import { AdminUiExtension } from '@vendure/common/lib/shared-types';
import * as fs from 'fs-extra';
import * as path from 'path';

const EXTENSIONS_DIR = path.join(__dirname, '../src/app/extensions');
const EXTENSIONS_MODULES_DIR = 'modules';
const originalExtensionsModuleFile = path.join(EXTENSIONS_DIR, 'extensions.module.ts');
const tempExtensionsModuleFile = path.join(EXTENSIONS_DIR, 'extensions.module.ts.temp');

/**
 * Returns true if currently being executed from inside the Vendure monorepo.
 */
export function isInVendureMonorepo(): boolean {
    return fs.existsSync(path.join(__dirname, '../../dev-server'));
}

/**
 * Restores the placeholder ExtensionsModule file from a template.
 */
export function restoreExtensionsModule() {
    fs.copyFileSync(path.join(__dirname, 'extensions.module.ts.template'), originalExtensionsModuleFile);
}

/**
 * Deletes the contents of the /modules directory, which contains the plugin
 * extension modules copied over during the last compilation.
 */
export function deleteExistingExtensionModules() {
    fs.removeSync(path.join(EXTENSIONS_DIR, EXTENSIONS_MODULES_DIR));
}

/**
 * Copies all files from the ngModulePaths of the configured extensions into the
 * admin-ui source tree.
 */
export function copyExtensionModules(extensions: Array<Required<AdminUiExtension>>) {
    for (const extension of extensions) {
        const dirName = path.basename(path.dirname(extension.ngModulePath));
        const dest = getModuleOutputDir(extension);
        fs.copySync(extension.ngModulePath, dest);
    }
}

export function getModuleOutputDir(extension: Required<AdminUiExtension>): string {
    return path.join(EXTENSIONS_DIR, EXTENSIONS_MODULES_DIR, extension.id);
}

export function createExtensionsModule(extensions: Array<Required<AdminUiExtension>>) {
    const removeTsExtension = (filename: string): string => filename.replace(/\.ts$/, '');
    const importPath = (e: Required<AdminUiExtension>): string =>
        `./${EXTENSIONS_MODULES_DIR}/${e.id}/${removeTsExtension(e.ngModuleFileName)}`;
    fs.renameSync(originalExtensionsModuleFile, tempExtensionsModuleFile);

    const source = generateExtensionModuleTsSource(
        extensions.map(e => ({ className: e.ngModuleName, path: importPath(e) })),
    );
    fs.writeFileSync(path.join(EXTENSIONS_DIR, 'extensions.module.ts'), source, 'utf-8');
}

export function restoreOriginalExtensionsModule() {
    fs.renameSync(originalExtensionsModuleFile, path.join(EXTENSIONS_DIR, 'extensions.module.ts.generated'));
    restoreExtensionsModule();
}

function generateExtensionModuleTsSource(modules: Array<{ className: string; path: string }>): string {
    return `/** This file is generated by the build() function. Do not edit. */
import { CommonModule } from '@angular/common';
import { NgModule } from '@angular/core';

${modules.map(e => `import { ${e.className} } from '${e.path}';`).join('\n')}

@NgModule({
    imports: [
        CommonModule,
        ${modules.map(e => e.className + ',').join('\n')}
    ],
})
export class ExtensionsModule {}
`;
}