# frozen_string_literal: true

require "optparse"

require "rerb"
require "rerb/templater"

module RERB
  # Command Line Interface for invoking RERB
  module CLI
    def parse(args)
      parser = OptionParser.new do |o|
        o.banner = "Usage: werb [options...] FILE"
        o.on(
          "--template TYPE",
          ["umd", "iife", "nil"],
          "Specify which html template to use to wrap the generated code. " \
            "Valid options are umd, iife, and nil.",
          "nil will use no template and just output raw ruby.wasm code. " \
            "Defaults to umd",
        )
        o.on(
          "--root NAME",
          "The html id of the root element to add all other DOM nodes to. " \
            'Defaults to "root"',
        )
        o.on("-v", "--version", "Output version information and exit.")
      end
      opts = {
        template: "umd",
        document: "document",
        root: "root",
        el_prefix: "el",
      }
      parser.parse!(args, into: opts)

      filename = args.shift
      return puts parser.help if filename.nil?

      input = File.read(filename)
      case opts[:template]
      when "umd"
        res = UMDTemplater.new(filename, opts[:root])
          .generate(input)
      when "iife"
        res = IIFETemplater.new(filename, opts[:root])
          .generate(input)
      when "nil"
        res = Templater.new(filename, opts[:root])
          .generate(input)
      else
        raise "Invalid template option. Choose between umd, iife, nil."
      end
      puts res
    end

    module_function :parse
  end
end