import fs from 'fs-extra';
import fsorig from 'fs';
import deepmerge from 'deepmerge';
import { dirname } from 'path';
import { fileURLToPath } from 'url';

const localpath = dirname( fileURLToPath( import.meta.url ) );

(async function start() {
	let args = process.argv.slice(2);
	let source = args?.[0];
	let variation = args?.[1];
	if ( source && variation ) {
		return await buildVariation(source, variation);
	}
	return await buildAllVariations();
})();

async function buildAllVariations(){
	for (let source of getDirectories( localpath )){
		for (let variation of getDirectories( `${localpath}/${source}` )){
			await buildVariation(source, variation);
		}
	}
}

async function buildVariation(source, variation) {
	const srcDir = localpath + '/../' + source;
	const srcVariationDir = localpath + '/' + source + '/' + variation;
	const destDir = localpath + '/../' + variation;

	console.log( `Copying the source ${source} to the variation ${variation}` );

	try {

		// First empty the old directory.
		await fs.emptyDir( destDir );

		// Then copy the source directory.
		await fs.copy( srcDir, destDir );

		// remove unneeded resources
		await fs.remove( destDir + '/sass');
		await fs.remove( destDir + '/node_modules' );
		await fs.remove( destDir + '/template-mods.json');
		await fs.remove( destDir + '/package.json');
		await fs.remove( destDir + '/package-lock.json');

		// copy the variation directory.
		await fs.copy( srcVariationDir, destDir );

		// copy the readme
		await fs.copy( localpath + '/variation-readme.md', destDir + '/variation-readme.md' );

		// make template modifications
		const hasMods = fs.existsSync( `${srcVariationDir}/template-mods.json`);
		if(hasMods) {
			const srcModsFile = await fs.readFile( `${srcVariationDir}/template-mods.json`, 'utf8' );
			const modsJson = JSON.parse( srcModsFile );
			modsJson.forEach(mod => {
				modifyTemplates(mod.from, mod.to, destDir + '/block-templates');
			});
		}
	
		// merge the theme.json files
		const srcJsonFile = await fs.readFile( srcDir + '/theme.json', 'utf8' );
		const srcVariationJsonFile = await fs.readFile( srcVariationDir + '/theme.json', 'utf8' )
		const srcJson = JSON.parse( srcJsonFile );
		const srcVariationJson = JSON.parse( srcVariationJsonFile );
		const mergedJson = deepmerge(srcJson, srcVariationJson, {
			arrayMerge: ( dest, source ) => source
		});
		await fs.writeFile ( destDir + '/theme.json', JSON.stringify( mergedJson, null, '\t' ), 'utf8' );

		console.log('Finished sucessfully.\n\n');
	}
	catch (err){
		console.log('ERROR: ', err, '\n\n');
	}
}

function getDirectories ( path ) {
	return fsorig.readdirSync( path, { withFileTypes: true } )
		.filter( item => item.isDirectory() )
		.map ( item => item.name )
}

function getTemplates ( path ) {
	return fsorig.readdirSync( path, { withFileTypes: true } )
		.map ( item => item.name )
}

function modifyTemplates ( from, to, basePath ) {
	console.log('modifying templates changing ', from, 'to', to);
	const templates = getTemplates(basePath);
	for ( let template of templates ) {
		let templatePath = basePath + '/' + template;
		let srcTemplate = fs.readFileSync( templatePath, 'utf8' );
		let resultTemplate = srcTemplate.replace(from, to);
		fs.writeFileSync ( templatePath, resultTemplate, 'utf8' );
	}
}