import type { InlangConfig, InlangConfigModule } from "./schema.js"
import { setupPlugins } from "../plugin/setupPlugins.js"
import type { InlangEnvironment } from "../environment/types.js"
import { dedent } from "ts-dedent"
import { parseConfig } from "./parseConfig.js"
import { ZodError } from "zod"

/**
 * Sets up the inlang config module.
 *
 * @example
 * 	import { setupConfig, type InlangConfigModule } from "@inlang/core/config"
 *
 * 	const module = (await import("./inlang.config.js")) as InlangConfigModule
 * 	const config = await setupConfig({ module, env })
 */
export async function setupConfig(args: {
	module: InlangConfigModule
	env: InlangEnvironment
}): Promise<InlangConfig> {
	if (args.module.defineConfig === undefined) {
		throw new Error(`The "defineConfig" function is missing from the "inlang.config.js" file.`)
	}
	let config = await args.module.defineConfig(args.env)
	const [configWithPlugins, pluginErrors] = await setupPlugins({ config, env: args.env })
	config = configWithPlugins
	const [parsedConfig, testConfigException] = await parseConfig({ config: config as InlangConfig })

	// throw an error. the config is broken without a path to recovery
	if (testConfigException) {
		throw new Error(dedent`
			The inlang.config.js is invalid.

			# The following errors occurred during the setup of plugins:

			${pluginErrors ? pluginErrors.map((e) => e.message).join("\n") : "None ✅"}

			# The following errors occurred during the validation of the config:

			${formatErrors(testConfigException)}

			---

			If plugins return errors, chances are high that the plugin errors are the root cause
			for the config errors. Try to fix the plugin errors first.

		`)
	}

	// plugins returned an error but the config is still usable
	// -> only log the errors
	if (pluginErrors) {
		for (const e of pluginErrors) console.error(e)
	}

	return parsedConfig
}

const formatErrors = (error: Error) => {
	if (error instanceof ZodError) {
		return error.errors.map((e) => `[${e.path}] ${e.message}`).join("\n")
	}

	return error.message
}