#!/bin/sh
 
. git-sh-setup
 
indent='  '
 
make_node()
{
  sha=$1
  type=$2
  shape=$3
  color=$4
  short_sha=$(echo $sha | cut -c 1-10)
  echo "$indent" \"$sha\" [ label=\"$type $short_sha...\", shape=$shape, color=$color ] \;
}
 
make_edge()
{
  source=$1
  destination=$2
  label=$3
  if [ -n "$label" ] ; then label=label=\"$label\" ; fi
  echo "$indent" \"$source\" '->' \"$destination\" [ $label ] \;
}
 
graph_blob()
{
  make_node $1 blob ellipse red
}
 
graph_commit_parts()
{
  commit=$1
  while read type sha
  do
    if [ "$type" = 'parent' -o "$type" = 'tree' ]
    then
      make_edge $commit $sha $type
    fi
  done
}
 
graph_commit()
{
  sha=$1
  make_node $1 commit box3d green
  git cat-file commit $sha | graph_commit_parts $sha
}
 
graph_tree_parts()
{
  tree=$1
  while read mode type sha name
  do
    make_edge $tree $sha $name
  done
}
 
graph_tree()
{
  sha=$1
  make_node $sha tree box blue
  git ls-tree $sha | graph_tree_parts $sha
}
 
graph_refs()
{
  while read sha name
  do
    echo "$indent" \"$name\" [ shape=plaintext ] \;
    make_edge $name $sha
  done
}
 
make_edges()
{
  while read sha type
  do
    graph_$type $sha
  done
}
 
echo digraph
echo {
echo   bgcolor = black ;
echo   node [ color = white, fontcolor = white ] ;
echo   edge [ color = white, fontcolor = white ] ;
git ls-objects | make_edges
git show-ref | graph_refs
echo }