Dinu Andreea Sabina
322CB

Homework 3 PC - Web Client
			
In order to implement this homework, I used the files and functions from
lab10.

-> request.c contains functions for making the request. For functions 
compute_get_request and compute_post_request, I added as parameter the JWT
token, which I concatenated in the request if it is not empty. 
In compute_post_request, I printed the host,
content type, followed by the actual content. The content comes in the body_data
array of strings, and they are parsed using json_object_set_string from parson
library, then the data is transformed into a serialized string using
json_serialize_to_string_pretty and copied into the body_data_buffer. Then, the
content length is printed, the cookies and jwt_tokens if there are any.
Function compute_delete_request is used to delete a book, which prints a DELETE
message, the host, the cookies and jwt_tokens if there are any. 

-> client.c file contains auxiliary functions for all the instructions
read from STDIN.

->access_account could receive a receive or login intruction and 
compute a POST request with the data (username and password) of the user
read from STDIN. Then, it compose the request with the coresponding URL,
get a reply and print the response.

->login_command is used in order to make the login, compute
a POST request and print the response using the last function, then it extract 
and return the cookie from the response. If it finds the cookie, it sets the
already_logged variables to 1, to know that the user is logged in and is 
able to work with the library.

->extract_jwt_token function extract a JWT token from a response by using 
parson library. It parses the last line into a json value,
then it gets the json object and it converts it to string and it copies it
into the jwt_token. 

->enter_library compute a GET request with the cookie received as parameter, if the 
user is already logged, and return the JWT token. If no user is connected, make
the request without the cookie, else allocate an array of cookies and copies the 
cookie into the first element. Then compose the request, send it to the server,
get a response and print it.

->get_books function is used when the get_books command is received and calls
compute_get_request with the given jwt token. If the jwt_token is null, the
function is called without it. Else, an array of jwt_tokens is allocated and the
token is copied to the first element, then the function is called with it.
Then, sends the message  to the server, receives a response and print it.

->book_operation receives either a get_book or delete_book command and
calls the suitable function for the given command. It reads the id and adds it to
the url. If the jwt token is null, it calls either compute_get_request or
compute_delete_request without it. Else, an array or token is allocated and the
token is copied to the first element and one of the functions is called, according
to the command given. Then, it prints the message, sends it to server, receives
a response and print it.

->add_book function is used when the user wants to add a new book in the library. If
the JWT token is empty, compute a POST request without it. Else, I collected the information
about the new book from STDIN, allocate and array of tokens and copy the JWT token 
into the first element and then compute the request. Then I send it to the server, got 
a response and print it.

->logout_command is used when a user wants to logout. If the user is not logged, make a GET 
request without a cookie, else allocate an array of cookie and copies the first element, 
then compute a request. Finally, send it to the server, get a reply and print it.

-> In the main function, I read intructions from STDIN, and open a new coonnection
everytime I receive a command. For every intruction, I call the suitable function, and 
check if the user is logged, then close the socket. At the end, after the istruction 
"exit", I fred all the memory allocated.