import copy
import re

import common

from autotest_lib.client.common_lib import global_config


# Number of times to retry if a gs command fails. Defaults to 10,
# which is far too long given that we already wait on these files
# before starting HWTests.
_GS_RETRIES = 1


_HTTP_ERROR_THRESHOLD = 400
BUG_CONFIG_SECTION = 'BUG_REPORTING'

# global configurations needed for build artifacts
_gs_domain = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'gs_domain', default='')
_chromeos_image_archive = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'chromeos_image_archive', default='')
_arg_prefix = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'arg_prefix', default='')


# global configurations needed for results log
_retrieve_logs_cgi = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'retrieve_logs_cgi', default='')
_generic_results_bin = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'generic_results_bin', default='')
_debug_dir = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'debug_dir', default='')


# Template for the url used to generate the link to the job
_job_view = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'job_view', default='')


# gs prefix to perform file like operations (gs://)
_gs_file_prefix = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'gs_file_prefix', default='')


_CRBUG_URL = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'crbug_url')


WMATRIX_RETRY_URL = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'wmatrix_retry_url')
WMATRIX_TEST_HISTORY_URL = global_config.global_config.get_config_value(
    BUG_CONFIG_SECTION, 'wmatrix_test_history_url')


class InvalidBugTemplateException(Exception):
    """Exception raised when a bug template is not valid, e.g., missing value
    for essential attributes.
    """
    pass


class BugTemplate(object):
    """Wrapper class to merge a suite and test bug templates, and do validation.
    """

    # Names of expected attributes.
    EXPECTED_BUG_TEMPLATE_ATTRIBUTES = ['owner', 'labels', 'status', 'title',
                                        'cc', 'summary', 'components']
    LIST_ATTRIBUTES = ['cc', 'labels']
    EMAIL_ATTRIBUTES = ['owner', 'cc']

    EMAIL_REGEX = re.compile(r'[^@]+@[^@]+\.[^@]+')


    def __init__(self, bug_template):
        """Initialize a BugTemplate object.

        @param bug_template: initial bug template, e.g., bug template from suite
                             control file.
        """
        self.bug_template = self.cleanup_bug_template(bug_template)


    @classmethod
    def validate_bug_template(cls, bug_template):
        """Verify if a bug template has value for all essential attributes.

        @param bug_template: bug template to be verified.
        @raise InvalidBugTemplateException: raised when a bug template
                is invalid, e.g., has missing essential attribute, or any given
                template is not a dictionary.
        """
        if not type(bug_template) is dict:
            raise InvalidBugTemplateException('Bug template must be a '
                                              'dictionary.')

        unexpected_keys = []
        for key, value in bug_template.iteritems():
            if not key in cls.EXPECTED_BUG_TEMPLATE_ATTRIBUTES:
                raise InvalidBugTemplateException('Key %s is not expected in '
                                                  'bug template.' % key)
            if (key in cls.LIST_ATTRIBUTES and
                not isinstance(value, list)):
                raise InvalidBugTemplateException('Value for %s must be a list.'
                                                  % key)
            if key in cls.EMAIL_ATTRIBUTES:
                emails = value if isinstance(value, list) else [value]
                for email in emails:
                    if not email or not cls.EMAIL_REGEX.match(email):
                        raise InvalidBugTemplateException(
                                'Invalid email address: %s.' % email)


    @classmethod
    def cleanup_bug_template(cls, bug_template):
        """Remove empty entries in given bug template.

        @param bug_template: bug template to be verified.

        @return: A cleaned up bug template.
        @raise InvalidBugTemplateException: raised when a bug template
                is not a dictionary.
        """
        if not type(bug_template) is dict:
            raise InvalidBugTemplateException('Bug template must be a '
                                              'dictionary.')
        template = copy.deepcopy(bug_template)
        # If owner or cc is set but the value is empty or None, remove it from
        # the template.
        for email_attribute in cls.EMAIL_ATTRIBUTES:
            if email_attribute in template:
                value = template[email_attribute]
                if isinstance(value, list):
                    template[email_attribute] = [email for email in value
                                                 if email]
                if not template[email_attribute]:
                    del(template[email_attribute])
        return template


    def finalize_bug_template(self, test_template):
        """Merge test and suite bug templates.

        @param test_template: Bug template from test control file.
        @return: Merged bug template.

        @raise InvalidBugTemplateException: raised when the merged template is
                invalid, e.g., has missing essential attribute, or any given
                template is not a dictionary.
        """
        test_template = self.cleanup_bug_template(test_template)
        self.validate_bug_template(self.bug_template)
        self.validate_bug_template(test_template)

        merged_template = test_template
        merged_template.update((k, v) for k, v in self.bug_template.iteritems()
                               if k not in merged_template)

        # test_template wins for common keys, unless values are list that can be
        # merged.
        for key in set(merged_template.keys()).intersection(
                                                    self.bug_template.keys()):
            if (type(merged_template[key]) is list and
                type(self.bug_template[key]) is list):
                merged_template[key] = (merged_template[key] +
                                        self.bug_template[key])
            elif not merged_template[key]:
                merged_template[key] = self.bug_template[key]
        self.validate_bug_template(merged_template)
        return merged_template


def link_build_artifacts(build):
    """Returns a url to build artifacts on google storage.

    @param build: A string, e.g. stout32-release/R30-4433.0.0

    @returns: A url to build artifacts on google storage.

    """
    return (_gs_domain + _arg_prefix +
            _chromeos_image_archive + build)


def link_job(job_id, instance_server=None):
    """Returns an url to the job on cautotest.

    @param job_id: A string, representing the job id.
    @param instance_server: The instance server.
        Eg: cautotest, cautotest-cq, localhost.

    @returns: An url to the job on cautotest.

    """
    if not job_id:
        return 'Job did not run, or was aborted prematurely'
    if not instance_server:
        instance_server = global_config.global_config.get_config_value(
            'SERVER', 'hostname', default='localhost')
    if 'cautotest' in instance_server:
        instance_server += '.corp.google.com'
    return _job_view % (instance_server, job_id)


def _base_results_log(job_id, result_owner, hostname):
    """Returns the base url of the job's results.

    @param job_id: A string, representing the job id.
    @param result_owner: A string, representing the onwer of the job.
    @param hostname: A string, representing the host on which
                     the job has run.

    @returns: The base url of the job's results.

    """
    if job_id and result_owner and hostname:
        path_to_object = '%s-%s/%s' % (job_id, result_owner,
                                       hostname)
        return (_retrieve_logs_cgi + _generic_results_bin +
                path_to_object)


def link_result_logs(job_id, result_owner, hostname):
    """Returns a url to test logs on google storage.

    @param job_id: A string, representing the job id.
    @param result_owner: A string, representing the owner of the job.
    @param hostname: A string, representing the host on which the
                     jot has run.

    @returns: A url to test logs on google storage.

    """
    base_results = _base_results_log(job_id, result_owner, hostname)
    if base_results:
        return '%s/%s' % (base_results, _debug_dir)
    return ('Could not generate results log: the job with id %s, '
            'scheduled by: %s on host: %s did not run' %
            (job_id, result_owner, hostname))


def link_status_log(job_id, result_owner, hostname):
    """Returns an url to status log of the job.

    @param job_id: A string, representing the job id.
    @param result_owner: A string, representing the owner of the job.
    @param hostname: A string, representing the host on which the
                     jot has run.

    @returns: A url to status log of the job.

    """
    base_results = _base_results_log(job_id, result_owner, hostname)
    if base_results:
        return '%s/%s' % (base_results, 'status.log')
    return 'NA'


def link_retry_url(test_name):
    """Link to the wmatrix retry stats page for this test.

    @param test_name: Test we want to search the retry stats page for.

    @return: A link to the wmatrix retry stats dashboard for this test.
    """
    return WMATRIX_RETRY_URL % test_name


def link_test_history(test_name):
  """Link to the wmatrix test history page for this test.

  @param test_name: Test we want to search the test history for.

  @return: A link to the wmatrix test history page for this test.
  """
  return WMATRIX_TEST_HISTORY_URL % test_name


def link_crbug(bug_id):
    """Generate a bug link for the given bug_id.

    @param bug_id: The id of the bug.
    @return: A link, eg: https://crbug.com/<bug_id>.
    """
    return _CRBUG_URL % (bug_id,)