require 'picsolve_docker_builder/base'
require 'psych'
require 'git'

module PicsolveDockerBuilder
  module Helpers
    # Parses the config file
    class ConfigVersionUpdate
      include PicsolveDockerBuilder::Base

      def self.update_task
        log = Logger.new(STDOUT)

        if ENV['service_name'].nil? || ENV['service_tag'].nil?
          log.info 'No update needed as environment variables service_name '\
            'and service_tag are not in place'

          return
        end

        cvu = new
        cvu.update_commit_push(
          ENV['service_name'],
          ENV['service_tag'],
          ENV['service_commit'],
          ENV['service_url']
        )
      end

      def initialize(path = nil)
        @path = path || config_file
      end

      def check_for_uncommitted
        return unless git.status.changed.keys.include? config_path

        log.error "Uncommited changes to '#{config_path}'. Can't continue ..."
        exit(1)
      end

      def commit_and_push(
        container_name,
        tag,
        git_commit,
        git_url
      )
        git.add config_path
        message = "Upgrades version of '#{container_name}'"\
          " to tag '#{tag}'"

        message += "\n  git_commit=#{git_commit}" if git_commit
        message += "\n  git_url=#{git_url}" if git_url
        git.commit message
        git.push(git_remote, git_branch)
      rescue Git::GitExecuteError => exception
        log.warn "Problem during commiting: #{exception}"
      end

      def git_remote_branch
        ENV['GIT_BRANCH'] || 'origin/develop'
      end

      def git_remote
        git_remote_branch.split('/')[0]
      end

      def git_branch
        git_remote_branch.split('/')[1]
      end

      def config_file
        unless File.file?(config_path)
          File.open(config_path, 'w') do |file|
            file.write('')
          end
        end
        File.new config_path
      end

      def config_path
        '.docker-builder.version.yml'
      end

      def git
        @git ||= Git.open('.')
      end

      def update_commit_push(*args)
        check_for_uncommitted
        update(*args)
        commit_and_push(*args)
      end

      def update(
        container_name,
        tag,
        git_commit,
        git_url
      )
        read
        config = {
          'compose' => {
            'containers' => {
              container_name => {
                'tag' => tag
              }
            }
          }
        }
        c = config['compose']['containers'][container_name]

        c['git_commit'] = git_commit unless git_commit.nil?
        c['git_url'] = git_url unless git_url.nil?

        @config = @config.deep_merge(config)
        write
      end

      def write
        File.open(@path, 'w') do |file|
          file.write(Psych.dump(config))
        end
      end

      def default
        {}
      end

      def config
        return @config unless @config.nil?
        read
      end

      def read
        @config = default
        begin
          yaml = Psych.load_file @path
          @config = @config.deep_merge(yaml) if yaml
        rescue Errno::ENOENT
          raise "cannot find config at '#{path}'"
        end
      end
    end
  end
end