import json
import os
import random
import re
from http.server import BaseHTTPRequestHandler, HTTPServer
from socketserver import ThreadingMixIn

# 	SETUP	#
#
hostAddress = os.environ.get("SIMULATION_BIND_ADDRESS", "0.0.0.0")
hostPort = 8081
network = re.compile(r"(127)\.(0)\.(0)\..*")
#
#############

maxPicID = 7


class Account:
    def __init__(self, realName, name, picID):
        self.realName = realName
        self.name = name

        if maxPicID < picID or picID < 0:
            picID = 0

        self.picID = picID

    def toJSON(self):
        return '{{ "realName": "{}", "name": "{}", "picID": {} }}'.format(
            self.realName, self.name, self.picID
        )


fakeAccounts = [
    Account("Andrew Melting", "lorip", 0),
    Account("Donald Trump", "realDonaldTrump", 1),
    Account("Dalai Lama", "realDonaldTrump", 2),
    Account("Pope Francis", "Pontifex", 3),
    Account("Barack Obama", "POTUS44", 4),
    Account("Lorem Ipsum", "Andrew", 5),
    Account("Lorem Ipsum", "lorip", 6),
    Account("Lorem Ipsum", "lorip", 7),
]


def getFakeAccount():
    return fakeAccounts[random.randint(0, len(fakeAccounts) - 1)]


class Tweet:
    def __init__(self, account, message):
        self.account = account
        self.message = message

    def toJSON(self):
        return '{{ "account": {}, "message": "{}" }}'.format(
            self.account.toJSON(), self.message
        )


class TweetHandler:
    def __init__(self):
        self.tweets = []

    def addTweetFromRandom(self, message):
        self.tweets.append(Tweet(getFakeAccount(), message))

    def getTweetCount(self):
        return len(self.tweets)

    def getTweetAtIndex(self, index):
        if index == "last":
            return self.getLastTweet()

        index = int(index)
        if 0 <= index and index < self.getTweetCount():
            return self.tweets[index].toJSON()
        else:
            raise ValueError("Invalid index.")

    def getLastTweet(self):
        if len(self.tweets) > 0:
            return self.tweets[len(self.tweets) - 1].toJSON()

        return ""

    def delete(self, index):
        if index == "last":
            self.tweets.pop()

        index = int(index)
        if 0 <= index and index < self.getTweetCount():
            self.tweets.pop(index)
        else:
            raise ValueError("Invalid index.")

    def toJSON(self):
        json = "{ tweets: [ "
        for tweet in self.tweets:
            json += tweet.toJSON() + ", "

        if json[-2:] == ", ":
            json = json[:-2] + " "
        json += "]}"

        return json


tweetHandler = TweetHandler()

tweetHandler.addTweetFromRandom("this is a tweet")
tweetHandler.addTweetFromRandom("covfefe")
tweetHandler.addTweetFromRandom("love thy enemy")
tweetHandler.addTweetFromRandom("this is also a tweet")
tweetHandler.addTweetFromRandom("lorem ipsum dolor sit amet")


reTweets = re.compile(r"/tweets/d*")


class server(BaseHTTPRequestHandler):
    def respondWith(self, code):
        self.send_response(code)
        self.send_header("Access-Control-Allow-Origin", "*")
        self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS, DELETE")
        self.send_header("Access-Control-Allow-Headers", "*")
        self.send_header("Content-type", "application/json")
        self.end_headers()

    def do_GET(self):

        if self.path == "/tweets/":
            self.respondWith(200)
            self.wfile.write(bytes(tweetHandler.toJSON(), "utf-8"))

        elif self.path == "/tweetCount":
            self.respondWith(200)
            self.wfile.write(bytes(str(tweetHandler.getTweetCount()), "utf-8"))

        elif reTweets.match(self.path):
            index = self.path[8:]

            try:
                tweet = tweetHandler.getTweetAtIndex(index)
            except Exception:
                self.respondWith(404)
                return

            self.respondWith(200)

            self.wfile.write(bytes(tweet, "utf-8"))

        else:
            self.respondWith(404)

    def do_POST(self):
        if not network.match(self.client_address[0]):
            print(
                "Unauthorized access: "
                + str(self.client_address[0])
                + ":"
                + str(self.client_address[1])
            )
            self.respondWith(401)
            return

        length = int(self.headers["Content-Length"])
        data = self.rfile.read(length).decode("utf-8")

        if self.path == "/tweets/":
            tweetHandler.addTweetFromRandom(data)
            self.respondWith(201)
            self.wfile.write(bytes(tweetHandler.getLastTweet(), "utf-8"))

        else:
            self.respondWith(404)

    def do_DELETE(self):
        if reTweets.match(self.path):
            index = self.path[8:]

            try:
                tweetHandler.delete(index)

            except Exception:
                self.respondWith(404)
                return

            self.respondWith(204)

        else:
            self.respondWith(404)

    def do_OPTIONS(self):
        self.respondWith(200)

    def log_request(code="-", size="-"):
        pass


class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
    """Handle requests in a separate thread."""


try:
    backendServer = ThreadedHTTPServer((hostAddress, hostPort), server)
    print("The EVENT server has been started. {}:{}".format(hostAddress, hostPort))
    backendServer.serve_forever()
except KeyboardInterrupt:
    backendServer.server_close()
    print("The EVENT server has been stopped.")