"""
Caffe network visualization: draw the NetParameter protobuffer.

NOTE: this requires pydot>=1.0.2, which is not included in requirements.txt
since it requires graphviz and other prerequisites outside the scope of the
Caffe.
"""

from caffe.proto import caffe_pb2
from google.protobuf import text_format
import pydot

# Internal layer and blob styles.
LAYER_STYLE = {'shape': 'record', 'fillcolor': '#6495ED',
         'style': 'filled'}
NEURON_LAYER_STYLE = {'shape': 'record', 'fillcolor': '#90EE90',
         'style': 'filled'}
BLOB_STYLE = {'shape': 'octagon', 'fillcolor': '#F0E68C',
        'style': 'filled'}
def get_enum_name_by_value():
  desc = caffe_pb2.LayerParameter.LayerType.DESCRIPTOR
  d = {}
  for k,v in desc.values_by_name.items():
    d[v.number] = k
  return d

def get_pydot_graph(caffe_net):
  pydot_graph = pydot.Dot(caffe_net.name, graph_type='digraph', rankdir="BT")
  pydot_nodes = {}
  pydot_edges = []
  d = get_enum_name_by_value()
  for layer in caffe_net.layers:
    name = layer.name
    layertype = d[layer.type]
    if (len(layer.bottom) == 1 and len(layer.top) == 1 and
        layer.bottom[0] == layer.top[0]):
      # We have an in-place neuron layer.
      pydot_nodes[name + '_' + layertype] = pydot.Node(
          '%s (%s)' % (name, layertype), **NEURON_LAYER_STYLE)
    else:
      pydot_nodes[name + '_' + layertype] = pydot.Node(
          '%s (%s)' % (name, layertype), **LAYER_STYLE)
    for bottom_blob in layer.bottom:
      pydot_nodes[bottom_blob + '_blob'] = pydot.Node(
        '%s' % (bottom_blob), **BLOB_STYLE)
      pydot_edges.append((bottom_blob + '_blob', name + '_' + layertype))
    for top_blob in layer.top:
      pydot_nodes[top_blob + '_blob'] = pydot.Node(
        '%s' % (top_blob))
      pydot_edges.append((name + '_' + layertype, top_blob + '_blob'))
  # Now, add the nodes and edges to the graph.
  for node in pydot_nodes.values():
    pydot_graph.add_node(node)
  for edge in pydot_edges:
    pydot_graph.add_edge(
        pydot.Edge(pydot_nodes[edge[0]], pydot_nodes[edge[1]]))
  return pydot_graph

def draw_net(caffe_net, ext='png'):
  """Draws a caffe net and returns the image string encoded using the given
  extension.

  Input:
    caffe_net: a caffe.proto.caffe_pb2.NetParameter protocol buffer.
    ext: the image extension. Default 'png'.
  """
  return get_pydot_graph(caffe_net).create(format=ext)

def draw_net_to_file(caffe_net, filename):
  """Draws a caffe net, and saves it to file using the format given as the
  file extension. Use '.raw' to output raw text that you can manually feed
  to graphviz to draw graphs.
  """
  ext = filename[filename.rfind('.')+1:]
  with open(filename, 'wb') as fid:
    fid.write(draw_net(caffe_net, ext))