from collections import defaultdict
import logging

from django.conf import settings
from django.core.mail import mail_admins

from zerver.lib.actions import internal_send_message

def format_subject(subject):
    """
    Escape CR and LF characters, and limit length to MAX_SUBJECT_LENGTH.
    """
    from zerver.models import MAX_SUBJECT_LENGTH
    subject = subject.replace('\n', '\\n').replace('\r', '\\r')

    if len(subject) > MAX_SUBJECT_LENGTH:
        subject = subject[:MAX_SUBJECT_LENGTH-3].rstrip() + "..."

    return subject

def user_info_str(report):
    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 notify_browser_error(report):
    report = defaultdict(lambda: None, report)
    if settings.ERROR_BOT:
        zulip_browser_error(report)
    email_browser_error(report)

def email_browser_error(report):
    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"
            "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.iteritems():
            body += "\n  %s: %s" % (key, value)

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

    mail_admins(subject, body)

def zulip_browser_error(report):
    subject = "JS error: %s" % (report['user_email'],)

    user_info = user_info_str(report)

    body =  "User: %s\n" % (user_info,)
    body += (
        "Message: %(message)s\n"
        "~~~\n%(stacktrace)s\n~~~\n~~~\n"
        "- User agent: %(user_agent)s\n"
        "- href: %(href)s\n"
        "- Server path: %(server_path)s\n"
        "- Deployed version: %(version)s\n~~~\n"
        % report )

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

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

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

def notify_server_error(report):
    report = defaultdict(lambda: None, report)
    email_server_error(report)
    if settings.ERROR_BOT:
        zulip_server_error(report)

def zulip_server_error(report):
    subject = '%(node)s: %(message)s' %  report
    stack_trace = report['stack_trace'] or "No stack trace available"

    user_info = user_info_str(report)

    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 += "~~~~"

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

def email_server_error(report):
    subject = '%(node)s: %(message)s' % (report)

    user_info = user_info_str(report)

    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" % (user_info, report['stack_trace'],
                                                     request_repr)

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