import * as program from 'commander'
import * as fs      from 'fs'
import * as path    from 'path'

import { generateOutput } from './utilities'

/**
 * Use Babel to transpile schema files
 */
import 'babel-register'

program.on('--help', () => {
	console.log('  Examples:')
	console.log('')
	console.log('    $ ms2tsi -h')
	console.log('    $ ms2tsi generate --module-name myModule --output-dir ./interfaces ./**/schema.js')
	console.log('')
})

program
	.command('generate [schemas...]')
	.option('-o, --output-dir <output-dir>', 'Where should the generated .d.ts file be written to?')
	.option('-m, --module-name <module-name>', 'What should the TypeScript module and filename be?')
	.option('-e, --extend-refs', 'Experimental: Should refs be extended?')
	.action((schemas: string[], cmd: any) => {

		const { outputDir, moduleName, extendRefs } = cmd

		if (!outputDir) {
			console.error('An output directory is required. Use -o or --output-dir')
			return process.exit(1)
		}

		if (!moduleName) {
			console.error('A module name is required. Use -m or --module-name')
			return process.exit(1)
		}

		if (!schemas || !schemas.length) {
			console.error('No schema files could be found. Please check the required usage by running `ms2tsi -h`')
			return process.exit(1)
		}

		const currentDir = process.env.PWD
		const resolvedSchemaFiles = schemas.map((schemaPath: string) => {

			const schemaFile = require(path.resolve(currentDir, schemaPath))

			/**
			 * Allow for vanilla objects or full mongoose.Schema instances to
			 * have been exported by normalising the exported `schema` property
			 */
			if (schemaFile.schema && schemaFile.schema.tree) {
				schemaFile.schema = schemaFile.schema.tree
				return schemaFile
			}

			return schemaFile

		})

		const output = generateOutput(moduleName, currentDir, resolvedSchemaFiles, extendRefs)

		fs.writeFile(path.resolve(currentDir, `${outputDir}/${moduleName}.d.ts`), output)

	})

program.parse(process.argv)