from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.deps import (
    ensure_service_employee,
    ensure_vehicle_owner_or_access,
    get_current_telegram_user,
)
from app.db.session import get_session
from app.models.car import ServiceCenter, ServiceVisit
from app.models.expense import FuelEntry, ServiceEntry
from app.models.gamification import Achievement, EngagementEvent, UserAchievement
from app.models.user import User
from app.schemas.gamification import (
    AchievementRead,
    ServiceCenterScoreRead,
    TimelineItem,
    VehicleScoreRead,
)
from app.services.scoring import (
    compute_service_center_score,
    compute_vehicle_score,
    evaluate_garage_achievements,
    record_engagement_event,
)

router = APIRouter(tags=["gamification"])


@router.get("/me/achievements", response_model=list[AchievementRead])
async def my_achievements(
    session: AsyncSession = Depends(get_session),
    current_user: User = Depends(get_current_telegram_user),
) -> list[AchievementRead]:
    await evaluate_garage_achievements(session, current_user.id)
    result = await session.execute(
        select(UserAchievement, Achievement)
        .join(Achievement, Achievement.id == UserAchievement.achievement_id)
        .where(UserAchievement.user_id == current_user.id)
        .order_by(UserAchievement.unlocked_at.desc(), UserAchievement.id.desc())
    )
    await session.commit()
    return [
        AchievementRead(
            code=achievement.code,
            scope=achievement.scope,
            title=achievement.title,
            description=achievement.description,
            icon=achievement.icon,
            category=achievement.category,
            unlocked_at=user_achievement.unlocked_at,
            vehicle_id=user_achievement.vehicle_id,
            service_center_id=user_achievement.service_center_id,
        )
        for user_achievement, achievement in result.all()
    ]


@router.get("/my/vehicles/{vehicle_id}/score", response_model=VehicleScoreRead)
async def vehicle_score(
    vehicle_id: int,
    session: AsyncSession = Depends(get_session),
    current_user: User = Depends(get_current_telegram_user),
):
    car = await ensure_vehicle_owner_or_access(session, vehicle_id, current_user)
    score = await compute_vehicle_score(session, car)
    await record_engagement_event(
        session,
        event_type="vehicle_score_viewed",
        user_id=current_user.id,
        vehicle_id=vehicle_id,
        metadata={"completeness_score": score.completeness_score},
    )
    await session.commit()
    await session.refresh(score)
    return score


@router.get("/my/vehicles/{vehicle_id}/timeline", response_model=list[TimelineItem])
async def vehicle_timeline(
    vehicle_id: int,
    limit: int = 80,
    offset: int = 0,
    session: AsyncSession = Depends(get_session),
    current_user: User = Depends(get_current_telegram_user),
) -> list[TimelineItem]:
    if limit < 1:
        limit = 1
    limit = min(limit, 200)
    offset = max(offset, 0)
    car = await ensure_vehicle_owner_or_access(session, vehicle_id, current_user)
    await record_engagement_event(
        session,
        event_type="vehicle_timeline_viewed",
        user_id=current_user.id,
        vehicle_id=vehicle_id,
    )
    fuel_entries = list((await session.execute(select(FuelEntry).where(FuelEntry.car_id == car.id))).scalars())
    service_entries = list((await session.execute(select(ServiceEntry).where(ServiceEntry.car_id == car.id))).scalars())
    visits = list((await session.execute(select(ServiceVisit).where(ServiceVisit.vehicle_id == car.id))).scalars())
    achievements = list(
        (
            await session.execute(
                select(UserAchievement, Achievement)
                .join(Achievement, Achievement.id == UserAchievement.achievement_id)
                .where(UserAchievement.user_id == current_user.id, UserAchievement.vehicle_id == car.id)
            )
        ).all()
    )
    events = list(
        (
            await session.execute(
                select(EngagementEvent).where(EngagementEvent.vehicle_id == car.id).order_by(EngagementEvent.created_at.desc())
            )
        ).scalars()
    )

    items: list[TimelineItem] = []
    for entry in fuel_entries:
        items.append(
            TimelineItem(
                id=f"fuel:{entry.id}",
                date=entry.entry_date.isoformat(),
                type="fuel",
                title=f"Fuel refill {float(entry.liters):.1f} L",
                description=entry.station,
                amount=entry.total_cost,
                metadata={"odometer": entry.odometer, "full_tank": entry.is_full_tank},
            )
        )
    for entry in service_entries:
        items.append(
            TimelineItem(
                id=f"service:{entry.id}",
                date=entry.entry_date.isoformat(),
                type="service",
                title=entry.title,
                status="self_reported",
                description=entry.vendor,
                amount=entry.total_cost,
                metadata={"odometer": entry.odometer, "service_type": entry.service_type.value},
            )
        )
    for visit in visits:
        items.append(
            TimelineItem(
                id=f"visit:{visit.id}",
                date=visit.visit_date.isoformat(),
                type="service_visit",
                title="Service-center visit",
                status=visit.status,
                description=visit.notes,
                amount=visit.total_cost,
                metadata={"odometer": visit.odometer, "service_center_id": visit.service_center_id},
            )
        )
    for user_achievement, achievement in achievements:
        items.append(
            TimelineItem(
                id=f"achievement:{user_achievement.id}",
                date=user_achievement.unlocked_at,
                type="achievement",
                title=achievement.title,
                status="unlocked",
                description=achievement.description,
                metadata={"code": achievement.code, "category": achievement.category},
            )
        )
    for event in events:
        items.append(
            TimelineItem(
                id=f"event:{event.id}",
                date=event.created_at,
                type="event",
                title=event.event_type.replace("_", " ").title(),
                metadata=event.metadata_json,
            )
        )

    items.sort(key=lambda item: str(item.date), reverse=True)
    return items[offset : offset + limit]


@router.get("/service-centers/{service_center_id}/trust-score", response_model=ServiceCenterScoreRead)
async def service_center_trust_score(
    service_center_id: int,
    session: AsyncSession = Depends(get_session),
    current_user: User = Depends(get_current_telegram_user),
):
    center = await session.get(ServiceCenter, service_center_id)
    if center is None:
        raise HTTPException(status_code=404, detail="Service center not found")
    await ensure_service_employee(session, service_center_id, current_user)
    score = await compute_service_center_score(session, center)
    await record_engagement_event(
        session,
        event_type="service_trust_score_viewed",
        user_id=current_user.id,
        service_center_id=service_center_id,
        metadata={"trust_score": score.trust_score, "trust_level": score.trust_level},
    )
    await session.commit()
    await session.refresh(score)
    return score