import { WechatReceivedBaseMessage } from "../types/received-message";

export interface WechatReplyBuilderOptions {
    /** 接收方账号(收到的OpenID) */
    toUserName: string;
    /** 发送方账号(公众号微信号) */
    fromUserName: string;

    /** 消息创建时间(整型) */
    createTime: number;
}

/**
 * 微信被动回复消息构造器
 * 
 * - 微信公众号/服务号被动回复用户消息时使用
 * - 对应微信官方XML消息结构
 * 
 * @see 微信官方文档: [被动回复用户消息](https://developers.weixin.qq.com/doc/service/guide/product/message/Passive_user_reply_message.html)
 */
export class WechatReplyBuilder {
    /** 接收方账号(收到的OpenID) */
    private toUserName: string;
    /** 发送方账号(公众号微信号) */
    private fromUserName: string
    /** 消息创建时间(整型) */
    private createTime: number;

    /**
     * WechatReplyBuilder 构造函数
     * 
     * @param options WechatReplyBuilderOptions 配置项
     */
    private constructor(options: WechatReplyBuilderOptions) {
        const {
            toUserName,
            fromUserName,
            createTime,
        } = options;

        this.toUserName = toUserName;
        this.fromUserName = fromUserName;
        this.createTime = createTime;
    }

    static fromReceivedMessage(msg: WechatReceivedBaseMessage): WechatReplyBuilder {
        return new WechatReplyBuilder({
            toUserName: msg.FromUserName,
            fromUserName: msg.ToUserName,
            createTime: Date.now(),
        });
    }

    static fromOptions(options: Omit<WechatReplyBuilderOptions, "createTime"> & {
        createTime?: number;
    }): WechatReplyBuilder {
        return new WechatReplyBuilder({
            ...options,
            createTime: options.createTime ?? Date.now(),
        });
    }

    /**
     * 构造文本消息回复XML
     * 
     * @param content 文本消息内容
     * @returns 文本消息回复XML字符串
     */
    buildTextReply(content: string): string {
        return `<xml>
        <ToUserName><![CDATA[${this.toUserName}]]></ToUserName>
        <FromUserName><![CDATA[${this.fromUserName}]]></FromUserName>
        <CreateTime>${this.createTime}</CreateTime>
        <MsgType><![CDATA[text]]></MsgType>
        <Content><![CDATA[${content}]]></Content>
      </xml>`;
    }

    /**
     * 构造图文消息回复XML
     * 
     * @param title 图文消息标题
     * @param description 图文消息描述
     * @param picUrl 图文消息图片链接
     * @param url 图文消息跳转链接
     * @returns 图文消息回复XML字符串
     */
    buildNewsReply(title: string, description: string, picUrl: string, url: string): string {
        return `<xml>
        <ToUserName><![CDATA[${this.toUserName}]]></ToUserName>
        <FromUserName><![CDATA[${this.fromUserName}]]></FromUserName>
        <CreateTime>${this.createTime}</CreateTime>
        <MsgType><![CDATA[news]]></MsgType>
        <ArticleCount>1</ArticleCount>
        <Articles>
          <item>
            <Title><![CDATA[${title}]]></Title>
            <Description><![CDATA[${description}]]></Description>
            <PicUrl><![CDATA[${picUrl}]]></PicUrl>
            <Url><![CDATA[${url}]]></Url>
          </item>
        </Articles>
      </xml>`;
    }
}