# Copyright 2019 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.
# ==============================================================================
"""Utils for make_zip tests."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import functools
import itertools
import operator
import os
import re
import string
import traceback
import zipfile
import numpy as np
from six import StringIO

# pylint: disable=g-import-not-at-top
import tensorflow as tf
from google.protobuf import text_format
from tensorflow.lite.testing import generate_examples_report as report_lib
from tensorflow.lite.testing import string_util_wrapper
from tensorflow.python.framework import graph_util as tf_graph_util

# A map from names to functions which make test cases.
_MAKE_TEST_FUNCTIONS_MAP = {}


# A decorator to register the make test functions.
# Usage:
# All the make_*_test should be registered. Example:
#   @register_make_test_function()
#   def make_conv_tests(options):
#     # ...
# If a function is decorated by other decorators, it's required to specify the
# name explicitly. Example:
#   @register_make_test_function(name="make_unidirectional_sequence_lstm_tests")
#   @test_util.enable_control_flow_v2
#   def make_unidirectional_sequence_lstm_tests(options):
#     # ...
def register_make_test_function(name=None):

  def decorate(function, name=name):
    if name is None:
      name = function.__name__
    _MAKE_TEST_FUNCTIONS_MAP[name] = function

  return decorate


def get_test_function(test_function_name):
  """Get the test function according to the test function name."""

  if test_function_name not in _MAKE_TEST_FUNCTIONS_MAP:
    return None
  return _MAKE_TEST_FUNCTIONS_MAP[test_function_name]


RANDOM_SEED = 342

TF_TYPE_INFO = {
    tf.float32: (np.float32, "FLOAT"),
    tf.float16: (np.float16, "FLOAT"),
    tf.int32: (np.int32, "INT32"),
    tf.uint8: (np.uint8, "QUANTIZED_UINT8"),
    tf.int16: (np.int16, "QUANTIZED_INT16"),
    tf.int64: (np.int64, "INT64"),
    tf.bool: (np.bool, "BOOL"),
    tf.string: (np.string_, "STRING"),
}


class ExtraTocoOptions(object):
  """Additional toco options besides input, output, shape."""

  def __init__(self):
    # Whether to ignore control dependency nodes.
    self.drop_control_dependency = False
    # Allow custom ops in the toco conversion.
    self.allow_custom_ops = False
    # Rnn states that are used to support rnn / lstm cells.
    self.rnn_states = None
    # Split the LSTM inputs from 5 inoputs to 18 inputs for TFLite.
    self.split_tflite_lstm_inputs = None
    # The inference input type passed to TFLiteConvert.
    self.inference_input_type = None
    # The inference output type passed to TFLiteConvert.
    self.inference_output_type = None


def create_tensor_data(dtype, shape, min_value=-100, max_value=100):
  """Build tensor data spreading the range [min_value, max_value)."""

  if dtype in TF_TYPE_INFO:
    dtype = TF_TYPE_INFO[dtype][0]

  if dtype in (tf.float32, tf.float16):
    value = (max_value - min_value) * np.random.random_sample(shape) + min_value
  elif dtype in (tf.int32, tf.uint8, tf.int64, tf.int16):
    value = np.random.randint(min_value, max_value + 1, shape)
  elif dtype == tf.bool:
    value = np.random.choice([True, False], size=shape)
  elif dtype == np.string_:
    # Not the best strings, but they will do for some basic testing.
    letters = list(string.ascii_uppercase)
    return np.random.choice(letters, size=shape).astype(dtype)
  return np.dtype(dtype).type(value) if np.isscalar(value) else value.astype(
      dtype)


def create_scalar_data(dtype, min_value=-100, max_value=100):
  """Build scalar tensor data range from min_value to max_value exclusively."""

  if dtype in TF_TYPE_INFO:
    dtype = TF_TYPE_INFO[dtype][0]

  if dtype in (tf.float32, tf.float16):
    value = (max_value - min_value) * np.random.random() + min_value
  elif dtype in (tf.int32, tf.uint8, tf.int64, tf.int16):
    value = np.random.randint(min_value, max_value + 1)
  return np.array(value, dtype=dtype)


def freeze_graph(session, outputs):
  """Freeze the current graph.

  Args:
    session: Tensorflow sessions containing the graph
    outputs: List of output tensors

  Returns:
    The frozen graph_def.
  """
  return tf_graph_util.convert_variables_to_constants(
      session, session.graph.as_graph_def(), [x.op.name for x in outputs])


def format_result(t):
  """Convert a tensor to a format that can be used in test specs."""
  if t.dtype.kind not in [np.dtype(np.string_).kind, np.dtype(np.object_).kind]:
    # Output 9 digits after the point to ensure the precision is good enough.
    values = ["{:.9f}".format(value) for value in list(t.flatten())]
    return ",".join(values)
  else:
    return string_util_wrapper.SerializeAsHexString(t.flatten())


def write_examples(fp, examples):
  """Given a list `examples`, write a text format representation.

  The file format is csv like with a simple repeated pattern. We would ike
  to use proto here, but we can't yet due to interfacing with the Android
  team using this format.

  Args:
    fp: File-like object to write to.
    examples: Example dictionary consiting of keys "inputs" and "outputs"
  """

  def write_tensor(fp, x):
    """Write tensor in file format supported by TFLITE example."""
    fp.write("dtype,%s\n" % x.dtype)
    fp.write("shape," + ",".join(map(str, x.shape)) + "\n")
    fp.write("values," + format_result(x) + "\n")

  fp.write("test_cases,%d\n" % len(examples))
  for example in examples:
    fp.write("inputs,%d\n" % len(example["inputs"]))
    for i in example["inputs"]:
      write_tensor(fp, i)
    fp.write("outputs,%d\n" % len(example["outputs"]))
    for i in example["outputs"]:
      write_tensor(fp, i)


def write_test_cases(fp, model_name, examples):
  """Given a dictionary of `examples`, write a text format representation.

  The file format is protocol-buffer-like, even though we don't use proto due
  to the needs of the Android team.

  Args:
    fp: File-like object to write to.
    model_name: Filename where the model was written to, relative to filename.
    examples: Example dictionary consiting of keys "inputs" and "outputs"
  """

  fp.write("load_model: %s\n" % os.path.basename(model_name))
  for example in examples:
    fp.write("reshape {\n")
    for t in example["inputs"]:
      fp.write("  input: \"" + ",".join(map(str, t.shape)) + "\"\n")
    fp.write("}\n")
    fp.write("invoke {\n")

    for t in example["inputs"]:
      fp.write("  input: \"" + format_result(t) + "\"\n")
    for t in example["outputs"]:
      fp.write("  output: \"" + format_result(t) + "\"\n")
      fp.write("  output_shape: \"" + ",".join([str(dim) for dim in t.shape]) +
               "\"\n")
    fp.write("}\n")


def get_input_shapes_map(input_tensors):
  """Gets a map of input names to shapes.

  Args:
    input_tensors: List of input tensor tuples `(name, shape, type)`.

  Returns:
    {string : list of integers}.
  """
  input_arrays = [tensor[0] for tensor in input_tensors]
  input_shapes_list = []

  for _, shape, _ in input_tensors:
    dims = None
    if shape:
      dims = [dim.value for dim in shape.dims]
    input_shapes_list.append(dims)

  input_shapes = {
      name: shape
      for name, shape in zip(input_arrays, input_shapes_list)
      if shape
  }
  return input_shapes


def _normalize_output_name(output_name):
  """Remove :0 suffix from tensor names."""
  return output_name.split(":")[0] if output_name.endswith(
      ":0") else output_name


# How many test cases we may have in a zip file. Too many test cases will
# slow down the test data generation process.
_MAX_TESTS_PER_ZIP = 500


def make_zip_of_tests(options,
                      test_parameters,
                      make_graph,
                      make_test_inputs,
                      extra_toco_options=ExtraTocoOptions(),
                      use_frozen_graph=False,
                      expected_tf_failures=0):
  """Helper to make a zip file of a bunch of TensorFlow models.

  This does a cartestian product of the dictionary of test_parameters and
  calls make_graph() for each item in the cartestian product set.
  If the graph is built successfully, then make_test_inputs() is called to
  build expected input/output value pairs. The model is then converted to tflite
  with toco, and the examples are serialized with the tflite model into a zip
  file (2 files per item in the cartesian product set).

  Args:
    options: An Options instance.
    test_parameters: Dictionary mapping to lists for each parameter.
      e.g. `{"strides": [[1,3,3,1], [1,2,2,1]], "foo": [1.2, 1.3]}`
    make_graph: function that takes current parameters and returns tuple
      `[input1, input2, ...], [output1, output2, ...]`
    make_test_inputs: function taking `curr_params`, `session`, `input_tensors`,
      `output_tensors` and returns tuple `(input_values, output_values)`.
    extra_toco_options: Additional toco options.
    use_frozen_graph: Whether or not freeze graph before toco converter.
    expected_tf_failures: Number of times tensorflow is expected to fail in
      executing the input graphs. In some cases it is OK for TensorFlow to fail
      because the one or more combination of parameters is invalid.

  Raises:
    RuntimeError: if there are converter errors that can't be ignored.
  """
  zip_path = os.path.join(options.output_path, options.zip_to_output)
  parameter_count = 0
  for parameters in test_parameters:
    parameter_count += functools.reduce(
        operator.mul, [len(values) for values in parameters.values()])

  all_parameter_count = parameter_count
  if options.multi_gen_state:
    all_parameter_count += options.multi_gen_state.parameter_count
  if not options.no_tests_limit and all_parameter_count > _MAX_TESTS_PER_ZIP:
    raise RuntimeError(
        "Too many parameter combinations for generating '%s'.\n"
        "There are at least %d combinations while the upper limit is %d.\n"
        "Having too many combinations will slow down the tests.\n"
        "Please consider splitting the test into multiple functions.\n" %
        (zip_path, all_parameter_count, _MAX_TESTS_PER_ZIP))
  if options.multi_gen_state:
    options.multi_gen_state.parameter_count = all_parameter_count

  # TODO(aselle): Make this allow multiple inputs outputs.
  if options.multi_gen_state:
    archive = options.multi_gen_state.archive
  else:
    archive = zipfile.PyZipFile(zip_path, "w")
  zip_manifest = []
  convert_report = []
  toco_errors = 0

  processed_labels = set()

  if options.make_edgetpu_tests:
    extra_toco_options.inference_input_type = tf.uint8
    extra_toco_options.inference_output_type = tf.uint8
    # Only count parameters when fully_quantize is True.
    parameter_count = 0
    for parameters in test_parameters:
      if True in parameters.get("fully_quantize", []):
        parameter_count += functools.reduce(operator.mul, [
            len(values)
            for key, values in parameters.items()
            if key != "fully_quantize"
        ])

  label_base_path = zip_path
  if options.multi_gen_state:
    label_base_path = options.multi_gen_state.label_base_path

  for parameters in test_parameters:
    keys = parameters.keys()
    for curr in itertools.product(*parameters.values()):
      label = label_base_path.replace(".zip", "_") + (",".join(
          "%s=%r" % z for z in sorted(zip(keys, curr))).replace(" ", ""))
      if label[0] == "/":
        label = label[1:]
      if label in processed_labels:
        # Do not populate data for the same label more than once. It will cause
        # errors when unzipping.
        continue
      processed_labels.add(label)

      param_dict = dict(zip(keys, curr))

      if options.make_edgetpu_tests and not param_dict.get(
          "fully_quantize", False):
        continue

      def generate_inputs_outputs(tflite_model_binary,
                                  min_value=0,
                                  max_value=255):
        """Generate input values and output values of the given tflite model.

        Args:
          tflite_model_binary: A serialized flatbuffer as a string.
          min_value: min value for the input tensor.
          max_value: max value for the input tensor.

        Returns:
          (input_values, output_values): input values and output values built.
        """
        interpreter = tf.lite.Interpreter(model_content=tflite_model_binary)
        interpreter.allocate_tensors()

        input_details = interpreter.get_input_details()
        input_values = []
        for input_detail in input_details:
          input_value = create_tensor_data(
              input_detail["dtype"],
              input_detail["shape"],
              min_value=min_value,
              max_value=max_value)
          interpreter.set_tensor(input_detail["index"], input_value)
          input_values.append(input_value)

        interpreter.invoke()

        output_details = interpreter.get_output_details()
        output_values = []
        for output_detail in output_details:
          output_values.append(interpreter.get_tensor(output_detail["index"]))

        return input_values, output_values

      def build_example(label, param_dict_real):
        """Build the model with parameter values set in param_dict_real.

        Args:
          label: Label of the model (i.e. the filename in the zip).
          param_dict_real: Parameter dictionary (arguments to the factories
            make_graph and make_test_inputs)

        Returns:
          (tflite_model_binary, report) where tflite_model_binary is the
          serialized flatbuffer as a string and report is a dictionary with
          keys `toco_log` (log of toco conversion), `tf_log` (log of tf
          conversion), `toco` (a string of success status of the conversion),
          `tf` (a string success status of the conversion).
        """

        np.random.seed(RANDOM_SEED)
        report = {"toco": report_lib.NOTRUN, "tf": report_lib.FAILED}

        # Build graph
        report["tf_log"] = ""
        report["toco_log"] = ""
        tf.compat.v1.reset_default_graph()

        with tf.device("/cpu:0"):
          try:
            inputs, outputs = make_graph(param_dict_real)
          except (tf.errors.UnimplementedError, tf.errors.InvalidArgumentError,
                  ValueError):
            report["tf_log"] += traceback.format_exc()
            return None, report

        sess = tf.compat.v1.Session()
        try:
          baseline_inputs, baseline_outputs = (
              make_test_inputs(param_dict_real, sess, inputs, outputs))
        except (tf.errors.UnimplementedError, tf.errors.InvalidArgumentError,
                ValueError):
          report["tf_log"] += traceback.format_exc()
          return None, report
        report["toco"] = report_lib.FAILED
        report["tf"] = report_lib.SUCCESS
        # Convert graph to toco
        input_tensors = [(input_tensor.name.split(":")[0], input_tensor.shape,
                          input_tensor.dtype) for input_tensor in inputs]
        output_tensors = [_normalize_output_name(out.name) for out in outputs]
        # pylint: disable=g-long-ternary
        graph_def = freeze_graph(
            sess,
            tf.global_variables() + inputs +
            outputs) if use_frozen_graph else sess.graph_def

        if "split_tflite_lstm_inputs" in param_dict_real:
          extra_toco_options.split_tflite_lstm_inputs = param_dict_real[
              "split_tflite_lstm_inputs"]
        tflite_model_binary, toco_log = options.tflite_convert_function(
            options,
            graph_def,
            input_tensors,
            output_tensors,
            extra_toco_options=extra_toco_options,
            test_params=param_dict_real)
        report["toco"] = (
            report_lib.SUCCESS
            if tflite_model_binary is not None else report_lib.FAILED)
        report["toco_log"] = toco_log

        if options.save_graphdefs:
          archive.writestr(label + ".pbtxt",
                           text_format.MessageToString(graph_def),
                           zipfile.ZIP_DEFLATED)

        if tflite_model_binary:
          if options.make_edgetpu_tests:
            # Set proper min max values according to input dtype.
            baseline_inputs, baseline_outputs = generate_inputs_outputs(
                tflite_model_binary, min_value=0, max_value=255)
          archive.writestr(label + ".bin", tflite_model_binary,
                           zipfile.ZIP_DEFLATED)
          example = {"inputs": baseline_inputs, "outputs": baseline_outputs}

          example_fp = StringIO()
          write_examples(example_fp, [example])
          archive.writestr(label + ".inputs", example_fp.getvalue(),
                           zipfile.ZIP_DEFLATED)

          example_fp2 = StringIO()
          write_test_cases(example_fp2, label + ".bin", [example])
          archive.writestr(label + "_tests.txt", example_fp2.getvalue(),
                           zipfile.ZIP_DEFLATED)

          zip_manifest.append(label + "\n")

        return tflite_model_binary, report

      _, report = build_example(label, param_dict)

      if report["toco"] == report_lib.FAILED:
        ignore_error = False
        if not options.known_bugs_are_errors:
          for pattern, bug_number in options.known_bugs.items():
            if re.search(pattern, label):
              print("Ignored converter error due to bug %s" % bug_number)
              ignore_error = True
        if not ignore_error:
          toco_errors += 1
          print("-----------------\nconverter error!\n%s\n-----------------\n" %
                report["toco_log"])

      convert_report.append((param_dict, report))

  if not options.no_conversion_report:
    report_io = StringIO()
    report_lib.make_report_table(report_io, zip_path, convert_report)
    if options.multi_gen_state:
      archive.writestr("report_" + options.multi_gen_state.test_name + ".html",
                       report_io.getvalue())
    else:
      archive.writestr("report.html", report_io.getvalue())

  if options.multi_gen_state:
    options.multi_gen_state.zip_manifest.extend(zip_manifest)
  else:
    archive.writestr("manifest.txt", "".join(zip_manifest),
                     zipfile.ZIP_DEFLATED)

  # Log statistics of what succeeded
  total_conversions = len(convert_report)
  tf_success = sum(
      1 for x in convert_report if x[1]["tf"] == report_lib.SUCCESS)
  toco_success = sum(
      1 for x in convert_report if x[1]["toco"] == report_lib.SUCCESS)
  percent = 0
  if tf_success > 0:
    percent = float(toco_success) / float(tf_success) * 100.
  tf.compat.v1.logging.info(
      ("Archive %s Considered %d graphs, %d TF evaluated graphs "
       " and %d TOCO converted graphs (%.1f%%"), zip_path, total_conversions,
      tf_success, toco_success, percent)

  tf_failures = parameter_count - tf_success

  if tf_failures / parameter_count > 0.8:
    raise RuntimeError(("Test for '%s' is not very useful. "
                        "TensorFlow fails in %d percent of the cases.") %
                       (zip_path, int(100 * tf_failures / parameter_count)))

  if not options.make_edgetpu_tests and tf_failures != expected_tf_failures:
    raise RuntimeError(("Expected TF to fail %d times while generating '%s', "
                        "but that happened %d times") %
                       (expected_tf_failures, zip_path, tf_failures))

  if not options.ignore_converter_errors and toco_errors > 0:
    raise RuntimeError("Found %d errors while generating toco models" %
                       toco_errors)
