"use strict";

const Promise = require("bluebird");
const fs = require("fs");
const fsPromises = require("fs").promises;
const path = require("path");
const escapeStringRegexp = require("escape-string-regexp");

const pipe = require("@promistream/pipe");
const walkFolder = require("@promistream/walk-folder");
const map = require("@promistream/map");
const filter = require("@promistream/filter");
const collect = require("@promistream/collect");

if (process.argv[2] == null) {
	throw new Error(`Must specify a path`);
}

let boilerplate = fs.readFileSync(path.join(__dirname, "_boilerplate.js"), "utf8");

function parseBoilerplate(code) {
	let lines = code.split("\n");
	let items = [];
	let currentItem = "";
	
	for (let line of lines) {
		if (line.trim() === "//##--") {
			items.push(currentItem);
			currentItem = "";
		} else {
			currentItem += line + "\n";
		}
	}

	items.push(currentItem);

	return items.filter((item) => item.trim() !== "");
}

let regexes = parseBoilerplate(boilerplate)
	.map((text) => escapeStringRegexp(text).trim().replace(/\s+/g, "\\s+"))
	.map((regex) => new RegExp(regex, "g"));

return Promise.try(() => {
	return pipe([
		walkFolder(process.argv[2], {
			throughStream: filter((path) => !path.includes("node_modules"))
		}),
		filter((item) => !item.stats.isDirectory()),
		filter((item) => item.path.match(/\.(?:c|m)?jsx?$/)),
		map((item) => {
			return Promise.try(() => {
				return fsPromises.readFile(item.path, "utf8");
			}).then((contents) => {
				let replaceCount = 0;

				for (let [ index, regex ] of Object.entries(regexes)) {
					contents = contents.replace(regex, () => {
						// console.log(" - " + regex);
						replaceCount += 1;
						return `// Transpiler boilerplate removed by boilerplate-remover (rule ${index})`;
					});
				}

				if (replaceCount > 0) {
					console.log(`Replaced ${replaceCount} items in ${item.path}`);

					return fsPromises.writeFile(item.path, contents, "utf8");
				}
			});
		}),
		collect()
	]).read();
}).then(() => {
	console.log("Completed!");
});