<?php
declare(strict_types=1);

class TaskSubmissionRepository
{
    public function create(
        int $assignmentId,
        int $methodId,
        int $contactId,
        string $status,
        array $payload,
        ?int $score = null,
        ?int $maxScore = null
    ): int {
        return TaskCertDb::insert(
            'INSERT INTO task_submission (
                assignment_id, method_id, main_contact_id, status, payload_json, score, max_score
             ) VALUES (?, ?, ?, ?, ?, ?, ?)',
            'iiissii',
            [
                $assignmentId,
                $methodId,
                $contactId,
                $status,
                json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
                $score,
                $maxScore,
            ]
        );
    }

    public function findById(int $submissionId): ?array
    {
        $row = TaskCertDb::fetchOne(
            'SELECT * FROM task_submission WHERE id = ?',
            'i',
            [$submissionId]
        );

        if ($row === null) {
            return null;
        }

        $row['payload'] = $this->decodePayload($row['payload_json'] ?? null);
        unset($row['payload_json']);

        return $row;
    }

    public function findLatestByAssignmentAndMethod(int $assignmentId, int $methodId): ?array
    {
        $row = TaskCertDb::fetchOne(
            'SELECT * FROM task_submission
             WHERE assignment_id = ? AND method_id = ?
             ORDER BY id DESC
             LIMIT 1',
            'ii',
            [$assignmentId, $methodId]
        );

        if ($row === null) {
            return null;
        }

        $row['payload'] = $this->decodePayload($row['payload_json'] ?? null);
        unset($row['payload_json']);

        return $row;
    }

    public function findLatestByAssignmentAndMethodAndStatuses(int $assignmentId, int $methodId, array $statuses): ?array
    {
        $statuses = array_values(array_filter(array_map('strval', $statuses), static function (string $status): bool {
            return trim($status) !== '';
        }));

        if ($statuses === []) {
            return null;
        }

        $placeholders = implode(',', array_fill(0, count($statuses), '?'));
        $types = 'ii' . str_repeat('s', count($statuses));
        $params = array_merge([$assignmentId, $methodId], $statuses);

        $row = TaskCertDb::fetchOne(
            'SELECT * FROM task_submission
             WHERE assignment_id = ?
               AND method_id = ?
               AND status IN (' . $placeholders . ')
             ORDER BY id DESC
             LIMIT 1',
            $types,
            $params
        );

        if ($row === null) {
            return null;
        }

        $row['payload'] = $this->decodePayload($row['payload_json'] ?? null);
        unset($row['payload_json']);

        return $row;
    }

    public function listByAssignment(int $assignmentId): array
    {
        $rows = TaskCertDb::fetchAll(
            'SELECT s.*, m.method_type
             FROM task_submission s
             INNER JOIN task_method m ON m.id = s.method_id
             WHERE s.assignment_id = ?
             ORDER BY s.id DESC',
            'i',
            [$assignmentId]
        );

        foreach ($rows as &$row) {
            $row['payload'] = $this->decodePayload($row['payload_json'] ?? null);
            unset($row['payload_json']);
        }

        return $rows;
    }

    public function listAssignmentIdsWithSubmissions(array $assignmentIds): array
    {
        $assignmentIds = array_values(array_unique(array_map('intval', $assignmentIds)));
        $assignmentIds = array_values(array_filter($assignmentIds, static function (int $assignmentId): bool {
            return $assignmentId > 0;
        }));

        if ($assignmentIds === []) {
            return [];
        }

        $placeholders = implode(',', array_fill(0, count($assignmentIds), '?'));
        $rows = TaskCertDb::fetchAll(
            'SELECT DISTINCT assignment_id
             FROM task_submission
             WHERE assignment_id IN (' . $placeholders . ')',
            str_repeat('i', count($assignmentIds)),
            $assignmentIds
        );

        $result = [];
        foreach ($rows as $row) {
            $assignmentId = (int) ($row['assignment_id'] ?? 0);
            if ($assignmentId <= 0) {
                continue;
            }

            $result[] = $assignmentId;
        }

        $result = array_values(array_unique($result));
        sort($result);

        return $result;
    }

    public function hasApprovedOrAutoPassedForMethod(int $assignmentId, int $methodId): bool
    {
        $count = TaskCertDb::scalar(
            'SELECT COUNT(*)
             FROM task_submission
             WHERE assignment_id = ?
               AND method_id = ?
               AND status IN ("auto_passed", "approved")',
            'ii',
            [$assignmentId, $methodId]
        );

        return (int) $count > 0;
    }

    public function listPendingApprovals(int $taskId = 0, string $searchQuery = ''): array
    {
        $searchQuery = trim($searchQuery);

        $sql = 'SELECT
            s.*,
            m.method_type,
            a.task_id,
            a.cycle_key,
            d.title AS task_title,
            c.name AS contact_name,
            c.email AS contact_email
        FROM task_submission s
        INNER JOIN task_method m ON m.id = s.method_id
        INNER JOIN task_assignment a ON a.id = s.assignment_id
        INNER JOIN task_definition d ON d.id = a.task_id
        LEFT JOIN main_contact c ON c.id = s.main_contact_id
        WHERE s.status = "awaiting_approval"';

        $types = '';
        $params = [];
        if ($taskId > 0) {
            $sql .= ' AND a.task_id = ?';
            $types .= 'i';
            $params[] = $taskId;
        }

        if ($searchQuery !== '') {
            $searchLike = '%' . $searchQuery . '%';
            $sql .= ' AND (
                CAST(s.id AS CHAR) LIKE ?
                OR d.title LIKE ?
                OR COALESCE(c.name, "") LIKE ?
                OR COALESCE(c.email, "") LIKE ?
                OR m.method_type LIKE ?
            )';
            $types .= 'sssss';
            $params[] = $searchLike;
            $params[] = $searchLike;
            $params[] = $searchLike;
            $params[] = $searchLike;
            $params[] = $searchLike;
        }

        $sql .= ' ORDER BY s.submitted_at ASC, s.id ASC';

        $rows = TaskCertDb::fetchAll($sql, $types, $params);
        foreach ($rows as &$row) {
            $row['payload'] = $this->decodePayload($row['payload_json'] ?? null);
            unset($row['payload_json']);
        }

        return $rows;
    }

    public function review(int $submissionId, string $newStatus, int $adminId, string $note): void
    {
        TaskCertDb::execute(
            'UPDATE task_submission
             SET status = ?, reviewed_by = ?, reviewed_at = NOW(), review_note = ?
             WHERE id = ?',
            'sisi',
            [$newStatus, $adminId, $note, $submissionId]
        );
    }

    /**
     * Sammelt alle in den Payloads referenzierten Datei-Pfade (form_values mit
     * file_path) für die gegebenen Assignments — damit der Aufrufer die Dateien
     * vor dem Löschen der Einreichungen von der Platte entfernen kann.
     *
     * @return string[] eindeutige relative Pfade
     */
    public function collectFilePathsByAssignmentIds(array $assignmentIds): array
    {
        $assignmentIds = array_values(array_unique(array_map('intval', $assignmentIds)));
        $assignmentIds = array_values(array_filter($assignmentIds, static function (int $assignmentId): bool {
            return $assignmentId > 0;
        }));

        if ($assignmentIds === []) {
            return [];
        }

        $placeholders = implode(',', array_fill(0, count($assignmentIds), '?'));
        $rows = TaskCertDb::fetchAll(
            'SELECT payload_json FROM task_submission WHERE assignment_id IN (' . $placeholders . ')',
            str_repeat('i', count($assignmentIds)),
            $assignmentIds
        );

        return $this->extractFilePathsFromRows($rows);
    }

    /**
     * Wie collectFilePathsByAssignmentIds, aber für alle Einreichungen einer
     * Aufgabe (für das harte Löschen, das per FK-CASCADE die Zeilen entfernt).
     *
     * @return string[] eindeutige relative Pfade
     */
    public function collectFilePathsByTaskId(int $taskId): array
    {
        if ($taskId <= 0) {
            return [];
        }

        $rows = TaskCertDb::fetchAll(
            'SELECT s.payload_json
             FROM task_submission s
             INNER JOIN task_assignment a ON a.id = s.assignment_id
             WHERE a.task_id = ?',
            'i',
            [$taskId]
        );

        return $this->extractFilePathsFromRows($rows);
    }

    private function extractFilePathsFromRows(array $rows): array
    {
        $paths = [];
        foreach ($rows as $row) {
            $payload = $this->decodePayload($row['payload_json'] ?? null);
            $formValues = is_array($payload['form_values'] ?? null) ? $payload['form_values'] : [];

            foreach ($formValues as $value) {
                if (!is_array($value)) {
                    continue;
                }

                foreach ($value as $fileMeta) {
                    if (is_array($fileMeta) && isset($fileMeta['file_path'])) {
                        $path = trim((string) $fileMeta['file_path']);
                        if ($path !== '') {
                            $paths[$path] = true;
                        }
                    }
                }
            }
        }

        return array_keys($paths);
    }

    public function deleteByAssignmentIds(array $assignmentIds): int
    {
        $assignmentIds = array_values(array_unique(array_map('intval', $assignmentIds)));
        $assignmentIds = array_values(array_filter($assignmentIds, static function (int $assignmentId): bool {
            return $assignmentId > 0;
        }));

        if ($assignmentIds === []) {
            return 0;
        }

        $placeholders = implode(',', array_fill(0, count($assignmentIds), '?'));

        return TaskCertDb::execute(
            'DELETE FROM task_submission
             WHERE assignment_id IN (' . $placeholders . ')',
            str_repeat('i', count($assignmentIds)),
            $assignmentIds
        );
    }

    private function decodePayload(?string $json): array
    {
        if ($json === null || trim($json) === '') {
            return [];
        }

        $decoded = json_decode($json, true);
        return is_array($decoded) ? $decoded : [];
    }
}