'use strict';

const AiDify = require('../lib/ai_dify');

/**
 * 全局业务查询助手
 *
 * @param {Object} app Egg应用
 * @return {Object} 助手Controller
 * @author Codex
 */
module.exports = app => {
    class AssistantController extends app.BaseController {
        /**
         * 查询业务数据
         *
         * @param {Object} ctx - egg全局页面
         * @return {void}
         */
        async query(ctx) {
            try {
                const data = JSON.parse(ctx.request.body.data || '{}');
                const question = data.question ? data.question.trim() : '';
                if (!question) throw '请输入要查询的内容';
                if (question.length > 200) throw '问题不能超过200个字符';
                ctx.body = {
                    err: 0,
                    msg: '',
                    data: await ctx.service.assistant.query(question, data.context || {}),
                };
            } catch (err) {
                console.log(err);
                this.log(err);
                ctx.body = this.ajaxErrorBody(err, '助手查询失败');
            }
        }

        /** v2：Chatflow 分类和解析，共用 assistant Service 的业务查询。 */
        async queryV2(ctx) {
            try {
                const data = JSON.parse(ctx.request.body.data || '{}');
                const question = typeof data.question === 'string' ? data.question.trim() : '';
                if (!question) throw '请输入要查询的内容';
                if (question.length > 200) throw '问题不能超过200个字符';
                const sessionUser = ctx.session.sessionUser;
                if (sessionUser.loginType === 4) throw '游客账号暂不支持使用查询助手';
                const context = data.context && typeof data.context === 'object' ? data.context : {};
                const path = typeof context.path === 'string' ? context.path.split(/[?#]/)[0] : '';
                if (path.length > 1024 || (path && !/^\/(?!\/)/.test(path))) throw '页面路径不正确';
                const conversationId = data.conversationId || '';
                if (typeof conversationId !== 'string' || (conversationId && !/^[a-f0-9-]{36}$/i.test(conversationId))) {
                    throw '助手会话参数不正确，请清空对话后重试';
                }
                const config = app.config.difyInfo;
                if (!config || !config.apiKey || !config.apiKey.assistant || !config.baseUrl) throw '尚未配置查询助手 Chatflow';
                const dify = new AiDify({ baseUrl: config.baseUrl, apiKey: config.apiKey.assistant });
                // 会话归属由 Dify 按服务端生成的 user 校验，不能使用客户端传入的用户 ID。
                const user = `assistant-${app.config.env}-${ctx.session.sessionProject.id}-${sessionUser.accountId}`;
                let response;
                try {
                    response = await dify.askAssistant({ question, path, user, conversationId });
                } catch (err) {
                    // ai_dify 已将网络错误转换为不含密钥、请求正文的安全提示。
                    throw err.message;
                }
                const parsed = response.result;
                let result = {
                    answer: parsed.answer,
                    summary: [],
                    items: parsed.sources.filter(source => source && typeof source.title === 'string' &&
                        typeof source.url === 'string' && /^https?:\/\//i.test(source.url))
                        .slice(0, 20).map(source => ({ title: source.title, url: source.url })),
                    suggestions: [],
                };
                if (parsed.type === 'business' && parsed.status === 'query') {
                    try {
                        result = await ctx.service.assistant.queryParameters(parsed.query, Object.assign({}, context, { path }));
                    } catch (err) {
                        this.log(err);
                        // 保留已完成解析的会话，让用户能补充标段、期号等条件。
                        result = { answer: typeof err === 'string' ? err : '业务查询失败，请稍后重试。', summary: [], items: [], suggestions: [] };
                    }
                }
                result.conversationId = response.conversationId;
                ctx.body = { err: 0, msg: '', data: result };
            } catch (err) {
                console.log(err);
                this.log(err);
                ctx.body = this.ajaxErrorBody(err, '助手查询失败');
            }
        }

        /** 下载查询助手返回的统一附件。 */
        async attachment(ctx) {
            try {
                const file = await ctx.service.assistant.getAttachmentFile(ctx.params.source, ctx.params.id);
                const disposition = `attachment; filename*=UTF-8''${encodeURIComponent(file.filename)}`;
                const headers = {
                    'Content-Type': 'application/octet-stream',
                    'Content-Disposition': disposition,
                };
                if (/^[1-9]\d*$/.test(String(file.filesize))) headers['Content-Length'] = file.filesize;
                ctx.response.set(headers);
                ctx.body = await ctx.helper.ossFileGet(file.filepath);
            } catch (err) {
                this.log(err);
                ctx.status = 404;
                ctx.body = this.ajaxErrorBody(err, '附件下载失败');
            }
        }
    }

    return AssistantController;
};