#
# Copyright 2015 (c) Anna Schumaker.
#
from . import api
from . import auth
from . import chat

#
# This class represents a slack "thread", which could be a channel, group,
# or chat.  Note that child classes need to define the following variables:
#
# - self.api_info:    The slack api method and return code to find channel info
# - self.api_history: The slack api method to find unread messages
# - self.api_mark:    Call <whatever>.mark to set unread cursor.
#
class Thread:
    def __init__(self, json):
        self.__id      = json.get("id", 0)
        self.__name    = json.get("name", "").title()
        self.__topic   = json.get("topic", {}).get("value", "").encode("utf-8").decode(errors="replace")
        self.__purpose = json.get("purpose", {}).get("value", "").encode("utf-8").decode(errors="replace")
        self.__unread  = json.get("unread_count", None)
        self.__last_ts = json.get("last_read", None)

    def __str__(self):
        topic=""
        if self.__topic != "":
            topic = "\nTopic: %s" % self.__topic
        return "%s: %s%s" % (self.__name, self.__purpose, topic)

    def call_fetch_info(self):
        return api.call(self.api_info["call"], token = auth.token(),
                                               channel = self.__id)

    def fetch_info(self):
        json = self.call_fetch_info()
        if json["ok"] == True:
            self.__unread  = json[self.api_info["ret"]].get("unread_count", None)
            self.__last_ts = json[self.api_info["ret"]].get("last_read", None)

    def fetch_messages(self):
        json = api.call(self.api_history, token = auth.token(),
                        channel = self.__id, oldest = self.__last_ts)
        if json["ok"] == False:
            return None
        return json["messages"]

    def mark_messages(self, stamp):
        api.call(self.api_mark, token = auth.token(),
                                channel = self.__id, ts = stamp)

    def id(self):
        return self.__id

    def is_member(self):
        return True

    def name(self):
        return self.__name

    def url(self, base):
        return "%s/messages/%s/" % (base, self.__name)

    def read(self):
        if self.__last_ts == None:
            self.fetch_info()

        # Read original message list
        messages = self.fetch_messages()
        o_list = [ chat.Message(msg) for msg in messages ]
        o_list.sort()
        if len(o_list) == 0:
            return o_list

        # Merge together messages from the same user
        m_list = [ o_list[0] ]
        for msg in o_list[1:]:
            if msg.user() == m_list[-1].user():
                m_list[-1].merge(msg)
            else:
                m_list += [ msg ]

        self.mark_messages(m_list[-1].ts())
        return m_list

    def unread_count(self):
        if self.__unread == None:
            self.fetch_info()
        return self.__unread

    def post(self, text):
        return chat.post_message(self.__id, text)