from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from datetime import datetime
from ..database import get_db
from ..models import Match, Player, Court, Stage
from ..schemas import MatchScoreUpdate, MatchCourtAssign

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


def _match_detail(match: Match, db: Session) -> dict:
    p1 = db.query(Player).filter(Player.id == match.player1_id).first() if match.player1_id else None
    p2 = db.query(Player).filter(Player.id == match.player2_id).first() if match.player2_id else None
    court = db.query(Court).filter(Court.id == match.court_id).first() if match.court_id else None
    return {
        "id": match.id,
        "stage_id": match.stage_id,
        "court_id": match.court_id,
        "court_name": court.name if court else None,
        "round_number": match.round_number,
        "match_number": match.match_number,
        "player1_id": match.player1_id,
        "player2_id": match.player2_id,
        "player1_name": p1.name if p1 else None,
        "player2_name": p2.name if p2 else None,
        "team1_players": match.team1_players,
        "team2_players": match.team2_players,
        "score1": match.score1,
        "score2": match.score2,
        "winner_id": match.winner_id,
        "winner_team": match.winner_team,
        "status": match.status,
        "bracket_position": match.bracket_position,
        "next_winner_match_id": match.next_winner_match_id,
        "next_loser_match_id": match.next_loser_match_id,
        "started_at": match.started_at,
        "completed_at": match.completed_at,
    }


@router.get("/{match_id}")
def get_match(match_id: int, db: Session = Depends(get_db)):
    match = db.query(Match).filter(Match.id == match_id).first()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")
    return _match_detail(match, db)


@router.post("/{match_id}/start")
def start_match(match_id: int, db: Session = Depends(get_db)):
    match = db.query(Match).filter(Match.id == match_id).first()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")

    match.status = "in_progress"
    match.started_at = datetime.utcnow()

    # Auto-assign available court if none assigned
    if not match.court_id:
        stage = db.query(Stage).filter(Stage.id == match.stage_id).first()
        if stage:
            # Find available court
            in_use_court_ids = db.query(Match.court_id).filter(
                Match.status == "in_progress", Match.court_id.isnot(None)
            ).all()
            in_use_ids = [r[0] for r in in_use_court_ids]
            available_court = db.query(Court).filter(
                Court.status.in_(["available", "reserved"]),
                Court.id.notin_(in_use_ids)
            ).first()
            if available_court:
                match.court_id = available_court.id
                available_court.status = "in_use"

    db.commit()
    return _match_detail(match, db)


@router.post("/{match_id}/score")
def enter_score(match_id: int, data: MatchScoreUpdate, db: Session = Depends(get_db)):
    match = db.query(Match).filter(Match.id == match_id).first()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")

    match.score1 = data.score1
    match.score2 = data.score2
    match.status = "completed"
    match.completed_at = datetime.utcnow()

    # Determine winner
    if data.score1 > data.score2:
        match.winner_id = match.player1_id
        match.winner_team = 1
        winner_id = match.player1_id
        loser_id = match.player2_id
    else:
        match.winner_id = match.player2_id
        match.winner_team = 2
        winner_id = match.player2_id
        loser_id = match.player1_id

    # Free up court
    if match.court_id:
        court = db.query(Court).filter(Court.id == match.court_id).first()
        if court:
            court.status = "available"

    # Update player stats
    if winner_id:
        winner = db.query(Player).filter(Player.id == winner_id).first()
        if winner:
            winner.wins += 1
            winner.matches_played += 1
            winner.elo += 20  # Simple ELO gain
    if loser_id:
        loser = db.query(Player).filter(Player.id == loser_id).first()
        if loser:
            loser.losses += 1
            loser.matches_played += 1
            loser.elo = max(800, loser.elo - 15)

    # Advance bracket: place winner into next match
    if match.next_winner_match_id:
        next_match = db.query(Match).filter(Match.id == match.next_winner_match_id).first()
        if next_match:
            if next_match.player1_id is None:
                next_match.player1_id = winner_id
            elif next_match.player2_id is None:
                next_match.player2_id = winner_id

    db.commit()
    return _match_detail(match, db)


@router.patch("/{match_id}/court")
def assign_court(match_id: int, data: MatchCourtAssign, db: Session = Depends(get_db)):
    match = db.query(Match).filter(Match.id == match_id).first()
    if not match:
        raise HTTPException(status_code=404, detail="Match not found")

    # Free old court
    if match.court_id:
        old_court = db.query(Court).filter(Court.id == match.court_id).first()
        if old_court and old_court.status == "in_use":
            old_court.status = "available"

    match.court_id = data.court_id

    # Mark new court in use if match is in progress
    if data.court_id and match.status == "in_progress":
        new_court = db.query(Court).filter(Court.id == data.court_id).first()
        if new_court:
            new_court.status = "in_use"

    db.commit()
    return {"ok": True}