import { parseArgs } from "node:util";
import { z } from "zod";
import { CLIError, MuseError } from "#lib";

const Renderers = ["json", "html"] as const;
const RendererSchema = z.enum(Renderers);
type Renderer = z.infer<typeof RendererSchema>;

/**
 * A shape representing the arguments passed to the CLI
 */
export interface CLIArguments {
  inputFilePath: string;

  options: {
    write: boolean;
    check: boolean;
    outfile: string;
    help: boolean;
    minify: boolean;
    renderer: Renderer;
    watch: boolean;
  };
}

/**
 * Given an array of CLI arguments, parse them into a structured object
 *
 * @param argv The arguments to parse
 * @returns The parsed CLI arguments
 *
 * @throws {CLIError} if the arguments are invalid
 */
export function parseCLIArguments(argv: string[]): CLIArguments {
  const { values: options, positionals: args } = parseArgs({
    args: argv,
    options: {
      write: {
        short: "w",
        type: "boolean",
        default: false,
      },
      check: {
        short: "c",
        type: "boolean",
        default: false,
      },
      outfile: {
        short: "o",
        type: "string",
        default: "playbill.json",
      },
      help: {
        short: "h",
        default: false,
        type: "boolean",
      },
      minify: {
        short: "m",
        default: false,
        type: "boolean",
      },
      renderer: {
        short: "r",
        default: "json",
        type: "string",
      },
      watch: {
        default: false,
        type: "boolean",
      },
    },
    strict: true,
    allowPositionals: true,
  });

  // -- ARG VALIDATION -- //
  if (options.check && options.write) {
    throw new CLIError("Cannot use --check and --write together");
  }

  const parsedRenderer = RendererSchema.safeParse(options.renderer);

  if (!parsedRenderer.success) {
    throw new MuseError(`Invalid renderer: ${parsedRenderer.data}`);
  }

  return {
    inputFilePath: args[0] ?? "./binding.yaml",

    options: {
      write: options.write,
      check: options.check,
      outfile: options.outfile,
      help: options.help,
      minify: options.minify,
      renderer: parsedRenderer.data,
      watch: options.watch,
    },
  };
}