from datetime import datetime

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field
from sqlalchemy import func, select
from sqlalchemy.orm import Session

from app.auth.jwt_auth import create_access_token, get_current_user, require_admin, CurrentUser
from app.database import get_db
from app.models.user import User
from app.models.mobile_settings import LOGIN_MODES
from app.services.mobile_devices import (
    get_device_or_raise,
    list_mobile_devices,
    revoke_device,
    touch_device,
    update_fcm_token,
    assert_device_active,
)
from app.services.mobile_enrollment import (
    create_enrollment_code,
    enroll_device,
    list_enrollment_codes,
    revoke_enrollment_code,
)
from app.services.mobile_notify import (
    MobileNotConfiguredError,
    MobileSendError,
    get_effective_fcm_config,
    send_test_push,
)
from app.services.mobile_settings import upsert_mobile_settings, get_effective_mobile_settings
from app.services.mobile_tokens import find_valid_refresh_token, revoke_refresh_tokens_for_device, store_refresh_token

router = APIRouter(prefix="/mobile", tags=["mobile"])


class MobileSettingsResponse(BaseModel):
    devices_allowed: bool
    max_devices_per_user: int
    min_app_version: str | None = None
    fcm_enabled: bool
    fcm_configured: bool
    source: str


class MobileSettingsUpdate(BaseModel):
    devices_allowed: bool
    max_devices_per_user: int = Field(ge=1, le=50)
    min_app_version: str | None = None


class EnrollmentCodeCreate(BaseModel):
    label: str = ""
    target_user_id: int | None = None
    login_mode: str = "password"
    max_uses: int = Field(default=1, ge=1, le=100)
    expires_in_hours: int = Field(default=24, ge=1, le=720)


class EnrollmentCodeResponse(BaseModel):
    id: int
    label: str
    code_prefix: str
    target_user_id: int | None
    target_username: str | None
    login_mode: str
    max_uses: int
    use_count: int
    expires_at: datetime
    revoked_at: datetime | None
    created_at: datetime
    is_active: bool


class EnrollmentCodeCreatedResponse(EnrollmentCodeResponse):
    enrollment_code: str = Field(description="Показывается один раз при создании")


class MobileDeviceResponse(BaseModel):
    id: int
    user_id: int
    username: str
    device_uuid: str
    display_name: str
    platform: str
    app_version: str | None
    has_fcm_token: bool
    enrolled_at: datetime
    last_seen_at: datetime | None
    revoked_at: datetime | None
    is_active: bool


class EnrollRequest(BaseModel):
    enrollment_code: str
    username: str | None = None
    password: str | None = None
    device_uuid: str
    display_name: str = "Android"
    platform: str = "android"
    app_version: str | None = None
    fcm_token: str | None = None


class EnrollResponse(BaseModel):
    access_token: str
    refresh_token: str
    token_type: str = "bearer"
    device_id: int
    username: str
    role: str


class RefreshRequest(BaseModel):
    refresh_token: str
    device_uuid: str


class FcmTokenUpdate(BaseModel):
    fcm_token: str


class TestPushResponse(BaseModel):
    ok: bool = True
    message: str


def _settings_response(db: Session) -> MobileSettingsResponse:
    cfg = get_effective_mobile_settings(db)
    fcm = get_effective_fcm_config()
    return MobileSettingsResponse(
        devices_allowed=cfg.devices_allowed,
        max_devices_per_user=cfg.max_devices_per_user,
        min_app_version=cfg.min_app_version,
        fcm_enabled=fcm.enabled,
        fcm_configured=fcm.configured,
        source=cfg.source,
    )


def _code_to_response(item) -> EnrollmentCodeResponse:
    return EnrollmentCodeResponse(
        id=item.id,
        label=item.label,
        code_prefix=item.code_prefix,
        target_user_id=item.target_user_id,
        target_username=item.target_username,
        login_mode=item.login_mode,
        max_uses=item.max_uses,
        use_count=item.use_count,
        expires_at=item.expires_at,
        revoked_at=item.revoked_at,
        created_at=item.created_at,
        is_active=item.is_active,
    )


def _device_to_response(item) -> MobileDeviceResponse:
    return MobileDeviceResponse(
        id=item.id,
        user_id=item.user_id,
        username=item.username,
        device_uuid=item.device_uuid,
        display_name=item.display_name,
        platform=item.platform,
        app_version=item.app_version,
        has_fcm_token=item.has_fcm_token,
        enrolled_at=item.enrolled_at,
        last_seen_at=item.last_seen_at,
        revoked_at=item.revoked_at,
        is_active=item.is_active,
    )


def _admin_user_id(db: Session, username: str) -> int | None:
    user = db.scalar(select(User).where(func.lower(User.username) == username.lower()))
    return user.id if user else None


@router.get("/settings", response_model=MobileSettingsResponse)
def get_mobile_settings(
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> MobileSettingsResponse:
    return _settings_response(db)


@router.put("/settings", response_model=MobileSettingsResponse)
def update_mobile_settings(
    body: MobileSettingsUpdate,
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> MobileSettingsResponse:
    try:
        upsert_mobile_settings(
            db,
            devices_allowed=body.devices_allowed,
            max_devices_per_user=body.max_devices_per_user,
            min_app_version=body.min_app_version,
        )
    except ValueError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    return _settings_response(db)


@router.get("/enrollment-codes", response_model=list[EnrollmentCodeResponse])
def get_enrollment_codes(
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> list[EnrollmentCodeResponse]:
    return [_code_to_response(item) for item in list_enrollment_codes(db)]


@router.post("/enrollment-codes", response_model=EnrollmentCodeCreatedResponse)
def post_enrollment_code(
    body: EnrollmentCodeCreate,
    db: Session = Depends(get_db),
    user: CurrentUser = Depends(require_admin),
) -> EnrollmentCodeCreatedResponse:
    if body.login_mode not in LOGIN_MODES:
        raise HTTPException(status_code=422, detail=f"login_mode must be one of: {sorted(LOGIN_MODES)}")
    try:
        summary, plaintext = create_enrollment_code(
            db,
            created_by_user_id=_admin_user_id(db, user.username),
            label=body.label,
            target_user_id=body.target_user_id,
            login_mode=body.login_mode,
            max_uses=body.max_uses,
            expires_in_hours=body.expires_in_hours,
        )
        db.commit()
    except ValueError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    base = _code_to_response(summary)
    return EnrollmentCodeCreatedResponse(**base.model_dump(), enrollment_code=plaintext)


@router.delete("/enrollment-codes/{code_id}", status_code=204)
def delete_enrollment_code(
    code_id: int,
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> None:
    try:
        revoke_enrollment_code(db, code_id)
    except ValueError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc


@router.get("/devices", response_model=list[MobileDeviceResponse])
def get_devices(
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> list[MobileDeviceResponse]:
    return [_device_to_response(item) for item in list_mobile_devices(db)]


@router.delete("/devices/{device_id}", response_model=MobileDeviceResponse)
def delete_device(
    device_id: int,
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> MobileDeviceResponse:
    try:
        summary = revoke_device(db, device_id)
    except ValueError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    return _device_to_response(summary)


@router.post("/devices/{device_id}/test-push", response_model=TestPushResponse)
def test_device_push(
    device_id: int,
    db: Session = Depends(get_db),
    _user=Depends(require_admin),
) -> TestPushResponse:
    try:
        send_test_push(db=db, device_id=device_id)
    except MobileNotConfiguredError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    except MobileSendError as exc:
        raise HTTPException(status_code=502, detail=str(exc)) from exc
    return TestPushResponse(message="Тестовое push отправлено на устройство")


@router.post("/enroll", response_model=EnrollResponse)
def post_enroll(body: EnrollRequest, db: Session = Depends(get_db)) -> EnrollResponse:
    try:
        result = enroll_device(
            db,
            enrollment_code=body.enrollment_code,
            username=body.username,
            password=body.password,
            device_uuid=body.device_uuid,
            display_name=body.display_name,
            platform=body.platform,
            app_version=body.app_version,
            fcm_token=body.fcm_token,
            create_access_token=create_access_token,
        )
    except PermissionError as exc:
        raise HTTPException(status_code=403, detail=str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    return EnrollResponse(
        access_token=result.access_token,
        refresh_token=result.refresh_token,
        device_id=result.device_id,
        username=result.username,
        role=result.role,
    )


@router.post("/auth/refresh", response_model=EnrollResponse)
def post_refresh(body: RefreshRequest, db: Session = Depends(get_db)) -> EnrollResponse:
    token_row = find_valid_refresh_token(db, body.refresh_token.strip())
    if token_row is None:
        raise HTTPException(status_code=401, detail="Invalid or expired refresh token")
    device = get_device_or_raise(db, token_row.device_id)
    try:
        assert_device_active(device)
    except PermissionError as exc:
        raise HTTPException(status_code=401, detail=str(exc)) from exc
    if device.device_uuid != body.device_uuid.strip():
        raise HTTPException(status_code=401, detail="device_uuid mismatch")

    user = db.get(User, device.user_id)
    if user is None or not user.is_active:
        raise HTTPException(status_code=401, detail="User inactive")

    revoke_refresh_tokens_for_device(db, device.id)
    refresh_plain = store_refresh_token(db, device_id=device.id)
    touch_device(db, device)
    access_token = create_access_token(user.username, user.role, device_id=device.id)
    db.commit()

    return EnrollResponse(
        access_token=access_token,
        refresh_token=refresh_plain,
        device_id=device.id,
        username=user.username,
        role=user.role,
    )


@router.put("/devices/me/fcm", status_code=204)
def put_my_fcm_token(
    body: FcmTokenUpdate,
    db: Session = Depends(get_db),
    user: CurrentUser = Depends(get_current_user),
) -> None:
    if user.device_id is None:
        raise HTTPException(status_code=403, detail="Mobile device token required")
    device = get_device_or_raise(db, user.device_id)
    try:
        assert_device_active(device)
        update_fcm_token(db, device, body.fcm_token)
    except PermissionError as exc:
        raise HTTPException(status_code=401, detail=str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc