use crate::z80::{Z80, Z80_io};

struct IO {
    pub mem: [u8; 0x10000],
}

impl Z80_io for IO {
    fn read_byte(&self, addr: u16) -> u8 {
        self.mem[addr as usize]
    }

    fn write_byte(&mut self, addr: u16, value: u8) {
        self.mem[addr as usize] = value;
    }
}

fn run_test(cpu: &mut Z80<IO>, rom: &[u8], cyc_expected: u64) {
    for (i, byte) in rom.iter().enumerate() {
        cpu.io.write_byte(0x100 + i as u16, *byte);
    }

    let mut cyc: u64 = 0;

    cpu.init();
    cpu.pc = 0x100;
    cpu.io.write_byte(0,0xd3);
    cpu.io.write_byte(1,0);
    cpu.io.write_byte(5,0xdb);
    cpu.io.write_byte(6,0);
    cpu.io.write_byte(7,0xc9);

    let mut nb_instructions: u64 = 0;
    while !cpu.test_finished {
        nb_instructions += 1;
        cyc = cyc.wrapping_add(cpu.step().into());
    }
    let diff = cyc_expected.wrapping_sub(cyc);
    println!(
        "\n*** {} instructions executed on {} cycles (expected={}, diff={})\n\n",
        nb_instructions,
        cyc,
        cyc_expected,
        diff,
    );

    assert_eq!(cyc, cyc_expected);
}

#[test]
pub fn main() {
    let mut memory = IO {
        mem: [0; 0x10000],
    };

    let mut cpu = Z80::new(memory);

    run_test(&mut cpu, include_bytes!("./roms/prelim.com"), 8721);
    run_test(&mut cpu, include_bytes!("./roms/zexdoc.cim"), 46734978649);
    run_test(&mut cpu, include_bytes!("roms/zexall.cim"), 46734978649);
}