import logging
from datetime import datetime, timezone
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, MemberTrendScore, MemberNewsArticle
from app.schemas.schemas import (
    BillSchema, MemberSchema, MemberTrendScoreSchema,
    MemberNewsArticleSchema, PaginatedResponse,
)
from app.services import congress_api

logger = logging.getLogger(__name__)

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")

    # Kick off member interest scoring on first view (non-blocking)
    if member.detail_fetched is None:
        try:
            from app.workers.member_interest import fetch_member_news, calculate_member_trend_score
            fetch_member_news.delay(bioguide_id)
            calculate_member_trend_score.delay(bioguide_id)
        except Exception:
            pass

    # Lazy-enrich with detail data from Congress.gov on first view
    if member.detail_fetched is None:
        try:
            detail_raw = congress_api.get_member_detail(bioguide_id)
            enriched = congress_api.parse_member_detail_from_api(detail_raw)
            for field, value in enriched.items():
                if value is not None:
                    setattr(member, field, value)
            member.detail_fetched = datetime.now(timezone.utc)
            await db.commit()
            await db.refresh(member)
        except Exception as e:
            logger.warning(f"Could not enrich member detail for {bioguide_id}: {e}")

    # Attach latest trend score
    result_schema = MemberSchema.model_validate(member)
    latest_trend = (
        await db.execute(
            select(MemberTrendScore)
            .where(MemberTrendScore.member_id == bioguide_id)
            .order_by(desc(MemberTrendScore.score_date))
            .limit(1)
        )
    )
    trend = latest_trend.scalar_one_or_none()
    if trend:
        result_schema.latest_trend = MemberTrendScoreSchema.model_validate(trend)
    return result_schema


@router.get("/{bioguide_id}/trend", response_model=list[MemberTrendScoreSchema])
async def get_member_trend(
    bioguide_id: str,
    days: int = Query(30, ge=7, le=365),
    db: AsyncSession = Depends(get_db),
):
    from datetime import date, timedelta
    cutoff = date.today() - timedelta(days=days)
    result = await db.execute(
        select(MemberTrendScore)
        .where(MemberTrendScore.member_id == bioguide_id, MemberTrendScore.score_date >= cutoff)
        .order_by(MemberTrendScore.score_date)
    )
    return result.scalars().all()


@router.get("/{bioguide_id}/news", response_model=list[MemberNewsArticleSchema])
async def get_member_news(bioguide_id: str, db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(MemberNewsArticle)
        .where(MemberNewsArticle.member_id == bioguide_id)
        .order_by(desc(MemberNewsArticle.published_at))
        .limit(20)
    )
    return result.scalars().all()


@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),
    )