"""Evaluation routes for assessing player performance during tryouts.

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

from flask import Blueprint, flash, redirect, render_template, request, url_for
from flask_babel import gettext as _
from flask_login import current_user, login_required
from marshmallow import ValidationError
from sqlalchemy import func
from sqlalchemy.orm import aliased

from app.extensions import db
from app.forms import flash_validation_errors, form_payload
from app.models import (
    GAME_POSITIONS,
    Admin,
    Evaluation,
    Player,
    Tryout,
    TryoutRegistration,
    User,
)
from app.pagination import paginate
from app.validators import EvaluationSchema

evaluations_bp = Blueprint('evaluations', __name__, url_prefix='/evaluations')


def _users_by_id(user_ids):
    """Load a set of users once for aggregate/list views."""
    wanted = {user_id for user_id in user_ids if user_id}
    if not wanted:
        return {}
    return {user.id: user for user in User.query.filter(User.id.in_(wanted)).all()}


@evaluations_bp.route('')
@login_required
def list_evaluations():
    """List all evaluations accessible to the current user."""
    user = current_user

    if isinstance(user, Player):
        flash(_('You do not have permission to view evaluations.'), 'danger')
        return redirect(url_for('main.dashboard'))

    sort_column = request.args.get('sort', 'created_at')
    sort_order = request.args.get('order', 'desc')
    if sort_order not in ('asc', 'desc'):
        sort_order = 'desc'

    player_alias = aliased(User, name='eval_player')
    evaluator_alias = aliased(User, name='eval_evaluator')

    sort_map = {
        'tryout': Tryout.title,
        'player': player_alias.username,
        'evaluator': evaluator_alias.username,
        'mecanics_score': Evaluation.mecanics_score,
        'cohesion_score': Evaluation.cohesion_score,
        'communication_score': Evaluation.communication_score,
        'gamesense_score': Evaluation.gamesense_score,
        'versatility_score': Evaluation.versatility_score,
        'discipline_score': Evaluation.discipline_score,
        'analysis_score': Evaluation.analysis_score,
        'sport_ethics_score': Evaluation.sport_ethics_score,
        'mental_score': Evaluation.mental_score,
        'overall_score': Evaluation.overall_score,
        'position_recommendation': Evaluation.position_recommendation,
        'created_at': Evaluation.created_at,
    }

    sort_expr = sort_map.get(sort_column, Evaluation.created_at)
    if sort_order == 'asc':
        sort_expr = sort_expr.asc()
    else:
        sort_expr = sort_expr.desc()

    if isinstance(user, Admin):
        evaluations_page = paginate(
            Evaluation.query.outerjoin(Tryout, Evaluation.tryout_id == Tryout.id)
            .outerjoin(player_alias, Evaluation.player_id == player_alias.id)
            .outerjoin(evaluator_alias, Evaluation.evaluator_id == evaluator_alias.id)
            .order_by(sort_expr, Evaluation.id)
        )
        avg_scores = (
            db.session.query(
                Evaluation.player_id,
                func.count(Evaluation.id).label('eval_count'),
                func.avg(Evaluation.overall_score).label('avg_score'),
            )
            .group_by(Evaluation.player_id)
            .all()
        )
        players_by_id = _users_by_id(row.player_id for row in avg_scores)
        player_scores = {}
        for row in avg_scores:
            p = players_by_id.get(row.player_id)
            if p:
                player_scores[p.id] = {
                    'player': p,
                    'count': row.eval_count,
                    'avg': round(row.avg_score, 1) if row.avg_score else 0,
                }
    else:
        # Everyone still here evaluates: players were redirected above, and
        # can_evaluate() is true for the four remaining roles. The former
        # `else` branch listed evaluations *received* — a player's view,
        # unreachable from this point (ARCH-007).
        evaluations_page = paginate(
            Evaluation.query.outerjoin(Tryout, Evaluation.tryout_id == Tryout.id)
            .outerjoin(player_alias, Evaluation.player_id == player_alias.id)
            .outerjoin(evaluator_alias, Evaluation.evaluator_id == evaluator_alias.id)
            .filter(Evaluation.evaluator_id == user.id)
            .order_by(sort_expr, Evaluation.id)
        )
        player_scores = {}

    return render_template(
        'pages/evaluations.html',
        evaluations=evaluations_page.items,
        pagination=evaluations_page,
        player_scores=player_scores,
        sort_column=sort_column,
        sort_order=sort_order,
    )


@evaluations_bp.route('/<int:tryout_id>/<int:player_id>', methods=['GET', 'POST'])
@login_required
def evaluate_player(tryout_id, player_id):
    """Evaluate a specific player in a tryout."""
    if not current_user.can_evaluate():
        flash(_('You do not have permission to evaluate players.'), 'danger')
        return redirect(url_for('main.dashboard'))

    tryout = db.get_or_404(Tryout, tryout_id)
    if not current_user.can_manage_this_tryout(tryout):
        flash(_('You do not have permission to evaluate players in this tryout.'), 'danger')
        return redirect(url_for('tryouts.list_tryouts'))

    is_registered = (
        TryoutRegistration.query.filter_by(
            tryout_id=tryout_id,
            player_id=player_id,
        ).first()
        is not None
    )
    if not is_registered:
        flash(_('Player is not registered for this tryout.'), 'danger')
        return redirect(url_for('tryouts.view_tryout', tryout_id=tryout_id))

    player = db.get_or_404(User, player_id)
    if not isinstance(player, Player):
        flash(_('Can only evaluate players.'), 'danger')
        return redirect(url_for('tryouts.view_tryout', tryout_id=tryout_id))

    existing_eval = Evaluation.query.filter_by(
        tryout_id=tryout_id,
        player_id=player_id,
        evaluator_id=current_user.id,
    ).first()

    def render_evaluation_form():
        evaluators = None
        if isinstance(current_user, Admin):
            all_evaluations = Evaluation.query.filter_by(
                tryout_id=tryout_id,
                player_id=player_id,
            ).all()
            evaluators_by_id = _users_by_id(e.evaluator_id for e in all_evaluations)
            evaluators = [
                {'evaluator': evaluators_by_id.get(e.evaluator_id), 'eval': e}
                for e in all_evaluations
            ]

        return render_template(
            'pages/evaluate_player.html',
            tryout=tryout,
            player=player,
            existing_eval=existing_eval,
            evaluators=evaluators,
            game_positions=GAME_POSITIONS,
        )

    if request.method == 'POST':
        try:
            data = EvaluationSchema().load(form_payload(list_fields=(), optional_blank=()))
        except ValidationError as err:
            flash_validation_errors(err)
            return render_evaluation_form()

        evaluation = existing_eval
        if evaluation is None:
            evaluation = Evaluation(
                tryout_id=tryout_id,
                player_id=player_id,
                evaluator_id=current_user.id,
            )
            db.session.add(evaluation)
            flash(_('Evaluation submitted successfully!'), 'success')
        else:
            flash(_('Evaluation updated!'), 'success')

        evaluation.apply_scores(data)
        evaluation.comments = data['comments']
        evaluation.position_recommendation = data['position_recommendation']

        db.session.commit()
        return redirect(url_for('tryouts.view_tryout', tryout_id=tryout_id))

    return render_evaluation_form()


@evaluations_bp.route('/<int:tryout_id>/players')
@login_required
def players_to_evaluate(tryout_id):
    """List players that need evaluation in a specific tryout."""
    if not current_user.can_evaluate():
        flash(_('Permission denied.'), 'danger')
        return redirect(url_for('main.dashboard'))

    tryout = db.get_or_404(Tryout, tryout_id)
    if not current_user.can_manage_this_tryout(tryout):
        flash(_('You do not have permission to evaluate players in this tryout.'), 'danger')
        return redirect(url_for('tryouts.list_tryouts'))

    registrations = TryoutRegistration.query.filter_by(tryout_id=tryout_id).all()
    players_by_id = _users_by_id(reg.player_id for reg in registrations)
    evaluated_player_ids = {
        player_id
        for (player_id,) in db.session.query(Evaluation.player_id)
        .filter_by(tryout_id=tryout_id, evaluator_id=current_user.id)
        .all()
    }
    players = [
        {
            'player': player,
            'evaluated': player.id in evaluated_player_ids,
            'registration': registration,
        }
        for registration in registrations
        if (player := players_by_id.get(registration.player_id)) and isinstance(player, Player)
    ]

    return render_template('pages/players_to_evaluate.html', tryout=tryout, players=players)