<?php
/**
 * 邮件管理API
 */

// 设置错误报告
error_reporting(E_ALL);
ini_set('display_errors', 0);

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

// 包含必要的类
require_once '../../utils/Config.php';
require_once '../../utils/Logger.php';
require_once '../../utils/Helper.php';
require_once '../../utils/Database.php';

// 处理请求
try {
    // 获取请求方法
    $method = $_SERVER['REQUEST_METHOD'] ?? 'GET';
    
    // 连接数据库
    $db = Database::getInstance();
    
    // 根据请求方法处理
    switch ($method) {
        case 'GET':
            // 获取邮件列表或邮件详情
            if (isset($_GET['id'])) {
                // 获取邮件详情
                getEmailDetails($db, $_GET['id']);
            } else {
                // 获取邮件列表
                getEmailList($db);
            }
            break;
        case 'POST':
            // 发送邮件或保存草稿
            saveEmail($db);
            break;
        case 'PUT':
            // 更新邮件（标记为已读/未读、移动文件夹等）
            updateEmail($db);
            break;
        case 'DELETE':
            // 删除邮件
            deleteEmail($db);
            break;
        default:
            echo json_encode([
                'success' => false,
                'message' => '不支持的请求方法'
            ]);
            break;
    }
} catch (Exception $e) {
    echo json_encode([
        'success' => false,
        'message' => '服务器内部错误: ' . $e->getMessage()
    ]);
}

/**
 * 获取邮件列表
 * @param Database $db 数据库实例
 */
function getEmailList($db) {
    // 获取请求参数
    $page = isset($_GET['page']) ? (int)$_GET['page'] : 1;
    $perPage = isset($_GET['perPage']) ? (int)$_GET['perPage'] : 10;
    $folder = isset($_GET['folder']) ? $_GET['folder'] : 'inbox';
    $search = isset($_GET['search']) ? $_GET['search'] : '';
    $isRead = isset($_GET['isRead']) ? $_GET['isRead'] : null;
    $username = isset($_GET['username']) ? $_GET['username'] : '';
    
    // 验证必要参数
    if (empty($username)) {
        echo json_encode([
            'success' => false,
            'message' => '缺少用户名参数'
        ]);
        return;
    }
    
    // 构建查询条件
    $where = "WHERE rcpt_to = (SELECT email FROM user WHERE username = ?) AND folder = ? AND is_deleted = 0";
    $params = [$username, $folder];
    
    if (!empty($search)) {
        $where .= " AND (subject LIKE ? OR `from` LIKE ? OR `to` LIKE ?)";
        $searchParam = "%$search%";
        $params[] = $searchParam;
        $params[] = $searchParam;
        $params[] = $searchParam;
    }
    
    if ($isRead !== null) {
        $where .= " AND is_read = ?";
        $params[] = (int)$isRead;
    }
    
    // 计算偏移量
    $offset = ($page - 1) * $perPage;
    
    // 查询总数
    $totalSql = "SELECT COUNT(*) as total FROM email $where";
    $totalResult = $db->fetchOne($totalSql, $params);
    $total = $totalResult['total'];
    
    // 查询邮件列表
    $sql = "SELECT id, `from`, `to`, subject, date, folder, is_read, is_deleted FROM email $where ORDER BY date DESC LIMIT ? OFFSET ?";
    $params[] = $perPage;
    $params[] = $offset;
    
    $emails = $db->fetchAll($sql, $params);
    
    // 返回响应
    echo json_encode([
        'success' => true,
        'data' => [
            'emails' => $emails,
            'total' => $total,
            'page' => $page,
            'perPage' => $perPage,
            'totalPages' => ceil($total / $perPage)
        ]
    ]);
}

/**
 * 获取邮件详情
 * @param Database $db 数据库实例
 * @param string $id 邮件ID
 */
function getEmailDetails($db, $id) {
    // 获取请求参数
    $username = isset($_GET['username']) ? $_GET['username'] : '';
    
    // 验证必要参数
    if (empty($username)) {
        echo json_encode([
            'success' => false,
            'message' => '缺少用户名参数'
        ]);
        return;
    }
    
    // 查询邮件详情
    $sql = "SELECT * FROM email WHERE id = ? AND rcpt_to = (SELECT email FROM user WHERE username = ?)";
    $email = $db->fetchOne($sql, [$id, $username]);
    
    if ($email) {
        // 标记为已读
        if (!$email['is_read']) {
            $db->execute("UPDATE email SET is_read = 1 WHERE id = ?", [$id]);
            $email['is_read'] = 1;
        }
        
        echo json_encode([
            'success' => true,
            'data' => [
                'email' => $email
            ]
        ]);
    } else {
        echo json_encode([
            'success' => false,
            'message' => '邮件不存在或无权访问'
        ]);
    }
}

/**
 * 发送邮件或保存草稿
 * @param Database $db 数据库实例
 */
function saveEmail($db) {
    // 获取请求数据
    $data = json_decode(file_get_contents('php://input'), true);
    
    // 验证请求数据
    if (!$data || empty($data['username']) || empty($data['to']) || empty($data['subject'])) {
        echo json_encode([
            'success' => false,
            'message' => '缺少必要参数'
        ]);
        return;
    }
    
    // 获取用户邮箱
    $user = $db->fetchOne("SELECT email FROM user WHERE username = ?", [$data['username']]);
    if (!$user) {
        echo json_encode([
            'success' => false,
            'message' => '用户不存在'
        ]);
        return;
    }
    
    // 构建邮件数据
    $emailData = [
        'id' => uniqid(),
        'from' => $user['email'],
        'to' => $data['to'],
        'subject' => $data['subject'],
        'date' => date('Y-m-d H:i:s'),
        'content' => isset($data['content']) ? $data['content'] : '',
        'folder' => isset($data['isDraft']) && $data['isDraft'] ? 'draft' : 'sent',
        'is_read' => 1, // 已发送的邮件自动标记为已读
        'is_deleted' => 0,
        'created_at' => date('Y-m-d H:i:s')
    ];
    
    // 保存邮件到email表
    $sql = "INSERT INTO email (id, `from`, `to`, subject, date, data, folder, is_read, is_deleted, created_at, mail_from, rcpt_to) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
    
    $db->insert($sql, [
        $emailData['id'],
        $emailData['from'],
        $emailData['to'],
        $emailData['subject'],
        $emailData['date'],
        $emailData['content'],
        $emailData['folder'],
        $emailData['is_read'],
        $emailData['is_deleted'],
        $emailData['created_at'],
        $emailData['from'],
        $emailData['to']
    ]);
    
    echo json_encode([
        'success' => true,
        'message' => isset($data['isDraft']) && $data['isDraft'] ? '草稿保存成功' : '邮件发送成功',
        'data' => [
            'emailId' => $emailData['id']
        ]
    ]);
}

/**
 * 更新邮件（标记为已读/未读、移动文件夹等）
 * @param Database $db 数据库实例
 */
function updateEmail($db) {
    // 获取请求数据
    $data = json_decode(file_get_contents('php://input'), true);
    
    // 验证请求数据
    if (!$data || empty($data['id']) || empty($data['username'])) {
        echo json_encode([
            'success' => false,
            'message' => '缺少必要参数'
        ]);
        return;
    }
    
    // 构建更新字段
    $updateFields = [];
    $params = [];
    
    if (isset($data['isRead'])) {
        $updateFields[] = "is_read = ?";
        $params[] = (int)$data['isRead'];
    }
    
    if (isset($data['folder'])) {
        $updateFields[] = "folder = ?";
        $params[] = $data['folder'];
    }
    
    if (empty($updateFields)) {
        echo json_encode([
            'success' => false,
            'message' => '没有需要更新的字段'
        ]);
        return;
    }
    
    // 添加邮件ID和用户名参数
    $params[] = $data['id'];
    $params[] = $data['username'];
    
    // 更新邮件
    $sql = "UPDATE email SET " . implode(', ', $updateFields) . " WHERE id = ? AND rcpt_to = (SELECT email FROM user WHERE username = ?)";
    
    $db->execute($sql, $params);
    
    echo json_encode([
        'success' => true,
        'message' => '邮件更新成功'
    ]);
}

/**
 * 删除邮件
 * @param Database $db 数据库实例
 */
function deleteEmail($db) {
    // 获取请求参数
    $id = isset($_GET['id']) ? $_GET['id'] : '';
    $username = isset($_GET['username']) ? $_GET['username'] : '';
    
    // 验证必要参数
    if (empty($id) || empty($username)) {
        echo json_encode([
            'success' => false,
            'message' => '缺少必要参数'
        ]);
        return;
    }
    
    // 软删除邮件
    $sql = "UPDATE email SET is_deleted = 1, folder = 'trash' WHERE id = ? AND rcpt_to = (SELECT email FROM user WHERE username = ?)";
    
    $db->execute($sql, [$id, $username]);
    
    echo json_encode([
        'success' => true,
        'message' => '邮件删除成功'
    ]);
}