use std::fs;
use core::slice::Iter;

fn main() {
    let file = fs::read("/home/lea/Downloads/invadeez/invadeez/rom/invaders.h").expect("where file");
    let mut data = file.iter();

    while let Some(byte) = data.next() {
        fn next(data: &mut Iter<u8>, len: u8) -> String {
            let mut res = String::new();

            for _ in 0..len {
                res.insert_str(0, format!("{:x}", data.next().expect("Expected data")).as_str());
            }

            return res;
        }

        // http://www.emulator101.com/reference/8080-by-opcode.html

        let instruction: String = match byte {
            0x00 => format!("NOP"),
            0x01 => format!("LXI    B,#${}", next(&mut data, 2)),
            0x02 => format!("STAX   B"),
            0x03 => format!("INX    B"),
            0x04 => format!("INR    B"),
            0x05 => format!("DCR    B"),
            0x06 => format!("MVI    B,#0x{}", next(&mut data, 1)),
            0x07 => format!("RLC"),
            0x09 => format!("DAD    B"),
            0x0a => format!("LDAX   B"),
            0x0b => format!("DCX    B"),
            0x0c => format!("INR    C"),
            0x0d => format!("DCR    C"),
            0x0e => format!("MVI    C,#0x{}", next(&mut data, 1)),
            0x0f => format!("RRC"),
            0x11 => format!("LXI    D,#0x{}", next(&mut data, 2)),
            0x12 => format!("STAX   D"),
            0x13 => format!("INX    D"),
            0x14 => format!("INR    D"),
            0x15 => format!("DCR    D"),
            0x16 => format!("MVI    D,#0x{}", next(&mut data, 1)),
            0x17 => format!("RAL"),
            0x19 => format!("DAD    D"),
            0x1a => format!("LDAX   D"),
            0x1b => format!("DCX    D"),
            0x1c => format!("INR    E"),
            0x1d => format!("DCR    E"),
            0x1e => format!("MVI    E,#0x{}", next(&mut data, 1)),
            0x1f => format!("RAR"),
            0x21 => format!("LXI    H,#0x{}", next(&mut data, 2)),
            0x22 => format!("SLHD   %0x{}", next(&mut data, 2)),
            0x23 => format!("INX    H"),
            0x24 => format!("INR    H"),
            0x25 => format!("DCR    H"),
            0x26 => format!("MVI    H,{}", next(&mut data, 1)),
            0x27 => format!("DAA"),
            0x29 => format!("DAD    H"),
            0x2a => format!("LHLD   ${}", next(&mut data, 2)),
            0x2b => format!("DCX    H"),
            0x2c => format!("INR    L"),
            0x2d => format!("DCR    L"),
            0x2e => format!("MVI    L,#0x{}", next(&mut data, 1)),
            0x2f => format!("CMA"),
            0x31 => format!("LXI    SP,#0x{}", next(&mut data, 2)),
            0x32 => format!("STA    ${}", next(&mut data, 2)),
            0x33 => format!("INX    SP"),
            0x34 => format!("INR    M"),
            0x35 => format!("DCR    M"),
            0x36 => format!("MVI    M,#0x{}", next(&mut data, 1)),
            0x37 => format!("STC"),
            0x39 => format!("DAD    SP"),
            0x3a => format!("LDA    ${}", next(&mut data, 2)),
            0x3b => format!("DCX    SP"),
            0x3c => format!("INR    A"),
            0x3d => format!("DCR    A"),
            0x3e => format!("MVI    A,#0x{}", next(&mut data, 1)),
            0x3f => format!("CMC"),
            // -- continue here --
            0xc3 => format!("JMP    ${}", next(&mut data, 2)),
            0xc5 => format!("PUSH   B"),
            0xd5 => format!("PUSH   D"),
            0xe5 => format!("PUSH   H"),
            0xf5 => format!("PUSH   PSW"),
            _ => panic!("Unimplemented instruction {:#x}", byte),
        };

        println!("{}", instruction);
    }
}