module Git

# File lib/git/branch/stray.rb, line 59
def branch_name_from(symbolic_ref)
  # extract the branch name from a given symbolic ref
  # local:  e.g. "refs/heads/master"
  # remote: e.g. "refs/remotes/origin/master"
  symbolic_ref.sub(%r{\Arefs/(heads|remotes/[^/]+)/}, '')
end

# File lib/git/branch/stray.rb, line 83
def delete_stray_branches
  stray_branches.each_consented('Delete stray branch "%s"', inspector: :yellow) do |stray|
    system("git branch -d #{stray}")
    next if $CHILD_STATUS.success?

    Array(stray).each_consented('Delete unmerged branch "%s"', inspector: :red) do |unmerged|
      system("git branch -D #{unmerged}")
    end
  end
end

# File lib/git/branch/stray.rb, line 33
def head_refs_for(remote)
  # alternative implementation that requires
  # access to the remote tracking repository
  #
  # git("ls-remote --quiet --refs --heads #{remote}")
  #   .map { |sha_and_ref| sha_and_ref.split(/\s+/).last }
  #
  # but we assume that this utility will mainly be
  # used as part of a "git workflow" that includes
  # regular pruning of remote tracking references,
  # which means we don't have to go over the wire!
  git("for-each-ref --format='%(refname)' refs/remotes/#{remote}")
end

# File lib/git/branch/stray.rb, line 94
def list_stray_branches
  stray_branches.each do |stray|
    system("git --no-pager branch -vv --list #{stray}")
  end
end

# File lib/git/branch/stray.rb, line 29
def local_head_refs
  git("for-each-ref --format='%(refname)' refs/heads")
end

# File lib/git/branch/stray.rb, line 55
def merge_ref_for(branch)
  git("config --local --get branch.#{branch}.merge").first
end

# File lib/git/branch/stray.rb, line 51
def remote_for(branch)
  git("config --local --get branch.#{branch}.remote").first
end

# File lib/git/branch/stray.rb, line 66
def stray_branches
  to_branch_name = method(:branch_name_from)

  local_branch_names = local_head_refs.map(&to_branch_name)

  remote_branch_names = Hash.new { |branch_names, remote|
    branch_names[remote] = head_refs_for(remote).map(&to_branch_name)
  }

  local_branch_names.find_all { |local_branch|
    (remote = remote_for(local_branch)) &&
    (merge_ref = merge_ref_for(local_branch)) &&
    (upstream_branch = to_branch_name[merge_ref]) &&
    !remote_branch_names[remote].include?(upstream_branch)
  }
end

# File lib/git/branch/stray.rb, line 47
def upstream_reference_for(branch)
  git("rev-parse --verify --abbrev-ref #{branch}@{upstream}").first
end