/**
 * http.c - Basic HTTP framework implentation
 * 
 * hashtable.c for routing
 * listen.c for socket creation
 * 
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>

#include "hashtable.h"
#include "listen.h"
#include "http.h"

#define BUF_SIZE 65536
#define HTTP_RES "HTTP/1.1 %d MESSAGE\n"\
"Connection: close\n"\
"Content-Length: %d\n"\
"Content-Type: %s\n"\
"\n"\
"%s"

HT* routes;

void use(char* path, Handler handler)
{
    if (routes == NULL)
    {
        routes = ht_create();
    }

    // TODO: handle for key exist
    ht_put(routes, path, (void*) handler);
}

void send_response(int client, Res* res)
{
    char res_raw[BUF_SIZE];

    sprintf( res_raw, 
             HTTP_RES, 
             res->status,
             res->content_length, 
             res->content_type, 
             res->body) ;

    int num_sent = send(client, res_raw, strlen(res_raw), 0);

    if (num_sent < 0) 
    {
        perror("send");
    }   
}

void fallback_handler(Res* res)
{
    char* content = "Bad request\n";

    res->status = 400;
    res->content_length = strlen(content);
    res->content_type = "text/html";
    res->body = content;
}

void parse_req_raw(char* raw, Req* req)
{
    printf("%s\n", raw);

    sscanf(raw, "%s %s", req->type, req->path);
}

void handle_request(int client)
{
    char req_raw[BUF_SIZE];
    Req req;
    Res res;

    int num_recvd = recv(client, req_raw, BUF_SIZE - 1, 0);

    if (num_recvd < 0)
    {
        perror("recv");
        return;
    }

    parse_req_raw(req_raw, &req); // TODO: handle for parse.

    printf("Request: %s, %s\n", req.type, req.path);

    Handler handler = ht_get(routes, req.path);

    if (handler == NULL)
    {
        fallback_handler(&res);
    }
    else
    {
        handler(&req, &res);
    }

    send_response(client, &res);
}

int http_start(char* port)
{
    int client, server;

    if ((server = init_server_socket(port)) < 0)
    {
        puts("Error when establishing the server.");
        exit(1);
    }

    printf("Waiting for connections on port %s...\n", port);

    while(1)
    {
        client = accept(server, (struct sockaddr*) NULL, NULL);

        if (client == -1)
        {   
            perror("accept");
            continue;
        }

        printf("Client connected.\n");

        handle_request(client);
        close(client);
    }

    return 0;
}