use std::fs::File;
use std::io::prelude::*;

fn create_fake_rom(file_name: String) {
    let mut buffer = File::create(file_name).unwrap();
    let header = vec![
        0x4E, 0x45, 0x53, 0x1A, 0x02, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00,
    ];

    let pre = [0; 0x600];
    let code = vec![
        0x20, 0x06, 0x86, 0x20, 0x38, 0x86, 0x20, 0x0d, 0x86, 0x20, 0x2a, 0x86, 0x60, 0xa9, 0x02,
        0x85, 0x02, 0xa9, 0x06, 0x85, 0x03, 0xa9, 0x11, 0x85, 0x10, 0xa9, 0x10, 0x85, 0x12, 0xa9,
        0x0f, 0x85, 0x14, 0xa9, 0x04, 0x85, 0x11, 0x85, 0x13, 0x85, 0x15, 0x60, 0xa5, 0xfe, 0x85,
        0x00, 0xa5, 0xfe, 0x29, 0x03, 0x18, 0x69, 0x02, 0x85, 0x01, 0x60, 0x20, 0x4d, 0x86, 0x20,
        0x8d, 0x86, 0x20, 0xc3, 0x86, 0x20, 0x19, 0x87, 0x20, 0x20, 0x87, 0x20, 0x2d, 0x87, 0x4c,
        0x38, 0x86, 0xa5, 0xff, 0xc9, 0x77, 0xf0, 0x0d, 0xc9, 0x64, 0xf0, 0x14, 0xc9, 0x73, 0xf0,
        0x1b, 0xc9, 0x61, 0xf0, 0x22, 0x60, 0xa9, 0x04, 0x24, 0x02, 0xd0, 0x26, 0xa9, 0x01, 0x85,
        0x02, 0x60, 0xa9, 0x08, 0x24, 0x02, 0xd0, 0x1b, 0xa9, 0x02, 0x85, 0x02, 0x60, 0xa9, 0x01,
        0x24, 0x02, 0xd0, 0x10, 0xa9, 0x04, 0x85, 0x02, 0x60, 0xa9, 0x02, 0x24, 0x02, 0xd0, 0x05,
        0xa9, 0x08, 0x85, 0x02, 0x60, 0x60, 0x20, 0x94, 0x86, 0x20, 0xa8, 0x86, 0x60, 0xa5, 0x00,
        0xc5, 0x10, 0xd0, 0x0d, 0xa5, 0x01, 0xc5, 0x11, 0xd0, 0x07, 0xe6, 0x03, 0xe6, 0x03, 0x20,
        0x2a, 0x86, 0x60, 0xa2, 0x02, 0xb5, 0x10, 0xc5, 0x10, 0xd0, 0x06, 0xb5, 0x11, 0xc5, 0x11,
        0xf0, 0x09, 0xe8, 0xe8, 0xe4, 0x03, 0xf0, 0x06, 0x4c, 0xaa, 0x86, 0x4c, 0x35, 0x87, 0x60,
        0xa6, 0x03, 0xca, 0x8a, 0xb5, 0x10, 0x95, 0x12, 0xca, 0x10, 0xf9, 0xa5, 0x02, 0x4a, 0xb0,
        0x09, 0x4a, 0xb0, 0x19, 0x4a, 0xb0, 0x1f, 0x4a, 0xb0, 0x2f, 0xa5, 0x10, 0x38, 0xe9, 0x20,
        0x85, 0x10, 0x90, 0x01, 0x60, 0xc6, 0x11, 0xa9, 0x01, 0xc5, 0x11, 0xf0, 0x28, 0x60, 0xe6,
        0x10, 0xa9, 0x1f, 0x24, 0x10, 0xf0, 0x1f, 0x60, 0xa5, 0x10, 0x18, 0x69, 0x20, 0x85, 0x10,
        0xb0, 0x01, 0x60, 0xe6, 0x11, 0xa9, 0x06, 0xc5, 0x11, 0xf0, 0x0c, 0x60, 0xc6, 0x10, 0xa5,
        0x10, 0x29, 0x1f, 0xc9, 0x1f, 0xf0, 0x01, 0x60, 0x4c, 0x35, 0x87, 0xa0, 0x00, 0xa5, 0xfe,
        0x91, 0x00, 0x60, 0xa6, 0x03, 0xa9, 0x00, 0x81, 0x10, 0xa2, 0x00, 0xa9, 0x01, 0x81, 0x10,
        0x60, 0xa2, 0x00, 0xea, 0xea, 0xca, 0xd0, 0xfb, 0x60,
    ];

    let mut pos = 0;
    while pos < header.len() {
        let bytes_written = buffer.write(&header[pos..]).unwrap();
        pos += bytes_written;
    }

    pos = 0;

    while pos < header.len() {
        let bytes_written = buffer.write(&pre[pos..]).unwrap();
        pos += bytes_written;
    }

    pos = 0;
    while pos < header.len() {
        let bytes_written = buffer.write(&code[pos..]).unwrap();
        pos += bytes_written;
    }

    pos = 0x600 + code.len();

    while pos < (0xFFFC - 0x8000) {
        buffer.write(&[0]).unwrap();
        pos += 1;
    }
    buffer.write(&[0x0, 0x86, 0, 0]).unwrap();

    buffer.flush().unwrap();
}