import SiteConfigModel from "../model/site-config"
import { logger } from "@/logger.js"

/**
 * 站点配置服务类
 * 提供站点配置相关的业务逻辑
 */
class SiteConfigService {
    /**
     * 获取配置值
     * @param {string} key - 配置键
     * @param {*} defaultValue - 默认值
     * @returns {Promise<*>} 配置值
     */
    static async get(key, defaultValue = null) {
        try {
            const value = await SiteConfigModel.get(key)
            return value !== null ? value : defaultValue
        } catch (error) {
            logger.error(`获取配置失败 (${key}):`, error)
            throw error
        }
    }

    /**
     * 设置配置值
     * @param {string} key - 配置键
     * @param {*} value - 配置值
     * @returns {Promise<Object>} 配置对象
     */
    static async set(key, value) {
        try {
            // 验证配置键
            this.validateConfigKey(key)
            
            // 序列化值
            const serializedValue = this.serializeValue(value)
            
            const config = await SiteConfigModel.set(key, serializedValue)
            
            logger.info(`配置设置成功: ${key}`)
            return this.formatConfigResponse(config)
        } catch (error) {
            logger.error(`设置配置失败 (${key}):`, error)
            throw error
        }
    }

    /**
     * 批量获取配置
     * @param {Array} keys - 配置键数组
     * @returns {Promise<Object>} 配置对象
     */
    static async getMany(keys) {
        try {
            if (!Array.isArray(keys) || keys.length === 0) {
                return {}
            }

            const configs = await SiteConfigModel.getMany(keys)
            
            // 反序列化值
            const result = {}
            for (const [key, value] of Object.entries(configs)) {
                result[key] = this.deserializeValue(value)
            }
            
            return result
        } catch (error) {
            logger.error(`批量获取配置失败:`, error)
            throw error
        }
    }

    /**
     * 获取所有配置
     * @returns {Promise<Object>} 所有配置
     */
    static async getAll() {
        try {
            const configs = await SiteConfigModel.getAll()
            
            // 反序列化值
            const result = {}
            for (const [key, value] of Object.entries(configs)) {
                result[key] = this.deserializeValue(value)
            }
            
            return result
        } catch (error) {
            logger.error(`获取所有配置失败:`, error)
            throw error
        }
    }

    /**
     * 批量设置配置
     * @param {Object} configs - 配置对象
     * @returns {Promise<Array>} 设置结果
     */
    static async setMany(configs) {
        try {
            if (!configs || typeof configs !== 'object') {
                throw new Error("配置对象不能为空")
            }

            const results = []
            for (const [key, value] of Object.entries(configs)) {
                try {
                    this.validateConfigKey(key)
                    const serializedValue = this.serializeValue(value)
                    const config = await SiteConfigModel.set(key, serializedValue)
                    results.push(this.formatConfigResponse(config))
                } catch (error) {
                    logger.error(`设置配置失败 (${key}):`, error)
                    results.push({ key, error: error.message })
                }
            }

            logger.info(`批量设置配置完成: ${Object.keys(configs).length} 个配置`)
            return results
        } catch (error) {
            logger.error(`批量设置配置失败:`, error)
            throw error
        }
    }

    /**
     * 删除配置
     * @param {string} key - 配置键
     * @returns {Promise<boolean>} 删除结果
     */
    static async delete(key) {
        try {
            const result = await SiteConfigModel.deleteByKey(key)
            
            logger.info(`配置删除成功: ${key}`)
            return result > 0
        } catch (error) {
            logger.error(`删除配置失败 (${key}):`, error)
            throw error
        }
    }

    /**
     * 检查配置是否存在
     * @param {string} key - 配置键
     * @returns {Promise<boolean>} 是否存在
     */
    static async has(key) {
        try {
            return await SiteConfigModel.hasKey(key)
        } catch (error) {
            logger.error(`检查配置是否存在失败 (${key}):`, error)
            throw error
        }
    }

    /**
     * 获取配置统计
     * @returns {Promise<Object>} 统计信息
     */
    static async getStats() {
        try {
            return await SiteConfigModel.getConfigStats()
        } catch (error) {
            logger.error(`获取配置统计失败:`, error)
            throw error
        }
    }

    /**
     * 获取站点基本信息配置
     * @returns {Promise<Object>} 站点基本信息
     */
    static async getSiteInfo() {
        try {
            const keys = [
                'site_name',
                'site_description',
                'site_keywords',
                'site_author',
                'site_url',
                'site_logo',
                'site_favicon',
                'site_theme',
                'site_language',
                'site_timezone'
            ]

            const configs = await this.getMany(keys)
            
            return {
                name: configs.site_name || '我的网站',
                description: configs.site_description || '',
                keywords: configs.site_keywords || '',
                author: configs.site_author || '',
                url: configs.site_url || '',
                logo: configs.site_logo || '',
                favicon: configs.site_favicon || '',
                theme: configs.site_theme || 'default',
                language: configs.site_language || 'zh-CN',
                timezone: configs.site_timezone || 'Asia/Shanghai'
            }
        } catch (error) {
            logger.error(`获取站点基本信息失败:`, error)
            throw error
        }
    }

    /**
     * 设置站点基本信息配置
     * @param {Object} siteInfo - 站点信息
     * @returns {Promise<Object>} 设置结果
     */
    static async setSiteInfo(siteInfo) {
        try {
            const configs = {}
            
            if (siteInfo.name) configs.site_name = siteInfo.name
            if (siteInfo.description) configs.site_description = siteInfo.description
            if (siteInfo.keywords) configs.site_keywords = siteInfo.keywords
            if (siteInfo.author) configs.site_author = siteInfo.author
            if (siteInfo.url) configs.site_url = siteInfo.url
            if (siteInfo.logo) configs.site_logo = siteInfo.logo
            if (siteInfo.favicon) configs.site_favicon = siteInfo.favicon
            if (siteInfo.theme) configs.site_theme = siteInfo.theme
            if (siteInfo.language) configs.site_language = siteInfo.language
            if (siteInfo.timezone) configs.site_timezone = siteInfo.timezone

            return await this.setMany(configs)
        } catch (error) {
            logger.error(`设置站点基本信息失败:`, error)
            throw error
        }
    }

    /**
     * 获取邮件配置
     * @returns {Promise<Object>} 邮件配置
     */
    static async getEmailConfig() {
        try {
            const keys = [
                'email_host',
                'email_port',
                'email_secure',
                'email_user',
                'email_password',
                'email_from',
                'email_name'
            ]

            const configs = await this.getMany(keys)
            
            return {
                host: configs.email_host || '',
                port: parseInt(configs.email_port) || 587,
                secure: configs.email_secure === 'true',
                user: configs.email_user || '',
                password: configs.email_password || '',
                from: configs.email_from || '',
                name: configs.email_name || ''
            }
        } catch (error) {
            logger.error(`获取邮件配置失败:`, error)
            throw error
        }
    }

    /**
     * 设置邮件配置
     * @param {Object} emailConfig - 邮件配置
     * @returns {Promise<Object>} 设置结果
     */
    static async setEmailConfig(emailConfig) {
        try {
            const configs = {}
            
            if (emailConfig.host) configs.email_host = emailConfig.host
            if (emailConfig.port) configs.email_port = emailConfig.port.toString()
            if (emailConfig.secure !== undefined) configs.email_secure = emailConfig.secure.toString()
            if (emailConfig.user) configs.email_user = emailConfig.user
            if (emailConfig.password) configs.email_password = emailConfig.password
            if (emailConfig.from) configs.email_from = emailConfig.from
            if (emailConfig.name) configs.email_name = emailConfig.name

            return await this.setMany(configs)
        } catch (error) {
            logger.error(`设置邮件配置失败:`, error)
            throw error
        }
    }

    /**
     * 获取系统配置
     * @returns {Promise<Object>} 系统配置
     */
    static async getSystemConfig() {
        try {
            const keys = [
                'maintenance_mode',
                'registration_enabled',
                'email_verification_required',
                'max_upload_size',
                'allowed_file_types',
                'session_timeout',
                'password_min_length',
                'login_attempts_limit'
            ]

            const configs = await this.getMany(keys)
            
            return {
                maintenanceMode: configs.maintenance_mode === 'true',
                registrationEnabled: configs.registration_enabled !== 'false',
                emailVerificationRequired: configs.email_verification_required === 'true',
                maxUploadSize: parseInt(configs.max_upload_size) || 10485760, // 10MB
                allowedFileTypes: configs.allowed_file_types ? configs.allowed_file_types.split(',') : ['jpg', 'jpeg', 'png', 'gif', 'pdf'],
                sessionTimeout: parseInt(configs.session_timeout) || 3600, // 1小时
                passwordMinLength: parseInt(configs.password_min_length) || 6,
                loginAttemptsLimit: parseInt(configs.login_attempts_limit) || 5
            }
        } catch (error) {
            logger.error(`获取系统配置失败:`, error)
            throw error
        }
    }

    /**
     * 设置系统配置
     * @param {Object} systemConfig - 系统配置
     * @returns {Promise<Object>} 设置结果
     */
    static async setSystemConfig(systemConfig) {
        try {
            const configs = {}
            
            if (systemConfig.maintenanceMode !== undefined) configs.maintenance_mode = systemConfig.maintenanceMode.toString()
            if (systemConfig.registrationEnabled !== undefined) configs.registration_enabled = systemConfig.registrationEnabled.toString()
            if (systemConfig.emailVerificationRequired !== undefined) configs.email_verification_required = systemConfig.emailVerificationRequired.toString()
            if (systemConfig.maxUploadSize) configs.max_upload_size = systemConfig.maxUploadSize.toString()
            if (systemConfig.allowedFileTypes) configs.allowed_file_types = Array.isArray(systemConfig.allowedFileTypes) ? systemConfig.allowedFileTypes.join(',') : systemConfig.allowedFileTypes
            if (systemConfig.sessionTimeout) configs.session_timeout = systemConfig.sessionTimeout.toString()
            if (systemConfig.passwordMinLength) configs.password_min_length = systemConfig.passwordMinLength.toString()
            if (systemConfig.loginAttemptsLimit) configs.login_attempts_limit = systemConfig.loginAttemptsLimit.toString()

            return await this.setMany(configs)
        } catch (error) {
            logger.error(`设置系统配置失败:`, error)
            throw error
        }
    }

    /**
     * 重置配置为默认值
     * @param {Array} keys - 要重置的配置键数组（可选，默认重置所有）
     * @returns {Promise<Object>} 重置结果
     */
    static async resetToDefaults(keys = null) {
        try {
            const defaultConfigs = {
                site_name: '我的网站',
                site_description: '欢迎来到我的网站',
                site_keywords: '网站,博客,个人网站',
                site_author: '网站管理员',
                site_url: 'http://localhost:3000',
                site_theme: 'default',
                site_language: 'zh-CN',
                site_timezone: 'Asia/Shanghai',
                maintenance_mode: 'false',
                registration_enabled: 'true',
                email_verification_required: 'false',
                max_upload_size: '10485760',
                allowed_file_types: 'jpg,jpeg,png,gif,pdf',
                session_timeout: '3600',
                password_min_length: '6',
                login_attempts_limit: '5'
            }

            const configsToReset = keys ? 
                Object.fromEntries(keys.filter(key => defaultConfigs[key]).map(key => [key, defaultConfigs[key]])) :
                defaultConfigs

            return await this.setMany(configsToReset)
        } catch (error) {
            logger.error(`重置配置为默认值失败:`, error)
            throw error
        }
    }

    /**
     * 验证配置键
     * @param {string} key - 配置键
     */
    static validateConfigKey(key) {
        if (!key || typeof key !== 'string') {
            throw new Error("配置键不能为空")
        }

        if (key.length > 100) {
            throw new Error("配置键长度不能超过100个字符")
        }

        if (!/^[a-zA-Z0-9_]+$/.test(key)) {
            throw new Error("配置键只能包含字母、数字和下划线")
        }
    }

    /**
     * 序列化值
     * @param {*} value - 要序列化的值
     * @returns {string} 序列化后的字符串
     */
    static serializeValue(value) {
        if (value === null || value === undefined) {
            return ''
        }

        if (typeof value === 'string') {
            return value
        }

        if (typeof value === 'number' || typeof value === 'boolean') {
            return value.toString()
        }

        return JSON.stringify(value)
    }

    /**
     * 反序列化值
     * @param {string} value - 要反序列化的字符串
     * @returns {*} 反序列化后的值
     */
    static deserializeValue(value) {
        if (value === null || value === undefined || value === '') {
            return null
        }

        // 尝试解析为JSON
        try {
            return JSON.parse(value)
        } catch (e) {
            // 如果不是有效的JSON，返回原字符串
            return value
        }
    }

    /**
     * 格式化配置响应数据
     * @param {Object} config - 配置数据
     * @returns {Object} 格式化后的配置数据
     */
    static formatConfigResponse(config) {
        return {
            ...config,
            // 确保数字字段为数字类型
            id: parseInt(config.id),
            // 反序列化值
            value: this.deserializeValue(config.value),
            // 格式化日期字段
            created_at: config.created_at,
            updated_at: config.updated_at
        }
    }

    /**
     * 导出配置
     * @returns {Promise<Object>} 导出的配置
     */
    static async exportConfig() {
        try {
            const configs = await this.getAll()
            return {
                exported_at: new Date().toISOString(),
                configs
            }
        } catch (error) {
            logger.error(`导出配置失败:`, error)
            throw error
        }
    }

    /**
     * 导入配置
     * @param {Object} configData - 配置数据
     * @returns {Promise<Object>} 导入结果
     */
    static async importConfig(configData) {
        try {
            if (!configData || !configData.configs) {
                throw new Error("无效的配置数据")
            }

            const results = await this.setMany(configData.configs)
            
            logger.info(`配置导入完成: ${Object.keys(configData.configs).length} 个配置`)
            return {
                success: results.filter(r => !r.error).length,
                failed: results.filter(r => r.error).length,
                results
            }
        } catch (error) {
            logger.error(`导入配置失败:`, error)
            throw error
        }
    }
}

export default SiteConfigService
export { SiteConfigService }