/*********************************
* Class: MAGSHIMIM C2            *
* Name:  Itay                    *
**********************************/

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

#define NUM_OF_ARGS 4
#define MODE_PARAM (*(argv + 1))
#define SRC_PARAM (*(argv + 2))
#define DST_PARAM (*(argv + 3))

#define MODE_TXT 1
#define MODE_BIN 2

#define FALSE 0
#define TRUE 1


int fileExists(char* fileName)
{
    FILE* pf = 0;

    if (pf = fopen(fileName, "r"))
    {
        fclose(pf);
        return TRUE;
    }

    return FALSE;
}


void checkInput(int argc, char** argv)
{
    if (argc != NUM_OF_ARGS) // if there are not enough args
    {
        printf("Bad arguments!\n");

        printf("Press Enter to continue...\n");
        getchar();
        exit(0);
    }

    if (strcmp(MODE_PARAM, "textCopy") && strcmp(MODE_PARAM, "binaryCopy")) // if the first param is not a valid action
    {
        printf("Bad arguments!\n");

        printf("Press Enter to continue...\n");
        getchar();
        exit(0);
    }

    if (!fileExists(SRC_PARAM))
    {
        printf("Source file does not exist!\n");

        printf("Press Enter to continue...\n");
        getchar();
        exit(0);
    }
}


void initializeFiles(int argc, char** argv, FILE** in, FILE** out, int mode)
{
    int choice = 0;

    if (!fileExists(SRC_PARAM)) // if the file does not exist, tell the user and exit
    {
        printf("%s file does not exist.\n", SRC_PARAM);
        getchar();

        printf("Press Enter to continue...\n");
        getchar();
        exit(0);
    }

    *in = fopen(SRC_PARAM, mode == MODE_TXT ? "r" : "rb");

    if (fileExists(DST_PARAM)) // if the file exist, ask the user what to do
    {
        printf("Do you want to overwrite? 0 (no) / 1 (yes)\n");
        scanf("%d", &choice);
        getchar();

        if (choice == FALSE)
        {
            fclose(*in);

            printf("Press Enter to continue...\n");
            getchar();
            exit(0);
        }
    }

    *out = fopen(DST_PARAM, mode == MODE_TXT ? "w" : "wb"); // if user want to overwrite open a new file
}


void copyTxt(FILE* src, FILE* dst)
{
    char ch = 0;

    while ((ch = fgetc(src)) != EOF)
    {
        fputc(ch, dst);
    }
}


void copyBin(FILE* src, FILE* dst)
{
    char byte[1] = { 0 };

    while (!feof(src))
    {
        fread(byte, sizeof(char), 1, src);
        fwrite(byte, sizeof(char), 1, dst);
    }
}


int main(int argc, char** argv)
{
    FILE* fsrc = 0;
    FILE* fdst = 0;

    checkInput(argc, argv); // exits the program if input is not valid
    initializeFiles(argc, argv, &fsrc, &fdst, !strcmp(MODE_PARAM, "textCopy") ? MODE_TXT : MODE_BIN);

    !strcmp(MODE_PARAM, "textCopy") ? copyTxt(fsrc, fdst) : copyBin(fsrc, fdst); // call copyTxt() or copyBin() based on action

    fclose(fsrc);
    fclose(fdst);

    printf("Press Enter to continue...\n");
    getchar();
    return 0;
}