from uuid import UUID

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

from app.api import deps
from app.api.utils import (  # adjust import path if different
    assert_project_exists_or_404,
    verify_id_list,
)
from app.models import OrgRole, Slot, Sms, User, Volunteer, VolunteerGroup
from app.schemas.requests import (
    GroupMembershipRequest,
    GroupSmsRequest,
    VolunteerGroupCreateRequest,
    VolunteerGroupUpdateRequest,
)
from app.schemas.responses import SMSResponse, VolunteerGroupResponse, VolunteerResponse

router = APIRouter(prefix="/project/{project_id}", tags=["volunteer_groups"])

MANAGE_GROUPS = (OrgRole.ORG_ADMIN, OrgRole.RESPO_BENEVOLE)


def _get_group_or_404(session: Session, project_id: UUID, group_id: UUID) -> VolunteerGroup:
    group = session.get(VolunteerGroup, group_id)
    if group is None or group.project_id != str(project_id):
        raise HTTPException(status_code=404, detail="Group not found")
    return group


@router.get("/groups", response_model=list[VolunteerGroupResponse])
async def list_project_groups(
    project_id: UUID,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """List volunteer groups from project"""
    assert_project_exists_or_404(session, project_id)
    results = session.execute(select(VolunteerGroup).where(VolunteerGroup.project_id == project_id))
    return results.scalars().all()


@router.post("/group", response_model=VolunteerGroupResponse)
async def create_group(
    project_id: UUID,
    new_group: VolunteerGroupCreateRequest,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Create a new volunteer group in the project"""
    assert_project_exists_or_404(session, project_id)
    group = VolunteerGroup(project_id=project_id, **new_group.model_dump())
    session.add(group)
    session.commit()
    session.refresh(group)
    return group


@router.get("/group/{group_id}", response_model=VolunteerGroupResponse)
async def get_group(
    project_id: UUID,
    group_id: UUID,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Get a single volunteer group"""
    return _get_group_or_404(session, project_id, group_id)


@router.post("/group/{group_id}", response_model=VolunteerGroupResponse)
async def update_group(
    project_id: UUID,
    group_id: UUID,
    edit_group: VolunteerGroupUpdateRequest,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Edit a volunteer group"""
    group = _get_group_or_404(session, project_id, group_id)
    group.name = edit_group.name
    group.color = edit_group.color
    session.commit()
    session.refresh(group)
    return group


@router.delete("/group/{group_id}")
async def delete_group(
    project_id: UUID,
    group_id: UUID,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Delete a volunteer group (does not delete its volunteers)"""
    group = _get_group_or_404(session, project_id, group_id)
    session.delete(group)
    session.commit()


@router.post("/group/{group_id}/volunteers", response_model=VolunteerGroupResponse)
async def add_volunteers_to_group(
    project_id: UUID,
    group_id: UUID,
    payload: GroupMembershipRequest,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Bulk-add volunteers to a group (idempotent -- already-members are skipped)"""
    group = _get_group_or_404(session, project_id, group_id)

    await verify_id_list(
        session, payload.volunteer_ids, project_id, Volunteer, "Invalid volunteer list"
    )

    existing_ids = {v.id for v in group.volunteers}
    for vid in payload.volunteer_ids:
        if str(vid) in existing_ids:
            continue
        volunteer = session.get(Volunteer, vid)
        group.volunteers.append(volunteer)

    session.commit()
    session.refresh(group)
    return group


@router.delete("/group/{group_id}/volunteer/{volunteer_id}", response_model=VolunteerGroupResponse)
async def remove_volunteer_from_group(
    project_id: UUID,
    group_id: UUID,
    volunteer_id: UUID,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Remove a single volunteer from a group"""
    group = _get_group_or_404(session, project_id, group_id)
    volunteer = session.get(Volunteer, volunteer_id)
    if volunteer is not None and volunteer in group.volunteers:
        group.volunteers.remove(volunteer)
        session.commit()
        session.refresh(group)
    return group


@router.post("/group/{group_id}/add-to-slot/{slot_id}", response_model=list[VolunteerResponse])
async def add_group_to_slot(
    project_id: UUID,
    group_id: UUID,
    slot_id: UUID,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Bulk-assigns every member of the group to the slot in one call.
    This is a one-time copy, not a live link: adding someone to the group
    later does NOT retroactively add them to slots already assigned."""
    group = _get_group_or_404(session, project_id, group_id)

    slot = session.get(Slot, slot_id)
    if slot is None or slot.project_id != str(project_id):
        raise HTTPException(status_code=404, detail="Slot not found in this project")

    existing_ids = {v.id for v in slot.volunteers}
    for volunteer in group.volunteers:
        if volunteer.id not in existing_ids:
            slot.volunteers.append(volunteer)

    session.commit()
    session.refresh(slot)
    return slot.volunteers


@router.post("/group/{group_id}/send-sms", response_model=list[SMSResponse])
async def send_sms_to_group(
    project_id: UUID,
    group_id: UUID,
    payload: GroupSmsRequest,
    current_user: User = Depends(deps.require_org_role(*MANAGE_GROUPS)),
    session: Session = Depends(deps.get_session),
):
    """Sends an SMS immediately to every group member who has automatic_sms
    enabled and a phone number on file."""
    group = _get_group_or_404(session, project_id, group_id)

    sms_list = []
    for volunteer in group.volunteers:
        if not volunteer.automatic_sms or not volunteer.phone_number:
            continue
        content = payload.content.replace("{prenom}", volunteer.name).replace(
            "{nom}", volunteer.surname
        )
        sms = Sms(
            project_id=project_id,
            volunteer_id=volunteer.id,
            content=content,
            phone_number=volunteer.phone_number,
        )
        sms_list.append(sms)

    session.add_all(sms_list)
    session.commit()
    return sms_list