from typing import List, Optional

from django.http import HttpRequest, HttpResponse
from django.shortcuts import render
from django.template import loader

from zerver.lib.avatar import get_gravatar_url
from zerver.lib.exceptions import JsonableError
from zerver.lib.response import json_success
from zerver.lib.streams import get_stream_by_id
from zerver.lib.timestamp import datetime_to_timestamp
from zerver.lib.topic import get_topic_history_for_public_stream, messages_for_topic
from zerver.models import Message, UserProfile


def archive(request: HttpRequest, stream_id: int, topic_name: str) -> HttpResponse:
    def get_response(
        rendered_message_list: List[str], is_web_public: bool, stream_name: str
    ) -> HttpResponse:
        return render(
            request,
            "zerver/archive/index.html",
            context={
                "is_web_public": is_web_public,
                "message_list": rendered_message_list,
                "stream": stream_name,
                "topic": topic_name,
            },
        )

    try:
        stream = get_stream_by_id(stream_id)
    except JsonableError:
        return get_response([], False, "")

    if not stream.is_web_public:
        return get_response([], False, "")

    all_messages = list(
        messages_for_topic(
            stream_recipient_id=stream.recipient_id,
            topic_name=topic_name,
        )
        .select_related("sender")
        .order_by("date_sent"),
    )

    if not all_messages:
        return get_response([], True, stream.name)

    rendered_message_list = []
    prev_sender: Optional[UserProfile] = None
    for msg in all_messages:
        include_sender = False
        status_message = Message.is_status_message(msg.content, msg.rendered_content)
        if not prev_sender or prev_sender != msg.sender or status_message:
            if status_message:
                prev_sender = None
            else:
                prev_sender = msg.sender
            include_sender = True
        if status_message:
            status_message = msg.rendered_content[4 + 3 : -4]
        context = {
            "sender_full_name": msg.sender.full_name,
            "timestampstr": datetime_to_timestamp(
                msg.last_edit_time if msg.last_edit_time else msg.date_sent
            ),
            "message_content": msg.rendered_content,
            "avatar_url": get_gravatar_url(msg.sender.delivery_email, 1),
            "include_sender": include_sender,
            "status_message": status_message,
        }
        rendered_msg = loader.render_to_string("zerver/archive/single_message.html", context)
        rendered_message_list.append(rendered_msg)
    return get_response(rendered_message_list, True, stream.name)


def get_web_public_topics_backend(request: HttpRequest, stream_id: int) -> HttpResponse:
    try:
        stream = get_stream_by_id(stream_id)
    except JsonableError:
        return json_success(dict(topics=[]))

    if not stream.is_web_public:
        return json_success(dict(topics=[]))

    result = get_topic_history_for_public_stream(recipient_id=stream.recipient_id)

    return json_success(dict(topics=result))