#!/usr/bin/env python
# Copyright 2015 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 pngdiffer
import suppressor

# 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 test_one_file(input_filename, source_dir, working_dir,
                  pdfium_test_path, image_differ, redirect_output=False):
  input_path = os.path.join(source_dir, input_filename)
  pdf_path = os.path.join(working_dir, input_filename)

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

  shutil.copyfile(input_path, pdf_path)
  sys.stdout.flush()
  error = common.RunCommand([pdfium_test_path, '--png', pdf_path],
                            redirect_output)
  if error:
    print "FAILURE: " + input_filename + "; " + str(error)
    return False
  return not image_differ.HasDifferences(input_filename, source_dir,
                                         working_dir, redirect_output)


def test_one_file_parallel(working_dir, pdfium_test_path, image_differ,
                           test_case):
  """Wrapper function to call test_one_file() and redirect output to stdout."""
  old_stdout = sys.stdout
  old_stderr = sys.stderr
  sys.stdout = cStringIO.StringIO()
  sys.stderr = sys.stdout
  input_filename, source_dir = test_case
  result = test_one_file(input_filename, source_dir, working_dir,
                         pdfium_test_path, image_differ, True);
  output = sys.stdout
  sys.stdout = old_stdout
  sys.stderr = old_stderr
  return (result, output.getvalue(), input_filename, source_dir)


def handle_result(test_suppressor, input_filename, input_path, result,
                  surprises, failures):
  if test_suppressor.IsSuppressed(input_filename):
    if result:
      surprises.append(input_path)
  else:
    if not result:
      failures.append(input_path)


def main():
  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')
  options, args = parser.parse_args()
  finder = common.DirectoryFinder(options.build_dir)
  pdfium_test_path = finder.ExecutablePath('pdfium_test')
  if not os.path.exists(pdfium_test_path):
    print "FAILURE: Can't find test executable '%s'" % pdfium_test_path
    print "Use --build-dir to specify its location."
    return 1
  working_dir = finder.WorkingDir(os.path.join('testing', 'corpus'))
  if not os.path.exists(working_dir):
    os.makedirs(working_dir)

  test_suppressor = suppressor.Suppressor(finder)
  image_differ = pngdiffer.PNGDiffer(finder)

  # test files are under .../pdfium/testing/corpus.
  failures = []
  surprises = []
  walk_from_dir = finder.TestingDir('corpus');
  input_file_re = re.compile('^[a-zA-Z0-9_.]+[.]pdf$')
  test_cases = []
  for source_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(source_dir, input_filename)
        if os.path.isfile(input_path):
          test_cases.append((input_filename, source_dir))

  if options.num_workers > 1:
    pool = multiprocessing.Pool(options.num_workers)
    worker_func = functools.partial(test_one_file_parallel, working_dir,
                                    pdfium_test_path, image_differ)
    worker_results = pool.imap(worker_func, test_cases)
    for worker_result in worker_results:
      result, output, input_filename, source_dir = worker_result
      input_path = os.path.join(source_dir, input_filename)
      sys.stdout.write(output)
      handle_result(test_suppressor, input_filename, input_path, result,
                    surprises, failures)
  else:
    for test_case in test_cases:
      input_filename, source_dir = test_case
      result = test_one_file(input_filename, source_dir, working_dir,
                             pdfium_test_path, image_differ)
      handle_result(test_suppressor, input_filename, input_path, result,
                    surprises, failures)

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

  if failures:
    failures.sort()
    print '\n\nSummary of Failures:'
    for failure in failures:
      print failure
    return 1

  return 0


if __name__ == '__main__':
  sys.exit(main())