"""Main dashboard routes for the Team Tryouts application.

Uses polymorphic isinstance checks instead of role-string comparisons.
"""

from flask import Blueprint, render_template, redirect, url_for, flash, request
from flask_login import login_required, current_user
from flask_babel import gettext as _
from app.extensions import db
from app.models import (
    Admin, Manager, Coach, Player, Scout,
    User, Tryout, Evaluation, TryoutRegistration, TeamMember,
    Match, MatchParticipant,
)
from app.permissions import coach_tryout_ids
from sqlalchemy import func
from datetime import date

main_bp = Blueprint('main', __name__)


@main_bp.route('/')
def index():
    """Redirect root URL to login page."""
    return redirect(url_for('auth.login'))


@main_bp.route('/lang/<locale>')
def set_language(locale):
    """Switch the interface language and return where the user came from.

    Available to anonymous visitors too: the login page has to be readable
    before anyone can sign in.

    A GET link rather than a form: the only thing a forged request could
    achieve is changing the visitor's own display language, which carries
    no consequence worth a token. The redirect target is still validated —
    an unchecked `Referer` would make this an open redirect.
    """
    from app.i18n import set_locale
    from app.routes.auth import is_safe_url

    if not set_locale(locale):
        flash(_('That language is not available.'), 'warning')

    target = request.referrer
    if target and is_safe_url(target):
        return redirect(target)
    return redirect(url_for('main.dashboard') if current_user.is_authenticated
                    else url_for('auth.login'))


@main_bp.route('/dashboard')
@login_required
def dashboard():
    """Render the main dashboard with role-specific statistics.

    Each User subclass provides its own stats view.
    """
    user = current_user
    stats = {}

    if isinstance(user, Admin):
        stats['total_users'] = User.query.count()
        stats['total_players'] = User.query.filter_by(role='player').count()
        stats['total_tryouts'] = Tryout.query.count()
        stats['total_evaluations'] = Evaluation.query.count()
        stats['active_tryouts'] = Tryout.query.filter_by(status='in_progress').count()
        stats['completed_tryouts'] = Tryout.query.filter_by(status='completed').count()
        stats['recent_users'] = User.query.order_by(User.created_at.desc()).limit(10).all()
        stats['recent_tryouts'] = Tryout.query.order_by(Tryout.created_at.desc()).limit(10).all()
        today = date.today()
        stats['upcoming_matches'] = Match.query.filter(
            Match.status == 'scheduled', Match.date >= today,
        ).order_by(Match.date, Match.start_time).limit(5).all()

    elif isinstance(user, Manager):
        stats['total_tryouts'] = Tryout.query.filter_by(created_by=user.id).count()
        stats['active_tryouts'] = Tryout.query.filter_by(
            created_by=user.id, status='in_progress').count()
        stats['total_evaluations'] = Evaluation.query.filter_by(evaluator_id=user.id).count()
        stats['my_tryouts'] = Tryout.query.filter_by(
            created_by=user.id).order_by(Tryout.date.desc()).limit(5).all()
        today = date.today()
        manager_tryout_ids = [t.id for t in Tryout.query.filter_by(created_by=user.id).all()]
        stats['upcoming_matches'] = Match.query.filter(
            Match.tryout_id.in_(manager_tryout_ids),
            Match.status == 'scheduled', Match.date >= today,
        ).order_by(Match.date, Match.start_time).limit(5).all() if manager_tryout_ids else []

    elif isinstance(user, Coach):
        stats['my_evaluations'] = Evaluation.query.filter_by(evaluator_id=user.id).count()
        registrations = TryoutRegistration.query.filter(
            TryoutRegistration.status.in_(['registered', 'attended'])).all()
        registered_player_ids = [r.player_id for r in registrations]
        evaluated_player_ids = [e.player_id for e in Evaluation.query.filter_by(evaluator_id=user.id).all()]
        stats['pending_evaluations'] = len(set(registered_player_ids) - set(evaluated_player_ids))
        stats['my_recent_evaluations'] = Evaluation.query.filter_by(
            evaluator_id=user.id).order_by(Evaluation.created_at.desc()).limit(10).all()
        today = date.today()
        # Was: the first team matching the legacy coach_id column, and only
        # the tryouts targeting it. A coach attached by the many-to-many
        # relationship, or coaching a second team, saw no upcoming match.
        tryout_ids = coach_tryout_ids(user)
        stats['upcoming_matches'] = Match.query.filter(
            Match.tryout_id.in_(tryout_ids),
            Match.status == 'scheduled', Match.date >= today,
        ).order_by(Match.date, Match.start_time).limit(5).all() if tryout_ids else []

    elif isinstance(user, Player):
        stats['my_tryouts'] = TryoutRegistration.query.filter_by(player_id=user.id).count()
        stats['my_registrations'] = TryoutRegistration.query.filter_by(
            player_id=user.id).order_by(TryoutRegistration.registered_at.desc()).limit(5).all()

        today = date.today()
        next_matches = []
        all_registrations = TryoutRegistration.query.filter_by(player_id=user.id).all()
        registered_tryout_ids = [r.tryout_id for r in all_registrations]
        player_participant_matches = MatchParticipant.query.filter_by(player_id=user.id).all()
        player_match_ids = [p.match_id for p in player_participant_matches]
        player_team_memberships = TeamMember.query.filter_by(player_id=user.id).all()
        player_team_ids = [tm.team_id for tm in player_team_memberships]

        upcoming_matches = Match.query.filter(
            Match.tryout_id.in_(registered_tryout_ids),
            Match.status == 'scheduled', Match.date >= today,
        ).order_by(Match.date, Match.start_time).all()

        for match in upcoming_matches:
            is_participant = False
            team = None
            if match.match_type == 'team_vs_team':
                if match.team1_id in player_team_ids:
                    is_participant = True
                    team = next((tm for tm in player_team_memberships
                                 if tm.team_id == match.team1_id), None)
                elif match.team2_id in player_team_ids:
                    is_participant = True
                    team = next((tm for tm in player_team_memberships
                                 if tm.team_id == match.team2_id), None)
            else:
                if match.id in player_match_ids:
                    is_participant = True

            if is_participant:
                next_matches.append({
                    'tryout': match.tryout, 'match': match,
                    'team': team.team if team else None,
                })

        stats['next_matches'] = next_matches

    elif isinstance(user, Scout):
        stats['total_players'] = User.query.filter_by(role='player').count()
        stats['total_evaluations'] = Evaluation.query.count()
        stats['avg_scores'] = db.session.query(
            Evaluation.player_id,
            func.avg(Evaluation.overall_score).label('avg_score'),
        ).group_by(Evaluation.player_id).order_by(
            func.avg(Evaluation.overall_score).desc()).limit(5).all()
        stats['top_players'] = []
        for row in stats['avg_scores']:
            p = User.query.get(row.player_id)
            if p:
                stats['top_players'].append((p, round(row.avg_score, 1)))

    return render_template('pages/dashboard.html', user=user, stats=stats)