# System documented in https://zulip.readthedocs.io/en/latest/subsystems/logging.html
from collections import defaultdict
from typing import Any, Dict

from django.conf import settings
from django.core.mail import mail_admins
from django.http import HttpResponse
from django.utils.translation import ugettext as _

from zerver.filters import clean_data_from_query_parameters
from zerver.lib.actions import internal_send_stream_message
from zerver.lib.response import json_error, json_success
from zerver.models import get_stream, get_system_bot


def format_email_subject(email_subject: str) -> str:
    """
    Escape CR and LF characters.
    """
    return email_subject.replace('\n', '\\n').replace('\r', '\\r')

def logger_repr(report: Dict[str, Any]) -> str:
    return ("Logger %(logger_name)s, from module %(log_module)s line %(log_lineno)d:"
            % dict(report))

def user_info_str(report: Dict[str, Any]) -> str:
    if report['user_full_name'] and report['user_email']:
        user_info = "%(user_full_name)s (%(user_email)s)" % dict(report)
    else:
        user_info = "Anonymous user (not logged in)"

    user_info += " on %s deployment"  % (report['deployment'],)
    return user_info

def deployment_repr(report: Dict[str, Any]) -> str:
    deployment = 'Deployed code:\n'
    for field, val in report['deployment_data'].items():
        deployment += f'- {field}: {val}\n'
    return deployment

def notify_browser_error(report: Dict[str, Any]) -> None:
    report = defaultdict(lambda: None, report)
    if settings.ERROR_BOT:
        zulip_browser_error(report)
    email_browser_error(report)

def email_browser_error(report: Dict[str, Any]) -> None:
    email_subject = f"Browser error for {user_info_str(report)}"

    body = ("User: %(user_full_name)s <%(user_email)s> on %(deployment)s\n\n"
            "Message:\n%(message)s\n\nStacktrace:\n%(stacktrace)s\n\n"
            "IP address: %(ip_address)s\n"
            "User agent: %(user_agent)s\n"
            "href: %(href)s\n"
            "Server path: %(server_path)s\n"
            "Deployed version: %(version)s\n"
            % dict(report))

    more_info = report['more_info']
    if more_info is not None:
        body += "\nAdditional information:"
        for (key, value) in more_info.items():
            body += f"\n  {key}: {value}"

    body += "\n\nLog:\n{}".format(report['log'])

    mail_admins(email_subject, body)

def zulip_browser_error(report: Dict[str, Any]) -> None:
    email_subject = "JS error: {}".format(report['user_email'])

    user_info = user_info_str(report)

    body = f"User: {user_info}\n"
    body += ("Message: %(message)s\n"
             % dict(report))

    error_bot = get_system_bot(settings.ERROR_BOT)
    realm = error_bot.realm
    errors_stream = get_stream('errors', realm)

    internal_send_stream_message(
        realm,
        error_bot,
        errors_stream,
        format_email_subject(email_subject),
        body,
    )

def notify_server_error(report: Dict[str, Any], skip_error_zulip: bool=False) -> None:
    report = defaultdict(lambda: None, report)
    email_server_error(report)
    if settings.ERROR_BOT and not skip_error_zulip:
        zulip_server_error(report)

def zulip_server_error(report: Dict[str, Any]) -> None:
    email_subject = '%(node)s: %(message)s' % dict(report)

    logger_str = logger_repr(report)
    user_info = user_info_str(report)
    deployment = deployment_repr(report)

    if report['has_request']:
        request_repr = (
            "Request info:\n~~~~\n"
            "- path: %(path)s\n"
            "- %(method)s: %(data)s\n") % dict(report)
        for field in ["REMOTE_ADDR", "QUERY_STRING", "SERVER_NAME"]:
            val = report.get(field.lower())
            if field == "QUERY_STRING":
                val = clean_data_from_query_parameters(str(val))
            request_repr += f"- {field}: \"{val}\"\n"
        request_repr += "~~~~"
    else:
        request_repr = "Request info: none"

    message = ("%s\nError generated by %s\n\n~~~~ pytb\n%s\n\n~~~~\n%s\n%s"
               % (logger_str, user_info, report['stack_trace'], deployment, request_repr))

    error_bot = get_system_bot(settings.ERROR_BOT)
    realm = error_bot.realm
    errors_stream = get_stream('errors', realm)

    internal_send_stream_message(
        realm,
        error_bot,
        errors_stream,
        format_email_subject(email_subject),
        message,
    )

def email_server_error(report: Dict[str, Any]) -> None:
    email_subject = '%(node)s: %(message)s' % dict(report)

    logger_str = logger_repr(report)
    user_info = user_info_str(report)
    deployment = deployment_repr(report)

    if report['has_request']:
        request_repr = (
            "Request info:\n"
            "- path: %(path)s\n"
            "- %(method)s: %(data)s\n") % dict(report)
        for field in ["REMOTE_ADDR", "QUERY_STRING", "SERVER_NAME"]:
            val = report.get(field.lower())
            if field == "QUERY_STRING":
                val = clean_data_from_query_parameters(str(val))
            request_repr += f"- {field}: \"{val}\"\n"
    else:
        request_repr = "Request info: none\n"

    message = ("%s\nError generated by %s\n\n%s\n\n%s\n\n%s"
               % (logger_str, user_info, report['stack_trace'], deployment, request_repr))

    mail_admins(format_email_subject(email_subject), message, fail_silently=True)

def do_report_error(deployment_name: str, type: str, report: Dict[str, Any]) -> HttpResponse:
    report['deployment'] = deployment_name
    if type == 'browser':
        notify_browser_error(report)
    elif type == 'server':
        notify_server_error(report)
    else:
        return json_error(_("Invalid type parameter"))
    return json_success()