#!/usr/bin/env python

"""This example demonstrates the flow for retrieving a refresh token.

In order for this example to work your application's redirect URI must be set
to http://localhost:8080.

This tool can be used to conveniently create refresh tokens for later use with
your web application OAuth2 credentials.

"""
import random
import socket
import sys

import praw


def receive_connection():
    """Wait for and then return a connected socket..

    Opens a TCP connection on port 8080, and waits for a single client.

    """
    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    server.bind(("localhost", 8080))
    server.listen(1)
    client = server.accept()[0]
    server.close()
    return client


def send_message(client, message):
    """Send message to client and close the connection."""
    print(message)
    client.send("HTTP/1.1 200 OK\r\n\r\n{}".format(message).encode("utf-8"))
    client.close()


def main():
    """Provide the program's entry point when directly executed."""
    print(
        "Go here while logged into the account you want to create a token for: "
        "https://www.reddit.com/prefs/apps/"
    )
    print(
        "Click the create an app button. Put something in the name field and select the"
        " script radio button."
    )
    print("Put http://localhost:8080 in the redirect uri field and click create app")
    client_id = input(
        "Enter the client ID, it's the line just under Personal use script at the top: "
    )
    client_secret = input("Enter the client secret, it's the line next to secret: ")
    commaScopes = input(
        "Now enter a comma separated list of scopes, or all for all tokens: "
    )

    if commaScopes.lower() == "all":
        scopes = ["*"]
    else:
        scopes = commaScopes.strip().split(",")

    reddit = praw.Reddit(
        client_id=client_id.strip(),
        client_secret=client_secret.strip(),
        redirect_uri="http://localhost:8080",
        user_agent="praw_refresh_token_example",
    )
    state = str(random.randint(0, 65000))
    url = reddit.auth.url(scopes, state, "permanent")
    print("Now open this url in your browser: " + url)
    sys.stdout.flush()

    client = receive_connection()
    data = client.recv(1024).decode("utf-8")
    param_tokens = data.split(" ", 2)[1].split("?", 1)[1].split("&")
    params = {
        key: value for (key, value) in [token.split("=") for token in param_tokens]
    }

    if state != params["state"]:
        send_message(
            client,
            "State mismatch. Expected: {} Received: {}".format(state, params["state"]),
        )
        return 1
    elif "error" in params:
        send_message(client, params["error"])
        return 1

    refresh_token = reddit.auth.authorize(params["code"])
    send_message(client, "Refresh token: {}".format(refresh_token))
    return 0


if __name__ == "__main__":
    sys.exit(main())
