from collections import defaultdict
from typing import Annotated

from fastapi import Depends, FastAPI, Header, HTTPException, Query
from fastapi.middleware.cors import CORSMiddleware

from .adapter import HermesCliKanbanAdapter, KanbanAdapter, sanitize_error
from .auth import TelegramAuthError, validate_telegram_init_data
from .config import Settings, get_settings
from .models import AssignPayload, BlockPayload, CommentPayload, STATUSES, TaskCreate


def group_tasks(tasks: list[dict]) -> dict[str, list[dict]]:
    groups: dict[str, list[dict]] = {status: [] for status in STATUSES}
    extra: dict[str, list[dict]] = defaultdict(list)
    for task in tasks:
        status = task.get("status") or "todo"
        if status in groups:
            groups[status].append(task)
        else:
            extra[status].append(task)
    groups.update(extra)
    return groups


def create_app(settings: Settings | None = None, adapter: KanbanAdapter | None = None) -> FastAPI:
    settings = settings or get_settings()
    adapter = adapter or HermesCliKanbanAdapter(settings)

    app = FastAPI(title="Hermes Kanban Mini App API", version="0.1.0")
    app.state.settings = settings
    app.state.adapter = adapter

    app.add_middleware(
        CORSMiddleware,
        allow_origins=settings.allowed_origins or [],
        allow_credentials=True,
        allow_methods=["GET", "POST", "OPTIONS"],
        allow_headers=["Content-Type", "X-Telegram-Init-Data"],
    )

    async def require_user(x_telegram_init_data: Annotated[str | None, Header()] = None):
        if settings.auth_mode in {"none", "dev"}:
            return {"id": 0, "dev": True}
        if not x_telegram_init_data:
            raise HTTPException(status_code=401, detail={"error": "auth_required", "message": "Telegram initData required"})
        try:
            user = validate_telegram_init_data(x_telegram_init_data, settings.telegram_bot_token or "")
        except TelegramAuthError as exc:
            raise HTTPException(status_code=401, detail={"error": "auth_invalid", "message": str(exc)}) from exc
        allowed = settings.telegram_allowed_user_ids
        if allowed and int(user.get("id", -1)) not in allowed:
            raise HTTPException(status_code=403, detail={"error": "forbidden", "message": "Telegram user is not allowed"})
        return user

    def selected_board(board: str | None) -> str | None:
        return board or settings.default_board

    def safe_call(func, *args, **kwargs):
        try:
            return func(*args, **kwargs)
        except HTTPException:
            raise
        except Exception as exc:
            raise HTTPException(
                status_code=502,
                detail={"error": "adapter_error", "message": sanitize_error(str(exc))},
            ) from exc

    @app.get("/api/health")
    def health():
        return {"status": "ok", "auth_mode": settings.auth_mode}

    @app.get("/api/boards")
    def boards(user=Depends(require_user)):
        return {"boards": safe_call(adapter.boards)}

    @app.get("/api/tasks")
    def list_tasks(board: str | None = Query(default=None), user=Depends(require_user)):
        tasks = safe_call(adapter.list_tasks, selected_board(board))
        return {"tasks": tasks, "groups": group_tasks(tasks)}

    @app.get("/api/tasks/{task_id}")
    def show_task(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return {"task": safe_call(adapter.show_task, task_id, selected_board(board))}

    @app.get("/api/tasks/{task_id}/events")
    def events(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return {"events": safe_call(adapter.task_events, task_id, selected_board(board))}

    @app.get("/api/tasks/{task_id}/runs")
    def runs(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return {"runs": safe_call(adapter.task_runs, task_id, selected_board(board))}

    @app.get("/api/tasks/{task_id}/log")
    def log(task_id: str, board: str | None = Query(default=None), lines: int = 200, user=Depends(require_user)):
        return safe_call(adapter.task_log, task_id, selected_board(board), lines)

    @app.post("/api/tasks")
    def create_task(payload: TaskCreate, board: str | None = Query(default=None), user=Depends(require_user)):
        return {"task": safe_call(adapter.create_task, payload, selected_board(board))}

    @app.post("/api/tasks/{task_id}/comment")
    def comment(task_id: str, payload: CommentPayload, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.comment, task_id, payload.body, selected_board(board))

    @app.post("/api/tasks/{task_id}/assign")
    def assign(task_id: str, payload: AssignPayload, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.assign, task_id, payload.assignee, selected_board(board))

    @app.post("/api/tasks/{task_id}/promote")
    def promote(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.promote, task_id, selected_board(board))

    @app.post("/api/tasks/{task_id}/block")
    def block(task_id: str, payload: BlockPayload, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.block, task_id, payload.reason, selected_board(board))

    @app.post("/api/tasks/{task_id}/unblock")
    def unblock(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.unblock, task_id, selected_board(board))

    @app.post("/api/tasks/{task_id}/archive")
    def archive(task_id: str, board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.archive, task_id, selected_board(board))

    @app.post("/api/dispatch")
    def dispatch(board: str | None = Query(default=None), user=Depends(require_user)):
        return safe_call(adapter.dispatch, selected_board(board))

    return app


app = create_app()