<?php

declare(strict_types=1);

namespace App\Tests\Unit\Scolarite\Application\Query\GetClassStatisticsDetail;

use App\Scolarite\Application\Port\PeriodFinder;
use App\Scolarite\Application\Port\PeriodInfo;
use App\Scolarite\Application\Query\GetClassStatisticsDetail\GetClassStatisticsDetailHandler;
use App\Scolarite\Application\Query\GetClassStatisticsDetail\GetClassStatisticsDetailQuery;
use App\Scolarite\Domain\Service\AverageCalculator;
use App\Scolarite\Domain\Service\TeacherStatisticsCalculator;
use App\Scolarite\Infrastructure\ReadModel\InMemoryTeacherStatisticsReader;
use App\Shared\Domain\Tenant\TenantId;
use DateTimeImmutable;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;

final class GetClassStatisticsDetailHandlerTest extends TestCase
{
    private const string TEACHER_ID = '550e8400-e29b-41d4-a716-446655440010';
    private const string TENANT_ID = '550e8400-e29b-41d4-a716-446655440001';
    private const string CLASS_ID = '550e8400-e29b-41d4-a716-446655440020';
    private const string SUBJECT_ID = '550e8400-e29b-41d4-a716-446655440030';

    private InMemoryTeacherStatisticsReader $reader;

    protected function setUp(): void
    {
        $this->reader = new InMemoryTeacherStatisticsReader();
    }

    #[Test]
    public function itReturnsEmptyWhenNoPeriodFound(): void
    {
        $handler = $this->createHandler(periodInfo: null);

        $result = $handler($this->query());

        self::assertNull($result->average);
        self::assertSame(0.0, $result->successRate);
        self::assertSame([], $result->students);
    }

    #[Test]
    public function itComputesClassStatisticsFromGrades(): void
    {
        $this->reader->feedClassGrades([8.0, 10.0, 12.0, 14.0, 16.0]);
        $this->reader->feedMonthlyAverages([
            ['month' => '2026-01', 'average' => 11.0],
            ['month' => '2026-02', 'average' => 12.5],
        ]);
        $this->reader->feedStudentAverages([
            ['studentId' => 's1', 'studentName' => 'Alice Dupont', 'average' => 14.0],
            ['studentId' => 's2', 'studentName' => 'Bob Martin', 'average' => 7.0],
        ]);

        $handler = $this->createHandler(periodInfo: $this->currentPeriod());
        $result = $handler($this->query());

        self::assertSame(12.0, $result->average);
        self::assertSame(80.0, $result->successRate); // 4/5 >= 10
        self::assertSame([0, 0, 0, 1, 2, 1, 1, 0], $result->distribution);
        self::assertCount(2, $result->evolution);
        self::assertCount(2, $result->students);
        self::assertFalse($result->students[0]->inDifficulty); // Alice 14.0 >= 8.0
        self::assertTrue($result->students[1]->inDifficulty); // Bob 7.0 < 8.0
    }

    private function query(): GetClassStatisticsDetailQuery
    {
        return new GetClassStatisticsDetailQuery(
            teacherId: self::TEACHER_ID,
            classId: self::CLASS_ID,
            subjectId: self::SUBJECT_ID,
            tenantId: self::TENANT_ID,
        );
    }

    private function createHandler(?PeriodInfo $periodInfo): GetClassStatisticsDetailHandler
    {
        $periodFinder = new class($periodInfo) implements PeriodFinder {
            public function __construct(private readonly ?PeriodInfo $info)
            {
            }

            public function findForDate(DateTimeImmutable $date, TenantId $tenantId): ?PeriodInfo
            {
                return $this->info;
            }
        };

        return new GetClassStatisticsDetailHandler(
            $this->reader,
            $periodFinder,
            new TeacherStatisticsCalculator(),
            new AverageCalculator(),
        );
    }

    private function currentPeriod(): PeriodInfo
    {
        return new PeriodInfo(
            periodId: 'period-1',
            startDate: new DateTimeImmutable('2026-01-05'),
            endDate: new DateTimeImmutable('2026-03-31'),
        );
    }
}