module Berkshelf
  module RSpec
    module Git
      require_relative "path_helpers"
      include Berkshelf::RSpec::PathHelpers

      def git_origin_for(repo, options = {})
        "file://#{generate_fake_git_remote("git@github.com/chef/#{repo}.git", options)}/.git"
      end

      def generate_fake_git_remote(uri, options = {})
        name = uri.split("/").last || "rspec_cookbook"
        name = name.gsub(".git", "")
        path = remotes.join(name)

        capture(:stdout) do
          Dir.chdir(remotes) { generate_git_cookbook(name) }

          Dir.chdir(path) do
            shell_out "git config receive.denyCurrentBranch ignore"
            shell_out "echo \"# a change!\" >> content_file"
            shell_out "git add ."
            shell_out "git commit -am \"A commit.\""

            if options[:tags]
              options[:tags].each do |tag|
                shell_out "echo \"#{tag}\" > content_file"
                shell_out "git add content_file"
                shell_out "git commit -am \"#{tag} content\""
                shell_out "git tag \"#{tag}\""
              end
            end

            if options[:branches]
              options[:branches].each do |branch|
                shell_out "git checkout -b #{branch} master"
                shell_out "echo \"#{branch}\" > content_file"
                shell_out "git add content_file"
                shell_out "git commit -am \"#{branch} content\""
                shell_out "git checkout master"
              end
            end
          end
        end

        path
      end

      # Calculate the git sha for the given ref.
      #
      # @param [#to_s] repo
      #   the repository to show the ref for
      # @param [#to_s] ref
      #   the ref to show
      #
      # @return [String]
      def sha_for_ref(repo, ref)
        Dir.chdir(remote_path(repo)) do
          shell_out("git show-ref #{ref}").stdout.split(/\s/).first
        end
      end

      # The clone path the given repo.
      #
      # @param [#to_s] repo
      #   the name of the local repo
      #
      # @return [Pathname]
      #   the path to the clone
      def clone_path(repo)
        clones.join(repo.to_s)
      end

      # The clone path the remote repo.
      #
      # @param [#to_s] repo
      #   the name of the remote repo
      #
      # @return [Pathname]
      #   the path to the clone
      def remote_path(repo)
        remotes.join(repo.to_s)
      end

      private

      # The path to store the local git clones.
      #
      # @return [Pathname]
      def clones
        ensure_and_return(tmp_path.join("clones"))
      end

      # The path to store the git remotes.
      #
      # @return [Pathname]
      def remotes
        ensure_and_return(tmp_path.join("remotes"))
      end

      # Generate a cookbook by the given name.
      #
      # @param [#to_s] name
      #   the name of the cookbook to create
      # @param [Hash] options
      #   the list ooptions to pass to the generator
      def generate_git_cookbook(name, options = {})
        options = {
          skip_vagrant: true,
          skip_test_kitchen: true,
          force: true,
        }.merge(options)

        Berkshelf::Cli.new.invoke(:cookbook, [name.to_s], options)
      end

      # Make sure the given path exists and return the path
      #
      # @param [#to_s] path
      #   the path to create and return
      #
      # @return [Pathname]
      def ensure_and_return(path)
        FileUtils.mkdir(path) unless File.exist?(path)
        Pathname.new(path).expand_path
      end
    end
  end
end