"""任务路由：列表 / 状态 / 下载字幕。"""

from __future__ import annotations

from pathlib import Path

from fastapi import APIRouter, Depends, HTTPException, Query
from fastapi.responses import FileResponse
from sqlalchemy.orm import Session

from ..config import get_settings
from ..database import get_db
from ..models.task import Task
from ..schemas.task import TaskListResponse, TaskResponse

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


def _to_resp(task: Task) -> TaskResponse:
    return TaskResponse(
        id=task.id,
        filename=task.filename,
        status=task.status,
        progress=task.progress,
        error=task.error,
        created_at=task.created_at,
        updated_at=task.updated_at,
    )


@router.get("", response_model=TaskListResponse, summary="任务列表")
def list_tasks(
    limit: int = Query(100, ge=1, le=500),
    offset: int = Query(0, ge=0),
    q: str = Query("", description="按文件名模糊搜索（大小写不敏感，匹配子串）"),
    db: Session = Depends(get_db),
) -> TaskListResponse:
    q_base = db.query(Task).order_by(Task.id.desc())
    if q.strip():
        # SQLite 的 LIKE 默认大小写不敏感（ASCII），ilike 等价于 LIKE
        like = f"%{q.strip()}%"
        q_base = q_base.filter(Task.filename.ilike(like))
    total = q_base.count()
    tasks = q_base.offset(offset).limit(limit).all()
    return TaskListResponse(tasks=[_to_resp(t) for t in tasks], total=total)


@router.get("/{task_id}", response_model=TaskResponse, summary="任务状态")
def get_task(task_id: int, db: Session = Depends(get_db)) -> TaskResponse:
    task = db.get(Task, task_id)
    if task is None:
        raise HTTPException(404, f"任务不存在：{task_id}")
    return _to_resp(task)


@router.get("/{task_id}/subtitle", summary="下载字幕")
def download_subtitle(
    task_id: int,
    type: str = Query("bilingual", pattern="^(bilingual|en|zh)$"),
    db: Session = Depends(get_db),
) -> FileResponse:
    task = db.get(Task, task_id)
    if task is None:
        raise HTTPException(404, f"任务不存在：{task_id}")
    if task.status != "done":
        raise HTTPException(409, f"任务尚未完成（当前状态：{task.status}）")

    rel = {
        "bilingual": task.bilingual_srt_path,
        "en": task.en_srt_path,
        "zh": task.zh_srt_path,
    }[type]
    if not rel:
        raise HTTPException(404, f"该类型字幕不存在：{type}")

    s = get_settings()
    path = s.output_dir() / rel
    if not path.is_file():
        raise HTTPException(404, f"字幕文件丢失：{path}")

    base = Path(task.filename).stem
    suffix = "" if type == "bilingual" else f".{type}"
    download_name = f"{base}{suffix}.srt"
    return FileResponse(
        path=path,
        media_type="application/x-subrip",
        filename=download_name,
    )