import uuid

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

from app.crud import crud_championship, crud_registration
from app.database import get_db
from app.dependencies import get_approved_user, get_organizer
from app.models.user import User
from app.schemas.registration import (
    RegistrationCreate,
    RegistrationListItem,
    RegistrationOut,
    RegistrationUpdate,
    RegistrationWithUser,
)

router = APIRouter()


@router.post("", response_model=RegistrationOut, status_code=status.HTTP_201_CREATED)
async def register_for_championship(
    data: RegistrationCreate,
    current_user: User = Depends(get_approved_user),
    db: AsyncSession = Depends(get_db),
):
    champ = await crud_championship.get(db, data.championship_id)
    if not champ:
        raise HTTPException(status_code=404, detail="Championship not found")
    if champ.status != "open":
        raise HTTPException(status_code=400, detail="Registration is not open for this championship")

    existing = await crud_registration.get_by_user_and_championship(db, current_user.id, data.championship_id)
    if existing:
        raise HTTPException(status_code=409, detail="Already registered for this championship")

    return await crud_registration.create(db, current_user.id, data)


@router.get("/my", response_model=list[RegistrationListItem])
async def my_registrations(
    current_user: User = Depends(get_approved_user),
    db: AsyncSession = Depends(get_db),
):
    return await crud_registration.list_for_user(db, current_user.id)


@router.get("/{reg_id}", response_model=RegistrationOut)
async def get_registration(
    reg_id: uuid.UUID,
    current_user: User = Depends(get_approved_user),
    db: AsyncSession = Depends(get_db),
):
    reg = await crud_registration.get(db, reg_id)
    if not reg:
        raise HTTPException(status_code=404, detail="Registration not found")
    if reg.user_id != current_user.id and current_user.role not in ("organizer", "admin"):
        raise HTTPException(status_code=403, detail="Access denied")
    return reg


@router.patch("/{reg_id}", response_model=RegistrationOut)
async def update_registration(
    reg_id: uuid.UUID,
    data: RegistrationUpdate,
    current_user: User = Depends(get_approved_user),
    db: AsyncSession = Depends(get_db),
):
    reg = await crud_registration.get(db, reg_id)
    if not reg:
        raise HTTPException(status_code=404, detail="Registration not found")

    # Members can only update their own registration (video_url, notes)
    if current_user.role == "member":
        if reg.user_id != current_user.id:
            raise HTTPException(status_code=403, detail="Access denied")
        allowed_fields = {"video_url", "notes"}
        update_data = data.model_dump(exclude_none=True)
        if not set(update_data.keys()).issubset(allowed_fields):
            raise HTTPException(status_code=403, detail="Members can only update video_url and notes")

    return await crud_registration.update(db, reg, data)


@router.delete("/{reg_id}", status_code=status.HTTP_204_NO_CONTENT)
async def cancel_registration(
    reg_id: uuid.UUID,
    current_user: User = Depends(get_approved_user),
    db: AsyncSession = Depends(get_db),
):
    reg = await crud_registration.get(db, reg_id)
    if not reg:
        raise HTTPException(status_code=404, detail="Registration not found")
    if reg.user_id != current_user.id and current_user.role not in ("organizer", "admin"):
        raise HTTPException(status_code=403, detail="Access denied")
    await crud_registration.delete(db, reg)


# Organizer: list all registrations for a championship
@router.get("/championship/{champ_id}", response_model=list[RegistrationWithUser])
async def list_registrations_for_championship(
    champ_id: uuid.UUID,
    _user: User = Depends(get_organizer),
    db: AsyncSession = Depends(get_db),
    skip: int = 0,
    limit: int = 100,
):
    return await crud_registration.list_for_championship(db, champ_id, skip=skip, limit=limit)