# -*- coding: utf-8 -*-
"""业务层 · 任务状态机（抢单 / 投标 / 交付 / 中标 / 验收）。

业务层只处理业务逻辑；不感知 HTTP 之外的框架细节。依赖基础设施层
Repository（经 Database 门面），不反向依赖接口层。
"""
from __future__ import annotations

from fastapi import HTTPException

from ..infrastructure.repositories import Database


class TaskService:
    """统一任务状态流转：grab/bid/deliver/win/review。"""

    def __init__(self, db: Database):
        self.db = db

    async def grab(self, task_id: str, actor: dict) -> dict:
        """抢单（兼容旧入口）：published + grab → claimed，记录接单流水。"""
        return await self.claim_by_id(task_id, actor, source="grab")

    async def claim(self, task_code: str, actor: dict, source: str = "scan") -> dict:
        """扫码/按短码接单：解析 task_code 后领单。"""
        task = await self.db.tasks.get_by_code(task_code)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        return await self.claim_by_id(task["id"], actor, source=source)

    async def claim_by_id(self, task_id: str, actor: dict, source: str) -> dict:
        """published + grab 模式 → claimed（claimed_by/claimed_at + TaskClaim 流水）。

        校验接单限制：独占(exclusive) 仅一人可接；headcount>0 时达上限拒绝。
        """
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] not in ("published", "claimed"):
            raise HTTPException(status_code=400, detail="任务不可接单")
        if task["mode"] != "grab":
            raise HTTPException(status_code=400, detail="任务不支持扫码接单")
        active = await self.db.task_claims.count_active_by_task(task_id)
        if task.get("exclusive") and active >= 1:
            raise HTTPException(status_code=400, detail="该任务为独占，已被接单")
        if (task.get("headcount") or 0) > 0 and active >= task["headcount"]:
            raise HTTPException(status_code=400, detail="该任务接单人数已达上限")
        updated = await self.db.tasks.claim(task_id, actor["id"])
        await self.db.task_claims.create(
            task_id, actor["id"],
            actor.get("nickname") or actor.get("username", ""), source,
        )
        return updated

    async def assign(self, task_id: str, taker_user_id: str, actor: dict) -> dict:
        """指派：发包方直接指派某人 → claimed(claimed_by=taker)。仅 published + assign 模式。"""
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] != "published":
            raise HTTPException(status_code=400, detail="任务不可指派")
        if task["mode"] != "assign":
            raise HTTPException(status_code=400, detail="任务不支持指派")
        taker = await self.db.users.get_by_id(taker_user_id)
        taker_name = (taker or {}).get("nickname") or (taker or {}).get("username") or taker_user_id
        updated = await self.db.tasks.claim(task_id, taker_user_id)
        await self.db.task_claims.create(
            task_id, taker_user_id, taker_name, source="assign", status="assigned",
        )
        return updated

    async def recommend(self, task_id: str, candidates: list[str], actor: dict) -> list[dict]:
        """推荐：发包方/系统推荐候选人，逐个写 TaskClaim(status=recommended)。仅 published + recommend。"""
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] != "published":
            raise HTTPException(status_code=400, detail="任务不可推荐")
        if task["mode"] != "recommend":
            raise HTTPException(status_code=400, detail="任务不支持推荐")
        out: list[dict] = []
        for uid in candidates or []:
            u = await self.db.users.get_by_id(uid)
            name = (u or {}).get("nickname") or (u or {}).get("username") or uid
            record = await self.db.task_claims.create(
                task_id, uid, name, source="recommend", status="recommended",
            )
            out.append(record)
        return out

    async def select_recommend(self, task_id: str, taker_user_id: str, actor: dict) -> dict:
        """选定推荐人：published → claimed(claimed_by=所选)；该推荐 assigned、其余 withdrawn。"""
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] != "published":
            raise HTTPException(status_code=400, detail="任务不可选定")
        taker = await self.db.users.get_by_id(taker_user_id)
        taker_name = (taker or {}).get("nickname") or (taker or {}).get("username") or taker_user_id
        for rec in await self.db.task_claims.list_by_task(task_id):
            target = "assigned" if rec["claimer_user_id"] == taker_user_id else "withdrawn"
            await self.db.task_claims.set_status(rec["id"], target)
        updated = await self.db.tasks.claim(task_id, taker_user_id)
        if not any(t["claimer_user_id"] == taker_user_id
                   for t in await self.db.task_claims.list_by_task(task_id)):
            await self.db.task_claims.create(
                task_id, taker_user_id, taker_name, source="recommend", status="assigned",
            )
        return updated

    async def start_doing(self, task_id: str, actor: dict) -> dict:
        """claimed → doing。"""
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] != "claimed":
            raise HTTPException(status_code=400, detail="任务未接单，无法开始")
        return await self.db.tasks.set_doing(task_id)

    async def complete(self, task_id: str, actor: dict) -> dict:
        """doing → completed。"""
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="任务不存在")
        if task["status"] != "doing":
            raise HTTPException(status_code=400, detail="任务未在进行中，无法完成")
        return await self.db.tasks.set_status(task_id, "completed")

    async def bid(self, task_id: str, actor: dict, quote: int, plan: str) -> dict:
        """投标：仅 published + bid 模式可投。"""
        task = await self.db.tasks.get(task_id)
        if task is None or task["status"] != "published" or task["mode"] != "bid":
            raise HTTPException(status_code=400, detail="任务不可投标")
        return await self.db.bids.create(
            task_id, actor["id"], actor.get("nickname") or actor["username"],
            quote, plan,
        )

    async def deliver(self, task_id: str, actor: dict) -> dict:
        """交付：任务存在且处于进行中（in_progress）才可交付 → delivered。

        补齐原实现「无任何状态预检」的缺陷，防随意交付。
        """
        task = await self.db.tasks.get(task_id)
        if task is None:
            raise HTTPException(status_code=404, detail="Task not found")
        if task["status"] != "in_progress":
            raise HTTPException(status_code=400, detail="任务未在进行中，无法交付")
        return await self.db.tasks.set_status(task_id, "delivered")

    async def enterprise_submit(self, task_id: str) -> dict:
        """企业提交审核：pending 任务 → published。"""
        return await self.db.tasks.set_status(task_id, "published")

    async def win_bid(self, task_id: str, bid_id: str) -> dict:
        """企业评标中标：bid → win，task → in_progress（双状态联动）。"""
        bid = await self.db.bids.get(bid_id)
        if bid is None or bid["task_id"] != task_id:
            raise HTTPException(status_code=404, detail="竞标不存在")
        await self.db.bids.set_status(bid_id, "win")
        return await self.db.tasks.set_status(task_id, "in_progress")

    async def review(self, task_id: str, accept: bool) -> dict:
        """企业验收：accept → completed；reject → in_progress。"""
        target = "completed" if accept else "in_progress"
        return await self.db.tasks.set_status(task_id, target)