# Copyright (c) 2011 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.

import logging
import os

from autotest_lib.client.common_lib import log
from autotest_lib.client.common_lib import error, utils, global_config
from autotest_lib.client.bin import base_sysinfo, utils
from autotest_lib.client.cros import constants

get_value = global_config.global_config.get_config_value
collect_corefiles = get_value('CLIENT', 'collect_corefiles',
                              type=bool, default=False)


logfile = base_sysinfo.logfile
command = base_sysinfo.command


class logdir(base_sysinfo.loggable):
    """Represents a log directory."""

    DEFAULT_EXCLUDES = ("**autoserv*",)

    def __init__(self, directory, excludes=DEFAULT_EXCLUDES):
        super(logdir, self).__init__(directory, log_in_keyval=False)
        self.dir = directory
        self._excludes = excludes
        self._infer_old_attributes()


    def __setstate__(self, state):
        """Unpickle handler

        When client tests are run without SSP, we pickle this object on the
        server-side (using the version of the class deployed in the lab) and
        unpickle it on the DUT (using the version of the class from the build).
        This means that when adding a new attribute to this class, for a while
        the server-side code does not populate that attribute. So, deal with
        missing attributes in a sane way.
        """
        self.__dict__ = state
        if '_excludes' not in state:
            self._excludes = self.DEFAULT_EXCLUDES
            if self.additional_exclude:
                self._excludes += tuple(self.additional_exclude)


    def __repr__(self):
        return "site_sysinfo.logdir(%r, %s)" % (self.dir,
                                                self._excludes)


    def __eq__(self, other):
        if isinstance(other, logdir):
            return (self.dir == other.dir and self._excludes == other._excludes)
        elif isinstance(other, base_sysinfo.loggable):
            return False
        return NotImplemented


    def __ne__(self, other):
        result = self.__eq__(other)
        if result is NotImplemented:
            return result
        return not result


    def __hash__(self):
        return hash(self.dir) + hash(self._excludes)


    def run(self, log_dir):
        """Copies this log directory to the specified directory.

        @param log_dir: The destination log directory.
        """
        from_dir = os.path.realpath(self.dir)
        if os.path.exists(from_dir):
            parent_dir = os.path.dirname(from_dir)
            utils.system("mkdir -p %s%s" % (log_dir, parent_dir))

            excludes = [
                    "--exclude=%s" % self._anchored_exclude_pattern(from_dir, x)
                    for x in self._excludes]
            # Take source permissions and add ugo+r so files are accessible via
            # archive server.
            utils.system(
                    "rsync --no-perms --chmod=ugo+r -a --safe-links %s %s %s%s"
                    % (" ".join(excludes), from_dir, log_dir, parent_dir))


    def _anchored_exclude_pattern(self, from_dir, pattern):
        return '/%s/%s' % (os.path.basename(from_dir), pattern)


    def _infer_old_attributes(self):
        """ Backwards compatibility attributes.

        YOU MUST NEVER DROP / REINTERPRET THESE.
        A logdir object is pickled on server-side and unpickled on
        client-side. This means that, when running aginst client-side code
        from an older build, we need to be able to unpickle an instance of
        logdir pickled from a newer version of the class.

        Some old attributes are not sanely handled via __setstate__, so we can't
        drop them without breaking compatibility.
        """
        additional_excludes = list(set(self._excludes) -
                                   set(self.DEFAULT_EXCLUDES))
        if additional_excludes:
            # Old API only allowed a single additional exclude.
            # Best effort, keep the first one, throw the rest.
            self.additional_exclude = additional_excludes[0]
        else:
            self.additional_exclude = None


class file_stat(object):
    """Store the file size and inode, used for retrieving new data in file."""
    def __init__(self, file_path):
        """Collect the size and inode information of a file.

        @param file_path: full path to the file.

        """
        stat = os.stat(file_path)
        # Start size of the file, skip that amount of bytes when do diff.
        self.st_size = stat.st_size
        # inode of the file. If inode is changed, treat this as a new file and
        # copy the whole file.
        self.st_ino = stat.st_ino


class diffable_logdir(logdir):
    """Represents a log directory that only new content will be copied.

    An instance of this class should be added in both
    before_iteration_loggables and after_iteration_loggables. This is to
    guarantee the file status information is collected when run method is
    called in before_iteration_loggables, and diff is executed when run
    method is called in after_iteration_loggables.

    """
    def __init__(self, directory, excludes=logdir.DEFAULT_EXCLUDES,
                 keep_file_hierarchy=True, append_diff_in_name=True):
        """
        Constructor of a diffable_logdir instance.

        @param directory: directory to be diffed after an iteration finished.
        @param excludes: path patterns to exclude for rsync.
        @param keep_file_hierarchy: True if need to preserve full path, e.g.,
            sysinfo/var/log/sysstat, v.s. sysinfo/sysstat if it's False.
        @param append_diff_in_name: True if you want to append '_diff' to the
            folder name to indicate it's a diff, e.g., var/log_diff. Option
            keep_file_hierarchy must be True for this to take effect.

        """
        super(diffable_logdir, self).__init__(directory, excludes)
        self.keep_file_hierarchy = keep_file_hierarchy
        self.append_diff_in_name = append_diff_in_name
        # Init dictionary to store all file status for files in the directory.
        self._log_stats = {}


    def _get_init_status_of_src_dir(self, src_dir):
        """Get initial status of files in src_dir folder.

        @param src_dir: directory to be diff-ed.

        """
        # Dictionary used to store the initial status of files in src_dir.
        for file_path in self._get_all_files(src_dir):
            self._log_stats[file_path] = file_stat(file_path)
        self.file_stats_collected = True


    def _get_all_files(self, path):
        """Iterate through files in given path including subdirectories.

        @param path: root directory.
        @return: an iterator that iterates through all files in given path
            including subdirectories.

        """
        if not os.path.exists(path):
            yield []
        for root, dirs, files in os.walk(path):
            for f in files:
                if f.startswith('autoserv'):
                    continue
                yield os.path.join(root, f)


    def _copy_new_data_in_file(self, file_path, src_dir, dest_dir):
        """Copy all new data in a file to target directory.

        @param file_path: full path to the file to be copied.
        @param src_dir: source directory to do the diff.
        @param dest_dir: target directory to store new data of src_dir.

        """
        bytes_to_skip = 0
        if self._log_stats.has_key(file_path):
            prev_stat = self._log_stats[file_path]
            new_stat = os.stat(file_path)
            if new_stat.st_ino == prev_stat.st_ino:
                bytes_to_skip = prev_stat.st_size
            if new_stat.st_size == bytes_to_skip:
                return
            elif new_stat.st_size < prev_stat.st_size:
                # File is modified to a smaller size, copy whole file.
                bytes_to_skip = 0
        try:
            with open(file_path, 'r') as in_log:
                if bytes_to_skip > 0:
                    in_log.seek(bytes_to_skip)
                # Skip src_dir in path, e.g., src_dir/[sub_dir]/file_name.
                target_path = os.path.join(dest_dir,
                                           os.path.relpath(file_path, src_dir))
                target_dir = os.path.dirname(target_path)
                if not os.path.exists(target_dir):
                    os.makedirs(target_dir)
                with open(target_path, "w") as out_log:
                    out_log.write(in_log.read())
        except IOError as e:
            logging.error('Diff %s failed with error: %s', file_path, e)


    def _log_diff(self, src_dir, dest_dir):
        """Log all of the new data in src_dir to dest_dir.

        @param src_dir: source directory to do the diff.
        @param dest_dir: target directory to store new data of src_dir.

        """
        if self.keep_file_hierarchy:
            dir = src_dir.lstrip('/')
            if self.append_diff_in_name:
                dir = dir.rstrip('/') + '_diff'
            dest_dir = os.path.join(dest_dir, dir)

        if not os.path.exists(dest_dir):
            os.makedirs(dest_dir)

        for src_file in self._get_all_files(src_dir):
            self._copy_new_data_in_file(src_file, src_dir, dest_dir)


    def run(self, log_dir, collect_init_status=True, collect_all=False):
        """Copies new content from self.dir to the destination log_dir.

        @param log_dir: The destination log directory.
        @param collect_init_status: Set to True if run method is called to
            collect the initial status of files.
        @param collect_all: Set to True to force to collect all files.

        """
        if collect_init_status:
            self._get_init_status_of_src_dir(self.dir)
        elif os.path.exists(self.dir):
            # Always create a copy of the new logs to help debugging.
            self._log_diff(self.dir, log_dir)
            if collect_all:
                logdir_temp = logdir(self.dir)
                logdir_temp.run(log_dir)


class purgeable_logdir(logdir):
    """Represents a log directory that will be purged."""
    def __init__(self, directory, excludes=logdir.DEFAULT_EXCLUDES):
        super(purgeable_logdir, self).__init__(directory, excludes)

    def run(self, log_dir):
        """Copies this log dir to the destination dir, then purges the source.

        @param log_dir: The destination log directory.
        """
        super(purgeable_logdir, self).run(log_dir)

        if os.path.exists(self.dir):
            utils.system("rm -rf %s/*" % (self.dir))


class site_sysinfo(base_sysinfo.base_sysinfo):
    """Represents site system info."""
    def __init__(self, job_resultsdir):
        super(site_sysinfo, self).__init__(job_resultsdir)
        crash_exclude_string = None
        if not collect_corefiles:
            crash_exclude_string = "*.core"

        # This is added in before and after_iteration_loggables. When run is
        # called in before_iteration_loggables, it collects file status in
        # the directory. When run is called in after_iteration_loggables, diff
        # is executed.
        # self.diffable_loggables is only initialized if the instance does not
        # have this attribute yet. The sysinfo instance could be loaded
        # from an earlier pickle dump, which has already initialized attribute
        # self.diffable_loggables.
        if not hasattr(self, 'diffable_loggables'):
            diffable_log = diffable_logdir(constants.LOG_DIR)
            self.diffable_loggables = set()
            self.diffable_loggables.add(diffable_log)

        # add in some extra command logging
        self.boot_loggables.add(command("ls -l /boot",
                                        "boot_file_list"))
        self.before_iteration_loggables.add(
            command(constants.CHROME_VERSION_COMMAND, "chrome_version"))
        self.boot_loggables.add(command("crossystem", "crossystem"))
        self.test_loggables.add(
            purgeable_logdir(
                os.path.join(constants.CRYPTOHOME_MOUNT_PT, "log")))
        # We only want to gather and purge crash reports after the client test
        # runs in case a client test is checking that a crash found at boot
        # (such as a kernel crash) is handled.
        self.after_iteration_loggables.add(
            purgeable_logdir(
                os.path.join(constants.CRYPTOHOME_MOUNT_PT, "crash"),
                excludes=logdir.DEFAULT_EXCLUDES + (crash_exclude_string,)))
        self.after_iteration_loggables.add(
            purgeable_logdir(
                constants.CRASH_DIR,
                excludes=logdir.DEFAULT_EXCLUDES + (crash_exclude_string,)))
        self.test_loggables.add(
            logfile(os.path.join(constants.USER_DATA_DIR,
                                 ".Google/Google Talk Plugin/gtbplugin.log")))
        self.test_loggables.add(purgeable_logdir(
                constants.CRASH_DIR,
                excludes=logdir.DEFAULT_EXCLUDES + (crash_exclude_string,)))
        # Collect files under /tmp/crash_reporter, which contain the procfs
        # copy of those crashed processes whose core file didn't get converted
        # into minidump. We need these additional files for post-mortem analysis
        # of the conversion failure.
        self.test_loggables.add(
            purgeable_logdir(constants.CRASH_REPORTER_RESIDUE_DIR))


    @log.log_and_ignore_errors("pre-test sysinfo error:")
    def log_before_each_test(self, test):
        """Logging hook called before a test starts.

        @param test: A test object.
        """
        super(site_sysinfo, self).log_before_each_test(test)

        for log in self.diffable_loggables:
            log.run(log_dir=None, collect_init_status=True)


    @log.log_and_ignore_errors("post-test sysinfo error:")
    def log_after_each_test(self, test):
        """Logging hook called after a test finishs.

        @param test: A test object.
        """
        super(site_sysinfo, self).log_after_each_test(test)

        test_sysinfodir = self._get_sysinfodir(test.outputdir)

        for log in self.diffable_loggables:
            log.run(log_dir=test_sysinfodir, collect_init_status=False,
                    collect_all=not test.success)


    def _get_chrome_version(self):
        """Gets the Chrome version number and milestone as strings.

        Invokes "chrome --version" to get the version number and milestone.

        @return A tuple (chrome_ver, milestone) where "chrome_ver" is the
            current Chrome version number as a string (in the form "W.X.Y.Z")
            and "milestone" is the first component of the version number
            (the "W" from "W.X.Y.Z").  If the version number cannot be parsed
            in the "W.X.Y.Z" format, the "chrome_ver" will be the full output
            of "chrome --version" and the milestone will be the empty string.

        """
        version_string = utils.system_output(constants.CHROME_VERSION_COMMAND,
                                             ignore_status=True)
        return utils.parse_chrome_version(version_string)


    def log_test_keyvals(self, test_sysinfodir):
        """Generate keyval for the sysinfo.

        Collects keyval entries to be written in the test keyval.

        @param test_sysinfodir: The test's system info directory.
        """
        keyval = super(site_sysinfo, self).log_test_keyvals(test_sysinfodir)

        lsb_lines = utils.system_output(
            "cat /etc/lsb-release",
            ignore_status=True).splitlines()
        lsb_dict = dict(item.split("=") for item in lsb_lines)

        for lsb_key in lsb_dict.keys():
            # Special handling for build number
            if lsb_key == "CHROMEOS_RELEASE_DESCRIPTION":
                keyval["CHROMEOS_BUILD"] = (
                    lsb_dict[lsb_key].rstrip(")").split(" ")[3])
            keyval[lsb_key] = lsb_dict[lsb_key]

        # Get the hwid (hardware ID), if applicable.
        try:
            keyval["hwid"] = utils.system_output('crossystem hwid')
        except error.CmdError:
            # The hwid may not be available (e.g, when running on a VM).
            # If the output of 'crossystem mainfw_type' is 'nonchrome', then
            # we expect the hwid to not be avilable, and we can proceed in this
            # case.  Otherwise, the hwid is missing unexpectedly.
            mainfw_type = utils.system_output('crossystem mainfw_type')
            if mainfw_type == 'nonchrome':
                logging.info(
                    'HWID not available; not logging it as a test keyval.')
            else:
                logging.exception('HWID expected but could not be identified; '
                                  'output of "crossystem mainfw_type" is "%s"',
                                  mainfw_type)
                raise

        # Get the chrome version and milestone numbers.
        keyval["CHROME_VERSION"], keyval["MILESTONE"] = (
                self._get_chrome_version())

        # TODO(kinaba): crbug.com/707448 Import at the head of this file.
        # Currently a server-side script server/server_job.py is indirectly
        # importing this file, so we cannot globaly import cryptohome that
        # has dependency to a client-only library.
        from autotest_lib.client.cros import cryptohome
        # Get the dictionary attack counter.
        keyval["TPM_DICTIONARY_ATTACK_COUNTER"] = (
                cryptohome.get_tpm_more_status().get(
                    'dictionary_attack_counter', 'Failed to query cryptohome'))

        # Return the updated keyvals.
        return keyval


    def add_logdir(self, loggable):
        """Collect files in log_path to sysinfo folder.

        This method can be called from a control file for test to collect files
        in a specified folder. autotest creates a folder [test result
        dir]/sysinfo folder with the full path of log_path and copy all files in
        log_path to that folder.

        @param loggable: A logdir instance corresponding to the logs to collect.
        """
        self.test_loggables.add(loggable)