"""
demand Web API（异步任务：发起 -> 立即返回 task_id -> 另一个接口查询状态）
"""

import asyncio
import sys
from pathlib import Path
from typing import Literal, Optional

from fastapi import FastAPI, HTTPException
from pydantic import BaseModel

# 添加项目根目录到 Python 路径（与 run.py 保持一致）
sys.path.insert(0, str(Path(__file__).parent.parent.parent))

from examples.demand.changwen_prepare import changwen_prepare
from examples.demand.mysql import mysql_db
from examples.demand.piaoquan_prepare import piaoquan_prepare
from examples.demand.run import _create_demand_task, main

app = FastAPI(title="demand web api")


class DemandStartRequest(BaseModel):
    cluster_name: str
    platform_type: Literal["piaoquan", "changwen"]


@app.post("/demand/start")
async def demand_start(req: DemandStartRequest):
    # 注意：这里会同步计算 execution_id（prepare 阶段），随后 run_once 放到后台异步执行。
    if req.platform_type == "piaoquan":
        execution_id = piaoquan_prepare(req.cluster_name)
    else:
        execution_id = changwen_prepare(req.cluster_name)

    if not execution_id:
        raise HTTPException(status_code=400, detail="获取 execution_id 失败")

    task_name = req.cluster_name[:32] if req.cluster_name else None
    task_id = _create_demand_task(
        execution_id=execution_id,
        name=task_name,
        platform=req.platform_type,
    )
    if not task_id:
        raise HTTPException(status_code=500, detail="创建 demand_task 失败")

    async def _job():
        # run_once 内部会在 finally 里把 task 状态写回 MySQL。
        await main(
            req.cluster_name,
            req.platform_type,
            execution_id=execution_id,
            task_id=task_id,
        )

    asyncio.create_task(_job())
    return {"ok": True, "message": "调用成功", "task_id": task_id, "execution_id": execution_id}


@app.get("/demand/task/{task_id}/status")
def demand_task_status(task_id: int, max_log_chars: int = 2000):
    row = mysql_db.select_one(
        "demand_task",
        columns="id, execution_id, name, platform, status, log",
        where="id = %s",
        where_params=(task_id,),
    )
    if not row:
        raise HTTPException(status_code=404, detail="task not found")

    status = int(row.get("status") or 0)
    status_map = {0: "running", 1: "completed", 2: "failed"}

    log_text = row.get("log") or ""
    if max_log_chars and isinstance(log_text, str) and len(log_text) > max_log_chars:
        log_text = log_text[:max_log_chars] + "...(truncated)"

    execution_id = row.get("execution_id")
    final_text: Optional[str] = None
    if status == 1 and execution_id:
        try:
            result_path = Path(__file__).parent / "output" / str(execution_id) / "result.txt"
            if result_path.exists():
                with open(result_path, "r", encoding="utf-8") as f:
                    final_text = f.read()
        except Exception:
            final_text = None

    return {
        "task_id": task_id,
        "execution_id": execution_id,
        "name": row.get("name"),
        "platform": row.get("platform"),
        "status": status,
        "status_text": status_map.get(status, "unknown"),
        "final_text": final_text,
        "log": log_text,
    }


@app.get("/demand/tasks")
def demand_tasks(
    status: Optional[int] = None,
    name: Optional[str] = None,
    platform_type: Optional[str] = None,
    page: int = 1,
    page_size: int = 20,
):
    where_parts: list[str] = []
    where_params: list = []

    if status is not None:
        status_int = int(status)
        if status_int not in (0, 1, 2):
            raise HTTPException(status_code=400, detail="status 必须为 0/1/2")
        where_parts.append("status = %s")
        where_params.append(status_int)

    if name:
        name_str = str(name).strip()
        if name_str:
            # 支持模糊匹配：根据需求名称字段（varchar(32)）
            where_parts.append("name LIKE %s")
            where_params.append(f"%{name_str}%")

    if platform_type:
        platform_str = str(platform_type).strip()
        if platform_str:
            where_parts.append("platform = %s")
            where_params.append(platform_str)

    where = " AND ".join(where_parts)
    params = tuple(where_params) if where_params else None

    data = mysql_db.paginate(
        "demand_task",
        page=page,
        page_size=page_size,
        columns="id, execution_id, name, platform, status, create_time, update_time",
        where=where,
        where_params=params,
        order_by="id DESC",
    )

    # 返回分页结构（data + pagination），便于前端直接展示
    return data