#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>

#include <termios.h>

#include <unistd.h>

#define ZED_CAPACITY 1024

typedef struct {
    char data[ZED_CAPACITY];
    size_t count;
} Editor;

static Editor editor = {0};

int main(int argc, char **argv)
{
    if (!isatty(0)) {
        fprintf(stderr, "Please run in the terminal!\n");
        return 1;
    }

    if (argc < 2) {
        fprintf(stderr, "Usage: zed <input.txt>\n");
        fprintf(stderr, "ERROR: no input file was provided\n");
        return 1;
    }

    // stores the state of the terminal
    struct termios term;
    if (tcgetattr(0, &term)) {
        fprintf(stderr, "ERROR: could not save the state of the terminal: %s\n", strerror(errno));
        return 1;
    }

    term.c_lflag &= ~ECHO;
    if (tcsetattr(0, 0, &term)) {
        fprintf(stderr, "ERROR: could not update the state of the terminal: %s\n", strerror(errno));
        return 1;
    }

    const char *file_path = argv[1];
    FILE *f = fopen(file_path, "rb");
    if (f == NULL) {
        fprintf(
            stderr, 
            "ERROR: could not open file %s: %s\n", 
            file_path, 
            strerror(errno)
        );
        return 1;
    }

    editor.count = fread(editor.data, 1, ZED_CAPACITY, f);
    printf("\ncontents of %s:\n\n", file_path);
    fwrite(editor.data, 1, editor.count, stdout);

    fclose(f);

    bool quit = false;
    while (!quit && !feof(stdin)) {
        int x = fgetc(stdin);
        if (x == 'q') {
            quit = true;
        }
    }

    term.c_lflag |= ECHO;
    tcsetattr(0, 0, &term);

    return 0;
}