glanotte/guard-migrate

require 'guard/compat/plugin'

module Guard
  class Migrate < Plugin
    autoload :Notify, 'guard/migrate/notify'
    autoload :Migration, 'guard/migrate/migration'
    attr_reader :seed, :rails_env

    def initialize(options = {})
      super

      @bundler = true unless options[:bundler] == false
      @cmd = options[:cmd].to_s unless options[:cmd].to_s.empty?
      @reset = true if options[:reset] == true
      @test_prepare = options[:test_prepare]
      @run_on_start = true if options[:run_on_start] == true
      @rails_env = options[:rails_env]
      @seed = options[:seed]
    end

    def bundler?
      !!@bundler && File.exist?("#{Dir.pwd}/Gemfile")
    end

    def run_on_start?
      !!@run_on_start
    end

    def cmd?
      !!@cmd
    end

    def test_prepare?
      !!@test_prepare
    end

    def reset?
      !!@reset
    end

    # =================
    # = Guard methods =
    # =================

    # If one of those methods raise an exception, the Guard::GuardName instance
    # will be removed from the active guards.

    # Called once when Guard starts
    # Please override initialize method to init stuff
    def start
      migrate if run_on_start?
    end

    # Called on Ctrl-C signal (when Guard quits)
    def stop
      true
    end

    # Called on Ctrl-Z signal
    # This method should be mainly used for "reload" (really!) actions like reloading passenger/spork/bundler/...
    def reload
      migrate if run_on_start?
    end

    # Called on Ctrl-/ signal
    # This method should be principally used for long action like running all specs/tests/...
    def run_all
      migrate if run_on_start?
    end

    # Called on file(s) modifications
    def run_on_changes(paths)
      if paths.any? { |path| path.match(%r{^db/migrate/(\d+).+\.rb}) } || reset?
        migrations = paths.map { |path| Migration.new(path) }
        migrate(migrations)
      elsif paths.any? { |path| path.match(%r{^db/seeds\.rb$}) }
        seed_only
      end
    end

    def migrate(migrations = [])
      return if !reset? && migrations.empty?
      if reset?
        Compat::UI.info "Running #{rake_string}"
        result = system(rake_string)
        result &&= 'reset'
      else
        result = run_all_migrations(migrations)
      end

      Notify.new(result).notify
    end

    def seed_only
      Compat::UI.info "Running #{seed_only_string}"
      result = system(seed_only_string)
      result &&= 'seed'
      Notify.new(result).notify
    end

    def run_redo?(version)
      !reset? && version && !version.empty?
    end

    def rake_string(version = nil)
      [
        bundler_command,
        custom_command,
        rake_command,
        migrate_string(version),
        seed_string,
        prepare_string,
        rails_env_string
      ].compact.join(' ')
    end

    def seed_only_string
      [
        bundler_command,
        custom_command,
        rake_command,
        seed_string,
        prepare_string,
        rails_env_string
      ].compact.join(' ')
    end

    private

    def run_all_migrations(migrations)
      result = nil
      migrations.each do |migration|
        if migration.valid?
          Compat::UI.info "Running #{rake_string(migration.version)}"
          result = system rake_string(migration.version)
          break unless result
        else
          Compat::UI.info "Skip empty migration - #{migration.version}"
        end
      end

      result
    end

    def rake_command
      'rake' unless custom_command.to_s.match(/rake/)
    end

    def bundler_command
      'bundle exec' if bundler?
    end

    def custom_command
      "#{@cmd.strip}" if cmd?
    end

    def rails_env_string
      "RAILS_ENV=#{rails_env}" if rails_env
    end

    def prepare_string
      return if !test_prepare? || custom_command.to_s.match(/db:test:prepare/)
      'db:test:prepare'
    end

    def seed_string
      'db:seed' if @seed
    end

    def migrate_string(version)
      return if custom_command.to_s.match(/db:migrate/)

      string = 'db:migrate'
      string += ':reset' if reset?
      string += ":redo VERSION=#{version}" if run_redo?(version)
      string
    end
  end
end