#!/usr/bin/env ruby

require "clap"
require "erb"
require "ostruct"

class Tynn
  class CLI
    def self.parse(args)
      new.parse(args)
    end

    attr_reader :template_path

    def initialize
      @template_path = File.expand_path("..", __dir__)
    end

    def parse(args)
      args = Clap.run(args, opts)

      usage if args.empty?

      require(app_generator)

      generator = AppGenerator.new(template_path, args)
      generator.setup
    end

    def opts
      return {
        "-h"     => method(:usage),
        "--help" => method(:usage)
      }
    end

    def app_generator
      return File.join(template_path, "app_generator")
    end

    USAGE = <<-EOS
  Usage: tynn <dir> [options]

  Options:

      -h, --help          output usage information
  EOS

    def usage
      puts(USAGE); exit(0)
    end
  end

  class Generator
    attr_reader :base_dir, :app_name

    def initialize(base_dir, args)
      @base_dir = base_dir
      @app_name = args.first
    end

    def setup
      raise("#{ self.class }#setup not implemented")
    end

    def generate(path, vars = {})
      output_path = File.join(app_name, path)

      mkdir(File.dirname(output_path))

      write(output_path, render(path, vars))
    end

    def mkdir(path)
      unless Dir.exist?(path)
        Dir.mkdir(path)

        log(path)
      end
    end

    def write(path, content)
      File.write(path, content)

      log(path)
    end

    def render(path, vars = {})
      source = File.read(File.join(base_dir, "templates", path))
      params = OpenStruct.new(vars).instance_eval { binding }

      return ERB.new(source).result(params)
    end

    def log(str)
      puts("   \033[36mcreate\033[0m : #{ str }")
    end
  end
end

Tynn::CLI.parse(ARGV)