import {deleteAsync} from 'del';
import {exec, spawn} from 'child_process';
import {globby} from 'globby';
import browserSync from 'browser-sync';
import chalk from 'chalk';
import commandLineArgs from 'command-line-args';
import copy from 'recursive-copy';
import esbuild from 'esbuild';
import fs from 'fs/promises';
import getPort, {portNumbers} from 'get-port';
import ora from 'ora';
import util from 'util';
import * as path from 'path';
import {readFileSync} from 'fs';
import {replace} from 'esbuild-plugin-replace';

const {serve, dev} = commandLineArgs([
	{name: 'serve', type: Boolean},
	{name: 'dev', type: Boolean}
]);
const outdir = 'doc/dist';
const cdndir = 'cdn';
const sitedir = 'doc/dist/site';
const spinner = ora({hideCursor: false}).start();
const execPromise = util.promisify(exec);
let childProcess;
let buildResults;

const bundleDirectories = [outdir];
let packageData = JSON.parse(readFileSync(path.join(process.cwd(), 'package.json'), 'utf-8'));
const egwVersion = JSON.stringify(packageData.version.toString());

//
// Runs 11ty and builds the docs. The returned promise resolves after the initial publish has completed. The child
// process and an array of strings containing any output are included in the resolved promise.
//
// To debug:
// > DEBUG=Eleventy* npx @11ty/eleventy
//
async function buildTheDocs(watch = false)
{
	return new Promise(async (resolve, reject) =>
	{
		const afterSignal = '[eleventy.after]';
		const args = ['@11ty/eleventy', '--quiet'];
		const output = [];

		if (watch)
		{
			args.push('--watch');
			args.push('--incremental');
		}

		// To debug use this in terminal: DEBUG=Eleventy* npx @11ty/eleventy
		const child = spawn('npx', args, {
			stdio: 'pipe',
			cwd: 'doc/etemplate2',
			shell: true // for Windows
		});

		child.stdout.on('data', data =>
		{
			if (data.includes(afterSignal))
			{
				return;
			} // don't log the signal
			output.push(data.toString());
		});

		if (watch)
		{
			// The process doesn't terminate in watch mode so, before resolving, we listen for a known signal in stdout that
			// tells us when the first build completes.
			child.stdout.on('data', data =>
			{
				if (data.includes(afterSignal))
				{
					resolve({child, output});
				}
			});
		}
		else
		{
			child.on('close', () =>
			{
				resolve({child, output});
			});
		}
	});
}

//
// Builds the source with esbuild.
//
async function buildTheSource()
{
	const alwaysExternal = ['@lit'];

	const cdnConfig = {
		format: 'esm',
		target: 'es2017',
		entryPoints: [
			//
			// NOTE: Entry points must be mapped in package.json > exports, otherwise users won't be able to import them!
			//
			// The whole shebang
			'./src/shoelace.ts',
			// The auto-loader
			'./src/shoelace-autoloader.ts',
			// Components
			...(await globby('./src/components/**/!(*.(style|test)).ts')),
			// Translations
			...(await globby('./src/translations/**/*.ts')),
			// Public utilities
			...(await globby('./src/utilities/**/!(*.(style|test)).ts')),
			// Theme stylesheets
			...(await globby('./src/themes/**/!(*.test).ts')),
			// React wrappers
			...(await globby('./src/react/**/*.ts'))
		],
		outdir: cdndir,
		chunkNames: 'chunks/[name].[hash]',
		define: {
			// Floating UI requires this to be set
			'process.env.NODE_ENV': '"production"'
		},
		bundle: true,
		//
		// We don't bundle certain dependencies in the unbundled build. This ensures we ship bare module specifiers,
		// allowing end users to better optimize when using a bundler. (Only packages that ship ESM can be external.)
		//
		// We never bundle React or @lit-labs/react though!
		//
		external: alwaysExternal,
		splitting: true,
		plugins: [
			replace({
				__EGROUPWARE_VERSION__: egwVersion
			})
		]
	};

	const npmConfig = {
		...cdnConfig,
		external: undefined,
		minify: false,
		packages: 'external',
		outdir
	};

	if (serve)
	{
		// Use the context API to allow incremental dev builds
		const contexts = await Promise.all([esbuild.context(cdnConfig), esbuild.context(npmConfig)]);
		await Promise.all(contexts.map(context => context.rebuild()));
		return contexts;
	}
	else
	{
		// Use the standard API for production builds
		return await Promise.all([esbuild.build(cdnConfig), esbuild.build(npmConfig)]);
	}
}

async function rollup(watch = false)
{
	return new Promise(async (resolve, reject) =>
	{
		const afterSignal = '[rollup.after]';
		const args = ['--silent'];
		const output = [];

		if (watch)
		{
			args.push('--watch');
			args.push('--incremental');
		}

		// To debug use this in terminal: DEBUG=Eleventy* npx @11ty/eleventy
		const child = spawn('rollup', args, {
			stdio: 'pipe',
			cwd: '.',
			shell: true // for Windows
		});

		child.stdout.on('data', data =>
		{
			if (data.includes(afterSignal))
			{
				return;
			} // don't log the signal
			output.push(data.toString());
		});

		// Not even waiting
		resolve({child, output});
	});
}

//
// Called on SIGINT or SIGTERM to cleanup the build and child processes.
//
function handleCleanup()
{
	buildResults.forEach(result => result.dispose());

	if (childProcess)
	{
		childProcess.kill('SIGINT');
	}

	process.exit();
}

//
// Helper function to draw a spinner while tasks run.
//
async function nextTask(label, action)
{
	spinner.text = label;
	spinner.start();

	try
	{
		await action();
		spinner.stop();
		console.log(`${chalk.green('✔')} ${label}`);
	}
	catch (err)
	{
		spinner.stop();
		console.error(`${chalk.red('✘')} ${err}`);
		if (err.stdout)
		{
			console.error(chalk.red(err.stdout));
		}
		if (err.stderr)
		{
			console.error(chalk.red(err.stderr));
		}
		process.exit(1);
	}
}

await nextTask('Cleaning up the previous build', async () =>
{
	await Promise.all([deleteAsync(sitedir), ...bundleDirectories.map(dir => deleteAsync(dir))]);
	await fs.mkdir(outdir, {recursive: true});
});

await nextTask('Generating component metadata', () =>
{
	return Promise.all(
		bundleDirectories.map(dir =>
		{
			return execPromise(`node doc/scripts/metadata.mjs --outdir "${dir}"`, {stdio: 'inherit'});
		})
	);
});
/*
await nextTask('Generating themes', () =>
{
	return execPromise(`node scripts/make-themes.js --outdir "${outdir}"`, {stdio: 'inherit'});
});
*/
/* We don't do these
await nextTask('Running the TypeScript compiler', () =>
{
	return execPromise(`tsc --project ./tsconfig.json --outdir "${outdir}"`, {stdio: 'inherit'});
});
await nextTask('Building source files', async () =>
{
	buildResults = await buildTheSource();
});
*/

// EGroupware way of packaging
// We can't watch
await nextTask('Rolling up', async () =>
{
	await rollup(dev);
});


// Launch the dev server
if (serve)
{
	let result;

	// Spin up Eleventy and Wait for the search index to appear before proceeding. The search index is generated during
	// eleventy.after, so it appears after the docs are fully published. This is kinda hacky, but here we are.
	// Kick off the Eleventy dev server with --watch and --incremental
	await nextTask('Building docs', async () =>
	{
		result = await buildTheDocs(true);
	});

	const bs = browserSync.create();
	const port = await getPort({port: portNumbers(4000, 4999)});
	const browserSyncConfig = {
		startPath: '/',
		port,
		logLevel: 'silent',
		logPrefix: '[egw]',
		logFileChanges: true,
		notify: false,
		single: false,
		ghostMode: false,
		server: {
			baseDir: sitedir,
			routes: {
				'/dist': './cdn'
			}
		}
	};

	// Launch browser sync
	bs.init(browserSyncConfig, () =>
	{
		const url = `http://localhost:${port}`;
		console.log(chalk.cyan(`\n🥾 The dev server is available at ${url}`));

		// Log deferred output
		if (result.output.length > 0)
		{
			console.log('\n' + result.output.join('\n'));
		}

		// Log output that comes later on
		result.child.stdout.on('data', data =>
		{
			console.log(data.toString());
		});
	});

	// Rebuild and reload when source files change
	bs.watch('src/**/!(*.test).*').on('change', async filename =>
	{
		console.log('[build] File changed: ', filename);

		try
		{
			const isTheme = /^src\/themes/.test(filename);
			const isStylesheet = /(\.css|\.styles\.ts)$/.test(filename);

			// Rebuild the source
			const rebuildResults = buildResults.map(result => result.rebuild());
			await Promise.all(rebuildResults);

			// Rebuild stylesheets when a theme file changes
			if (isTheme)
			{
				await Promise.all(
					bundleDirectories.map(dir =>
					{
						execPromise(`node scripts/make-themes.js --outdir "${dir}"`, {stdio: 'inherit'});
					})
				);
			}

			// Rebuild metadata (but not when styles are changed)
			if (!isStylesheet)
			{
				await Promise.all(
					bundleDirectories.map(dir =>
					{
						return execPromise(`node scripts/make-metadata.js --outdir "${dir}"`, {stdio: 'inherit'});
					})
				);
			}

			bs.reload();
		}
		catch (err)
		{
			console.error(chalk.red(err));
		}
	});

	// Reload without rebuilding when the docs change
	bs.watch([`${sitedir}/**/*.*`]).on('change', filename =>
	{
		bs.reload();
	});
}


// Build for production
if (!serve)
{
	let result;

	await nextTask('Building the docs', async () =>
	{
		result = await buildTheDocs();
	});

	// Log deferred output
	if (result.output.length > 0)
	{
		console.log('\n' + result.output.join('\n'));
	}
}

// Cleanup on exit
process.on('SIGINT', handleCleanup);
process.on('SIGTERM', handleCleanup);