import { objectMap, objectRemap } from '@dzeio/object-util'
import type { AstroIntegration } from 'astro'
import fs from 'fs/promises'

interface Config {
	output?: string
}

/**
 * get every files recursivelly in a specific directory
 *
 * @param path the path to search
 * @returns the list of files recursivelly in the specific directory
 */
async function getFiles(path: string): Promise<Array<string>> {
	path = decodeURI(path)
	try {
		const dir = await fs.readdir(path)
		let files: Array<string> = []
		for (const file of dir) {
			if (file.startsWith('_')) {
				continue
			}
			const filePath = path + '/' + file
			if ((await fs.stat(filePath)).isDirectory()) {
				files = files.concat(await getFiles(filePath))
			} else if (file.endsWith('.ts')) {
				files.push(filePath)
			}
		}
		return files
	} catch {
		return []
	}
}

/**
 * format the path back to an url usable by the app
 *
 * @param path the path to format
 * @returns the path formatted as a URL
 */
function formatPath(basePath: string, path: string): string {
	// remove the base path
	path = path.replace(decodeURI(basePath), '')

	// handle the `/` endpoint
	if (path === '') {
		path = '/'
	}

	return path
}

async function run(config?: Config) {

	// get the files list
	const files = await getFiles('./src/pages/api').then((ev) => ev.map((it) => formatPath('./src/pages/api', it)))

	const methods = ['GET', 'POST', 'DELETE']

	let content = ''
	const items: Record<string, Record<string, string>> = {}
	for (const entry of files) {
		const file = await fs.readFile('./src/pages/api' + entry, 'utf-8')
		const availableMethods: Array<string> = []
		for (const method of methods) {
			if (file.includes(method)) {
				availableMethods.push(method)
			}
		}
		if (availableMethods.length === 0) {
			continue
		}
		const prefix = entry.replace(/[/.[\]-]/g, '')
		content += `import type { ${availableMethods.map((it) => `${it} as ${prefix}${it}`).join((', '))} } from './pages/api${entry}'\n`


		let path = entry
		// remove the extension if asked
		const lastDot = path.lastIndexOf('.')
		path = path.slice(0, lastDot)

		// remove the index from the element
		if (path.endsWith('/index')) {
			path = path.replace('/index', '')
		}

		items[path] = {
			...objectRemap(availableMethods, (value) => ({ key: value as string, value: `${prefix}${value as string}` }))
		}
	}

	content += `\ninterface APIRoutes {
${objectMap(items, (record, key) => `\t'${key}': {
${objectMap(record, (value, method) => `		${method}: typeof ${value}`).join('\n')}
}`).join('\n')}
}`

	content += '\n\nexport default APIRoutes\n'

	await fs.writeFile(config?.output ?? './src/api-routes.d.ts', content)
}

/**
 * launch the integration
 * @returns the routng integration
 */
const integration = (config?: Config): AstroIntegration => ({
	name: 'routing',
	hooks: {
		'astro:build:setup': () => run(config),
		'astro:server:setup': () => run(config)
	}
})

export default integration