# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Format tensors (ndarrays) for screen display and navigation."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import copy
import re

import numpy as np
from six.moves import xrange  # pylint: disable=redefined-builtin

from tensorflow.python.debug.cli import debugger_cli_common

_NUMPY_OMISSION = "...,"
_NUMPY_DEFAULT_EDGE_ITEMS = 3

_NUMBER_REGEX = re.compile(r"[-+]?([0-9][-+0-9eE\.]+|nan|inf)(\s|,|\])")

BEGIN_INDICES_KEY = "i0"
OMITTED_INDICES_KEY = "omitted"

DEFAULT_TENSOR_ELEMENT_HIGHLIGHT_FONT_ATTR = "bold"


class HighlightOptions(object):
  """Options for highlighting elements of a tensor."""

  def __init__(self,
               criterion,
               description=None,
               font_attr=DEFAULT_TENSOR_ELEMENT_HIGHLIGHT_FONT_ATTR):
    """Constructor of HighlightOptions.

    Args:
      criterion: (callable) A callable of the following signature:
        def to_highlight(X):
          # Args:
          #   X: The tensor to highlight elements in.
          #
          # Returns:
          #   (boolean ndarray) A boolean ndarray of the same shape as X
          #   indicating which elements are to be highlighted (iff True).
        This callable will be used as the argument of np.argwhere() to
        determine which elements of the tensor are to be highlighted.
      description: (str) Description of the highlight criterion embodied by
        criterion.
      font_attr: (str) Font attribute to be applied to the
        highlighted elements.

    """

    self.criterion = criterion
    self.description = description
    self.font_attr = font_attr


def format_tensor(tensor,
                  tensor_name,
                  include_metadata=False,
                  np_printoptions=None,
                  highlight_options=None):
  """Generate a RichTextLines object showing a tensor in formatted style.

  Args:
    tensor: The tensor to be displayed, as a numpy ndarray or other
      appropriate format (e.g., None representing uninitialized tensors).
    tensor_name: Name of the tensor, as a str. If set to None, will suppress
      the tensor name line in the return value.
    include_metadata: Whether metadata such as dtype and shape are to be
      included in the formatted text.
    np_printoptions: A dictionary of keyword arguments that are passed to a
      call of np.set_printoptions() to set the text format for display numpy
      ndarrays.
    highlight_options: (HighlightOptions) options for highlighting elements
      of the tensor.

  Returns:
    A RichTextLines object. Its annotation field has line-by-line markups to
    indicate which indices in the array the first element of each line
    corresponds to.
  """
  lines = []

  if tensor_name is not None:
    lines.append("Tensor \"%s\":" % tensor_name)

  if tensor is None:
    if lines:
      lines.append("")
    lines.append("Uninitialized tensor")
    return debugger_cli_common.RichTextLines(lines)
  elif not isinstance(tensor, np.ndarray):
    # If tensor is not a np.ndarray, return simple text-line representation of
    # the object without annotations.
    if lines:
      lines.append("")
    lines.extend(repr(tensor).split("\n"))
    return debugger_cli_common.RichTextLines(lines)

  if include_metadata:
    lines.append("  dtype: %s" % str(tensor.dtype))
    lines.append("  shape: %s" % str(tensor.shape))

  if lines:
    lines.append("")
  hlines = len(lines)

  # Apply custom string formatting options for numpy ndarray.
  if np_printoptions is not None:
    np.set_printoptions(**np_printoptions)

  array_lines = repr(tensor).split("\n")
  lines.extend(array_lines)

  if tensor.dtype.type is not np.string_:
    # Parse array lines to get beginning indices for each line.

    # TODO(cais): Currently, we do not annotate string-type tensors due to
    #   difficulty in escaping sequences. Address this issue.
    annotations = _annotate_ndarray_lines(
        array_lines, tensor, np_printoptions=np_printoptions, offset=hlines)

  formatted = debugger_cli_common.RichTextLines(lines, annotations=annotations)

  # Perform optional highlighting.
  if highlight_options is not None:
    indices_list = list(np.argwhere(highlight_options.criterion(tensor)))

    total_elements = np.size(tensor)
    highlight_summary = "Highlighted%s: %d of %d element(s) (%.2f%%)" % (
        "(%s)" % highlight_options.description if highlight_options.description
        else "", len(indices_list), total_elements,
        len(indices_list) / float(total_elements) * 100.0)

    formatted.lines[0] += " " + highlight_summary

    if indices_list:
      indices_list = [list(indices) for indices in indices_list]

      are_omitted, rows, start_cols, end_cols = locate_tensor_element(
          formatted, indices_list)
      for is_omitted, row, start_col, end_col in zip(are_omitted, rows,
                                                     start_cols, end_cols):
        if is_omitted or start_col is None or end_col is None:
          continue

        if row in formatted.font_attr_segs:
          formatted.font_attr_segs[row].append(
              (start_col, end_col, highlight_options.font_attr))
        else:
          formatted.font_attr_segs[row] = [(start_col, end_col,
                                            highlight_options.font_attr)]

  return formatted


def _annotate_ndarray_lines(
    array_lines, tensor, np_printoptions=None, offset=0):
  """Generate annotations for line-by-line begin indices of tensor text.

  Parse the numpy-generated text representation of a numpy ndarray to
  determine the indices of the first element of each text line (if any
  element is present in the line).

  For example, given the following multi-line ndarray text representation:
      ["array([[ 0.    ,  0.0625,  0.125 ,  0.1875],",
       "       [ 0.25  ,  0.3125,  0.375 ,  0.4375],",
       "       [ 0.5   ,  0.5625,  0.625 ,  0.6875],",
       "       [ 0.75  ,  0.8125,  0.875 ,  0.9375]])"]
  the generate annotation will be:
      {0: {BEGIN_INDICES_KEY: [0, 0]},
       1: {BEGIN_INDICES_KEY: [1, 0]},
       2: {BEGIN_INDICES_KEY: [2, 0]},
       3: {BEGIN_INDICES_KEY: [3, 0]}}

  Args:
    array_lines: Text lines representing the tensor, as a list of str.
    tensor: The tensor being formatted as string.
    np_printoptions: A dictionary of keyword arguments that are passed to a
      call of np.set_printoptions().
    offset: Line number offset applied to the line indices in the returned
      annotation.

  Returns:
    An annotation as a dict.
  """

  if np_printoptions and "edgeitems" in np_printoptions:
    edge_items = np_printoptions["edgeitems"]
  else:
    edge_items = _NUMPY_DEFAULT_EDGE_ITEMS

  annotations = {}

  # Put metadata about the tensor in the annotations["tensor_metadata"].
  annotations["tensor_metadata"] = {
      "dtype": tensor.dtype, "shape": tensor.shape}

  dims = np.shape(tensor)
  ndims = len(dims)
  if ndims == 0:
    # No indices for a 0D tensor.
    return annotations

  curr_indices = [0] * len(dims)
  curr_dim = 0
  for i in xrange(len(array_lines)):
    line = array_lines[i].strip()

    if not line:
      # Skip empty lines, which can appear for >= 3D arrays.
      continue

    if line == _NUMPY_OMISSION:
      annotations[offset + i] = {OMITTED_INDICES_KEY: copy.copy(curr_indices)}
      curr_indices[curr_dim - 1] = dims[curr_dim - 1] - edge_items
    else:
      num_lbrackets = line.count("[")  # TODO(cais): String array escaping.
      num_rbrackets = line.count("]")

      curr_dim += num_lbrackets - num_rbrackets

      annotations[offset + i] = {BEGIN_INDICES_KEY: copy.copy(curr_indices)}
      if num_rbrackets == 0:
        line_content = line[line.rfind("[") + 1:]
        num_elements = line_content.count(",")
        curr_indices[curr_dim - 1] += num_elements
      else:
        if curr_dim > 0:
          curr_indices[curr_dim - 1] += 1
          for k in xrange(curr_dim, ndims):
            curr_indices[k] = 0

  return annotations


def locate_tensor_element(formatted, indices):
  """Locate a tensor element in formatted text lines, given element indices.

  Given a RichTextLines object representing a tensor and indices of the sought
  element, return the row number at which the element is located (if exists).

  Args:
    formatted: A RichTextLines object containing formatted text lines
      representing the tensor.
    indices: Indices of the sought element, as a list of int or a list of list
      of int. The former case is for a single set of indices to look up,
      whereas the latter case is for looking up a batch of indices sets at once.
      In the latter case, the indices must be in ascending order, or a
      ValueError will be raised.

  Returns:
    1) A boolean indicating whether the element falls into an omitted line.
    2) Row index.
    3) Column start index, i.e., the first column in which the representation
       of the specified tensor starts, if it can be determined. If it cannot
       be determined (e.g., due to ellipsis), None.
    4) Column end index, i.e., the column right after the last column that
       represents the specified tensor. Iff it cannot be determined, None.

  For return values described above are based on a single set of indices to
    look up. In the case of batch mode (multiple sets of indices), the return
    values will be lists of the types described above.

  Raises:
    AttributeError: If:
      Input argument "formatted" does not have the required annotations.
    ValueError: If:
      1) Indices do not match the dimensions of the tensor, or
      2) Indices exceed sizes of the tensor, or
      3) Indices contain negative value(s).
      4) If in batch mode, and if not all sets of indices are in ascending
         order.
  """

  if isinstance(indices[0], list):
    indices_list = indices
    input_batch = True
  else:
    indices_list = [indices]
    input_batch = False

  # Check that tensor_metadata is available.
  if "tensor_metadata" not in formatted.annotations:
    raise AttributeError("tensor_metadata is not available in annotations.")

  # Sanity check on input argument.
  _validate_indices_list(indices_list, formatted)

  dims = formatted.annotations["tensor_metadata"]["shape"]
  batch_size = len(indices_list)
  lines = formatted.lines
  annot = formatted.annotations
  prev_r = 0
  prev_line = ""
  prev_indices = [0] * len(dims)

  # Initialize return values
  are_omitted = [None] * batch_size
  row_indices = [None] * batch_size
  start_columns = [None] * batch_size
  end_columns = [None] * batch_size

  batch_pos = 0  # Current position in the batch.

  for r in xrange(len(lines)):
    if r not in annot:
      continue

    if BEGIN_INDICES_KEY in annot[r]:
      indices_key = BEGIN_INDICES_KEY
    elif OMITTED_INDICES_KEY in annot[r]:
      indices_key = OMITTED_INDICES_KEY

    matching_indices_list = [
        ind for ind in indices_list[batch_pos:]
        if prev_indices <= ind < annot[r][indices_key]
    ]

    if matching_indices_list:
      num_matches = len(matching_indices_list)

      match_start_columns, match_end_columns = _locate_elements_in_line(
          prev_line, matching_indices_list, prev_indices)

      start_columns[batch_pos:batch_pos + num_matches] = match_start_columns
      end_columns[batch_pos:batch_pos + num_matches] = match_end_columns
      are_omitted[batch_pos:batch_pos + num_matches] = [
          OMITTED_INDICES_KEY in annot[prev_r]
      ] * num_matches
      row_indices[batch_pos:batch_pos + num_matches] = [prev_r] * num_matches

      batch_pos += num_matches
      if batch_pos >= batch_size:
        break

    prev_r = r
    prev_line = lines[r]
    prev_indices = annot[r][indices_key]

  if batch_pos < batch_size:
    matching_indices_list = indices_list[batch_pos:]
    num_matches = len(matching_indices_list)

    match_start_columns, match_end_columns = _locate_elements_in_line(
        prev_line, matching_indices_list, prev_indices)

    start_columns[batch_pos:batch_pos + num_matches] = match_start_columns
    end_columns[batch_pos:batch_pos + num_matches] = match_end_columns
    are_omitted[batch_pos:batch_pos + num_matches] = [
        OMITTED_INDICES_KEY in annot[prev_r]
    ] * num_matches
    row_indices[batch_pos:batch_pos + num_matches] = [prev_r] * num_matches

  if input_batch:
    return are_omitted, row_indices, start_columns, end_columns
  else:
    return are_omitted[0], row_indices[0], start_columns[0], end_columns[0]


def _validate_indices_list(indices_list, formatted):
  prev_ind = None
  for ind in indices_list:
    # Check indices match tensor dimensions.
    dims = formatted.annotations["tensor_metadata"]["shape"]
    if len(ind) != len(dims):
      raise ValueError("Dimensions mismatch: requested: %d; actual: %d" %
                       (len(ind), len(dims)))

    # Check indices is within size limits.
    for req_idx, siz in zip(ind, dims):
      if req_idx >= siz:
        raise ValueError("Indices exceed tensor dimensions.")
      if req_idx < 0:
        raise ValueError("Indices contain negative value(s).")

    # Check indices are in ascending order.
    if prev_ind and ind < prev_ind:
      raise ValueError("Input indices sets are not in ascending order.")

    prev_ind = ind


def _locate_elements_in_line(line, indices_list, ref_indices):
  """Determine the start and end indices of an element in a line.

  Args:
    line: (str) the line in which the element is to be sought.
    indices_list: (list of list of int) list of indices of the element to
       search for. Assumes that the indices in the batch are unique and sorted
       in ascending order.
    ref_indices: (list of int) reference indices, i.e., the indices of the
      first element represented in the line.

  Returns:
    start_columns: (list of int) start column indices, if found. If not found,
      None.
    end_columns: (list of int) end column indices, if found. If not found,
      None.
    If found, the element is represented in the left-closed-right-open interval
      [start_column, end_column].
  """

  batch_size = len(indices_list)
  offsets = [indices[-1] - ref_indices[-1] for indices in indices_list]

  start_columns = [None] * batch_size
  end_columns = [None] * batch_size

  if _NUMPY_OMISSION in line:
    ellipsis_index = line.find(_NUMPY_OMISSION)
  else:
    ellipsis_index = len(line)

  matches_iter = re.finditer(_NUMBER_REGEX, line)

  batch_pos = 0

  offset_counter = 0
  for match in matches_iter:
    if match.start() > ellipsis_index:
      # Do not attempt to search beyond ellipsis.
      break

    if offset_counter == offsets[batch_pos]:
      start_columns[batch_pos] = match.start()
      # Remove the final comma, right bracket, or whitespace.
      end_columns[batch_pos] = match.end() - 1

      batch_pos += 1
      if batch_pos >= batch_size:
        break

    offset_counter += 1

  return start_columns, end_columns
