import * as webpack from "webpack";
import { localIP } from "./utils";

export interface DevMapOptions {
	name: string;
	dllEntry: webpack.Entry;
	isProd: boolean;
	devPort?: number;
}

export default class MapPlugin {
	options: DevMapOptions;

	constructor(options: DevMapOptions) {
		this.options = options;
	}

	apply(compiler) {
		compiler.plugin("emit", (compilation, cb) => {
			const { name, dllEntry, isProd, devPort } = this.options;
			const { assets, chunks } = compilation.getStats().toJson();

			const allAssets = chunks
				.filter(chunk => chunk.initial)
				.map(chunk => chunk.files[0]) as string[];
			const end = Object.keys(dllEntry).length;
			const dllAssets = assets
				.reverse()
				.slice(0, end)
				.map(asset => asset.name);

			const mapContent = {};
			const resource = {};
			const namePrefix = isProd ? "" : `http://${localIP}:${devPort}/`;
			dllAssets.concat(allAssets).forEach((fullName: string) => {
				const name = fullName.split(".")[0].replace("js/", "");
				const filePath = `${namePrefix}${fullName}`;

				mapContent[name] = filePath;
				resource[name] = filePath;
			});

			const source = `var EZPackMap = ${JSON.stringify(mapContent)};`;
			compilation.assets[`${name}.js`] = {
				source: () => source,
				size: () => source.length
			};

			const resourceContent = JSON.stringify(resource, null, 4);
			compilation.assets[`${name}.json`] = {
				source: () => resourceContent,
				size: () => resourceContent.length
			};
			return cb();
		});
	}
}