"use strict";

const Promise = require("bluebird");
const path = require("path");
const chalk = require("chalk");
const pad = require("pad");
const yargs = require("yargs");
const nanoid = require("nanoid");
const fs = Promise.promisifyAll(require("fs"));

const ldd = require("./lib/ldd");
const findPackages = require("./lib/find-packages");
const generateEnvironment = require("./lib/generate-environment");
const nixBuild = require("./lib/nix-build");
const runProgram = require("./lib/run-program");

let argv = yargs
	.boolean("run")
	.argv;

function printPackages(groupedPackages) {
	let packageNameWidth = Object.keys(groupedPackages).reduce((highest, pkg) => Math.max(highest, pkg.length), 0);

	Object.keys(groupedPackages).sort().forEach((pkg) => {
		console.log(`  ${chalk.bold(pad(pkg, packageNameWidth))}    ${groupedPackages[pkg].join(", ")}`);
	});
}

function groupPackages(packages) {
	let grouped = {};

	packages.forEach((pkg) => {
		if (grouped[pkg.package] == null) {
			grouped[pkg.package] = [];
		}

		grouped[pkg.package].push(pkg.library);
	});

	return grouped;
}

let target = argv._[0];

Promise.try(() => {
	if (target == null) {
		throw new Error("Must specify a binary to analyze");
	} else {
		return ldd(target);
	}
}).then((libraries) => {
	let missingLibraries = libraries
		.filter((item) => item.location == null)
		.map((item) => item.library);

	return Promise.try(() => {
		return findPackages(missingLibraries)
	}).then((groupedResults) => {
		return Object.entries(groupedResults).map(([ library, pkg ]) => {
			return { library, package: pkg };
		});
	});
}).then((results) => {
	let groupedPackages = groupPackages(results);
	let binaryName = path.basename(target);

	console.log("");
	console.log(chalk.cyan(`DepFish has guessed the following set of dependencies for ${chalk.bold(binaryName)}:`));
	console.log("");
	printPackages(groupedPackages);
	console.log("");

	if (argv.run) {
		console.log(chalk.cyan(`Preparing to run ${chalk.bold(binaryName)}...`));
		
		let buildExpression = generateEnvironment({
			binaryName: binaryName,
			targetBinary: target,
			packages: Object.keys(groupedPackages)
				.concat([ "systemd" ]) /* Hack for libudev SIGTRAP issue; this may need to be detected interactively in the future */
		});

		let expressionPath = `/tmp/depfish-expr-${nanoid()}`;

		return Promise.try(() => {
			return fs.writeFileAsync(expressionPath, buildExpression);
		}).then(() => {
			console.log("Expression path:", expressionPath);
			
			return nixBuild(expressionPath);
		}).then((outPath) => {
			console.log("Build path:", outPath);

			return runProgram(`${outPath}/bin/${binaryName}`);
		});
	}
});