# System documented in https://zulip.readthedocs.io/en/latest/subsystems/logging.html

import logging
import os
import subprocess

from collections import defaultdict
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 typing import Any, Dict, Optional, Text

from zerver.models import get_system_bot
from zerver.lib.actions import internal_send_message
from zerver.lib.response import json_success, json_error
from version import ZULIP_VERSION

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

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)" % (report)
    else:
        user_info = "Anonymous user (not logged in)"

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

def try_git_describe() -> Optional[str]:
    try:
        return subprocess.check_output(
            ['git',
             '--git-dir', os.path.join(os.path.dirname(__file__), '../../.git'),
             'describe', '--tags', '--always', '--dirty', '--long'],
            stderr=subprocess.PIPE,
        ).strip().decode('utf-8')
    except Exception:
        return None

def deployment_repr() -> str:
    deployment = 'Deployed code:\n'

    git_described = try_git_describe()
    if git_described is not None:
        deployment += '- git: %s\n' % (git_described,)

    deployment += '- ZULIP_VERSION: %s\n' % (ZULIP_VERSION,)

    version_path = os.path.join(os.path.dirname(__file__), '../../version')
    if os.path.exists(version_path):
        deployment += '- version: %s\n' % (open(version_path).read().strip(),)

    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:
    subject = "Browser error for %s" % (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"
            % (report))

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

    body += "\n\nLog:\n%s" % (report['log'],)

    mail_admins(subject, body)

def zulip_browser_error(report: Dict[str, Any]) -> None:
    subject = "JS error: %s" % (report['user_email'],)

    user_info = user_info_str(report)

    body = "User: %s\n" % (user_info,)
    body += ("Message: %(message)s\n"
             % (report))

    realm = get_system_bot(settings.ERROR_BOT).realm
    internal_send_message(realm, settings.ERROR_BOT,
                          "stream", "errors", format_subject(subject), body)

def notify_server_error(report: Dict[str, Any]) -> None:
    report = defaultdict(lambda: None, report)
    email_server_error(report)
    if settings.ERROR_BOT:
        zulip_server_error(report)

def zulip_server_error(report: Dict[str, Any]) -> None:
    subject = '%(node)s: %(message)s' % (report)
    stack_trace = report['stack_trace'] or "No stack trace available"

    user_info = user_info_str(report)
    deployment = deployment_repr()

    request_repr = (
        "Request info:\n~~~~\n"
        "- path: %(path)s\n"
        "- %(method)s: %(data)s\n") % (report)

    for field in ["REMOTE_ADDR", "QUERY_STRING", "SERVER_NAME"]:
        request_repr += "- %s: \"%s\"\n" % (field, report.get(field.lower()))
    request_repr += "~~~~"

    realm = get_system_bot(settings.ERROR_BOT).realm
    internal_send_message(realm, settings.ERROR_BOT,
                          "stream", "errors", format_subject(subject),
                          "Error generated by %s\n\n~~~~ pytb\n%s\n\n~~~~\n%s\n%s"
                          % (user_info, stack_trace, deployment, request_repr))

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

    user_info = user_info_str(report)
    deployment = deployment_repr()

    request_repr = (
        "Request info:\n"
        "- path: %(path)s\n"
        "- %(method)s: %(data)s\n") % (report)

    for field in ["REMOTE_ADDR", "QUERY_STRING", "SERVER_NAME"]:
        request_repr += "- %s: \"%s\"\n" % (field, report.get(field.lower()))

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

    mail_admins(format_subject(subject), message, fail_silently=True)

def do_report_error(deployment_name: Text, type: Text, 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()