#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>

#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/stat.h>

#define DIM_BUFFER 1024
#define P 100

typedef enum{
    CMD_LIST,
    CMD_SIZE,
    CMD_SEARCH,
    CMD_ERROR,
    RPL_DATA,
    RPL_DATA_STOP
}cmd;

typedef struct{
    long dest;
    char nome_file[DIM_BUFFER];
    char stringa[DIM_BUFFER];
    int dim;
    cmd comando;
}message;

void child(int msg, char *path, int num){
    message message;
    char buffer[DIM_BUFFER];
    int ricorrenze = 0;
    struct dirent *entry;
    struct stat statbuf;
    FILE *file;
    DIR *dir;

    while(1){
        msgrcv(msg, &message, sizeof(message) - sizeof(long), num, 0);

        switch(message.comando){
            case CMD_LIST:
                chdir(path);
                if((dir = opendir(path)) == NULL){
                    perror("dir");
                    exit(0);
                }
                while((entry = readdir(dir)) != NULL){
                    lstat(entry->d_name, &statbuf);

                    if(S_ISREG(statbuf.st_mode)){
                        strcpy(message.nome_file, entry->d_name);
                        message.comando = RPL_DATA;
                        message.dest = P;
                        msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);
                    }
                }
                message.comando = RPL_DATA_STOP;
                message.dest = P;
                msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);
                break;

            case CMD_SIZE:
                chdir(path);
                lstat(message.nome_file, &statbuf);
                if(S_ISREG(statbuf.st_mode)){
                    message.dest = P;
                    message.dim = statbuf.st_size;
                    message.comando = RPL_DATA;
                    strcpy(message.nome_file, path);
                    msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);
                }
                break;

            case CMD_SEARCH:
                chdir(path);
                if((file = fopen(message.nome_file, "r")) == NULL){
                    perror("file");
                    exit(0);
                }
                while(fgets(buffer, DIM_BUFFER, file)){
                    if (buffer[strlen(buffer)-1] == '\n')
                        buffer[strlen(buffer)-1] = '\0';

                    if(strcmp(buffer, message.stringa) == 0){
                        ricorrenze++;
                    }
                }
                message.dest = P;
                message.dim = ricorrenze;
                message.comando = RPL_DATA;
                msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);
                break;

            default:
                break;
        }
    }
}

int main(int argc, char *argv[]){
    int msg, tok, len;
    int quit = 0;
    int child_ = 0;
    char *token;
    char buffer[DIM_BUFFER];
    message message;

    if((msg = msgget(IPC_PRIVATE, IPC_CREAT|0600)) == -1){
        perror("msg");
        exit(0);
    }

    for(int i = 1; i < argc; i++){
        child_++;
        if(fork() == 0){
            child(msg, argv[i], i);
        }
    }

        sleep(1);
    do{
        printf("file-shell> ");

        fgets(buffer, DIM_BUFFER, stdin);

        len = strlen(buffer);
        if (buffer[len-1] == '\n')
            buffer[len-1] = '\0';

        token = strtok(buffer, " ");
        if(strcmp(token, "list") == 0){
            message.comando = CMD_LIST;
            token = strtok(NULL, " ");
            tok = atoi(token);
            if(tok > child_ || tok < 0){
                printf("cartella non trovata! \n");
            }else{
                message.dest = tok;
            }
            msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);

            while(1){
                msgrcv(msg, &message, sizeof(message) - sizeof(long), P, 0);
                if(message.comando == RPL_DATA){
                    printf("file: %s \n", message.nome_file);
                }else if(message.comando == RPL_DATA_STOP){
                    break;
                }
            }

        }else if(strcmp(token, "size") == 0){
            message.comando = CMD_SIZE;
            token = strtok(NULL, " ");
            tok = atoi(token);
            if(tok > child_ || tok < 0){
                printf("cartella non trovata! \n");
            }else{
                message.dest = tok;
                token = strtok(NULL, " ");
                strcpy(message.nome_file, token);
            }
            msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);

            while(1){
                msgrcv(msg, &message, sizeof(message) - sizeof(long), P, 0);
                if(message.comando == RPL_DATA){
                    printf("dimensione %s: %d \n", message.nome_file, message.dim);
                    break;
                }
            }

        }else if(strcmp(token, "search") == 0){
            message.comando = CMD_SEARCH;
            token = strtok(NULL, " ");
            tok = atoi(token);
            if(tok > child_ || tok < 0){
                printf("cartella non trovata! \n");
            }else{
                message.dest = tok;
                token = strtok(NULL, " ");
                strcpy(message.nome_file, token);
                token = strtok(NULL, " ");
                strcpy(message.stringa, token);
            }
            msgsnd(msg, &message, sizeof(message) - sizeof(long), 0);

            while(1){
                msgrcv(msg, &message, sizeof(message) - sizeof(long), P, 0);
                if(message.comando == RPL_DATA){
                    printf("ricorrenze: %d \n", message.dim);
                    break;
                }
            }

        }else if(strcmp(token, "quit") == 0){
            quit = 1;
        }else{
            printf("comando errato! \n");
        }

    }while(quit == 0);

    exit(0);
}