<?php
declare(strict_types=1);

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

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

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

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

if ($memberId === '') {
    http_response_code(401);
    echo json_encode(['success' => false, 'message' => 'not_logged_in'], JSON_UNESCAPED_UNICODE);
    exit;
}

try {
    $pdo = db_conn();

    if ($sysCompCode === '') {
        $stmtComp = $pdo->prepare('SELECT sys_comp_code FROM edu_users WHERE member_id = ? ORDER BY sys_comp_code LIMIT 1');
        $stmtComp->execute([$memberId]);
        $sysCompCode = (string)($stmtComp->fetchColumn() ?: '');
    }

    if ($sysCompCode === '') {
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'sys_comp_code_missing'], JSON_UNESCAPED_UNICODE);
        exit;
    }

    $input = json_decode((string)file_get_contents('php://input'), true) ?: [];
    $goalCode = trim((string)($input['goal_code'] ?? ''));
    $quarter = trim((string)($input['quarter'] ?? ''));

    if ($goalCode === '') {
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'goal_code_required'], JSON_UNESCAPED_UNICODE);
        exit;
    }

    if ($quarter !== '') {
        $stmtGoal = $pdo->prepare('SELECT goal_code, quarter FROM edu_learning_goals WHERE is_active = \'1\' AND goal_code = ? AND quarter = ? LIMIT 1');
        $stmtGoal->execute([$goalCode, $quarter]);
    } else {
        $stmtGoal = $pdo->prepare('SELECT goal_code, quarter FROM edu_learning_goals WHERE is_active = \'1\' AND goal_code = ? LIMIT 1');
        $stmtGoal->execute([$goalCode]);
    }

    $goalRow = $stmtGoal->fetch(PDO::FETCH_ASSOC);
    if (!$goalRow) {
        http_response_code(404);
        echo json_encode(['success' => false, 'message' => 'goal_not_found'], JSON_UNESCAPED_UNICODE);
        exit;
    }

    $goalCode = (string)$goalRow['goal_code'];
    $quarter = trim((string)($goalRow['quarter'] ?? $quarter));

    $pdo->beginTransaction();

    if ($quarter !== '') {
        $stmtDeactivate = $pdo->prepare(
            'UPDATE edu_user_learning_goals
             SET is_active = \'0\', updated_by = ?, updated_at = NOW()
             WHERE member_id = ?
               AND sys_comp_code = ?
               AND quarter = ?
               AND goal_code <> ?
               AND is_active = \'1\'
               AND (completed_date IS NULL OR completed_date = \'0000-00-00\')'
        );
        $stmtDeactivate->execute([$memberId, $memberId, $sysCompCode, $quarter, $goalCode]);
    }

    $stmtExists = $pdo->prepare(
        'SELECT 1
         FROM edu_user_learning_goals
         WHERE member_id = ?
           AND sys_comp_code = ?
           AND goal_code = ?
         LIMIT 1'
    );
    $stmtExists->execute([$memberId, $sysCompCode, $goalCode]);
    $exists = (bool)$stmtExists->fetchColumn();

    if ($exists) {
        $stmtUp = $pdo->prepare(
            'UPDATE edu_user_learning_goals
             SET quarter = ?, is_active = \'1\', updated_by = ?, updated_at = NOW()
             WHERE member_id = ?
               AND sys_comp_code = ?
               AND goal_code = ?'
        );
        $stmtUp->execute([$quarter, $memberId, $memberId, $sysCompCode, $goalCode]);
    } else {
        $stmtIn = $pdo->prepare(
            'INSERT INTO edu_user_learning_goals
             (member_id, sys_comp_code, goal_code, quarter, is_active, created_by, created_at, updated_by, updated_at)
             VALUES (?, ?, ?, ?, \'1\', ?, NOW(), ?, NOW())'
        );
        $stmtIn->execute([$memberId, $sysCompCode, $goalCode, $quarter, $memberId, $memberId]);
    }

    $pdo->commit();

    echo json_encode([
        'success' => true,
        'member_id' => $memberId,
        'sys_comp_code' => $sysCompCode,
        'goal_code' => $goalCode,
        'quarter' => $quarter,
    ], JSON_UNESCAPED_UNICODE);
} catch (Throwable $e) {
    if (isset($pdo) && $pdo instanceof PDO && $pdo->inTransaction()) {
        $pdo->rollBack();
    }
    error_log('[save_user_learning_goal] ' . $e->getMessage());
    http_response_code(500);
    echo json_encode(['success' => false, 'message' => 'server_error'], JSON_UNESCAPED_UNICODE);
}