from fastapi import APIRouter, Depends, HTTPException
from sqlmodel import Session, select, func
from typing import List, Optional
from database import get_session
from models import (
    Vertical, Artist, Musician, BandMembership, 
    PerformanceGuest, Performance, Show, Song, Venue
)

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


@router.get("")
async def list_bands(
    scene: Optional[str] = None,
    is_featured: Optional[bool] = None,
    session: Session = Depends(get_session)
):
    """List all active bands, optionally filtered"""
    query = select(Vertical).where(Vertical.is_active == True)
    
    if is_featured is not None:
        query = query.where(Vertical.is_featured == is_featured)
    
    bands = session.exec(query.order_by(Vertical.name)).all()
    return bands


@router.get("/{slug}")
async def get_band_profile(slug: str, session: Session = Depends(get_session)):
    """Get comprehensive band profile including members and stats"""
    vertical = session.exec(
        select(Vertical).where(Vertical.slug == slug)
    ).first()
    
    if not vertical:
        raise HTTPException(status_code=404, detail="Band not found")
    
    # Get members via BandMembership if primary_artist_id exists
    current_members = []
    past_members = []
    
    if vertical.primary_artist_id:
        # Get all memberships for this band's artist
        memberships = session.exec(
            select(BandMembership, Musician)
            .join(Musician, BandMembership.musician_id == Musician.id)
            .where(BandMembership.artist_id == vertical.primary_artist_id)
            .order_by(BandMembership.start_date)
        ).all()
        
        for membership, musician in memberships:
            member_data = {
                "id": musician.id,
                "name": musician.name,
                "slug": musician.slug,
                "image_url": musician.image_url,
                "role": membership.role,
                "primary_instrument": musician.primary_instrument,
                "start_date": membership.start_date,
                "end_date": membership.end_date,
                "notes": membership.notes,
            }
            if membership.end_date is None:
                current_members.append(member_data)
            else:
                past_members.append(member_data)
    
    # Get stats
    show_count = session.exec(
        select(func.count(Show.id)).where(Show.vertical_id == vertical.id)
    ).one()
    
    song_count = session.exec(
        select(func.count(Song.id)).where(Song.vertical_id == vertical.id)
    ).one()
    
    # Get venue count (distinct venues from shows)
    venue_count = session.exec(
        select(func.count(func.distinct(Show.venue_id)))
        .where(Show.vertical_id == vertical.id)
    ).one()
    
    # Get first and last show dates
    first_show = session.exec(
        select(Show.date)
        .where(Show.vertical_id == vertical.id)
        .order_by(Show.date.asc())
        .limit(1)
    ).first()
    
    last_show = session.exec(
        select(Show.date)
        .where(Show.vertical_id == vertical.id)
        .order_by(Show.date.desc())
        .limit(1)
    ).first()
    
    stats = {
        "total_shows": show_count,
        "total_songs": song_count,
        "total_venues": venue_count,
        "first_show": first_show,
        "last_show": last_show,
    }
    
    return {
        "band": vertical,
        "current_members": current_members,
        "past_members": past_members,
        "stats": stats,
    }