from typing import Optional

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import desc, func, or_, select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.database import get_db
from app.models import Bill, Member
from app.schemas.schemas import BillSchema, MemberSchema, PaginatedResponse

router = APIRouter()


@router.get("", response_model=PaginatedResponse[MemberSchema])
async def list_members(
    chamber: Optional[str] = Query(None),
    party: Optional[str] = Query(None),
    state: Optional[str] = Query(None),
    q: Optional[str] = Query(None),
    page: int = Query(1, ge=1),
    per_page: int = Query(50, ge=1, le=250),
    db: AsyncSession = Depends(get_db),
):
    query = select(Member)
    if chamber:
        query = query.where(Member.chamber == chamber)
    if party:
        query = query.where(Member.party == party)
    if state:
        query = query.where(Member.state == state)
    if q:
        # name is stored as "Last, First" — also match "First Last" order
        first_last = func.concat(
            func.split_part(Member.name, ", ", 2), " ",
            func.split_part(Member.name, ", ", 1),
        )
        query = query.where(or_(
            Member.name.ilike(f"%{q}%"),
            first_last.ilike(f"%{q}%"),
        ))

    total = await db.scalar(select(func.count()).select_from(query.subquery())) or 0
    query = query.order_by(Member.last_name, Member.first_name).offset((page - 1) * per_page).limit(per_page)

    result = await db.execute(query)
    members = result.scalars().all()

    return PaginatedResponse(
        items=members,
        total=total,
        page=page,
        per_page=per_page,
        pages=max(1, (total + per_page - 1) // per_page),
    )


@router.get("/{bioguide_id}", response_model=MemberSchema)
async def get_member(bioguide_id: str, db: AsyncSession = Depends(get_db)):
    member = await db.get(Member, bioguide_id)
    if not member:
        raise HTTPException(status_code=404, detail="Member not found")
    return member


@router.get("/{bioguide_id}/bills", response_model=PaginatedResponse[BillSchema])
async def get_member_bills(
    bioguide_id: str,
    page: int = Query(1, ge=1),
    per_page: int = Query(20, ge=1, le=100),
    db: AsyncSession = Depends(get_db),
):
    query = select(Bill).options(selectinload(Bill.briefs), selectinload(Bill.sponsor)).where(Bill.sponsor_id == bioguide_id)
    total = await db.scalar(select(func.count()).select_from(query.subquery())) or 0
    query = query.order_by(desc(Bill.introduced_date)).offset((page - 1) * per_page).limit(per_page)

    result = await db.execute(query)
    bills = result.scalars().all()

    items = []
    for bill in bills:
        b = BillSchema.model_validate(bill)
        if bill.briefs:
            b.latest_brief = bill.briefs[0]
        items.append(b)

    return PaginatedResponse(
        items=items,
        total=total,
        page=page,
        per_page=per_page,
        pages=max(1, (total + per_page - 1) // per_page),
    )