<?php
/**
 * POST /api/result
 * Endergebnis bei Modul-Abschluss.
 */

declare(strict_types=1);
require_once __DIR__ . '/../../bootstrap.php';

v2_validate_method('POST');
$auth = v2_auth_require('student');
$studentId = (int) ($auth['sub'] ?? 0);
$classId = (int) ($auth['class_id'] ?? 0);

$body = v2_request_body_json_required();
v2_validate_required($body, [
    'moduleSlug', 'moduleVersion', 'specVersion',
    'completed', 'score', 'scoreMax', 'durationS',
    'difficulty', 'mode', 'lehrplanCoverage', 'ts',
]);

v2_validate_enum((string) $body['mode'], ['free', 'teacher_started', 'assessment', 'demo'], 'mode');

$pdo = v2_db();
$pdo->beginTransaction();

try {
    // Hauptdatensatz
    $stmt = $pdo->prepare("
        INSERT INTO assessments_v2
            (student_id, class_id, module_slug, module_version, spec_version,
             completed, abandoned, score, score_max, duration_s,
             difficulty, mode, module_specific_data, created_at)
        VALUES
            (:sid, :cid, :slug, :mv, :sv,
             :comp, :aban, :score, :scoremax, :dur,
             :diff, :mode, :msd, :ts)
    ");
    $stmt->execute([
        ':sid' => $studentId,
        ':cid' => $classId,
        ':slug' => $body['moduleSlug'],
        ':mv' => $body['moduleVersion'],
        ':sv' => $body['specVersion'],
        ':comp' => (int) (bool) $body['completed'],
        ':aban' => (int) (bool) ($body['abandoned'] ?? false),
        ':score' => (int) $body['score'],
        ':scoremax' => (int) $body['scoreMax'],
        ':dur' => (int) $body['durationS'],
        ':diff' => $body['difficulty'],
        ':mode' => $body['mode'],
        ':msd' => isset($body['moduleSpecificData'])
            ? json_encode($body['moduleSpecificData'], JSON_UNESCAPED_UNICODE)
            : null,
        ':ts' => date('Y-m-d H:i:s', strtotime($body['ts']) ?: time()),
    ]);
    $assessmentId = (int) $pdo->lastInsertId();

    // Milestones
    if (!empty($body['milestonesReached']) && is_array($body['milestonesReached'])) {
        $stmtMs = $pdo->prepare("
            INSERT IGNORE INTO assessment_milestones_v2 (assessment_id, milestone_id)
            VALUES (:aid, :mid)
        ");
        foreach ($body['milestonesReached'] as $mid) {
            $stmtMs->execute([':aid' => $assessmentId, ':mid' => (string) $mid]);
        }
    }

    // Lehrplan-Coverage
    if (!empty($body['lehrplanCoverage']) && is_array($body['lehrplanCoverage'])) {
        $stmtLp = $pdo->prepare("
            INSERT INTO assessment_lehrplan_v2 (assessment_id, anker_code, coverage)
            VALUES (:aid, :code, :cov)
            ON DUPLICATE KEY UPDATE coverage = VALUES(coverage)
        ");
        $stmtUpdLp = $pdo->prepare("
            INSERT INTO lehrplan_progress_v2 (student_id, anker_code, best_coverage, reached_via_module)
            VALUES (:sid, :code, :cov, :slug)
            ON DUPLICATE KEY UPDATE
                best_coverage = CASE
                    WHEN VALUES(best_coverage) = 'full' THEN 'full'
                    WHEN best_coverage = 'full' THEN best_coverage
                    WHEN VALUES(best_coverage) = 'partial' THEN 'partial'
                    ELSE best_coverage
                END,
                reached_via_module = VALUES(reached_via_module),
                reached_at = CURRENT_TIMESTAMP
        ");
        foreach ($body['lehrplanCoverage'] as $code => $cov) {
            v2_validate_enum((string) $cov, ['full', 'partial', 'none'], "lehrplanCoverage.$code");
            $stmtLp->execute([':aid' => $assessmentId, ':code' => $code, ':cov' => $cov]);
            if ($cov !== 'none') {
                $stmtUpdLp->execute([
                    ':sid' => $studentId, ':code' => $code,
                    ':cov' => $cov, ':slug' => $body['moduleSlug'],
                ]);
            }
        }
    }

    // Freitext
    if (!empty($body['freeTextAnswers']) && is_array($body['freeTextAnswers'])) {
        $stmtFt = $pdo->prepare("
            INSERT INTO assessment_freetext_v2
                (assessment_id, prompt_id, prompt_text, answer_text)
            VALUES (:aid, :pid, :ptx, :atx)
        ");
        foreach ($body['freeTextAnswers'] as $ft) {
            if (!is_array($ft) || empty($ft['promptId'])) continue;
            $stmtFt->execute([
                ':aid' => $assessmentId,
                ':pid' => (string) $ft['promptId'],
                ':ptx' => (string) ($ft['promptText'] ?? ''),
                ':atx' => (string) ($ft['answerText'] ?? ''),
            ]);
        }
    }

    // Artefakte verknüpfen (URLs aus separatem Upload, IDs aus body)
    if (!empty($body['artifacts']) && is_array($body['artifacts'])) {
        $stmtArt = $pdo->prepare("
            INSERT IGNORE INTO assessment_artifacts_v2 (assessment_id, artifact_id)
            VALUES (:aid, :artid)
        ");
        foreach ($body['artifacts'] as $art) {
            if (is_array($art) && !empty($art['id'])) {
                $stmtArt->execute([':aid' => $assessmentId, ':artid' => (int) $art['id']]);
            }
        }
    }

    // Schüler-Modul-Fortschritt aktualisieren
    $stmt = $pdo->prepare("
        INSERT INTO student_progress_v2
            (student_id, module_slug, total_attempts, best_score, best_score_max,
             last_completed_at, total_duration_s)
        VALUES
            (:sid, :slug, 1, :score, :scoremax,
             CASE WHEN :comp THEN CURRENT_TIMESTAMP ELSE NULL END, :dur)
        ON DUPLICATE KEY UPDATE
            total_attempts = total_attempts + 1,
            best_score = GREATEST(best_score, VALUES(best_score)),
            best_score_max = GREATEST(best_score_max, VALUES(best_score_max)),
            last_completed_at = CASE
                WHEN :comp2 THEN CURRENT_TIMESTAMP
                ELSE last_completed_at
            END,
            total_duration_s = total_duration_s + VALUES(total_duration_s)
    ");
    $stmt->execute([
        ':sid' => $studentId,
        ':slug' => $body['moduleSlug'],
        ':score' => (int) $body['score'],
        ':scoremax' => (int) $body['scoreMax'],
        ':comp' => (int) (bool) $body['completed'],
        ':comp2' => (int) (bool) $body['completed'],
        ':dur' => (int) $body['durationS'],
    ]);

    $pdo->commit();
    v2_response_created([
        'ok' => true,
        'assessmentId' => $assessmentId,
        'savedAt' => date('c'),
    ]);
} catch (Throwable $e) {
    $pdo->rollBack();
    throw $e;
}