#include <ctype.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

struct my_msgbuf {
    long mtype;
    char mtext[200];
};

int checkCLArgs(char *num1, char *num2) {
    int i;

    for(i = 0; num1[i] != '\0'; i++) {
        if(!isdigit(num1[i]))
            return 1;
    }

    for(i = 0; num2[i] != '\0'; i++) {
        if(!isdigit(num2[i]))
            return 1;
    }

    return 0;
}

void error(const char *errMsg) {
    fprintf(stderr, "%s\n", errMsg);
    exit(-1);
}

int main(int argc, char **argv) {

    if(argc != 3)
        error("Usage: ./main N M\nN - number of cannibal processes, M - number of missionary processes");

    if(checkCLArgs(argv[1], argv[2]))
        error("Please enter positive integers only!");

    int i;
    pid_t pid;
    struct my_msgbuf buf;
    int msqid;
    key_t key = (key_t) getuid();
    char text[]="Hello from boat!\n";

    int N = (int) strtol(argv[1], (char **)NULL, 10);
    int M = (int) strtol(argv[2], (char **)NULL, 10);

    if(N <= 0 || M <= 0)
        error("Value of N or M is not greater than 0");

    printf("N = %d, M = %d\n", N, M);

    int cannibalArr[N];
    int missionaryArr[M];

    for(i = 0; i < N; i++) {
        pid = fork();

        switch(pid) {
            case -1:
                error("Error while creating cannibal proccess!");
            case 0:
                execl("./person", "C", NULL);
                exit(1);
            default:
                continue;
        }
    }

    for(i = 0; i < M; i++) {
        pid = fork();

        switch(pid) {
            case -1:
                error("Error while creating missionary proccess!");
            case 0:
                execl("./person", "M", NULL);
                exit(1);
            default:
                continue;
        }
    }

    printf("Boat: created %d cannibals and %d missionaries\n", N, M);

    if ((msqid = msgget(key, 0600 | IPC_CREAT)) == -1) {
        error("msgget");
    }

    while(1) {
        sleep(2);
        if (msgsnd(msqid, (struct msgbuf *)&buf, strlen(text)+1, 0) == -1)
            error("msgsnd");
    }

    return 0;
}