from __future__ import annotations

from datetime import date

from fastapi import APIRouter, Depends, HTTPException, Query, Request, status

from api.config import settings
from api.deps import AuthUser, require_api_token, require_user
from api.schemas import (
    AuthSessionOut,
    AuthUserOut,
    BudgetActiveIn,
    BudgetCreateIn,
    BudgetOut,
    BudgetStatusOut,
    BudgetUpdateIn,
    BudgetUpsertIn,
    BudgetsListOut,
    ExpenseCreateIn,
    ExpenseOut,
    ExpensesPageOut,
    InternalAuthIn,
    TelegramLoginIn,
    UndoExpenseOut,
)
from api.telegram_auth import TelegramAuthError, verify_telegram_login
from api.tokens import create_access_token
from bot.services.budget import BudgetService, BudgetStatus, PeriodExpensesPage

router = APIRouter(prefix="/api")


def _status_out(status_data: BudgetStatus) -> BudgetStatusOut:
    b = status_data.budget
    return BudgetStatusOut(
        budget=BudgetOut(
            id=b.id,
            user_id=b.user_id,
            name=b.name,
            total_amount=b.total_amount,
            start_date=b.start_date,
            end_date=b.end_date,
            currency=b.currency,
            is_active=b.is_active,
        ),
        today=status_data.today,
        days_left=status_data.days_left,
        total_spent=status_data.total_spent,
        remaining=status_data.remaining,
        daily_limit=status_data.daily_limit,
        spent_today=status_data.spent_today,
        remaining_today=status_data.remaining_today,
        is_over_daily=status_data.is_over_daily,
        is_over_budget=status_data.is_over_budget,
        is_expired=status_data.is_expired,
        selected=status_data.selected,
    )


def _page_out(page: PeriodExpensesPage) -> ExpensesPageOut:
    return ExpensesPageOut(
        page=page.page,
        total_pages=page.total_pages,
        total_count=page.total_count,
        total_sum=page.total_sum,
        page_size=page.page_size,
        budget_id=page.budget.id,
        items=[
            ExpenseOut(
                id=item.id,
                budget_id=item.budget_id,
                amount=item.amount,
                note=item.note,
                spent_at=item.spent_at,
            )
            for item in page.items
        ],
    )


def _service(request: Request) -> BudgetService:
    return request.app.state.budget_service


@router.post("/auth/telegram", response_model=AuthSessionOut)
async def auth_telegram(body: TelegramLoginIn) -> AuthSessionOut:
    try:
        profile = verify_telegram_login(
            body.model_dump(),
            settings.bot_token,
            max_age_seconds=settings.telegram_auth_max_age_seconds,
        )
    except TelegramAuthError as exc:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=str(exc),
        ) from exc

    token = create_access_token(user_id=profile["id"], profile=profile)
    return AuthSessionOut(
        access_token=token,
        user=AuthUserOut(
            user_id=profile["id"],
            first_name=profile.get("first_name"),
            last_name=profile.get("last_name"),
            username=profile.get("username"),
            photo_url=profile.get("photo_url"),
        ),
    )


@router.post(
    "/auth/internal",
    response_model=AuthSessionOut,
    dependencies=[Depends(require_api_token)],
)
async def auth_internal(body: InternalAuthIn) -> AuthSessionOut:
    profile = {
        "id": body.user_id,
        "first_name": body.first_name,
        "last_name": body.last_name,
        "username": body.username,
    }
    token = create_access_token(user_id=body.user_id, profile=profile)
    return AuthSessionOut(
        access_token=token,
        user=AuthUserOut(
            user_id=body.user_id,
            first_name=body.first_name,
            last_name=body.last_name,
            username=body.username,
        ),
    )


@router.get("/me", response_model=AuthUserOut)
async def me(user: AuthUser = Depends(require_user)) -> AuthUserOut:
    return AuthUserOut(
        user_id=user.user_id,
        first_name=user.first_name,
        last_name=user.last_name,
        username=user.username,
    )


@router.get("/me/budgets", response_model=BudgetsListOut)
async def my_budgets(
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetsListOut:
    service = _service(request)
    items = await service.list_user_statuses(user.user_id)
    return BudgetsListOut(items=[_status_out(item) for item in items])


@router.post("/me/budgets", response_model=BudgetStatusOut)
async def create_my_budget(
    body: BudgetCreateIn,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.create_budget(
            user_id=user.user_id,
            total_amount=body.total_amount,
            end_date=body.end_date,
            name=body.name,
            is_active=body.is_active,
            select=body.select,
        )
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(exc),
        ) from exc
    return _status_out(status_data)


@router.put("/me/budgets/{budget_id}", response_model=BudgetStatusOut)
async def update_my_budget(
    budget_id: int,
    body: BudgetUpdateIn,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.update_budget(
            user.user_id,
            budget_id,
            name=body.name,
            total_amount=body.total_amount,
            end_date=body.end_date,
            reset_expenses=body.reset_expenses,
        )
    except ValueError as exc:
        code = (
            status.HTTP_404_NOT_FOUND
            if "не найден" in str(exc).lower()
            else status.HTTP_400_BAD_REQUEST
        )
        raise HTTPException(status_code=code, detail=str(exc)) from exc
    return _status_out(status_data)


@router.patch("/me/budgets/{budget_id}/active", response_model=BudgetStatusOut)
async def set_my_budget_active(
    budget_id: int,
    body: BudgetActiveIn,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.set_budget_active(
            user.user_id,
            budget_id,
            body.is_active,
        )
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _status_out(status_data)


@router.post("/me/budgets/{budget_id}/select", response_model=BudgetStatusOut)
async def select_my_budget(
    budget_id: int,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.select_budget(user.user_id, budget_id)
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _status_out(status_data)


@router.get("/me/budget", response_model=BudgetStatusOut)
async def my_budget(
    request: Request,
    user: AuthUser = Depends(require_user),
    budget_id: int | None = Query(default=None),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.get_status(user.user_id, budget_id=budget_id)
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _status_out(status_data)


@router.get("/me/expenses", response_model=ExpensesPageOut)
async def my_expenses(
    request: Request,
    user: AuthUser = Depends(require_user),
    page: int = Query(default=0, ge=0),
    page_size: int = Query(default=20, ge=1, le=100),
    spent_at: date | None = Query(default=None),
    budget_id: int | None = Query(default=None),
) -> ExpensesPageOut:
    service = _service(request)
    try:
        if spent_at is not None:
            page_data = await service.get_expenses_on_date_page(
                user.user_id,
                spent_at,
                page=page,
                page_size=page_size,
                budget_id=budget_id,
            )
        else:
            page_data = await service.get_period_expenses_page(
                user.user_id,
                page=page,
                page_size=page_size,
                budget_id=budget_id,
            )
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _page_out(page_data)


@router.post("/me/expenses", response_model=BudgetStatusOut)
async def create_my_expense(
    body: ExpenseCreateIn,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.add_expense(
            user_id=user.user_id,
            amount=body.amount,
            note=body.note,
            spent_at=body.spent_at,
            budget_id=body.budget_id,
        )
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(exc),
        ) from exc
    return _status_out(status_data)


@router.delete("/me/expenses/last", response_model=UndoExpenseOut)
async def undo_my_last_expense(
    request: Request,
    user: AuthUser = Depends(require_user),
    budget_id: int | None = Query(default=None),
) -> UndoExpenseOut:
    service = _service(request)
    status_data, amount = await service.undo_last_expense(
        user.user_id,
        budget_id=budget_id,
    )
    if amount is None or status_data is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Нечего отменять",
        )
    return UndoExpenseOut(deleted_amount=amount, status=_status_out(status_data))


@router.put("/me/budget", response_model=BudgetStatusOut)
async def upsert_my_budget(
    body: BudgetUpsertIn,
    request: Request,
    user: AuthUser = Depends(require_user),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.set_budget(
            user_id=user.user_id,
            total_amount=body.total_amount,
            end_date=body.end_date,
            reset_expenses=body.reset_expenses,
            name=body.name,
            budget_id=body.budget_id,
        )
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(exc),
        ) from exc
    return _status_out(status_data)


@router.get(
    "/budgets",
    response_model=BudgetsListOut,
    dependencies=[Depends(require_api_token)],
)
async def list_budgets(request: Request) -> BudgetsListOut:
    service = _service(request)
    items = await service.list_budget_summaries()
    return BudgetsListOut(items=[_status_out(item) for item in items])


@router.get(
    "/budgets/{user_id}",
    response_model=BudgetStatusOut,
    dependencies=[Depends(require_api_token)],
)
async def get_budget(
    user_id: int,
    request: Request,
    budget_id: int | None = Query(default=None),
) -> BudgetStatusOut:
    service = _service(request)
    try:
        status_data = await service.get_status(user_id, budget_id=budget_id)
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _status_out(status_data)


@router.get(
    "/budgets/{user_id}/expenses",
    response_model=ExpensesPageOut,
    dependencies=[Depends(require_api_token)],
)
async def list_expenses(
    user_id: int,
    request: Request,
    page: int = Query(default=0, ge=0),
    page_size: int = Query(default=20, ge=1, le=100),
    spent_at: date | None = Query(default=None),
    budget_id: int | None = Query(default=None),
) -> ExpensesPageOut:
    service = _service(request)
    try:
        if spent_at is not None:
            page_data = await service.get_expenses_on_date_page(
                user_id,
                spent_at,
                page=page,
                page_size=page_size,
                budget_id=budget_id,
            )
        else:
            page_data = await service.get_period_expenses_page(
                user_id,
                page=page,
                page_size=page_size,
                budget_id=budget_id,
            )
    except ValueError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=str(exc)) from exc
    return _page_out(page_data)