# frozen_string_literal: true

module Groundskeeper
  # Wraps git executable and adds a few convenience methods on top.
  class Git
    COMMAND = "git"
    # git arguments
    STATUS = "status"
    FETCH_WITH_TAGS = "fetch --tags"
    VERSION = "--version"
    TAGS_ASC = "tag -l --sort=v:refname"
    LATEST_TAG_COMMIT = "#{COMMAND} rev-list --tags --max-count=1"
    LATEST_TAG_NAME = format("describe --tags $(%s)", LATEST_TAG_COMMIT)
    LATEST_TAG_BRANCHES = format("branch --contains $(%s)", LATEST_TAG_COMMIT)
    LATEST_CHANGES = "log %s..HEAD --oneline"
    CREATE_AND_CHECKOUT_BRANCH = "checkout -b %s"
    ADD_UPDATE = "add -u"
    COMMIT = "commit -m \"%s\""
    ADD_TAG = "tag %s"
    PUSH_HEAD_WITH_TAGS = "push origin head --tags"

    attr_reader :git

    # Wraps the "git" shell command.
    class Executable
      def execute(arguments)
        `#{COMMAND} #{arguments}`
      end
    end

    def self.build
      new Executable.new
    end

    def initialize(git)
      @git = git
    end

    def status
      git.execute(STATUS)
    end

    def fetch
      git.execute(FETCH_WITH_TAGS)
    end

    def version
      semantic_version = /\d+.\d+.\d+/

      git.execute(VERSION).match(semantic_version)[0]
    end

    def list_tags
      git.execute(TAGS_ASC)
    end

    def latest_tag_name_across_branches
      git.execute(LATEST_TAG_NAME).chop
    end

    def branches_containing_latest_tag
      git.execute(LATEST_TAG_BRANCHES).split("\n").map(&:strip)
    end

    def raw_changes_since_latest_tag
      latest_changes = format(LATEST_CHANGES, latest_tag_name_across_branches)

      git.execute(latest_changes).split("\n")
    end

    def create_and_checkout_branch(name)
      git.execute(format(CREATE_AND_CHECKOUT_BRANCH, name))
    end

    def add_update
      git.execute(ADD_UPDATE)
    end

    def commit(message)
      git.execute(format(COMMIT, message))
    end

    def add_tag(name)
      git.execute(format(ADD_TAG, name))
    end

    def push_with_tags
      git.execute(PUSH_HEAD_WITH_TAGS)
    end
  end
end