require 'pathname'

require_relative 'slug/bucket'
require_relative 'repo'
require_relative 'shellable'

module Hillary
  class Slug
    include Shellable

    attr_reader :branch, :version

    SlugArchiveError = Class.new(StandardError)
    SlugNotFoundError = Class.new(StandardError)

    class << self
      def build(path = File.expand_path('.'), version = Repo::Version.create!, options = {})
        return unless version.sluggable?

        new(path, version, options).tap{|slug| slug.build}
      end
    end

    def initialize(path, version, options = {})
      @path = path
      @version = version
      @bucket = options[:bucket] || Bucket.new

      @logger = if options[:logger]
        options[:logger]
      else
        Logger.new($stdout).tap do |logger|
          logger.formatter = proc do |severity, time, _, msg|
            "#{time.strftime('%Y-%m-%d %H:%M:%S')} #{severity} - #{msg}\n"
          end
        end
      end
    end

    def build
      if version.master?
        create_slug_if_missing
        copy_slug
      elsif version.dev?
        create_slug
        upload_slug
      end
    end

    def name
      "#{project_name}_slug_#{version.name}"
    end

    def canonical_name
      "#{project_name}_slug_#{version.sha}"
    end

  private
    attr_reader :logger, :bucket, :path

    def create_slug_if_missing
      return if bucket.exists?(canonical_storage_slug_file)

      if version.production?
        raise SlugNotFoundError, "Attempted to create production slug from RC, but canonical slug (#{bucket.name}:/#{canonical_storage_slug_file}) couldn't be found"
      else
        logger.warn("Unable to find slug #{bucket.name}:/#{canonical_storage_slug_file}")
        create_slug
        upload_slug
      end
    end

    def copy_slug
      logger.info("Copying #{bucket.name}:/#{canonical_storage_slug_file} to #{bucket.name}:/#{storage_slug_file}")
      bucket.copy(canonical_storage_slug_file, storage_slug_file)
    end

    def create_slug
      Dir.chdir(project_parent_directory) do
        logger.info("Creating slug #{canonical_slug_file}")

        command = "tar --exclude \".git\" --exclude \"vendor/bundle\" -zcvf #{canonical_slug_file} #{project_name}"

        shell(command, logger: logger)
      end
    end

    def upload_slug
      logger.info("Uploading #{canonical_slug_file} to #{bucket.name}:/#{canonical_storage_slug_file}")
      bucket.write(canonical_storage_slug_file, project_parent_directory.join(canonical_slug_file))
    end

    def slug_file
      "#{name}.tar.gz"
    end

    def storage_slug_file
      if version.master?
        if version.production?
          "production/#{slug_file}"
        else
          "rc/#{slug_file}"
        end
      elsif version.dev?
        "dev/#{slug_file}"
      end
    end

    def canonical_slug_file
      "#{canonical_name}.tar.gz"
    end

    def canonical_storage_slug_file
      "dev/#{canonical_slug_file}"
    end

    def project_directory
      Pathname.new(path).expand_path
    end

    def project_parent_directory
      project_directory.join('..').expand_path
    end

    def project_name
      project_directory.basename.to_s
    end
  end
end