module Gitlab
  module Git
    class Blob
      include Linguist::BlobHelper

      attr_accessor :name, :path, :size, :data, :mode, :id, :commit_id

      class << self
        def find(repository, sha, path)
          commit = repository.lookup(sha)
          root_tree = commit.tree

          blob_entry = find_entry_by_path(repository, root_tree.oid, path)

          return nil unless blob_entry

          blob = repository.lookup(blob_entry[:oid])

          if blob
            Blob.new(
              id: blob.oid,
              name: blob_entry[:name],
              size: blob.size,
              data: blob.content,
              mode: blob_entry[:mode],
              path: path,
              commit_id: sha,
            )
          end
        end

        def raw(repository, sha)
          blob = repository.lookup(sha)

          Blob.new(
            id: blob.oid,
            size: blob.size,
            data: blob.content,
          )
        end

        # Recursive search of blob id by path
        #
        # Ex.
        #   blog/            # oid: 1a
        #     app/           # oid: 2a
        #       models/      # oid: 3a
        #       file.rb      # oid: 4a
        #
        #
        # Blob.find_entry_by_path(repo, '1a', 'app/file.rb') # => '4a'
        #
        def find_entry_by_path(repository, root_id, path)
          root_tree = repository.lookup(root_id)
          path_arr = path.split('/')

          entry = root_tree.find do |entry|
            entry[:name] == path_arr[0]
          end

          return nil unless entry

          if path_arr.size > 1
            return nil unless entry[:type] == :tree
          else
            return nil unless entry[:type] == :blob
          end

          if path_arr.size > 1
            path_arr.shift
            find_entry_by_path(repository, entry[:oid], path_arr.join('/'))
          else
            entry
          end
        end
      end

      def initialize(options)
        %w(id name path size data mode commit_id).each do |key|
          self.send("#{key}=", options[key.to_sym])
        end
      end

      def empty?
        !data || data == ''
      end
    end
  end
end