# -*- encoding : utf-8 -*-
class Git::Repository
  delegate :commits, :commit, :tree, :tags, :heads, :commit_count, :log, :branches, :to => :repo

  attr_accessor :path, :name, :repo, :last_actor

  def initialize(path)
    @path = path
    @update_callbacks = []
  end

  def master
    commits('master', 1).first
  end

  def to_s
    name
  end

  def repo
    @repo ||= Grit::Repo.new(path) rescue Grit::Repo.new(GAP_REPO_PATH)
  end

  # Adds a callback to be fired after update file.
  #
  # block - A block that expects this Git::Repository instance and the created
  #         commit's SHA1 as the arguments.
  #
  # For example:
  #
  # after_update_file do |repo, sha|
  #   # callback body
  # end
  #
  # Returns nothing.
  def after_update_file(&block)
    @update_callbacks << block
  end

  # Writes file to repo and runs 'after_update_file' callbacks
  #
  # path    - path to file in repository
  # data    - new content of file
  # options - an optional Hash of options
  #           :head    - branch name to write this commit to
  #                      (Default: 'master')
  #           :actor   - author of this commit. (See Git::Repository#get_actor)
  #                      (Default: nil)
  #           :message - commit message
  #                      (Default: "Updated file <filename>")
  #
  # Returns commits sha if committing was successful and false otherwise
  def update_file(path, data, options = {})
    head = options[:head].to_s || 'master'
    actor = get_actor(options[:actor])
    filename = File.split(path).last
    message = options[:message]
    message = "Updated file #{filename}" if message.nil? or message.empty?

    # can not write to unexisted branch
    return false if branches.select{|b| b.name == head}.size != 1

    parent = commits(head).first

    index = repo.index
    index.read_tree(parent.tree.id)

    # can not create new file
    return false if (index.current_tree / path).nil?

    index.add(path, data)
    sha = index.commit(message, :parents => [parent], :actor => actor,
                                :last_tree => parent.tree.id, :head => head)
    # call all defined callbacks
    @update_callbacks.each do |cb|
      cb.call(self, sha)
    end
    sha
  end

  def self.create(path)
    repo = Grit::Repo.init_bare(path)
    repo.enable_daemon_serve
  end

  def paginate_commits(treeish, options = {})
    options[:page] = 1 unless options[:page].present?
    options[:page] = options[:page].to_i

    options[:per_page] = 20 unless options[:per_page].present?
    options[:per_page] = options[:per_page].to_i

    skip = options[:per_page] * (options[:page] - 1)
    last_page = (skip + options[:per_page]) >= commit_count(treeish)

    [commits(treeish, options[:per_page], skip), options[:page], last_page]
  end

  # Pretty object inspection
  def inspect
    %Q{#<Git::Repository "#{@path}">}
  end

  protected

    # Creates new Grit::Actor instance
    #
    #           Might be:
    #                      * A Hash containing :name and :email
    #                      * An instance of Grit::Actor
    #                      * A String like "John Doe <j.doe@example.com>
    #                      * Any object that responds to `name` and `email` methods
    def get_actor(actor = nil)
      @last_actor = case actor.class.to_s
        when 'Grit::Actor' then options[:actor]
        when 'Hash'        then Grit::Actor.new(actor[:name], actor[:email])
        when 'String'      then Grit::Actor.from_stirng(actor)
        else begin
          if actor.respond_to?(:name) and actor.respond_to?(:email)
            Grit::Actor.new(actor.name, actor.email)
          else
            config = Grit::Config.new(repo)
            Grit::Actor.new(config['user.name'], config['user.email'])
          end
        end
      end
      @last_actor
    end

end