/*
 * An example plug-in, which implements the 'cd' command.
 */
#include <stdbool.h>
#include <stdio.h>
#include <pwd.h>
#include <unistd.h>
#include <sys/types.h>
#include "../esh.h"
#include <signal.h>
#include "../esh-sys-utils.h"

static bool 
init_plugin(struct esh_shell *shell)
{
    printf("Plugin 'cd' initialized...\n");
    return true;
}

/* Implement chdir built-in.
 * Returns true if handled, false otherwise. */
static bool
chdir_builtin(struct esh_command *cmd)
{
    if (strcmp(cmd->argv[0], "m"))
        return false;

     if (cmd -> argv[1] == NULL || cmd -> argv[2] == NULL || cmd -> argv[3] == NULL)
        {
                printf("Not enough arguments to execute 'math'\n");
        }
        char* operation = cmd -> argv[1];
        int a = atoi(cmd -> argv[2]);
        int b = atoi(cmd -> argv[3]);
        int c;
        if (strcmp(operation, "add") == 0)
        {
                c = a + b;
                printf("%d + %d is equal to: %d\n", a, b, c);
        }
        else if (strcmp(operation, "subtract") == 0)
        {
                c = a - b;
                printf("%d - %d is equal to: %d\n", a, b, c);
        }
        else if (strcmp(operation, "multiply") == 0)
        { 
                c = a * b;
                printf("%d * %d is equal to: %d\n", a, b, c);
        }
        else if (strcmp(operation, "divide") == 0)
        {
                c = a / b;
                printf("%d / %d is equal to: %d\n", a, b, c);
        }
        else
        {
                printf("Invalid mathematical operation\n");
        }

    return true;
}

struct esh_plugin esh_module = {
  .rank = 1,
  .init = init_plugin,
  .process_builtin = chdir_builtin
};