Obtaining a Refresh Token
*************************

The following program can be used to obtain a refresh token with the
desired scopes. Such a token can be used in conjunction with the
"refresh_token" keyword argument using in initializing an instance of
"Reddit". A list of all possible scopes can be found in the reddit API
docs

   #!/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(f"HTTP/1.1 200 OK\r\n\r\n{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(f"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,
               f"State mismatch. Expected: {state} Received: {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, f"Refresh token: {refresh_token}")
       return 0


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