<?php
/**
 * Questionnaire submission versioning (archive each coach upload).
 */

function qdb_next_submission_version(PDO $pdo, string $clientCode, string $questionnaireID): int {
    $stmt = $pdo->prepare(
        'SELECT COALESCE(MAX(version), 0) + 1 FROM questionnaire_submission
         WHERE clientCode = :cc AND questionnaireID = :qn'
    );
    $stmt->execute([':cc' => $clientCode, ':qn' => $questionnaireID]);
    return (int)$stmt->fetchColumn();
}

/**
 * Snapshot live answers + completion metadata after a successful submit.
 */
function qdb_record_submission_after_submit(
    PDO $pdo,
    string $clientCode,
    string $questionnaireID,
    array $tokenRec,
    ?int $startedAt,
    ?int $completedAt,
    int $sumPoints,
    string $assignedByCoach
): string {
    $version = qdb_next_submission_version($pdo, $clientCode, $questionnaireID);
    $submissionID = bin2hex(random_bytes(16));
    $now = time();

    $cq = $pdo->prepare(
        'SELECT status FROM completed_questionnaire WHERE clientCode = :cc AND questionnaireID = :qn'
    );
    $cq->execute([':cc' => $clientCode, ':qn' => $questionnaireID]);
    $status = $cq->fetchColumn() ?: 'completed';

    $pdo->prepare(
        'INSERT INTO questionnaire_submission (
            submissionID, clientCode, questionnaireID, version, submittedAt,
            submittedByUserID, submittedByRole, assignedByCoach,
            status, startedAt, completedAt, sumPoints
        ) VALUES (
            :sid, :cc, :qn, :ver, :sat,
            :uid, :role, :abc,
            :st, :sa, :ca, :sp
        )'
    )->execute([
        ':sid'  => $submissionID,
        ':cc'   => $clientCode,
        ':qn'   => $questionnaireID,
        ':ver'  => $version,
        ':sat'  => $now,
        ':uid'  => $tokenRec['userID'] ?? '',
        ':role' => $tokenRec['role'] ?? '',
        ':abc'  => $assignedByCoach !== '' ? $assignedByCoach : null,
        ':st'   => $status,
        ':sa'   => $startedAt,
        ':ca'   => $completedAt,
        ':sp'   => $sumPoints,
    ]);

    $copy = $pdo->prepare(
        'INSERT INTO client_answer_submission (submissionID, questionID, answerOptionID, freeTextValue, numericValue, answeredAt)
         SELECT :sid, questionID, answerOptionID, freeTextValue, numericValue, answeredAt
         FROM client_answer
         WHERE clientCode = :cc AND questionID IN (
             SELECT questionID FROM question WHERE questionnaireID = :qn
         )'
    );
    $copy->execute([':sid' => $submissionID, ':cc' => $clientCode, ':qn' => $questionnaireID]);

    return $submissionID;
}

/**
 * One-time: create version 1 submissions for existing completions without archive rows.
 */
function qdb_backfill_submissions_from_live(PDO $pdo): bool {
    $count = (int)$pdo->query('SELECT COUNT(*) FROM questionnaire_submission')->fetchColumn();
    if ($count > 0) {
        return false;
    }

    $rows = $pdo->query(
        'SELECT clientCode, questionnaireID, assignedByCoach, status, startedAt, completedAt, sumPoints
         FROM completed_questionnaire'
    )->fetchAll(PDO::FETCH_ASSOC);

    if (!$rows) {
        return false;
    }

    $pdo->beginTransaction();
    try {
        foreach ($rows as $cq) {
            $clientCode = $cq['clientCode'];
            $qnID = $cq['questionnaireID'];
            $chk = $pdo->prepare(
                'SELECT 1 FROM client_answer ca
                 JOIN question q ON q.questionID = ca.questionID
                 WHERE ca.clientCode = :cc AND q.questionnaireID = :qn LIMIT 1'
            );
            $chk->execute([':cc' => $clientCode, ':qn' => $qnID]);
            if (!$chk->fetchColumn()) {
                continue;
            }

            $submissionID = bin2hex(random_bytes(16));
            $completedAt = $cq['completedAt'] ?? time();
            $pdo->prepare(
                'INSERT INTO questionnaire_submission (
                    submissionID, clientCode, questionnaireID, version, submittedAt,
                    submittedByUserID, submittedByRole, assignedByCoach,
                    status, startedAt, completedAt, sumPoints
                ) VALUES (
                    :sid, :cc, :qn, 1, :sat,
                    \'\', \'\', :abc,
                    :st, :sa, :ca, :sp
                )'
            )->execute([
                ':sid' => $submissionID,
                ':cc'  => $clientCode,
                ':qn'  => $qnID,
                ':sat' => $completedAt,
                ':abc' => $cq['assignedByCoach'],
                ':st'  => $cq['status'] ?: 'completed',
                ':sa'  => $cq['startedAt'],
                ':ca'  => $cq['completedAt'],
                ':sp'  => $cq['sumPoints'],
            ]);

            $pdo->prepare(
                'INSERT INTO client_answer_submission (submissionID, questionID, answerOptionID, freeTextValue, numericValue, answeredAt)
                 SELECT :sid, questionID, answerOptionID, freeTextValue, numericValue, answeredAt
                 FROM client_answer
                 WHERE clientCode = :cc AND questionID IN (
                     SELECT questionID FROM question WHERE questionnaireID = :qn
                 )'
            )->execute([':sid' => $submissionID, ':cc' => $clientCode, ':qn' => $qnID]);
        }
        $pdo->commit();
        return true;
    } catch (Throwable $e) {
        if ($pdo->inTransaction()) {
            $pdo->rollBack();
        }
        throw $e;
    }
}

/**
 * Build CSV rows for all submission versions of one questionnaire (RBAC-scoped).
 *
 * @return list<array<string, string>>
 */
function qdb_export_all_versions_rows(
    PDO $pdo,
    string $questionnaireID,
    array $questions,
    array $resultColumns,
    array $optionTextMap,
    array $tokenRec
): array {
    [$rbacClause, $rbacParams] = rbac_client_filter($tokenRec, 'cl');

    $sql = "
        SELECT qs.submissionID, qs.version, qs.submittedAt, qs.submittedByUserID, qs.submittedByRole,
               qs.completedAt AS submissionCompletedAt, qs.sumPoints AS submissionSumPoints,
               qs.startedAt AS submissionStartedAt, qs.status AS submissionStatus,
               cl.clientCode, cl.coachID,
               co.username AS coachUsername,
               sv.username AS supervisorUsername
        FROM questionnaire_submission qs
        INNER JOIN client cl ON cl.clientCode = qs.clientCode
        LEFT JOIN coach co ON co.coachID = cl.coachID
        LEFT JOIN supervisor sv ON sv.supervisorID = co.supervisorID
        WHERE qs.questionnaireID = :qnid AND ($rbacClause)
        ORDER BY cl.clientCode ASC, qs.version ASC
    ";
    $params = array_merge([':qnid' => $questionnaireID], $rbacParams);
    $stmt = $pdo->prepare($sql);
    $stmt->execute($params);
    $submissions = $stmt->fetchAll(PDO::FETCH_ASSOC);

    $questionIDs = array_column($questions, 'questionID');
    $qPlaceholders = !empty($questionIDs)
        ? implode(',', array_fill(0, count($questionIDs), '?'))
        : "'__none__'";

    $answerStmt = $pdo->prepare("
        SELECT questionID, answerOptionID, freeTextValue, numericValue
        FROM client_answer_submission
        WHERE submissionID = ? AND questionID IN ($qPlaceholders)
    ");

    $userMap = [];
    $userStmt = $pdo->query('SELECT userID, username FROM users');
    foreach ($userStmt->fetchAll(PDO::FETCH_ASSOC) as $u) {
        $userMap[$u['userID']] = $u['username'];
    }

    $rows = [];
    foreach ($submissions as $s) {
        $row = [
            'submissionID'   => $s['submissionID'],
            'version'        => (string)(int)$s['version'],
            'submittedAt'    => $s['submittedAt'] ? date('Y-m-d H:i', (int)$s['submittedAt']) : '',
            'submittedByRole'=> $s['submittedByRole'] ?? '',
            'submittedBy'    => $userMap[$s['submittedByUserID'] ?? ''] ?? ($s['submittedByUserID'] ?? ''),
            'clientCode'     => $s['clientCode'],
            'coach'          => $s['coachUsername'] ?? $s['coachID'],
            'supervisor'     => $s['supervisorUsername'] ?? '',
            'status'         => $s['submissionStatus'] ?? '',
            'sumPoints'      => $s['submissionSumPoints'] ?? '',
            'startedAt'      => $s['submissionStartedAt'] ? date('Y-m-d H:i', (int)$s['submissionStartedAt']) : '',
            'completedAt'    => $s['submissionCompletedAt'] ? date('Y-m-d H:i', (int)$s['submissionCompletedAt']) : '',
        ];

        $bindParams = array_merge([$s['submissionID']], $questionIDs);
        $answerStmt->execute($bindParams);
        $answerMap = [];
        foreach ($answerStmt->fetchAll(PDO::FETCH_ASSOC) as $a) {
            $answerMap[$a['questionID']] = $a;
        }

        foreach ($resultColumns as $col) {
            $qid = $col['questionID'];
            $a = $answerMap[$qid] ?? null;
            $row[$col['header']] = qdb_results_column_cell_value($col, $a, $optionTextMap);
        }
        $rows[] = $row;
    }

    return $rows;
}

/**
 * @return array{questions: array, resultColumns: array, optionTextMap: array}
 */
function qdb_export_questionnaire_context(PDO $pdo, string $questionnaireID): array {
    $qStmt = $pdo->prepare(
        'SELECT questionID, defaultText, type, orderIndex, configJson FROM question WHERE questionnaireID = :id ORDER BY orderIndex'
    );
    $qStmt->execute([':id' => $questionnaireID]);
    $questions = $qStmt->fetchAll(PDO::FETCH_ASSOC);
    $questionIDs = array_column($questions, 'questionID');
    $resultColumns = qdb_results_export_columns($questions, $questionnaireID);

    $optionTextMap = [];
    foreach ($questionIDs as $qid) {
        $aoStmt = $pdo->prepare('SELECT answerOptionID, defaultText FROM answer_option WHERE questionID = :qid');
        $aoStmt->execute([':qid' => $qid]);
        foreach ($aoStmt->fetchAll(PDO::FETCH_ASSOC) as $ao) {
            $optionTextMap[$ao['answerOptionID']] = $ao['defaultText'];
        }
    }

    return [
        'questions'      => $questions,
        'resultColumns'  => $resultColumns,
        'optionTextMap'  => $optionTextMap,
    ];
}

/**
 * Current (live) response rows for one questionnaire, RBAC-scoped.
 *
 * @return list<array<string, string>>
 */
function qdb_export_current_rows(
    PDO $pdo,
    string $questionnaireID,
    array $questions,
    array $resultColumns,
    array $optionTextMap,
    array $tokenRec
): array {
    [$rbacClause, $rbacParams] = rbac_client_filter($tokenRec, 'cl');
    $questionIDs = array_column($questions, 'questionID');

    $sql = "
        SELECT cl.clientCode, cl.coachID,
               co.username AS coachUsername,
               sv.username AS supervisorUsername,
               cq.status, cq.sumPoints, cq.startedAt, cq.completedAt
        FROM client cl
        INNER JOIN completed_questionnaire cq ON cq.clientCode = cl.clientCode AND cq.questionnaireID = :qnid
        LEFT JOIN coach co ON co.coachID = cl.coachID
        LEFT JOIN supervisor sv ON sv.supervisorID = co.supervisorID
        WHERE $rbacClause
        ORDER BY cl.clientCode
    ";
    $params = array_merge([':qnid' => $questionnaireID], $rbacParams);
    $cStmt = $pdo->prepare($sql);
    $cStmt->execute($params);
    $clients = $cStmt->fetchAll(PDO::FETCH_ASSOC);

    $qPlaceholders = !empty($questionIDs) ? implode(',', array_fill(0, count($questionIDs), '?')) : "'__none__'";
    $answerStmt = $pdo->prepare("
        SELECT questionID, answerOptionID, freeTextValue, numericValue
        FROM client_answer
        WHERE clientCode = ? AND questionID IN ($qPlaceholders)
    ");

    $rows = [];
    foreach ($clients as $c) {
        $row = [
            'clientCode'  => $c['clientCode'],
            'coach'       => $c['coachUsername'] ?? $c['coachID'],
            'supervisor'  => $c['supervisorUsername'] ?? '',
            'status'      => $c['status'],
            'sumPoints'   => $c['sumPoints'],
            'startedAt'   => $c['startedAt'] ? date('Y-m-d H:i', (int)$c['startedAt']) : '',
            'completedAt' => $c['completedAt'] ? date('Y-m-d H:i', (int)$c['completedAt']) : '',
        ];

        $bindParams = array_merge([$c['clientCode']], $questionIDs);
        $answerStmt->execute($bindParams);
        $answerMap = [];
        foreach ($answerStmt->fetchAll(PDO::FETCH_ASSOC) as $a) {
            $answerMap[$a['questionID']] = $a;
        }

        foreach ($resultColumns as $col) {
            $qid = $col['questionID'];
            $a = $answerMap[$qid] ?? null;
            $row[$col['header']] = qdb_results_column_cell_value($col, $a, $optionTextMap);
        }
        $rows[] = $row;
    }

    return $rows;
}

function qdb_export_safe_basename(string $name): string {
    $safe = preg_replace('/[^a-zA-Z0-9_-]+/', '_', $name);
    return $safe !== '' ? $safe : 'questionnaire';
}

/** @param array<string, true> $used */
function qdb_export_unique_zip_name(array &$used, string $base): string {
    $name = $base;
    $n = 2;
    while (isset($used[$name])) {
        $name = preg_replace('/(\.csv)$/i', "_{$n}$1", $base, 1, $count);
        if (!$count) {
            $name = $base . '_' . $n;
        }
        $n++;
    }
    $used[$name] = true;
    return $name;
}

/**
 * @param list<array<string, string>> $rows
 * @param list<string> $fallbackHeader
 */
function qdb_export_rows_to_csv_string(array $rows, array $fallbackHeader = []): string {
    $fp = fopen('php://temp', 'r+');
    if ($fp === false) {
        return '';
    }
    fwrite($fp, "\xEF\xBB\xBF");
    if (!empty($rows)) {
        fputcsv($fp, array_keys($rows[0]));
        foreach ($rows as $row) {
            fputcsv($fp, array_values($row));
        }
    } elseif ($fallbackHeader !== []) {
        fputcsv($fp, $fallbackHeader);
    }
    rewind($fp);
    $csv = stream_get_contents($fp);
    fclose($fp);
    return $csv !== false ? $csv : '';
}

function qdb_export_current_csv_fallback_header(array $resultColumns): array {
    $header = ['clientCode', 'coach', 'supervisor', 'status', 'sumPoints', 'startedAt', 'completedAt'];
    foreach ($resultColumns as $col) {
        $header[] = $col['header'];
    }
    return $header;
}

function qdb_export_all_versions_csv_fallback_header(array $resultColumns): array {
    $header = [
        'submissionID', 'version', 'submittedAt', 'submittedByRole', 'submittedBy',
        'clientCode', 'coach', 'supervisor', 'status', 'sumPoints', 'startedAt', 'completedAt',
    ];
    foreach ($resultColumns as $col) {
        $header[] = $col['header'];
    }
    return $header;
}

/**
 * Build a ZIP of CSV exports for every questionnaire. Returns path to a temp file (caller must unlink).
 */
function qdb_build_server_export_zip(PDO $pdo, array $tokenRec, bool $allVersions): string {
    if (!class_exists('ZipArchive')) {
        json_error('SERVER_ERROR', 'ZIP export is not available on this server', 500);
    }

    $qnRows = $pdo->query(
        'SELECT questionnaireID, name, version FROM questionnaire ORDER BY orderIndex, name'
    )->fetchAll(PDO::FETCH_ASSOC);

    $tmpZip = tempnam(sys_get_temp_dir(), 'qdb_export_');
    if ($tmpZip === false) {
        json_error('SERVER_ERROR', 'Could not create export file', 500);
    }

    $zip = new ZipArchive();
    if ($zip->open($tmpZip, ZipArchive::OVERWRITE) !== true) {
        @unlink($tmpZip);
        json_error('SERVER_ERROR', 'Could not create ZIP archive', 500);
    }

    $usedNames = [];
    foreach ($qnRows as $qn) {
        $qnID = $qn['questionnaireID'];
        $ctx = qdb_export_questionnaire_context($pdo, $qnID);
        $questions = $ctx['questions'];
        $resultColumns = $ctx['resultColumns'];
        $optionTextMap = $ctx['optionTextMap'];

        if ($allVersions) {
            $rows = qdb_export_all_versions_rows($pdo, $qnID, $questions, $resultColumns, $optionTextMap, $tokenRec);
            $fallback = qdb_export_all_versions_csv_fallback_header($resultColumns);
            $base = qdb_export_safe_basename($qn['name']) . '_all_versions.csv';
        } else {
            $rows = qdb_export_current_rows($pdo, $qnID, $questions, $resultColumns, $optionTextMap, $tokenRec);
            $fallback = qdb_export_current_csv_fallback_header($resultColumns);
            $ver = preg_replace('/[^a-zA-Z0-9_.-]+/', '_', (string)($qn['version'] ?? ''));
            $base = qdb_export_safe_basename($qn['name']) . ($ver !== '' ? "_v{$ver}" : '') . '.csv';
        }

        $entryName = qdb_export_unique_zip_name($usedNames, $base);
        $csv = qdb_export_rows_to_csv_string($rows, $fallback);
        $zip->addFromString($entryName, $csv);
    }

    $readme = $allVersions
        ? "BW Schützt — all questionnaire response exports (every upload version).\nOne CSV per questionnaire.\n"
        : "BW Schützt — all questionnaire response exports (current data).\nOne CSV per questionnaire.\n";
    $zip->addFromString('README.txt', $readme);
    $zip->close();

    return $tmpZip;
}