'use strict';
const path = require('path')
// 是否为生产环境
const isProduction = process.env.NODE_ENV !== 'development';

// gzip压缩
const CompressionWebpackPlugin = require('compression-webpack-plugin')
function resolve(dir) {
    return path.join(__dirname, dir)
}

module.exports = {
    publicPath: '',
    assetsDir: 'static',
    productionSourceMap: true,
    devServer: {
        proxy: {
            '/xxx': {  //项目名
                target: '',// 接口的域名
                secure: false, // 如果是https接口，需要配置这个参数为true
                changeOrigin: true,// 如果接口跨域，需要进行这个参数配置
            },
        } // 代理转发配置，用于调试环境
    },
    lintOnSave: false,  //去除eslint
    configureWebpack: config => {
        // 生产环境相关配置
        if (isProduction) {
            //gzip压缩
            const productionGzipExtensions = ['html', 'js', 'css']
            config.plugins.push(
                new CompressionWebpackPlugin({
                    filename: '[path].gz[query]',
                    algorithm: 'gzip',
                    test: new RegExp(
                        '\\.(' + productionGzipExtensions.join('|') + ')$'
                    ),
                    threshold: 10240, // 只有大小大于该值的资源会被处理 10240
                    minRatio: 0.8, // 只有压缩率小于这个值的资源才会被处理
                    deleteOriginalAssets: false // 删除原文件
                })
            )
        }
    },
    chainWebpack(config) {
        // it can improve the speed of the first screen, it is recommended to turn on preload
        // config.plugins.delete('preload')
        // when there are many pages, it will cause too many meaningless requests
        config.plugin('preload').tap(() => [
            {
                rel: 'preload',
                // to ignore runtime.js
                // https://github.com/vuejs/vue-cli/blob/dev/packages/@vue/cli-service/lib/config/app.js#L171
                fileBlacklist: [/\.map$/, /hot-update\.js$/, /runtime\..*\.js$/],
                include: 'initial'
            }
        ])
        config.plugins.delete('prefetch')
        // set svg-sprite-loader
        config.module
            .rule('svg')
            .exclude.add(resolve('src/icons'))
            .end()
        config.module
            .rule('icons')
            .test(/\.svg$/)
            .include.add(resolve('src/icons'))
            .end()
            .use('svg-sprite-loader')
            .loader('svg-sprite-loader')
            .options({
                symbolId: 'icon-[name]'
            })
            .end()
        // set preserveWhitespace
        config.module
            .rule('vue')
            .use('vue-loader')
            .loader('vue-loader')
            .tap(options => {
                options.compilerOptions.preserveWhitespace = true
                return options
            })
            .end()
        config
            .when(process.env.NODE_ENV !== 'development',
                config => {
                    config
                        .plugin('ScriptExtHtmlWebpackPlugin')
                        .after('html')
                        .use('script-ext-html-webpack-plugin', [{
                            // `runtime` must same as runtimeChunk name. default is `runtime`
                            inline: /runtime\..*\.js$/
                        }])
                        .end()
                    config
                        .optimization.splitChunks({
                        chunks: 'all',
                        cacheGroups: {
                            libs: {
                                name: 'chunk-libs',
                                test: /[\\/]node_modules[\\/]/,
                                priority: 10,
                                chunks: 'initial' // only package third parties that are initially dependent
                            },
                            elementUI: {
                                name: 'chunk-elementUI', // split elementUI into a single package
                                priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
                                test: /[\\/]node_modules[\\/]_?element-ui(.*)/ // in order to adapt to cnpm
                            },
                            commons: {
                                name: 'chunk-commons',
                                test: resolve('src/components'), // can customize your rules
                                minChunks: 3, //  minimum common number
                                priority: 5,
                                reuseExistingChunk: true
                            }
                        }
                    })
                    config.optimization.runtimeChunk('single')
                }
            )
    }
};