<?php

/**
 * ticket_comment_api.php — Bearer-key endpoint to post a comment on a ticket.
 *
 * POST only. Requires 'read_write' scope.
 *
 * Identity = PER-KEY LABEL: the comment author (ticket_comments.user_name) is the
 * API key's key_name and the linked user_id is the key's created_by.
 *
 * Body (JSON): {
 *   "ticket_id":        "NNN"   (required),
 *   "comment_text":     "..."   (required, non-empty),
 *   "markdown_enabled": bool     (optional)
 * }
 * Response: {success:true, comment_id:...}
 */

header('Content-Type: application/json');

error_reporting(E_ALL);
ini_set('display_errors', 0);

require_once dirname(__DIR__) . '/middleware/RateLimitMiddleware.php';
RateLimitMiddleware::apply('api');

require_once dirname(__DIR__) . '/config/config.php';
require_once dirname(__DIR__) . '/helpers/Database.php';
require_once dirname(__DIR__) . '/middleware/ApiKeyAuth.php';
require_once dirname(__DIR__) . '/models/TicketModel.php';
require_once dirname(__DIR__) . '/models/CommentModel.php';
require_once dirname(__DIR__) . '/models/AuditLogModel.php';

try {
    $conn = Database::getConnection();
} catch (Throwable $e) {
    error_log('ticket_comment_api: DB connection failed: ' . $e->getMessage());
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => 'Internal server error']);
    exit;
}

$apiKeyAuth = new ApiKeyAuth($conn);

try {
    $apiKeyAuth->authenticate();
} catch (Exception $e) {
    // ApiKeyAuth already sent the 401 response.
    exit;
}

// Posting a comment is a write — reject 'read' keys with 403 before any mutation.
$apiKeyAuth->requireScope('read_write');

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => 'Method not allowed. Use POST.']);
    exit;
}

$context = $apiKeyAuth->getKeyContext();
$keyName = $context['key_name'] ?? 'API';
$createdBy = ($context['created_by'] ?? null) !== null ? (int)$context['created_by'] : null;

$rawInput = file_get_contents('php://input');
$data = json_decode($rawInput, true);
if (!is_array($data)) {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => 'Invalid JSON body']);
    exit;
}

$ticketId = isset($data['ticket_id']) ? trim((string)$data['ticket_id']) : '';
if ($ticketId === '') {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => 'ticket_id is required']);
    exit;
}

$commentText = isset($data['comment_text']) ? trim((string)$data['comment_text']) : '';
if ($commentText === '') {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => 'comment_text is required']);
    exit;
}

$markdownEnabled = !empty($data['markdown_enabled']);

// Validate the ticket exists.
$ticketModel = new TicketModel($conn);
$ticket = $ticketModel->getTicketById($ticketId);
if (!$ticket) {
    http_response_code(404);
    echo json_encode(['success' => false, 'error' => 'Ticket not found']);
    exit;
}

// Post the comment under the key's label / owner.
$commentModel = new CommentModel($conn);
$result = $commentModel->addComment($ticketId, [
    'user_name' => $keyName,
    'comment_text' => $commentText,
    'markdown_enabled' => $markdownEnabled,
], $createdBy);

if (empty($result['success'])) {
    error_log('ticket_comment_api: addComment failed for ticket ' . $ticketId
        . ': ' . ($result['error'] ?? 'unknown'));
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => 'Failed to add comment']);
    exit;
}

$commentId = $result['comment_id'] ?? null;

// Audit trail (action 'comment' / entity 'comment' are both whitelisted).
$auditLog = new AuditLogModel($conn);
$auditLog->log($createdBy, 'comment', 'comment', (string)$commentId, [
    'ticket_id' => $ticketId,
    'key_name' => $keyName,
    'via_api' => true,
]);

echo json_encode(['success' => true, 'comment_id' => $commentId]);
exit;