#!/usr/bin/env python
# Copyright 2016 The PDFium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import cStringIO
import functools
import multiprocessing
import optparse
import os
import re
import shutil
import subprocess
import sys

import common
import gold
import pngdiffer
import suppressor

class KeyboardInterruptError(Exception): pass

# Nomenclature:
#   x_root - "x"
#   x_filename - "x.ext"
#   x_path - "path/to/a/b/c/x.ext"
#   c_dir - "path/to/a/b/c"

def TestOneFileParallel(this, test_case):
  """Wrapper to call GenerateAndTest() and redirect output to stdout."""
  try:
    input_filename, source_dir = test_case
    result = this.GenerateAndTest(input_filename, source_dir);
    return (result, input_filename, source_dir)
  except KeyboardInterrupt:
    raise KeyboardInterruptError()


class TestRunner:
  def __init__(self, dirname):
    self.test_dir = dirname
    self.enforce_expected_images = False

  # GenerateAndTest returns a tuple <success, outputfiles> where
  # success is a boolean indicating whether the tests passed comparison
  # tests and outputfiles is a list tuples:
  #          (path_to_image, md5_hash_of_pixelbuffer)
  def GenerateAndTest(self, input_filename, source_dir):
    input_root, _ = os.path.splitext(input_filename)
    expected_txt_path = os.path.join(source_dir, input_root + '_expected.txt')

    pdf_path = os.path.join(self.working_dir, input_root + '.pdf')

    # Remove any existing generated images from previous runs.
    actual_images = self.image_differ.GetActualFiles(input_filename, source_dir,
                                                     self.working_dir)
    for image in actual_images:
      if os.path.exists(image):
        os.remove(image)

    sys.stdout.flush()

    raised_exception = self.Generate(source_dir, input_filename, input_root,
                                     pdf_path)

    if raised_exception is not None:
      print 'FAILURE: %s; %s' % (input_filename, raised_exception)
      return False, []

    results = []
    if os.path.exists(expected_txt_path):
      raised_exception = self.TestText(input_root, expected_txt_path, pdf_path)
    else:
      raised_exception, results = self.TestPixel(input_root, pdf_path)

    if raised_exception is not None:
      print 'FAILURE: %s; %s' % (input_filename, raised_exception)
      return False, results

    if actual_images:
      if self.image_differ.HasDifferences(input_filename, source_dir,
                                          self.working_dir):
        return False, results
    else:
      if (self.enforce_expected_images
          and not self.test_suppressor.IsImageDiffSuppressed(input_filename)):
        print 'FAILURE: %s; Missing expected images' % input_filename
        return False, results

    return True, results

  def Generate(self, source_dir, input_filename, input_root, pdf_path):
    original_path = os.path.join(source_dir, input_filename)
    input_path = os.path.join(source_dir, input_root + '.in')

    input_event_path = os.path.join(source_dir, input_root + '.evt')
    if os.path.exists(input_event_path):
      output_event_path = os.path.splitext(pdf_path)[0] + '.evt'
      shutil.copyfile(input_event_path, output_event_path)

    if not os.path.exists(input_path):
      if os.path.exists(original_path):
        shutil.copyfile(original_path, pdf_path)
      return None

    sys.stdout.flush()

    return common.RunCommand(
        [sys.executable, self.fixup_path, '--output-dir=' + self.working_dir,
            input_path])


  def TestText(self, input_root, expected_txt_path, pdf_path):
    txt_path = os.path.join(self.working_dir, input_root + '.txt')

    with open(txt_path, 'w') as outfile:
      cmd_to_run = [self.pdfium_test_path, pdf_path]
      subprocess.check_call(cmd_to_run, stdout=outfile)

    cmd = [sys.executable, self.text_diff_path, expected_txt_path, txt_path]
    return common.RunCommand(cmd)


  def TestPixel(self, input_root, pdf_path):
    cmd_to_run = [self.pdfium_test_path, '--send-events', '--png']
    if self.gold_results:
      cmd_to_run.append('--md5')
    cmd_to_run.append(pdf_path)
    return common.RunCommandExtractHashedFiles(cmd_to_run)

  def HandleResult(self, input_filename, input_path, result):
    success, image_paths = result
    if self.gold_results:
      if image_paths:
        for img_path, md5_hash in image_paths:
          # the output filename (without extension becomes the test name)
          test_name = os.path.splitext(os.path.split(img_path)[1])[0]
          self.gold_results.AddTestResult(test_name, md5_hash, img_path)

    if self.test_suppressor.IsResultSuppressed(input_filename):
      self.result_suppressed_cases.append(input_filename)
      if success:
        self.surprises.append(input_path)
    else:
      if not success:
        self.failures.append(input_path)


  def Run(self):
    parser = optparse.OptionParser()

    parser.add_option('--build-dir', default=os.path.join('out', 'Debug'),
                      help='relative path from the base source directory')

    parser.add_option('-j', default=multiprocessing.cpu_count(),
                      dest='num_workers', type='int',
                      help='run NUM_WORKERS jobs in parallel')

    parser.add_option('--gold_properties', default='', dest="gold_properties",
                      help='Key value pairs that are written to the top level of the JSON file that is ingested by Gold.')

    parser.add_option('--gold_key', default='', dest="gold_key",
                      help='Key value pairs that are added to the "key" field of the JSON file that is ingested by Gold.')

    parser.add_option('--gold_output_dir', default='', dest="gold_output_dir",
                      help='Path of where to write the JSON output to be uploaded to Gold.')

    parser.add_option('--gold_ignore_hashes', default='', dest="gold_ignore_hashes",
                      help='Path to a file with MD5 hashes we wish to ignore.')

    parser.add_option('--ignore_errors', action="store_true", dest="ignore_errors",
                      help='Prevents the return value from being non-zero when image comparison fails.')

    options, args = parser.parse_args()

    finder = common.DirectoryFinder(options.build_dir)
    self.fixup_path = finder.ScriptPath('fixup_pdf_template.py')
    self.text_diff_path = finder.ScriptPath('text_diff.py')

    self.source_dir = finder.TestingDir()
    if self.test_dir != 'corpus':
      test_dir = finder.TestingDir(os.path.join('resources', self.test_dir))
    else:
      test_dir = finder.TestingDir(self.test_dir)

    self.pdfium_test_path = finder.ExecutablePath('pdfium_test')
    if not os.path.exists(self.pdfium_test_path):
      print "FAILURE: Can't find test executable '%s'" % self.pdfium_test_path
      print 'Use --build-dir to specify its location.'
      return 1

    self.working_dir = finder.WorkingDir(os.path.join('testing', self.test_dir))
    if not os.path.exists(self.working_dir):
      os.makedirs(self.working_dir)

    self.feature_string = subprocess.check_output([self.pdfium_test_path,
                                                   '--show-config'])
    self.test_suppressor = suppressor.Suppressor(finder, self.feature_string)
    self.image_differ = pngdiffer.PNGDiffer(finder)

    walk_from_dir = finder.TestingDir(test_dir);

    self.test_cases = []
    self.execution_suppressed_cases = []
    input_file_re = re.compile('^.+[.](in|pdf)$')
    if args:
      for file_name in args:
        file_name.replace('.pdf', '.in')
        input_path = os.path.join(walk_from_dir, file_name)
        if not os.path.isfile(input_path):
          print "Can't find test file '%s'" % file_name
          return 1

        self.test_cases.append((os.path.basename(input_path),
                           os.path.dirname(input_path)))
    else:
      for file_dir, _, filename_list in os.walk(walk_from_dir):
        for input_filename in filename_list:
          if input_file_re.match(input_filename):
            input_path = os.path.join(file_dir, input_filename)
            if self.test_suppressor.IsExecutionSuppressed(input_path):
              self.execution_suppressed_cases.append(input_path)
            else:
              if os.path.isfile(input_path):
                self.test_cases.append((input_filename, file_dir))

    self.failures = []
    self.surprises = []
    self.result_suppressed_cases = []

    # Collect Gold results if an output directory was named.
    self.gold_results = None
    if options.gold_output_dir:
      self.gold_results = gold.GoldResults('pdfium',
                                           options.gold_output_dir,
                                           options.gold_properties,
                                           options.gold_key,
                                           options.gold_ignore_hashes)

    if options.num_workers > 1 and len(self.test_cases) > 1:
      try:
        pool = multiprocessing.Pool(options.num_workers)
        worker_func = functools.partial(TestOneFileParallel, self)

        worker_results = pool.imap(worker_func, self.test_cases)
        for worker_result in worker_results:
          result, input_filename, source_dir = worker_result
          input_path = os.path.join(source_dir, input_filename)

          self.HandleResult(input_filename, input_path, result)

      except KeyboardInterrupt:
        pool.terminate()
      finally:
        pool.close()
        pool.join()
    else:
      for test_case in self.test_cases:
        input_filename, input_file_dir = test_case
        result = self.GenerateAndTest(input_filename, input_file_dir)
        self.HandleResult(input_filename,
                          os.path.join(input_file_dir, input_filename), result)

    if self.gold_results:
      self.gold_results.WriteResults()

    if self.surprises:
      self.surprises.sort()
      print '\n\nUnexpected Successes:'
      for surprise in self.surprises:
        print surprise

    if self.failures:
      self.failures.sort()
      print '\n\nSummary of Failures:'
      for failure in self.failures:
        print failure

    self._PrintSummary()

    if self.failures:
      if not options.ignore_errors:
        return 1

    return 0

  def _PrintSummary(self):
    number_test_cases = len(self.test_cases)
    number_failures = len(self.failures)
    number_suppressed = len(self.result_suppressed_cases)
    number_successes = number_test_cases - number_failures - number_suppressed
    number_surprises = len(self.surprises)
    print
    print 'Test cases executed: %d' % number_test_cases
    print '  Successes: %d' % number_successes
    print '  Suppressed: %d' % number_suppressed
    print '    Surprises: %d' % number_surprises
    print '  Failures: %d' % number_failures
    print
    print 'Test cases not executed: %d' % len(self.execution_suppressed_cases)

  def SetEnforceExpectedImages(self, new_value):
    """Set whether to enforce that each test case provide an expected image."""
    self.enforce_expected_images = new_value