#!/usr/bin/env ruby


require 'rubygems'
require 'commander/import'
require 'yaml'

class ErbExecutor
  include Commander::Methods

  def run
    program :name, 'Erb Executor'
    program :version, '0.0.1'
    program :description, 'Render template from model'
    default_command :render

    command :render do |c|
      c.syntax = 'erb_executor [render] --model model_file_path --template template_file_path --output '
      c.description = 'Render template from model'
      c.option '--model STRING', String, 'Model file path'
      c.option '--template STRING', String, 'Template file path'
      c.option '--output STRING', String, 'Output file path'
      c.action do |args, options|
        unless File.exist? options.output
          File.open(options.output, File::RDWR|File::CREAT, 0644) do |f|
            unless options.model.nil?
              if File.exist? options.model and !File.directory? options.model
                model = YAML::load_file(options.model)
              else
                abort "Non-existed model file path"
              end
            else
              abort "Missing model parameter"
            end
            if File.exist? options.template and !File.directory? options.template
              template = File.read(options.template)
            else
              abort "Non-existed template file path"
            end
            b = binding
            f.flock(File::LOCK_EX)
            f.rewind
            f.write ERB.new(template).result(b)
            f.flush
            f.truncate(f.pos)
          end
        else
          abort "Output file path #{options.output} existed on the file system, please give a check"
        end
     end
    end
  end
end

ErbExecutor.new.run if $0 == __FILE__