const Vue = require('vue');
const VueI18n = require('vue-i18n');
const renderer = require('vue-server-renderer').createRenderer();
const fs = require('fs-extra');
// const pdf = require('phantom-html2pdf');
const pdf = require('html-pdf');
const juice = require('juice');

Vue.use(VueI18n);

if (!process.env.OPENSSL_CONF)
    process.env.OPENSSL_CONF = '/etc/ssl/';

module.exports = {

    path: `${appPath}/report`,

    /**
     * Renders a report component
     *
     * @param {String} name - Report name
     * @param {Object} ctx - Request context
     */
    async render(name, ctx) {
        const component = require(`${this.path}/${name}`);
        const result = await this.preFetch(component, ctx);
        const i18n = new VueI18n({
            locale: 'es',
            fallbackLocale: 'es'
        });
        const app = new Vue({i18n,
            render: h => h(result.component)});

        return renderer.renderToString(app);
    },

    /**
     * Prefetch all component data from asyncData method
     *
     * @param {Object} orgComponent - Component object
     * @param {Object} ctx - Request context
     */
    async preFetch(orgComponent, ctx) {
        let component = Object.create(orgComponent);
        let mergedData = {};
        let asyncData = {};
        let data = {};
        let params = {};

        if (Object.keys(ctx.body).length > 0)
            params = ctx.body;

        if (Object.keys(ctx.query).length > 0)
            params = ctx.query;

        await this.attachAssets(component);

        if (orgComponent.hasOwnProperty('data'))
            data = orgComponent.data();

        if (orgComponent.hasOwnProperty('asyncData'))
            asyncData = await orgComponent.asyncData(ctx, params);

        mergedData = Object.assign(mergedData, data, asyncData);

        component.data = function data() {
            return mergedData;
        };

        const components = orgComponent.components;
        if (components) {
            const promises = [];
            const childNames = [];
            component.components = {};

            Object.keys(components).forEach(childName => {
                childNames.push(childName);
                promises.push(this.preFetch(components[childName], ctx));
            });

            await Promise.all(promises).then(results => {
                results.forEach((result, i) => {
                    component.components[childNames[i]] = result.component;
                });
            });
        }

        return {component};
    },

    async attachAssets(component) {
        const localePath = `${this.path}/${component.name}/locale`;
        const templatePath = `${this.path}/${component.name}/index.html`;
        const stylePath = `${this.path}/${component.name}/assets/css/index`;

        const template = await fs.readFile(templatePath, 'utf8');
        const css = require(stylePath);
        const cssOptions = {inlinePseudoElements: true};

        component.i18n = require(localePath);
        component.template = juice.inlineContent(template, css, cssOptions);
    },

    async toPdf(name, ctx) {
        const html = await this.render(name, ctx);
        const options = {
            format: 'A4',
            border: '1.5cm',
            footer: {
                height: '60px',
            }
        };

        return new Promise(resolve => {
            pdf.create(html, options).toStream((err, stream) => {
                resolve(stream);
            });
        });
    },
};