
    title="皮肤分析任务接口",
    description="接收文件夹名称，触发皮肤分析任务",
    version="1.0.0",
    lifespan=lifespan,
)

# ==================== 数据模型 ====================
class TaskRequest(BaseModel):
    folder_name: str = Field(..., description="文件夹全路径")
    task_id: str = Field(..., description="目标文件夹名称（任务 ID）")

class TaskResponse(BaseModel):
    code: int = Field(..., description="状态码")
    message: str = Field(..., description="消息")
    task_id: str = Field(..., description="任务 ID")
    status: str = Field(..., description="任务状态")

class TaskStatus(BaseModel):
    task_id: str = Field(..., description="任务 ID")
    status: str = Field(..., description="状态")
    created_at: str = Field(..., description="创建时间")
    completed_at: Optional[str] = Field(default=None, description="完成时间")
    error: Optional[str] = Field(default=None, description="错误信息")

class CallbackRequest(BaseModel):
    task_id: str = Field(..., description="任务 ID")
    status: int = Field(..., description="处理状态，1=成功，0=失败")

# 每个任务槽位对应一个常驻模型进程；启动预热后才开放 API。
analysis_pool = ResidentPool(MODEL_PATH, MAX_CONCURRENT_TASKS, IMAGE_WORKERS,
                             API_HOST + API_CALLBACK)
task_queue = TaskQueue(TASK_DB_PATH, MAX_CONCURRENT_TASKS,
                       MAX_PENDING_TASKS, analysis_pool)

# ==================== API 接口 ====================
@app.get("/")
async def root():
    return {
        "service": "皮肤分析任务接口",
        "version": "1.0.0",
        "status": "running"
    }

@app.get("/health")
def health_check():
    return {
        "status": "healthy",
        "timestamp": datetime.now().isoformat(),
        "tasks": task_queue.counts(),
        "queue": {"max_concurrent": task_queue.concurrency,
                  "max_pending": task_queue.max_pending}
    }


@app.post("/api/v1/analysis/submit", response_model=TaskResponse)
def submit_task(request: TaskRequest):
    received_at = datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3]
    task_id = request.task_id if request.task_id else Path(request.folder_name).name
    logger.info("API 接收到任务时间：%s | task_id=%s | folder_name=%s",
                received_at, task_id, request.folder_name)
    if not task_id or len(task_id) < 3:
        raise HTTPException(status_code=400, detail="任务 ID 格式错误，至少 3 个字符")
    # Resolve the date at submission, not after a queued task starts tomorrow.
    input_dir = Path(request.folder_name)
    if not input_dir.is_absolute():
        input_dir = Path("/data/analysis") / datetime.now().strftime("%Y%m%d") / task_id
    try:
        task, created = task_queue.submit(
            task_id, {"folder_name": request.folder_name, "task_id": task_id},
            str(input_dir.resolve()))
    except QueueFull as exc:
        raise HTTPException(status_code=429, detail=str(exc),
                            headers={"Retry-After": "5"}) from exc
    logger.info("API 任务入队时间：%s | task_id=%s | status=%s | created=%s",
                datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3],
                task_id, task["status"], created)
    return TaskResponse(code=200,
                        message="任务已加入队列" if created else "任务已存在，正在等待或运行中",
                        task_id=task_id, status=task["status"])

@app.post("/api/v1/analysis/callback")
def analysis_callback(request: CallbackRequest):
    if request.status not in (0, 1):
        raise HTTPException(status_code=400, detail="状态只允许 0 或 1")
    status = task_queue.callback(request.task_id, request.status)
    if status is None:
        raise HTTPException(status_code=404, detail="任务不存在")
    return {"code": 200, "message": "回调接收成功", "task_id": request.task_id, "status": status}

@app.get("/api/v1/analysis/status/{task_id}", response_model=TaskStatus)
def get_task_status(task_id: str):
    task = task_queue.get(task_id)
    if task is None:
        raise HTTPException(status_code=404, detail=f"任务不存在：{task_id}")

    return TaskStatus(
        task_id=task["task_id"],
        status=task["status"],
        created_at=task["created_at"],
        completed_at=task.get("completed_at"),
        error=task.get("error")
    )

@app.get("/api/v1/analysis/list")
def list_tasks(
    status: Optional[str] = Query(default=None),
    limit: int = Query(default=20, ge=1, le=100)
):
    tasks = task_queue.list(status, limit)
    return {"total": len(tasks), "tasks": tasks}

# ==================== 启动服务 ====================
if __name__ == "__main__":
    print("="*60)
    print("皮肤分析 API 服务")
    print("="*60)
    print("监听地址：http://0.0.0.0:20001")
    print("提交接口：POST /api/v1/analysis/submit")
    print("状态查询：GET /api/v1/analysis/status/{task_id}")
    print("健康检查：GET /health")
    print("="*60)
    print()
    
    uvicorn.run(app, host="0.0.0.0", port=20001)