<?php
declare(strict_types=1);

header('Content-Type: application/json; charset=utf-8');

$debugLog = dirname(__DIR__) . '/_save_comment_debug.log';

require_once dirname(__DIR__) . '/db_conn.php';

if (session_status() !== PHP_SESSION_ACTIVE) {
	session_start();
}

$memberId = (string)($_SESSION['member_id'] ?? '');
$sysCompCode = (string)($_SESSION['sys_comp_code'] ?? '');

file_put_contents($debugLog, "[" . date('Y-m-d H:i:s') . "] REQUEST START\n", FILE_APPEND);
file_put_contents($debugLog, "SESSION: member_id={$memberId}, sys_comp_code={$sysCompCode}\n", FILE_APPEND);

if ($memberId === '') {
	file_put_contents($debugLog, "ERROR: member_id is empty\n", FILE_APPEND);
	http_response_code(401);
	echo json_encode(['success' => false, 'message' => 'not_logged_in'], JSON_UNESCAPED_UNICODE);
	exit;
}

$input = json_decode((string)file_get_contents('php://input'), true);
if (!is_array($input)) {
	$input = $_POST;
}

file_put_contents($debugLog, "INPUT: " . json_encode($input, JSON_UNESCAPED_UNICODE) . "\n", FILE_APPEND);

$contentId = trim((string)($input['content_id'] ?? ''));
$comment = trim((string)($input['comment'] ?? ''));
$commentId = (int)($input['id'] ?? 0);

if ($contentId === '') {
	file_put_contents($debugLog, "ERROR: content_id is empty\n", FILE_APPEND);
	http_response_code(400);
	echo json_encode(['success' => false, 'message' => 'content_id_required'], JSON_UNESCAPED_UNICODE);
	exit;
}

if ($comment === '') {
	file_put_contents($debugLog, "ERROR: comment is empty\n", FILE_APPEND);
	http_response_code(400);
	echo json_encode(['success' => false, 'message' => 'comment_required'], JSON_UNESCAPED_UNICODE);
	exit;
}

if (function_exists('mb_substr')) {
	$comment = mb_substr($comment, 0, 255, 'UTF-8');
} else {
	$comment = substr($comment, 0, 255);
}

try {
	$pdo = db_conn();

	if ($sysCompCode === '') {
		file_put_contents($debugLog, "ERROR: sys_comp_code is empty\n", FILE_APPEND);
		http_response_code(401);
		echo json_encode(['success' => false, 'message' => 'sys_comp_code_missing'], JSON_UNESCAPED_UNICODE);
		exit;
	}

	$stmtCategory = $pdo->prepare('SELECT category_code FROM edu_contents WHERE content_id = ? LIMIT 1');
	$stmtCategory->execute([$contentId]);
	$categoryCode = strtoupper((string)($stmtCategory->fetchColumn() ?: ''));

	if ($categoryCode === '') {
		http_response_code(404);
		echo json_encode(['success' => false, 'message' => 'content_not_found'], JSON_UNESCAPED_UNICODE);
		exit;
	}

	$pdo->beginTransaction();

	$savedId = 0;
	$mode = 'insert';

	// ── 마이클래스(CA10001): edu_learning_histories.comment 컬럼에 UPDATE ──
	if ($categoryCode === 'CA10001') {
		$sqlLh = 'UPDATE edu_learning_histories SET comment = ? WHERE content_id = ? AND member_id = ? AND sys_comp_code = ?';
		$paramsLh = [$comment, $contentId, $memberId, $sysCompCode];
		$stmtLh = $pdo->prepare($sqlLh);
		$stmtLh->execute($paramsLh);

		if ($stmtLh->rowCount() < 1) {
			$pdo->rollBack();
			echo json_encode(['success' => false, 'message' => '학습 이력이 없어 소감을 저장할 수 없습니다.'], JSON_UNESCAPED_UNICODE);
			exit;
		}

		$pdo->commit();
		echo json_encode([
			'success'  => true,
			'mode'     => 'update',
			'category' => $categoryCode,
		], JSON_UNESCAPED_UNICODE);
		exit;
	}

	// ── 기타 카테고리: 기존 edu_comments 테이블 사용 ──
	if ($commentId > 0) {
		$stmtUpdate = $pdo->prepare(
			'UPDATE edu_comments
			 SET comment = ?, updated_by = ?, updated_at = NOW()
			 WHERE id = ? AND member_id = ? AND sys_comp_code = ?'
		);
		$stmtUpdate->execute([$comment, $memberId, $commentId, $memberId, $sysCompCode]);

		if ($stmtUpdate->rowCount() < 1) {
			$pdo->rollBack();
			http_response_code(403);
			echo json_encode(['success' => false, 'message' => 'forbidden_or_not_found'], JSON_UNESCAPED_UNICODE);
			exit;
		}

		$savedId = $commentId;
		$mode = 'update';
	} else {
		$stmtInsert = $pdo->prepare(
			'INSERT INTO edu_comments
			 (parent_id, sys_comp_code, member_id, comment, content_id, created_by, created_at, updated_by, updated_at)
			 VALUES (NULL, ?, ?, ?, ?, ?, NOW(), ?, NOW())'
		);
		$stmtInsert->execute([$sysCompCode, $memberId, $comment, $contentId, $memberId, $memberId]);
		$savedId = (int)$pdo->lastInsertId();
		$mode = 'insert';
	}

	$pdo->commit();

	echo json_encode([
		'success' => true,
		'id' => $savedId,
		'mode' => $mode,
		'category' => $categoryCode,
	], JSON_UNESCAPED_UNICODE);
} catch (Throwable $e) {
	if (isset($pdo) && $pdo instanceof PDO && $pdo->inTransaction()) {
		$pdo->rollBack();
	}
	error_log('[save_comment] ' . $e->getMessage());
	http_response_code(500);
	echo json_encode(['success' => false, 'message' => 'server_error'], JSON_UNESCAPED_UNICODE);
}