# -*- coding: utf-8 -*-
# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Upload all debug symbols required for crash reporting purposes.

This script need only be used to upload release builds symbols or to debug
crashes on non-release builds (in which case try to only upload the symbols
for those executables involved).
"""

from __future__ import print_function

import itertools
import json
import os
import socket
import sys
import textwrap
import tempfile
import time

import requests
from six.moves import http_client as httplib
from six.moves import urllib

from chromite.lib import cache
from chromite.lib import commandline
from chromite.lib import constants
from chromite.lib import cros_build_lib
from chromite.lib import cros_logging as logging
from chromite.lib import gs
from chromite.lib import osutils
from chromite.lib import path_util
from chromite.lib import retry_stats
from chromite.scripts import cros_generate_breakpad_symbols

# Needs to be after chromite imports.
# We don't want to import the general keyring module as that will implicitly
# try to import & connect to a dbus server.  That's a waste of time.
sys.modules['keyring'] = None


# URLs used for uploading symbols.
OFFICIAL_UPLOAD_URL = 'https://prod-crashsymbolcollector-pa.googleapis.com/v1'
STAGING_UPLOAD_URL = 'https://staging-crashsymbolcollector-pa.googleapis.com/v1'

# The crash server rejects files that are this big.
CRASH_SERVER_FILE_LIMIT = 700 * 1024 * 1024
# Give ourselves a little breathing room from what the server expects.
DEFAULT_FILE_LIMIT = CRASH_SERVER_FILE_LIMIT - (10 * 1024 * 1024)


# The batch limit when talking to the dedup server.  We avoid sending one at a
# time as the round trip overhead will dominate.  Conversely, we avoid sending
# all at once so we can start uploading symbols asap -- the symbol server is a
# bit slow and will take longer than anything else.
DEDUPE_LIMIT = 100

# How long to wait for the server to respond with the results.  Note that the
# larger the limit above, the larger this will need to be.  So we give it ~1
# second per item max.
DEDUPE_TIMEOUT = DEDUPE_LIMIT

# How long to wait for the notification to finish (in seconds).
DEDUPE_NOTIFY_TIMEOUT = 240

# The minimum average rate (in bytes per second) that we expect to maintain
# when uploading symbols.  This has to allow for symbols that are up to
# CRASH_SERVER_FILE_LIMIT in size.
UPLOAD_MIN_RATE = CRASH_SERVER_FILE_LIMIT // (30 * 60)

# The lowest timeout (in seconds) we'll allow.  If the server is overloaded,
# then there might be a delay in setting up the connection, not just with the
# transfer.  So even a small file might need a larger value.
UPLOAD_MIN_TIMEOUT = 5 * 60


# Sleep for 500ms in between uploads to avoid DoS'ing symbol server.
SLEEP_DELAY = 0.5


# Number of seconds to wait before retrying an upload.  The delay will double
# for each subsequent retry of the same symbol file.
INITIAL_RETRY_DELAY = 1

# Allow up to 7 attempts to upload a symbol file (total delay may be
# 1+2+4+8+16+32=63 seconds).
MAX_RETRIES = 6

# Number of total errors, before uploads are no longer attempted.
# This is used to avoid lots of errors causing unreasonable delays.
MAX_TOTAL_ERRORS_FOR_RETRY = 30

# Category to use for collection upload retry stats.
UPLOAD_STATS = 'UPLOAD'


def BatchGenerator(iterator, batch_size):
  """Given an iterator, break into lists of size batch_size.

  The result is a generator, that will only read in as many inputs as needed for
  the current batch. The final result can be smaller than batch_size.
  """
  batch = []
  for i in iterator:
    batch.append(i)
    if len(batch) >= batch_size:
      yield batch
      batch = []

  if batch:
    # if there was anything left in the final batch, yield it.
    yield batch


def IsTarball(path):
  """Guess if this is a tarball based on the filename."""
  parts = path.split('.')
  if len(parts) <= 1:
    return False

  if parts[-1] == 'tar':
    return True

  if parts[-2] == 'tar':
    return parts[-1] in ('bz2', 'gz', 'xz')

  return parts[-1] in ('tbz2', 'tbz', 'tgz', 'txz')


class SymbolFile(object):
  """This class represents the state of a symbol file during processing.

  Attributes:
    display_path: Name of symbol file that should be consistent between builds.
    file_name: Transient path of the symbol file.
    header: ReadSymsHeader output. Dict with assorted meta-data.
    status: INITIAL, DUPLICATE, or UPLOADED based on status of processing.
    dedupe_item: None or instance of DedupeItem for this symbol file.
    dedupe_push_state: Opaque value to return to dedupe code for file.
    display_name: Read only friendly (short) file name for logging.
    file_size: Read only size of the symbol file.
  """
  INITIAL = 'initial'
  DUPLICATE = 'duplicate'
  UPLOADED = 'uploaded'
  ERROR = 'error'

  def __init__(self, display_path, file_name):
    """An instance of this class represents a symbol file over time.

    Args:
      display_path: A unique/persistent between builds name to present to the
                    crash server. It is the file name, relative to where it
                    came from (tarball, breakpad dir, etc).
      file_name: A the current location of the symbol file.
    """
    self.display_path = display_path
    self.file_name = file_name
    self.header = cros_generate_breakpad_symbols.ReadSymsHeader(file_name)
    self.status = SymbolFile.INITIAL

  @property
  def display_name(self):
    return os.path.basename(self.display_path)

  def FileSize(self):
    return os.path.getsize(self.file_name)


def FindSymbolFiles(tempdir, paths):
  """Locate symbol files in |paths|

  This returns SymbolFile objects that contain file references which are valid
  after this exits. Those files may exist externally, or be created in the
  tempdir (say, when expanding tarballs). The caller must not consider
  SymbolFile's valid after tempdir is cleaned up.

  Args:
    tempdir: Path to use for temporary files.
    paths: A list of input paths to walk. Files are returned w/out any checks.
      Dirs are searched for files that end in ".sym". Urls are fetched and then
      processed. Tarballs are unpacked and walked.

  Yields:
    A SymbolFile for every symbol file found in paths.
  """
  cache_dir = path_util.GetCacheDir()
  common_path = os.path.join(cache_dir, constants.COMMON_CACHE)
  tar_cache = cache.TarballCache(common_path)

  for p in paths:
    o = urllib.parse.urlparse(p)
    if o.scheme:
      # Support globs of filenames.
      ctx = gs.GSContext()
      for gspath in ctx.LS(p):
        logging.info('processing files inside %s', gspath)
        o = urllib.parse.urlparse(gspath)
        key = ('%s%s' % (o.netloc, o.path)).split('/')
        # The common cache will not be LRU, removing the need to hold a read
        # lock on the cached gsutil.
        ref = tar_cache.Lookup(key)
        try:
          ref.SetDefault(gspath)
        except cros_build_lib.RunCommandError as e:
          logging.warning('ignoring %s\n%s', gspath, e)
          continue
        for sym in FindSymbolFiles(tempdir, [ref.path]):
          yield sym

    elif os.path.isdir(p):
      for root, _, files in os.walk(p):
        for f in files:
          if f.endswith('.sym'):
            # If p is '/tmp/foo' and filename is '/tmp/foo/bar/bar.sym',
            # display_path = 'bar/bar.sym'
            filename = os.path.join(root, f)
            yield SymbolFile(display_path=filename[len(p):].lstrip('/'),
                             file_name=filename)

    elif IsTarball(p):
      logging.info('processing files inside %s', p)
      tardir = tempfile.mkdtemp(dir=tempdir)
      cache.Untar(os.path.realpath(p), tardir)
      for sym in FindSymbolFiles(tardir, [tardir]):
        yield sym

    else:
      yield SymbolFile(display_path=p, file_name=p)


def AdjustSymbolFileSize(symbol, tempdir, file_limit):
  """Examine symbols files for size problems, and reduce if needed.

  If the symbols size is too big, strip out the call frame info.  The CFI
  is unnecessary for 32bit x86 targets where the frame pointer is used (as
  all of ours have) and it accounts for over half the size of the symbols
  uploaded.

  Stripped files will be created inside tempdir, and will be the callers
  responsibility to clean up.

  We also warn, if a symbols file is still too large after stripping.

  Args:
    symbol: SymbolFile instance to be examined and modified as needed..
    tempdir: A temporary directory we can create files in that the caller will
             clean up.
    file_limit: We only strip files which are larger than this limit.

  Returns:
    SymbolFile instance (original or modified as needed)
  """
  file_size = symbol.FileSize()

  if file_limit and symbol.FileSize() > file_limit:
    with cros_build_lib.UnbufferedNamedTemporaryFile(
        prefix='upload_symbols',
        dir=tempdir, delete=False) as temp_sym_file:

      temp_sym_file.writelines(
          [x for x in open(symbol.file_name, 'rb').readlines()
           if not x.startswith('STACK CFI')]
      )

      original_file_size = file_size
      symbol.file_name = temp_sym_file.name
      file_size = symbol.FileSize()

      logging.warning('stripped CFI for %s reducing size %s > %s',
                      symbol.display_name, original_file_size, file_size)

  # Hopefully the crash server will let it through.  But it probably won't.
  # Not sure what the best answer is in this case.
  if file_size >= CRASH_SERVER_FILE_LIMIT:
    logging.PrintBuildbotStepWarnings()
    logging.warning('upload file %s is awfully large, risking rejection by '
                    'the symbol server (%s > %s)', symbol.display_path,
                    file_size, CRASH_SERVER_FILE_LIMIT)

  return symbol


def GetUploadTimeout(symbol):
  """How long to wait for a specific file to upload to the crash server.

  This is a function largely to make unittesting easier.

  Args:
    symbol: A SymbolFile instance.

  Returns:
    Timeout length (in seconds)
  """
  # Scale the timeout based on the filesize.
  return max(symbol.FileSize() // UPLOAD_MIN_RATE, UPLOAD_MIN_TIMEOUT)


def ExecRequest(operator, url, timeout, api_key, **kwargs):
  """Makes a web request with default timeout, returning the json result.

  This method will raise a requests.exceptions.HTTPError if the status
  code is not 4XX, 5XX

  Note: If you are using verbose logging it is entirely possible that the
  subsystem will write your api key to the logs!

  Args:
    operator: HTTP method.
    url: Endpoint URL.
    timeout: HTTP timeout for request.
    api_key: Authentication key.

  Returns:
    HTTP response content
  """
  resp = requests.request(operator, url,
                          params={'key': api_key},
                          headers={'User-agent': 'chromite.upload_symbols'},
                          timeout=timeout, **kwargs)
  # Make sure we don't leak secret keys by accident.
  if resp.status_code > 399:
    resp.url = resp.url.replace(urllib.parse.quote(api_key), 'XX-HIDDEN-XX')
    logging.warning('Url: %s, Status: %s, response: "%s", in: %s',
                    resp.url, resp.status_code, resp.text, resp.elapsed)
  elif resp.content:
    return resp.json()

  return {}


def FindDuplicates(symbols, status_url, api_key, timeout=DEDUPE_TIMEOUT):
  """Check whether the symbol files have already been uploaded.

  Args:
    symbols: A iterable of SymbolFiles to be uploaded
    status_url: The crash URL to validate the file existence.
    api_key: Authentication key.
    timeout: HTTP timeout for request.

  Yields:
    All SymbolFiles from symbols, but duplicates have status updated to
    DUPLICATE.
  """
  for batch in BatchGenerator(symbols, DEDUPE_LIMIT):
    items = []
    result = {}
    for x in batch:
      items.append({'debug_file': x.header.name,
                    'debug_id': x.header.id.replace('-', '')})
    symbol_data = {'symbol_ids': items}
    try:
      result = ExecRequest('post', '%s/symbols:checkStatuses' %
                           status_url,
                           timeout,
                           api_key=api_key,
                           data=json.dumps(symbol_data))
    except (requests.exceptions.HTTPError,
            requests.exceptions.Timeout,
            requests.exceptions.RequestException) as e:
      logging.warning('could not identify duplicates: HTTP error: %s', e)
    for b in batch:
      b.status = SymbolFile.INITIAL
      set_match = {'debugId': b.header.id.replace('-', ''),
                   'debugFile': b.header.name}
      for cs_result in result.get('pairs', []):
        if set_match == cs_result.get('symbolId'):
          if cs_result.get('status') == 'FOUND':
            logging.debug('Found duplicate: %s', b.display_name)
            b.status = SymbolFile.DUPLICATE
            break
      yield b


def UploadSymbolFile(upload_url, symbol, api_key):
  """Upload a symbol file to the crash server, returning the status result.

  Args:
    upload_url: The crash URL to POST the |sym_file| to
    symbol: A SymbolFile instance.
    api_key: Authentication key
  """
  timeout = GetUploadTimeout(symbol)
  upload = ExecRequest('post',
                       '%s/uploads:create' % upload_url, timeout, api_key)

  if upload and 'uploadUrl' in upload.keys():
    symbol_data = {'symbol_id':
                   {'debug_file': symbol.header.name,
                    'debug_id': symbol.header.id.replace('-', '')}
                  }
    with open(symbol.file_name, 'r') as fp:
      ExecRequest('put',
                  upload['uploadUrl'], timeout,
                  api_key=api_key,
                  data=fp.read())
    ExecRequest('post',
                '%s/uploads/%s:complete' % (
                    upload_url, upload['uploadKey']),
                timeout, api_key=api_key,
                # TODO(mikenichols): Validate product_name once it is added
                # to the proto; currently unsupported.
                data=json.dumps(symbol_data))
  else:
    raise requests.exceptions.HTTPError


def PerformSymbolsFileUpload(symbols, upload_url, api_key):
  """Upload the symbols to the crash server

  Args:
    symbols: An iterable of SymbolFiles to be uploaded.
    upload_url: URL of crash server to upload too.
    api_key: Authentication key.
    failures: Tracker for total upload failures.

  Yields:
    Each symbol from symbols, perhaps modified.
  """
  failures = 0

  for s in symbols:
    if (failures < MAX_TOTAL_ERRORS_FOR_RETRY and
        s.status in (SymbolFile.INITIAL, SymbolFile.ERROR)):
      # Keeps us from DoS-ing the symbol server.
      time.sleep(SLEEP_DELAY)
      logging.info('Uploading symbol_file: %s', s.display_path)
      try:
        # This command retries the upload multiple times with growing delays. We
        # only consider the upload a failure if these retries fail.
        def ShouldRetryUpload(exception):
          if isinstance(exception, (requests.exceptions.RequestException,
                                    IOError,
                                    httplib.HTTPException, socket.error)):
            logging.info('Request failed, retrying: %s', exception)
            return True
          return False

        with cros_build_lib.TimedSection() as timer:
          retry_stats.RetryWithStats(
              UPLOAD_STATS, ShouldRetryUpload, MAX_RETRIES,
              UploadSymbolFile,
              upload_url, s, api_key,
              sleep=INITIAL_RETRY_DELAY,
              log_all_retries=True)
        if s.status != SymbolFile.DUPLICATE:
          logging.info('upload of %10i bytes took %s', s.FileSize(),
                       timer.delta)
          s.status = SymbolFile.UPLOADED
      except (requests.exceptions.HTTPError,
              requests.exceptions.Timeout,
              requests.exceptions.RequestException) as e:
        logging.warning('could not upload: %s: HTTP error: %s',
                        s.display_name, e)
        s.status = SymbolFile.ERROR
        failures += 1
      except (httplib.HTTPException, IOError, socket.error) as e:
        logging.warning('could not upload: %s: %s %s', s.display_name,
                        type(e).__name__, e)
        s.status = SymbolFile.ERROR
        failures += 1

    # We pass the symbol along, on both success and failure.
    yield s


def ReportResults(symbols, failed_list):
  """Log a summary of the symbol uploading.

  This has the side effect of fully consuming the symbols iterator.

  Args:
    symbols: An iterator of SymbolFiles to be uploaded.
    failed_list: A filename at which to write out a list of our failed uploads.

  Returns:
    The number of symbols not uploaded.
  """
  upload_failures = []
  result_counts = {
      SymbolFile.INITIAL: 0,
      SymbolFile.UPLOADED: 0,
      SymbolFile.DUPLICATE: 0,
      SymbolFile.ERROR: 0,
  }

  for s in symbols:
    result_counts[s.status] += 1
    if s.status in [SymbolFile.INITIAL, SymbolFile.ERROR]:
      upload_failures.append(s)

  # Report retry numbers.
  _, _, retries = retry_stats.CategoryStats(UPLOAD_STATS)
  if retries:
    logging.warning('%d upload retries performed.', retries)

  logging.info('Uploaded %(uploaded)d, Skipped %(duplicate)d duplicates.',
               result_counts)

  if result_counts[SymbolFile.ERROR]:
    logging.PrintBuildbotStepWarnings()
    logging.warning('%d non-recoverable upload errors',
                    result_counts[SymbolFile.ERROR])

  if result_counts[SymbolFile.INITIAL]:
    logging.PrintBuildbotStepWarnings()
    logging.warning('%d upload(s) were skipped because of excessive errors',
                    result_counts[SymbolFile.INITIAL])

  if failed_list is not None:
    with open(failed_list, 'w') as fl:
      for s in upload_failures:
        fl.write('%s\n' % s.display_path)

  return result_counts[SymbolFile.INITIAL] + result_counts[SymbolFile.ERROR]


def UploadSymbols(sym_paths, upload_url, failed_list=None,
                  upload_limit=None, strip_cfi=None, timeout=None,
                  api_key=None):
  """Upload all the generated symbols for |board| to the crash server

  Args:
    sym_paths: Specific symbol files (or dirs of sym files) to upload,
      otherwise search |breakpad_dir|
    upload_url: URL of crash server to upload too.
    failed_list: A filename at which to write out a list of our failed uploads.
    upload_limit: Integer listing how many files to upload. None for no limit.
    strip_cfi: File size at which we strip out CFI data. None for no limit.
    timeout: HTTP timeout for request.
    api_key: A string based authentication key

  Returns:
    The number of errors that were encountered.
  """
  retry_stats.SetupStats()

  # Note: This method looks like each step of processing is performed
  # sequentially for all SymbolFiles, but instead each step is a generator that
  # produces the next iteration only when it's read. This means that (except for
  # some batching) each SymbolFile goes through all of these steps before the
  # next one is processed at all.

  # This is used to hold striped
  with osutils.TempDir(prefix='upload_symbols.') as tempdir:
    symbols = FindSymbolFiles(tempdir, sym_paths)

    # Sort all of our symbols so the largest ones (probably the most important)
    # are processed first.
    symbols = list(symbols)
    symbols.sort(key=lambda s: s.FileSize(), reverse=True)

    if upload_limit is not None:
      # Restrict symbols processed to the limit.
      symbols = itertools.islice(symbols, None, upload_limit)

    # Strip CFI, if needed.
    symbols = (AdjustSymbolFileSize(s, tempdir, strip_cfi) for s in symbols)

    # Find duplicates via batch API
    symbols = FindDuplicates(symbols, upload_url, api_key, timeout)

    # Perform uploads
    symbols = PerformSymbolsFileUpload(symbols, upload_url, api_key)

    # Log the final results, and consume the symbols generator fully.
    failures = ReportResults(symbols, failed_list)

  return failures


def main(argv):
  parser = commandline.ArgumentParser(description=__doc__)

  # TODO: Make sym_paths, breakpad_root, and root exclusive.

  parser.add_argument('sym_paths', type='path_or_uri', nargs='*', default=None,
                      help='symbol file or directory or URL or tarball')
  parser.add_argument('--board', default=None,
                      help='Used to find default breakpad_root.')
  parser.add_argument('--breakpad_root', type='path', default=None,
                      help='full path to the breakpad symbol directory')
  parser.add_argument('--root', type='path', default=None,
                      help='full path to the chroot dir')
  parser.add_argument('--official_build', action='store_true', default=False,
                      help='point to official symbol server')
  parser.add_argument('--server', type=str, default=None,
                      help='URI for custom symbol server')
  parser.add_argument('--regenerate', action='store_true', default=False,
                      help='regenerate all symbols')
  parser.add_argument('--upload-limit', type=int,
                      help='only upload # number of symbols')
  parser.add_argument('--strip_cfi', type=int,
                      default=DEFAULT_FILE_LIMIT,
                      help='strip CFI data for files above this size')
  parser.add_argument('--failed-list', type='path',
                      help='where to save a list of failed symbols')
  parser.add_argument('--dedupe', action='store_true', default=False,
                      help='use the swarming service to avoid re-uploading')
  parser.add_argument('--yes', action='store_true', default=False,
                      help='answer yes to all prompts')
  parser.add_argument('--product_name', type=str, default='ChromeOS',
                      help='Produce Name for breakpad stats.')
  parser.add_argument('--api_key', type=str, default=None,
                      help='full path to the API key file')

  opts = parser.parse_args(argv)
  opts.Freeze()

  # Figure out the symbol files/directories to upload.
  if opts.sym_paths:
    sym_paths = opts.sym_paths
  elif opts.breakpad_root:
    sym_paths = [opts.breakpad_root]
  elif opts.root:
    if not opts.board:
      cros_build_lib.Die('--board must be set if --root is used.')
    breakpad_dir = cros_generate_breakpad_symbols.FindBreakpadDir(opts.board)
    sym_paths = [os.path.join(opts.root, breakpad_dir.lstrip('/'))]
  else:
    cros_build_lib.Die('--sym_paths, --breakpad_root, or --root must be set.')

  if opts.sym_paths or opts.breakpad_root:
    if opts.regenerate:
      cros_build_lib.Die('--regenerate may not be used with specific files, '
                         'or breakpad_root')
  else:
    if opts.board is None:
      cros_build_lib.Die('--board is required')

  # Figure out which crash server to upload too.
  upload_url = opts.server
  if not upload_url:
    if opts.official_build:
      upload_url = OFFICIAL_UPLOAD_URL
    else:
      logging.warning('unofficial builds upload to the staging server')
      upload_url = STAGING_UPLOAD_URL

  # Set up the API key needed to authenticate to Crash server.
  # Allow for a local key file for testing purposes.
  if opts.api_key:
    api_key_file = opts.api_key
  else:
    api_key_file = constants.CRASH_API_KEY

  api_key = osutils.ReadFile(api_key_file)

  # Confirm we really want the long upload.
  if not opts.yes:
    prolog = '\n'.join(textwrap.wrap(textwrap.dedent("""
        Uploading symbols for an entire Chromium OS build is really only
        necessary for release builds and in a few cases for developers
        to debug problems.  It will take considerable time to run.  For
        developer debugging purposes, consider instead passing specific
        files to upload.
    """), 80)).strip()
    if not cros_build_lib.BooleanPrompt(
        prompt='Are you sure you want to upload all build symbols',
        default=False, prolog=prolog):
      cros_build_lib.Die('better safe than sorry')

  ret = 0

  # Regenerate symbols from binaries.
  if opts.regenerate:
    ret += cros_generate_breakpad_symbols.GenerateBreakpadSymbols(
        opts.board, breakpad_dir=opts.breakpad_root)

  # Do the upload.
  ret += UploadSymbols(
      sym_paths=sym_paths,
      upload_url=upload_url,
      failed_list=opts.failed_list,
      upload_limit=opts.upload_limit,
      strip_cfi=opts.strip_cfi,
      api_key=api_key)

  if ret:
    logging.error('encountered %i problem(s)', ret)
    # Since exit(status) gets masked, clamp it to 1 so we don't inadvertently
    # return 0 in case we are a multiple of the mask.
    return 1