#include <stdlib.h>
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>

#include "protocol.h"

typedef struct station {
    char* filePath;
    int currentChunk;
} station_t;

typedef struct user {
    int udpPort;
    int stationNum;
    int sockfd;
    pthread_t streamThread;
} user_t;

#define NUM_STATIONS 2
#define LINE_MAX 1024
#define MAX_USERS 1000

/* For safe condition variable usage, must use a boolean predicate and  */
/* a mutex with the condition.                                          */
int                 count = 0;
pthread_cond_t      cond  = PTHREAD_COND_INITIALIZER;
pthread_mutex_t     mutex = PTHREAD_MUTEX_INITIALIZER;


int start_threads = 0;

int max_active_users = 0;

pthread_mutex_t     mutex_user_data = PTHREAD_MUTEX_INITIALIZER;
// array from index to user_data
user_t  *user_data;
station_t station_data[NUM_STATIONS];
int sockfd_to_user[MAX_USERS + 4];

char* port = "4950";

void *send_udp_packet_routine(void* arg);
void *select_thread(void* arg);
void *synchronization_thread(void* arg);

void *get_in_addr(struct sockaddr *sa);

void *init_user(int sockfd);
void *update_user_udpPort(int sockfd, int udpPort);
void *update_user_station(int sockfd, int stationNum);
void *print_user_data(int sockfd);
void *destroy_user(int sockfd);


// void *load_file(void* arg);

main(int argc, char *argv[])
{
    // temporary
    station_data[0] = (station_t) {"mp3/Beethoven-SymphonyNo5.mp3", 0};
    station_data[1] = (station_t) {"mp3/DukeEllington-Caravan.mp3", 0};

    // threads to control reading files at chunks while the other threads sleep

    user_data = malloc(sizeof(user_t) * max_active_users);
    if (!user_data) {  perror("malloc"); return 1; }

    // thread that manages file descriptors
    pthread_t s_thread, sync_thread;
    pthread_create(&s_thread, NULL, select_thread, NULL);

    // starts the threads after created
    // sleep(1);
    // startThreads = 0;
    // pthread_cond_broadcast(&cond);

    // command line interface
    char input[LINE_MAX];
     while (1) {
	    char *line = fgets(input, LINE_MAX, stdin);

        if (line == NULL) {
            continue;
        } else if (strncmp("q\n", input, LINE_MAX) == 0) {
            // end code if type in q
            printf("Exiting.\n");
            break;
        } else if (strncmp("p\n", input, LINE_MAX) == 0) {
            // print all user data
            for (int i = 0; i < max_active_users; i++) {
                print_user_data(i);
            }
        } else if (strncmp("s\n", input, LINE_MAX) == 0) {
            // start the streaming threads
            pthread_create(&sync_thread, NULL, synchronization_thread, NULL);
        }
    }

    return 0;
}

/* Make the manager routine */
void *send_udp_packet_routine(void *arg) {
    // pthread_mutex_lock(&mutex);
    // while(startThreads) {
    //     pthread_cond_wait(&cond, &mutex);
    // }
    // pthread_mutex_unlock(&mutex);
    int did_send_data = 0;
    int did_load_data = 0;

    pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;

    int * i = (int *) arg;
    while (1)
        {
            pthread_mutex_lock(&m);
            if (!start_threads && did_send_data && did_load_data) {
                did_load_data = 0;
                did_send_data = 0;
            }
            while(!start_threads) {
                pthread_cond_wait(&cond, &m);
            }
            pthread_mutex_unlock(&m);
            if(!did_send_data) {
                printf("send data: thread %d \n", i);
                did_send_data = 1;
            }
            if(!did_load_data) {
                printf("load data: thread %d \n", i);
                did_load_data = 1;
            }

        }
    return NULL;
}

// /* Make the manager routine */
// void *load_file(void *arg) {
//     // read first data off the files
//     pthread_mutex_lock(&mutex);
//     while(startThreads) {
//         pthread_cond_wait(&cond, &mutex);
//     }
//     pthread_mutex_unlock(&mutex);

//     int * i = (int *) arg;
//     while (1)
//         {
//             pthread_mutex_lock(&mutex);
//             while(startThreads) {
//                 pthread_cond_wait(&cond, &mutex);
//             }
//             pthread_mutex_unlock(&mutex);
//             /* Do some work. */
//             printf("Thread %d \n", i);
//             // send data to port
//             // read data coming in off the file
//             // sleep for a secong
//             sleep(1);
//     }
//     return NULL;
// }

void *synchronization_thread(void *arg) {
    int c = 0;
    while (1)
    {
        start_threads = 1;
        printf("\nbroadcast %d\n", c++);
        pthread_cond_broadcast(&cond);
        usleep(1000);
        start_threads = 0;
        sleep(1);

    }
}

void *select_thread(void *arg) {
    fd_set master;    // master file descriptor list
    fd_set read_fds;  // temp file descriptor list for select()
    int fdmax;        // maximum file descriptor number

    int listener;     // listening socket descriptor
    int newfd;        // newly accept()ed socket descriptor
    struct sockaddr_storage remoteaddr; // client address
    socklen_t addrlen;

    char buf[256];    // buffer for client data
    int nbytes;


    char remoteIP[INET6_ADDRSTRLEN];

    int yes=1;        // for setsockopt() SO_REUSEADDR, below
    int i, j, rv;

    struct addrinfo hints, *ai, *p;

    // const char* port = argv[1];

    FD_ZERO(&master);    // clear the master and temp sets
    FD_ZERO(&read_fds);

    // LISTENER: get us a socket and bind it
    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_PASSIVE;
    if ((rv = getaddrinfo(NULL, port, &hints, &ai)) != 0) {
        fprintf(stderr, "snowcast_server: %s\n", gai_strerror(rv));
        exit(1);
    }

    for(p = ai; p != NULL; p = p->ai_next) {
        listener = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
        if (listener < 0) { 
            continue;
        }
        
        // lose the pesky "address already in use" error message
        setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));

        if (bind(listener, p->ai_addr, p->ai_addrlen) < 0) {
            close(listener);
            continue;
        }

        break;
    }

    // if we got here, it means we didn't get bound
    if (p == NULL) {
        fprintf(stderr, "snowcast_server: failed to bind\n");
        exit(2);
    }

    freeaddrinfo(ai); // all done with this

     // listen
    if (listen(listener, 10) == -1) {
        perror("listen");
        exit(3);
    }

    // add the listener to the master set
    FD_SET(listener, &master);

    // keep track of the biggest file descriptor
    fdmax = listener; // so far, it's this one

    while(1==1) {
        read_fds = master; // copy it
        if (select(fdmax+1, &read_fds, NULL, NULL, NULL) == -1) {
            perror("select");
            exit(4);
        }

        // run through the existing connections looking for data to read
        for(i = 0; i <= fdmax; i++) {
            if (FD_ISSET(i, &read_fds)) { // we got one!!
                if (i == listener) {
                    // handle new connections
                    addrlen = sizeof remoteaddr;
                    newfd = accept(listener,
                        (struct sockaddr *)&remoteaddr,
                        &addrlen);

                    if (newfd == -1) {
                        perror("accept");
                    } else {
                        FD_SET(newfd, &master); // add to master set
                        if (newfd > fdmax) {    // keep track of the max
                            fdmax = newfd;
                        }
                        printf("selectserver: new connection from %s on "
                            "socket %d\n.",
                            inet_ntop(remoteaddr.ss_family,
                                get_in_addr((struct sockaddr*)&remoteaddr),
                                remoteIP, INET6_ADDRSTRLEN),
                            newfd);

                        // init user with this newfd
                        init_user(newfd);

                        // send the welcome message to client
                        struct Welcome welcome;
                        welcome.replyType = 2;
                        welcome.numStations = htons(NUM_STATIONS);
                        if ((send(newfd, &welcome, sizeof(struct Welcome), 0)) == -1)
                            perror("send");
                    }
                } else {
                    // handle data from a client
                    struct Command command;
                    if ((nbytes = recv(i, (char*)&command, sizeof(struct Command), 0)) <= 0) {
                        // got error or connection closed by client
                        if (nbytes == 0) {
                            // connection closed
                            printf("selectserver: socket %d hung up\n", i);
                        } else {
                            perror("recv");
                        }
                        close(i); // bye!
                        FD_CLR(i, &master); // remove from master set
                        // remove user from data structures
                        destroy_user(i);
                    } else {
                        // we got some data from a client
                        if (command.commandType == 0) {
                            // hello message with udpPort
                            printf("udpPort (from Hello) for new connection is %d.\n", ntohs(command.number));
                            // update udp port of user
                            update_user_udpPort(i, ntohs(command.number));



                            // // TALKER: get us a udp socket and bind it
                            // struct addrinfo hintsUdp, *servinfoUdp, *pUdp;
                            // int rvUdp, sockfdUdp, numbytesUdp;
                            // memset(&hintsUdp, 0, sizeof hintsUdp);
                            // hintsUdp.ai_family = AF_INET; // IPv4
                            // hintsUdp.ai_socktype = SOCK_DGRAM; // UDP
                            // if ((rvUdp = getaddrinfo(argv[1], command.number, &hints, &servinfoUdp)) != 0) {
                            //     fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rvUdp));
                            //     return 1;
                            // }

                            // // loop through all the results and make a socket
                            // for(p = servinfoUdp; p != NULL; p = p->ai_next) {
                            //     if ((sockfdUdp = socket(p->ai_family, p->ai_socktype,
                            //             p->ai_protocol)) == -1) {
                            //         perror("talker: socket");
                            //         continue;
                            //     }
                            //     break;
                            // }

                            // if (p == NULL) {
                            //     fprintf(stderr, "talker: failed to create socket\n");
                            //     return 2;
                            // }


                            // if ((numbytesUdp = sendto(sockfdUdp, "test", strlen("test"), 0,
                            //         p->ai_addr, p->ai_addrlen)) == -1) {
                            //     perror("talker: sendto");
                            //     exit(1);
                            // }

                            // freeaddrinfo(servinfoUdp);

                            // printf("talker: sent %d bytes to %d\n", numbytesUdp, sockfdUdp);
                            // close(sockfdUdp);
                        }
                        else if (command.commandType == 1) {
                            // setStation command for the user
                            printf("TODO: set station to %d\n", ntohs(command.number));
                            // update station of user
                            update_user_station(i, ntohs(command.number));
                        }
                        else {
                            // send back in invalid command
                            struct InvalidCommand invalid;
                            invalid.replyType = 4;
                            invalid.replyStringSize = 21;
                            // make a string with the command.commmandType type in it
                            invalid.replyString = "Invalid command type";
                            if ((send(i, &invalid, sizeof(struct InvalidCommand), 0)) == -1)
                                perror("send");
                            
                            // drop connection upon invalid command
                            close(i);
                            FD_CLR(i, &master);
                        }
                    }
                } // END handle data from client
            } // END got new incoming connection
        } // END looping through file descriptors

        // broadcast the new files over the udp socket list for each use

    } // END for(;;)--and you thought it would never end!
}

void *init_user(int sockfd) {
    // add the user to the list of user data
    pthread_mutex_lock(&mutex_user_data);

    // this is to save memory space. 
    // in general, the displacement of 4 is where a user "used to be"
    int user_index = max_active_users++;
    if(user_data[sockfd-4].sockfd == -1) {
        printf("reusing memory\n");
        user_index = sockfd - 4;
    } else {
        printf("making new memory\n");
        // have to make more memory
        user_t *more_users = realloc(user_data, sizeof(user_t) * max_active_users);
        if (!more_users) { perror("realloc"); exit(1); }
        user_data = more_users;
    }
    // map sockfd to this user index & create its stream thread
    pthread_t user_thread;
    pthread_create(&user_thread, NULL, send_udp_packet_routine, (void *)user_index);
    user_data[user_index] = (user_t){-1, -1, sockfd, user_thread};
    sockfd_to_user[sockfd] = user_index;
    // free(user_stream_threads);
    pthread_mutex_unlock(&mutex_user_data);
}
void *update_user_udpPort(int sockfd, int udpPort) {
    pthread_mutex_lock(&mutex_user_data);
    user_data[sockfd_to_user[sockfd]].udpPort = udpPort;
    pthread_mutex_unlock(&mutex_user_data);
}
void *update_user_station(int sockfd, int stationNum) {
    pthread_mutex_lock(&mutex_user_data);
    user_data[sockfd_to_user[sockfd]].stationNum = stationNum;
    pthread_mutex_unlock(&mutex_user_data);
}
void *print_user_data(int index) {
    printf("udpPort: %d, stationNum: %d, sockfd: %d, threadId:%d\n", 
        user_data[index].udpPort, user_data[index].stationNum, user_data[index].sockfd, user_data[index].streamThread);
}
void *destroy_user(int sockfd) {
    pthread_mutex_lock(&mutex_user_data);

    // stop the thread streaming to the user
    pthread_cancel(user_data[sockfd_to_user[sockfd]].streamThread);
    // "remove" the user from the list of user data
    user_data[sockfd_to_user[sockfd]] = (user_t) {-1, -1, -1, -1};
    // map sockfd to -1
    sockfd_to_user[sockfd] = -1;

    pthread_mutex_unlock(&mutex_user_data);
}


void *get_in_addr(struct sockaddr *sa)
{
    if (sa->sa_family == AF_INET) {
        return &(((struct sockaddr_in*)sa)->sin_addr);
    }

    return &(((struct sockaddr_in6*)sa)->sin6_addr);
}