from uuid import UUID

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session

from app.auth.dependencies import get_current_user, require_roles
from app.models import Group
from app.models.auth import CognitoUser
from app.models.schemas import (
    GroupBulkSort,
    GroupCreate,
    GroupResponse,
    GroupSortUpdate,
    GroupUpdate,
)
from app.utils.database import get_db

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


@router.post("/", response_model=GroupResponse, status_code=status.HTTP_201_CREATED)
@require_roles("admin")
def create_group(
    group: GroupCreate,
    db: Session = Depends(get_db),
    user: CognitoUser = Depends(get_current_user),
):
    """Create a new channel group"""
    # Check for duplicate group name
    existing_group = db.query(Group).filter(Group.name == group.name).first()
    if existing_group:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Group with this name already exists",
        )

    db_group = Group(**group.model_dump())
    db.add(db_group)
    db.commit()
    db.refresh(db_group)
    return db_group


@router.get("/{group_id}", response_model=GroupResponse)
def get_group(group_id: UUID, db: Session = Depends(get_db)):
    """Get a group by id"""
    group = db.query(Group).filter(Group.id == group_id).first()
    if not group:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Group not found"
        )
    return group


@router.put("/{group_id}", response_model=GroupResponse)
@require_roles("admin")
def update_group(
    group_id: UUID,
    group: GroupUpdate,
    db: Session = Depends(get_db),
    user: CognitoUser = Depends(get_current_user),
):
    """Update a group's name or sort order"""
    db_group = db.query(Group).filter(Group.id == group_id).first()
    if not db_group:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Group not found"
        )

    # Check for duplicate name if name is being updated
    if group.name is not None and group.name != db_group.name:
        existing_group = db.query(Group).filter(Group.name == group.name).first()
        if existing_group:
            raise HTTPException(
                status_code=status.HTTP_409_CONFLICT,
                detail="Group with this name already exists",
            )

    # Update only provided fields
    update_data = group.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_group, key, value)

    db.commit()
    db.refresh(db_group)
    return db_group


@router.delete("/{group_id}", status_code=status.HTTP_204_NO_CONTENT)
@require_roles("admin")
def delete_group(
    group_id: UUID,
    db: Session = Depends(get_db),
    user: CognitoUser = Depends(get_current_user),
):
    """Delete a group (only if it has no channels)"""
    group = db.query(Group).filter(Group.id == group_id).first()
    if not group:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Group not found"
        )

    # Check if group has any channels
    if group.channels:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Cannot delete group with existing channels",
        )

    db.delete(group)
    db.commit()
    return None


@router.get("/", response_model=list[GroupResponse])
def list_groups(db: Session = Depends(get_db)):
    """List all groups sorted by sort_order"""
    return db.query(Group).order_by(Group.sort_order).all()


@router.put("/{group_id}/sort", response_model=GroupResponse)
@require_roles("admin")
def update_group_sort_order(
    group_id: UUID,
    sort_update: GroupSortUpdate,
    db: Session = Depends(get_db),
    user: CognitoUser = Depends(get_current_user),
):
    """Update a single group's sort order"""
    db_group = db.query(Group).filter(Group.id == group_id).first()
    if not db_group:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND, detail="Group not found"
        )

    db_group.sort_order = sort_update.sort_order
    db.commit()
    db.refresh(db_group)
    return db_group


@router.post("/reorder", response_model=list[GroupResponse])
@require_roles("admin")
def bulk_update_sort_orders(
    bulk_sort: GroupBulkSort,
    db: Session = Depends(get_db),
    user: CognitoUser = Depends(get_current_user),
):
    """Bulk update group sort orders"""
    groups_to_update = []

    for group_data in bulk_sort.groups:
        group_id = group_data["group_id"]
        sort_order = group_data["sort_order"]

        group = db.query(Group).filter(Group.id == str(group_id)).first()
        if not group:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail=f"Group with id {group_id} not found",
            )

        group.sort_order = sort_order
        groups_to_update.append(group)

    db.commit()

    # Return all groups in their new order
    return db.query(Group).order_by(Group.sort_order).all()