/**
 * © 2022 WavePlay <dev@waveplay.com>
 */
import { Command, OptionValues } from 'commander'
import fs from 'fs-extra'
import klaw from 'klaw'
import pino, { Logger } from 'pino'
import { getGenDir, syncManifest } from '../..'
import koder from '../../koder'
import type { BuildManifest } from '../../types'
import { getPkgManager } from '../dev'

const packageManager = getPkgManager()

// Name of the file that will be generated
const GENERATED_FILE = 'locales.js'

// Locale directories to read & write to/from
const LOCALES_ASSETS_DIR = process.cwd() + '/assets/locales'
const LOCALES_PUBLIC_DIR = process.cwd() + '/public/locales'

const command = new Command('sync:locales')
	.description('syncs locale files and generates static imports')
	.option('-s --silent', 'do not print anything')
	.option('-ud --up-dirs <upDirs>', 'number of directories to go up from current directory for generated files')
	.option('-v --verbose', 'print more information for debugging')
	.action(action)
export default command

export async function action(options: OptionValues, logger?: Logger) {
	const passedLogger = !!logger
	const startTime = Date.now()

	// Create a logger
	if (!logger) {
		logger = pino({
			enabled: !options.silent,
			level: options.verbose ? 'debug' : 'info',
			timestamp: false,
			transport: {
				target: 'pino-pretty',
				options: {
					colorize: true
				}
			}
		})
	}
	logger.debug(`[PilotJS] Starting sync:locales...`)

	// Make sure the public locales directory exists and return early if it doesn't
	logger.debug(`[PilotJS] Using root directory "${process.cwd()}"`)
	if (!fs.existsSync(LOCALES_PUBLIC_DIR)) {
		logger.debug(`[PilotJS] "/public/locales" does not exist! Skipping build:locales...`)
		return
	}

	// Copy all i18n files from /public into this library
	// This is because React Native apps load from /assets instead, yet importing dynamically is a pain
	await fs.copy(LOCALES_PUBLIC_DIR, LOCALES_ASSETS_DIR)

	// Register every file in a store first to prevent out-of-order imports
	const store = await readAllLocales(logger)

	// Generate the import file
	await writeGeneratedFile(store, logger, options.upDirs)

	// Apply newly read pages to the manifest
	await syncManifest((manifest: BuildManifest) => {
		manifest.locales = {}
		for (const locale in store) {
			manifest.locales[locale] = store[locale]
		}
	}, logger)

	if (!passedLogger) {
		logger.info(`[PilotJS] Built ${Object.keys(store).length} locales in ${Date.now() - startTime}ms ✨`)
	}
}

const readAllLocales = async (logger: Logger): Promise<any> => {
	const store: any = {}
	for await (const file of klaw(LOCALES_ASSETS_DIR)) {
		// Skip directories
		if (file.stats.isDirectory()) {
			continue
		}
		logger.debug(`[PilotJS] Reading locale namespace "${file.path}"...`)

		// Filter just the pure locale/namespace.json keys
		const path = file.path.substring(file.path.lastIndexOf('/locales') + '/locales'.length + 1)
		const locale = path.substring(0, path.indexOf('/'))
		const ns = path.substring(path.indexOf('/') + 1, path.lastIndexOf('.'))

		// Include this file in the store
		if (!store[locale]) {
			store[locale] = []
		}
		store[locale].push(ns)
	}

	return store
}

const writeGeneratedFile = async (store: any, logger: Logger, upDirs: number): Promise<void> => {
	const kode = koder({ comment: 'This file was automatically generated by PilotJS' })
		// Create an importResource function that will host all static import statements
		.function('importResource', { export: true, params: ['locale', 'ns'] })
		.block(
			koder()
				.switch('locale')
				.block(
					koder()
						// Create a nested switch statement for each locale
						.cases(
							Object.keys(store).map((locale) => ({
								case: locale,
								body: koder()
									.switch('ns')
									.block(
										koder()
											// Each namespace in the store's locales will get its own case
											.cases(
												store[locale].map((ns) => ({
													case: ns,
													body: koder().import(
														null,
														`../../../../../${
															packageManager === 'pnpm' ? '../../../' : ''
														}assets/locales/${locale}/${ns}.json`,
														{ dynamic: true, return: true }
													)
												}))
											)
											.default(koder().throw(new Error(`Could not find namespace in "${locale}" locale: \${ns}`)))
									)
							}))
						)
						.default(koder().throw(new Error(`Could not find locale: \${locale}`)))
				)
		)

	// Override existing stub file with the real deal!
	const file = getGenDir({ upDirs }) + GENERATED_FILE
	logger.debug(`[PilotJS] Writing ${Object.keys(store).length} locales to "${file}"`)
	await fs.outputFile(file, kode.toString())
}