#include "tcpdserver.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <sys/stat.h> // mkfifo
#include <linux/limits.h>

#define PORT 6000
#define BUF_SIZE 1024
#define TMPDIR "/tmp/ipc/"
#define NBCLIENT 5
#define SERVICE_TCP "tcpd"

int init_connection(const info_request *req)
{
    int yes = 1;
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    //struct sockaddr_in sin = { 0 };

    if(sock == -1)
    {
        perror("socket()");
        exit(errno);
    }

    /*"address already in use" error message */
    if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1)
    {
        perror("Server-setsockopt() error lol!");
        exit(1);
    }
    printf("Server-setsockopt() is OK...\n");

    if(bind(sock,(struct sockaddr *) &req->addr, sizeof(req->addr)) == -1)
    {
        perror("bind()");
        exit(errno);
    }

    if(listen(sock, 5) == -1)
    {
        perror("listen()");
        exit(errno);
    }

    return sock;
}

void write_message(int sock, const char *buffer)
{
    if(send(sock, buffer, strlen(buffer), 0) < 0)
    {
        perror("send()");
        exit(errno);
    }
}

int read_message(int sock, char *buffer)
{
    return recv(sock, buffer, BUF_SIZE - 1, 0);
}

void endConnection(int sock) {
    close(sock);
}

void printAddr(struct sockaddr_in *csin) {
    printf("IP Addr : %s\n", inet_ntoa(csin->sin_addr));
    printf("Port : %u\n", ntohs(csin->sin_port));
}


void * service_thread(void * c_data) {
    client_data *cda = (client_data*) c_data;
    char buffer[BUF_SIZE];
    char *service;
    int version;
    int clientSock = cda->sfd;
    int nbMessages = 0;

    if (read_message(clientSock, buffer) == -1) {
        perror("read_message()");
        return NULL;
    }else {
        parseServiceVersion(buffer, &service, &version);
    }

    /* TODO : service correspond au service que le client veut utiliser 
     ** il faut comparer service à un tableau qui contient les services 
     ** disponibles
     */

    //path service
    char servicePath[PATH_MAX];
    memset (servicePath, 0, PATH_MAX);
    if (servicePath == NULL) {
        perror("malloc()");
    }
    snprintf(servicePath , PATH_MAX, "%s%s" , TMPDIR, service);

    //pid index version
    char * piv = malloc(PATH_MAX);
    memset(piv , 0, PATH_MAX);
    if (piv == NULL) {
        perror("malloc()");
    }
    makePivMessage(&piv, getpid(), cda->index, version);

    //write pid index version in T/I/S of service
    int ret = file_write(servicePath, piv, strlen(piv));
    if(ret == 0) {
        perror("file_write()");
        return NULL;
    }
    free(piv);

    // gets the service path, such as /tmp/ipc/pid-index-version-in/out
    char * pathname[2];
    pathname[0] = (char*) malloc(PATH_MAX);
    memset(pathname[0], 0, PATH_MAX);
    if (pathname[0] == NULL) {
        perror("malloc()");
    }
    pathname[1] = malloc(PATH_MAX);
    memset(pathname[1] , 0, PATH_MAX);
    if (pathname[1] == NULL) {
        perror("malloc()");
    }
    inOutPathCreate(pathname, cda->index, version);

    //create in out files
    if(fifo_create(pathname[0]) != 0) {
        perror("fifo_create()");
        return NULL;
    }

    if(fifo_create(pathname[1]) != 0) {
        perror("fifo_create()");
        return NULL;
    }

    //open -in fifo file
    int fdin = open (pathname[0], O_RDWR);
    if (fdin <= 0) {
        printf("open: fd < 0\n");
        perror ("open()");
        return NULL;
    }


    //utilisation du select() pour surveiller la socket du client et fichier in
    fd_set rdfs;

    int max = clientSock > fdin ? clientSock : fdin;

    printf("Waitting for new messages...\n" );
    while(1) {
        FD_ZERO(&rdfs);

        //add client's socket
        FD_SET(clientSock, &rdfs);

        //add in file
        FD_SET(fdin, &rdfs);

        if(select(max + 1, &rdfs, NULL, NULL, NULL) == -1)
        {
            perror("select()");
            exit(errno);
        }

        if (FD_ISSET(fdin, &rdfs)){
            if(read(fdin, &buffer, BUF_SIZE) < 0) {
                perror("read()");
            }
            printf("message from file in : %s\n", buffer );
            write_message(clientSock, buffer);
            nbMessages--;
        } else if (FD_ISSET(clientSock, &rdfs)) {

            int n = read_message(clientSock, buffer);
            if(n > 0) {
                printf("Server : message (%d bytes) : %s\n", n, buffer);
                if(file_write(pathname[1], buffer, strlen(buffer)) < 0) {
                    perror("file_write");
                }
                nbMessages++;
            } else if (n == 0 && nbMessages == 0){
                //message end to server
                if(file_write(pathname[1], "exit", 4) < 0) {
                    perror("file_write");
                }

                //free
                free(pathname[0]);
                free(pathname[1]);

                //close the files descriptors
                close(fdin);
                close(clientSock);

                printf("------thread %d shutdown----------\n\n", cda->index );

                break;
            }
            
        }
    }

    return NULL;
}

void parseServiceVersion(char * buf, char ** service, int *version) {
    char *token = NULL, *saveptr = NULL;
    char *str = NULL;
    int i = 0;

    for (str = buf, i = 1; ; str = NULL, i++) {
        token = strtok_r(str, " ", &saveptr);
        if (token == NULL)
            break;

        if (i == 1) {
            *service = token;
        }
        else if (i == 2) {
            *version = strtoul(token, NULL, 10);
        }
    }

}

int fifo_create (char * path)
{
    int ret;
    if ((ret = mkfifo (path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) {
        switch (errno) {
            case EACCES :
                printf ("file %s : EACCES\n", path);
                return 1;
            case EEXIST :
                printf ("file %s : EEXIST\n", path);
                break;
            case ENAMETOOLONG :
                printf ("file %s : ENAMETOOLONG\n", path);
                return 2;
            case ENOENT :
                printf ("file %s : ENOENT\n", path);
                return 3;
            case ENOSPC :
                printf ("file %s : ENOSPC\n", path);
                return 4;
            case ENOTDIR :
                printf ("file %s : ENOTDIR\n", path);
                return 5;
            case EROFS :
                printf ("file %s : EROFS\n", path);
                return 6;
            default :
                printf ("err file %s unknown\n", path);
                return 7;
        }
    }

    return ret;
}

void inOutPathCreate(char ** pathname, int index, int version) {
    snprintf(pathname[0] , PATH_MAX, "%s%d-%d-%d-in" , TMPDIR, getpid(), index, version);
    snprintf(pathname[1] , PATH_MAX, "%s%d-%d-%d-out", TMPDIR, getpid(), index, version);
}

void makePivMessage (char ** piv, int pid, int index, int version) {

    snprintf(*piv , PATH_MAX, "%d %d %d" , getpid(), index, version);

}

void * server_thread(void * reqq) {
    info_request *req = (info_request*) reqq;

    //client 
    client_data tab_client[NBCLIENT];
    pthread_t tab_service_threads[NBCLIENT];
    int actual = 0;
    int i;

    int sock = init_connection(req);
    fd_set rdfs;

    printf("Waitting for new clients :\n" );
    while(1) {
        FD_ZERO(&rdfs);

        /* add STDIN_FILENO */
        FD_SET(STDIN_FILENO, &rdfs);

        //add listener's socket
        FD_SET(sock, &rdfs);

        if(select(sock + 1, &rdfs, NULL, NULL, NULL) == -1)
        {
            perror("select()");
            exit(errno);
        }

        /* something from standard input : i.e keyboard */
        if(FD_ISSET(STDIN_FILENO, &rdfs))
        {
            /* stop process when type on keyboard */
            for (i = 0; i < actual; i++) {
                if (pthread_cancel(tab_service_threads[i]) != 0) {
                    printf("Aucun thread correspond \n");
                }   
            }
            printf("server shutdown\n");
            break; 
        }
        else if (FD_ISSET(sock, &rdfs)){
            //New client
            socklen_t sinsize = sizeof (struct sockaddr_in);
            tab_client[actual].sfd = accept(sock, (struct sockaddr *)&tab_client[actual].c_addr, &sinsize);
            if(tab_client[actual].sfd == -1)
            {
                perror("accept()");
                close(sock);
                exit(errno);
            }

            printf("New client :\n");
            printAddr(&tab_client[actual].c_addr);

            tab_client[actual].index = actual;

            int ret = pthread_create( &tab_service_threads[actual], NULL, &service_thread, (void *) &tab_client[actual]);
            if (ret) {
                perror("pthread_create()");
                endConnection(sock);
                exit(errno);
            } else {
                printf("\n----------Creation of listen thread %d ------------\n", actual);
            }

            actual++;
        }
    }

    for (i = 0; i < actual; i++) {
        pthread_join(tab_service_threads[i], NULL); 
    }

    endConnection(sock);

    return NULL;
}

/*
*   user cans send 2 types of request to server : listen or connect
*   listen = server for a service such as pongd
*   connect = connect to a server
*/
int srv_get_new_request(const struct service *srv, info_request *req) {
    if (srv->spath == NULL) {
        return -1;
    }

    char *buf = NULL;
    size_t msize = 0;    
    int ret = file_read (srv->spath, &buf, &msize);
    if (ret <= 0) {
        fprintf (stderr, "err: listening on %s\n", srv->spath);
        return -1;
    }

    char *token = NULL, *saveptr = NULL;
    char *str = NULL;
    int i = 0;

    //for a "connect" request
    pid_t pid = 0;
    int index = 0;
    int version = 0;

    for (str = buf, i = 1; ; str = NULL, i++) {
        token = strtok_r(str, " ", &saveptr);
        if (token == NULL)
            break;

        if (i == 1) {
            if(strncmp("exit", token, 4) == 0 ) {
                free(str);
                return 0;
            }
            req->request = token;
        }
        else if (i == 2){ 
            req->addr.sin_addr.s_addr = inet_addr(token);
        }
        else if (i == 3) {
            req->addr.sin_port = htons(strtoul(token, NULL, 10));
        }
        else if (i == 4 && (strcmp("connect", req->request)) == 0){
            pid = strtoul(token, NULL, 10);
        }
        else if (i == 5 && (strcmp("connect", req->request)) == 0) {
            index = strtoul(token, NULL, 10);
        }
        else if (i == 6 && (strcmp("connect", req->request)) == 0) {
            version = strtoul(token, NULL, 10);
        }
        
    }

    req->addr.sin_family = AF_INET;

    if (strcmp("connect", req->request) == 0) {
        srv_process_gen (req->p, pid, index, version);
    }

    if (buf != NULL)
        free(buf);
    buf = NULL;
    msize = 0;

    return 1;
}

void * client_thread(void *reqq) {
    info_request *req = (info_request*) reqq;
    char buffer[BUF_SIZE];

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if(sock == -1)
    {
        perror("socket()");
        exit(errno);
    }

    if(connect(sock,(struct sockaddr *) &req->addr, sizeof(struct sockaddr)) == -1)
    {
        perror("connect()");
        exit(errno);
    }

    printf("Connected to server at :\n");
    printAddr(&req->addr);

    write_message(sock, "pongd 5");
    /*sleep(1);
    write_message(sock, "is it working ???");
    sleep(2);
    write_message(sock, "is it working ???");*/

    //open -out fifo file of client
    int fdout = open (req->p->path_out, O_RDWR);
    if (fdout <= 0) {
        printf("open: fd < 0\n");
        perror ("open()");
        return NULL;
    }

    //utilisation du select() pour surveiller la socket du server et fichier out du client
    fd_set rdfs;

    int max = sock > fdout ? sock : fdout;

    while(1) {
        FD_ZERO(&rdfs);

        //add client's socket
        FD_SET(sock, &rdfs);

        //add in file
        FD_SET(fdout, &rdfs);

        if(select(max + 1, &rdfs, NULL, NULL, NULL) == -1)
        {
            perror("select()");
            exit(errno);
        }

        if (FD_ISSET(fdout, &rdfs)){
            if(read(fdout, &buffer, BUF_SIZE) < 0) {
                perror("read()");
            }
            write_message(sock, buffer);

        } else if (FD_ISSET(sock, &rdfs)) {

            int n = read_message(sock, buffer);
            if(n > 0) {
                printf("Client : message (%d bytes) : %s\n", n, buffer);
                if(file_write(req->p->path_in, buffer, strlen(buffer)) < 0) {
                    perror("file_write");
                }

            } else if (n == 0){
                //message end from server
                printf("server down\n");

                //close the files descriptors
                close(fdout);
                close(sock);

                printf("------thread client shutdown----------\n");

                break;
            }
            
        }
    }
    close(sock);

    return NULL;

}

void request_print (const info_request *req) {
    printf("%s \n",req->request);
}

void main_loop (const struct service *srv) {
    //request
    info_request req;
    req.p = malloc(sizeof(struct process));
    int ret;
    pthread_t pidS;
    pthread_t pidC;

    while(1) {
        ret = srv_get_new_request(srv, &req);
        if (ret == -1) {
            perror("srv_get_new_request()");
            exit(1);
        } else if (ret == 0) {
            free(req.p);
            break;
        }

        request_print(&req);

        if (strcmp("listen", req.request) == 0) {
            int ret = pthread_create( &pidS, NULL, &server_thread, (void *) &req);
            if (ret) {
                perror("pthread_create()");
                exit(errno);
            } else {
                printf("\n----------Creation of server thread ------------\n");
            }
        }else {
            int ret = pthread_create( &pidC, NULL, &client_thread, (void *) &req);
            if (ret) {
                perror("pthread_create()");
                exit(errno);
            } else {
                printf("\n----------Creation of client thread ------------\n");
            }
        }
    }
}

int main(int argc, char * argv[], char **env) {
    struct service srv;
    srv_init (argc, argv, env, &srv, SERVICE_TCP, NULL);
    printf ("Listening on %s.\n", srv.spath);

    // creates the service named pipe, that listens to client applications
    int ret;
    if ((ret = srv_create (&srv))) {
        fprintf(stdout, "error service_create %d\n", ret);
        exit (1);
    }
    printf("MAIN: server created\n" );

    // the service will loop until the end of time, a specific message, a signal
    main_loop (&srv);

    // the application will shut down, and remove the service named pipe
    if ((ret = srv_close (&srv))) {
        fprintf(stdout, "error service_close %d\n", ret);
        exit (1);
    }

    return 0;
}