use std::ops::{BitAnd, BitOr, BitXor};

use crate::{Inner, Memory, Register, State};

#[allow(dead_code)]
enum FLAGS {
    Z = 7,
    N = 6,
    H = 5,
    C = 4,
}

pub struct CPU {
    pub memory: Memory,
    pub state: State,
}

impl CPU {
    pub fn exec_next(&mut self) -> u8 {
        let opcode = self.next_opcode();
        unsafe { println!("exec {:#4X} from {:#4X}", opcode, self.state.pc.as_u16 - 1) };
        match opcode {
            0x0 => {
                // noop
            }
            0x01 => self.state.bc = self.ld_immediate_word(),
            0x02 => unsafe {
                let address = self.state.bc.as_u16;
                self.memory.set(address, self.state.af.as_u8s.left);
            },
            0x03 => unsafe { self.state.bc.as_u16 = self.state.bc.as_u16.wrapping_add(1) },
            0x04 => unsafe {
                self.state.bc.as_u8s.left = self.state.bc.as_u8s.left.wrapping_add(1)
            },
            0x05 => unsafe {
                self.state.bc.as_u8s.left = self.state.bc.as_u8s.left.wrapping_sub(1)
            },
            0x06 => self.state.bc.as_u8s.left = self.ld_immediate_byte(),
            0x07 => panic!("RCLA instruction: 0x07"),
            0x08 => unsafe {
                let address = self.ld_immediate_word().as_u16;
                let word = self.state.sp;
                self.store_word(address, word);
            },
            0x09 => unsafe {
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(self.state.bc.as_u16)
            },
            0x0A => unsafe { self.state.af.as_u8s.left = self.memory.get(self.state.bc.as_u16) },
            0x0B => unsafe { self.state.bc.as_u16 = self.state.bc.as_u16.wrapping_sub(0x1) },
            0x0C => unsafe {
                self.state.bc.as_u8s.right = self.state.bc.as_u8s.right.wrapping_add(0x1)
            },
            0x0D => unsafe {
                self.state.bc.as_u8s.right = self.state.bc.as_u8s.right.wrapping_sub(0x1)
            },
            0x0E => self.state.bc.as_u8s.right = self.ld_immediate_byte(),
            0x0F => panic!("RRCA instruction: 0x0F"),
            0x10 => panic!("STOP instruction"),
            0x11 => self.state.de = self.ld_immediate_word(),
            0x12 => unsafe {
                let address = self.state.de.as_u16;
                let data = self.state.af.as_u8s.left;
                self.memory.set(address, data);
            },
            0x13 => unsafe { self.state.de.as_u16 = self.state.de.as_u16.wrapping_sub(0x1) },
            0x14 => unsafe {
                self.state.de.as_u8s.left = self.state.de.as_u8s.left.wrapping_add(0x1)
            },
            0x15 => unsafe {
                self.state.de.as_u8s.left = self.state.de.as_u8s.left.wrapping_sub(0x1)
            },
            0x16 => self.state.de.as_u8s.left = self.ld_immediate_byte(),
            0x17 => panic!("RLA instruction: 0x17"),
            0x18 => unsafe {
                self.state.pc.as_u16 = self
                    .state
                    .pc
                    .as_u16
                    .wrapping_add(self.ld_immediate_byte() as u16)
            },
            0x19 => unsafe {
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(self.state.de.as_u16)
            },
            0x1A => unsafe { self.state.af.as_u8s.left = self.memory.get(self.state.de.as_u16) },
            0x1B => unsafe { self.state.de.as_u16 = self.state.de.as_u16.wrapping_sub(1) },
            0x1C => unsafe {
                self.state.de.as_u8s.right = self.state.de.as_u8s.right.wrapping_add(1)
            },
            0x1D => unsafe {
                self.state.de.as_u8s.right = self.state.de.as_u8s.right.wrapping_sub(1)
            },
            0x1E => self.state.de.as_u8s.right = self.ld_immediate_byte(),
            0x1F => panic!("RRA instruction: 0x1F"),
            0x20 => {
                let jump_size = self.ld_immediate_byte();
                if self.get_flag(FLAGS::Z) == 0 {
                    unsafe {
                        self.state.pc.as_u16 = self.state.pc.as_u16.wrapping_add(jump_size as u16)
                    }
                }
            }
            0x21 => self.state.hl = self.ld_immediate_word(),
            0x22 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.af.as_u8s.left);
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(1);
            },
            0x23 => unsafe { self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(1) },
            0x24 => unsafe {
                self.state.hl.as_u8s.left = self.state.hl.as_u8s.left.wrapping_add(1)
            },
            0x25 => unsafe {
                self.state.hl.as_u8s.left = self.state.hl.as_u8s.left.wrapping_sub(1)
            },
            0x26 => self.state.hl.as_u8s.left = self.ld_immediate_byte(),
            0x27 => panic!("DAA instruction: 0x27"),
            0x28 => {
                let jump_size = self.ld_immediate_byte();
                if self.get_flag(FLAGS::Z) == 1 {
                    unsafe {
                        self.state.pc.as_u16 = self.state.pc.as_u16.wrapping_add(jump_size as u16)
                    }
                }
            }
            0x29 => unsafe { self.state.hl.as_u16 *= 2 },
            0x2A => unsafe {
                self.state.af.as_u8s.left = self.memory.get(self.state.hl.as_u16);
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(1);
            },
            0x2B => unsafe { self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_sub(1) },
            0x2C => unsafe {
                self.state.hl.as_u8s.right = self.state.hl.as_u8s.right.wrapping_add(1)
            },
            0x2D => unsafe {
                self.state.hl.as_u8s.right = self.state.hl.as_u8s.right.wrapping_sub(1)
            },
            0x2E => self.state.hl.as_u8s.right = self.ld_immediate_byte(),
            0x2F => unsafe { self.state.af.as_u8s.left = !self.state.af.as_u8s.left },
            0x30 => {
                let jump_size = self.ld_immediate_byte();
                if self.get_flag(FLAGS::C) == 0 {
                    unsafe {
                        self.state.pc.as_u16 = self.state.pc.as_u16.wrapping_add(jump_size as u16)
                    }
                }
            }
            0x31 => self.state.sp = self.ld_immediate_word(),
            0x32 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.af.as_u8s.left);
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_sub(1);
            },
            0x33 => unsafe { self.state.sp.as_u16 = self.state.sp.as_u16.wrapping_add(1) },
            0x34 => unsafe {
                let address = self.state.hl.as_u16;
                let data = self.memory.get(address) + 1;
                self.memory.set(address, data);
            },
            0x35 => unsafe {
                let address = self.state.hl.as_u16;
                let data = self.memory.get(address) - 1;
                self.memory.set(address, data);
            },
            0x36 => unsafe {
                let data = self.ld_immediate_byte();
                self.memory.set(self.state.hl.as_u16, data);
            },
            0x37 => self.set_flag(FLAGS::C),
            0x38 => {
                let jump_size = self.ld_immediate_byte();
                if self.get_flag(FLAGS::C) == 1 {
                    unsafe {
                        self.state.pc.as_u16 = self.state.pc.as_u16.wrapping_add(jump_size as u16)
                    }
                }
            }
            0x39 => unsafe {
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_add(self.state.sp.as_u16)
            },
            0x3A => unsafe {
                self.state.af.as_u8s.left = self.memory.get(self.state.hl.as_u16);
                self.state.hl.as_u16 = self.state.hl.as_u16.wrapping_sub(1);
            },
            0x3B => unsafe { self.state.sp.as_u16 = self.state.sp.as_u16.wrapping_sub(1) },
            0x3C => unsafe {
                self.state.af.as_u8s.left = self.state.af.as_u8s.left.wrapping_add(1)
            },
            0x3D => unsafe {
                self.state.af.as_u8s.left = self.state.af.as_u8s.left.wrapping_sub(1)
            },
            0x3E => self.state.af.as_u8s.left = self.ld_immediate_byte(),
            0x3F => self.toggle_flag(FLAGS::C),
            0x40 => {}
            0x41 => unsafe { self.state.bc.as_u8s.left = self.state.bc.as_u8s.right },
            0x42 => unsafe { self.state.bc.as_u8s.left = self.state.de.as_u8s.left },
            0x43 => unsafe { self.state.bc.as_u8s.left = self.state.de.as_u8s.right },
            0x44 => unsafe { self.state.bc.as_u8s.left = self.state.hl.as_u8s.left },
            0x45 => unsafe { self.state.bc.as_u8s.left = self.state.hl.as_u8s.right },
            0x46 => unsafe { self.state.bc.as_u8s.left = self.memory.get(self.state.hl.as_u16) },
            0x47 => unsafe { self.state.bc.as_u8s.left = self.state.af.as_u8s.left },
            0x48 => unsafe { self.state.bc.as_u8s.right = self.state.bc.as_u8s.left },
            0x49 => {}
            0x4A => unsafe { self.state.bc.as_u8s.right = self.state.de.as_u8s.left },
            0x4B => unsafe { self.state.bc.as_u8s.right = self.state.de.as_u8s.right },
            0x4C => unsafe { self.state.bc.as_u8s.right = self.state.hl.as_u8s.left },
            0x4D => unsafe { self.state.bc.as_u8s.right = self.state.hl.as_u8s.right },
            0x4E => unsafe { self.state.bc.as_u8s.right = self.memory.get(self.state.hl.as_u16) },
            0x4F => unsafe { self.state.bc.as_u8s.right = self.state.af.as_u8s.left },
            0x50 => unsafe { self.state.de.as_u8s.left = self.state.bc.as_u8s.left },
            0x51 => unsafe { self.state.de.as_u8s.left = self.state.bc.as_u8s.right },
            0x52 => {}
            0x53 => unsafe { self.state.de.as_u8s.left = self.state.de.as_u8s.right },
            0x54 => unsafe { self.state.de.as_u8s.left = self.state.hl.as_u8s.left },
            0x55 => unsafe { self.state.de.as_u8s.left = self.state.hl.as_u8s.right },
            0x56 => unsafe { self.state.de.as_u8s.left = self.memory.get(self.state.hl.as_u16) },
            0x57 => unsafe { self.state.de.as_u8s.left = self.state.af.as_u8s.left },
            0x58 => unsafe { self.state.de.as_u8s.right = self.state.bc.as_u8s.left },
            0x59 => unsafe { self.state.de.as_u8s.right = self.state.bc.as_u8s.right },
            0x5A => unsafe { self.state.de.as_u8s.right = self.state.de.as_u8s.left },
            0x5B => {}
            0x5C => unsafe { self.state.de.as_u8s.right = self.state.hl.as_u8s.left },
            0x5D => unsafe { self.state.de.as_u8s.right = self.state.hl.as_u8s.right },
            0x5E => unsafe { self.state.de.as_u8s.right = self.memory.get(self.state.hl.as_u16) },
            0x5F => unsafe { self.state.de.as_u8s.right = self.state.af.as_u8s.left },
            0x60 => unsafe { self.state.hl.as_u8s.left = self.state.bc.as_u8s.left },
            0x61 => unsafe { self.state.hl.as_u8s.left = self.state.bc.as_u8s.right },
            0x62 => unsafe { self.state.hl.as_u8s.left = self.state.de.as_u8s.left },
            0x63 => unsafe { self.state.hl.as_u8s.left = self.state.de.as_u8s.right },
            0x64 => {}
            0x65 => unsafe { self.state.hl.as_u8s.left = self.state.hl.as_u8s.right },
            0x66 => unsafe { self.state.hl.as_u8s.left = self.memory.get(self.state.hl.as_u16) },
            0x67 => unsafe { self.state.hl.as_u8s.left = self.state.af.as_u8s.left },
            0x68 => unsafe { self.state.hl.as_u8s.right = self.state.bc.as_u8s.left },
            0x69 => unsafe { self.state.hl.as_u8s.right = self.state.bc.as_u8s.right },
            0x6A => unsafe { self.state.hl.as_u8s.right = self.state.de.as_u8s.left },
            0x6B => unsafe { self.state.hl.as_u8s.right = self.state.de.as_u8s.right },
            0x6C => unsafe { self.state.hl.as_u8s.right = self.state.hl.as_u8s.left },
            0x6D => {}
            0x6E => unsafe { self.state.hl.as_u8s.right = self.memory.get(self.state.hl.as_u16) },
            0x6F => unsafe { self.state.hl.as_u8s.right = self.state.af.as_u8s.left },
            0x70 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.bc.as_u8s.left)
            },
            0x71 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.bc.as_u8s.right)
            },
            0x72 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.de.as_u8s.left)
            },
            0x73 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.de.as_u8s.right)
            },
            0x74 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.hl.as_u8s.left)
            },
            0x75 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.hl.as_u8s.right)
            },
            0x76 => panic!("HALT instruction: 0x76"),
            0x77 => unsafe {
                self.memory
                    .set(self.state.hl.as_u16, self.state.af.as_u8s.left)
            },
            0x78 => unsafe { self.state.af.as_u8s.left = self.state.bc.as_u8s.left },
            0x79 => unsafe { self.state.af.as_u8s.left = self.state.bc.as_u8s.right },
            0x7A => unsafe { self.state.af.as_u8s.left = self.state.de.as_u8s.left },
            0x7B => unsafe { self.state.af.as_u8s.left = self.state.de.as_u8s.right },
            0x7C => unsafe { self.state.af.as_u8s.left = self.state.hl.as_u8s.left },
            0x7D => unsafe { self.state.af.as_u8s.left = self.state.hl.as_u8s.right },
            0x7E => unsafe { self.state.af.as_u8s.left = self.memory.get(self.state.hl.as_u16) },
            0x7F => {}
            0x80 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.bc.as_u8s.left)
            },
            0x81 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.bc.as_u8s.right)
            },
            0x82 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.de.as_u8s.left)
            },
            0x83 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.de.as_u8s.right)
            },
            0x84 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.hl.as_u8s.left)
            },
            0x85 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.hl.as_u8s.right)
            },
            0x86 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.memory.get(self.state.hl.as_u16))
            },
            0x87 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.af.as_u8s.left)
            },
            0x88 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.bc.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x89 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.bc.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x8A => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.de.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x8B => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.de.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x8C => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.hl.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x8D => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.hl.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x8E => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.wrapping_add(
                        self.memory.get(self.state.hl.as_u16) + self.get_flag(FLAGS::C),
                    )
            },
            0x8F => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.state.af.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x90 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.bc.as_u8s.left)
            },
            0x91 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.bc.as_u8s.right)
            },
            0x92 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.de.as_u8s.left)
            },
            0x93 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.de.as_u8s.right)
            },
            0x94 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.hl.as_u8s.left)
            },
            0x95 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.hl.as_u8s.right)
            },
            0x96 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.memory.get(self.state.hl.as_u16))
            },
            0x97 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.af.as_u8s.left)
            },
            0x98 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.bc.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x99 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.bc.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x9A => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.de.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x9B => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.de.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x9C => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.hl.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0x9D => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.hl.as_u8s.right + self.get_flag(FLAGS::C))
            },
            0x9E => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.wrapping_sub(
                        self.memory.get(self.state.hl.as_u16) + self.get_flag(FLAGS::C),
                    )
            },
            0x9F => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_sub(self.state.af.as_u8s.left + self.get_flag(FLAGS::C))
            },
            0xA0 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.bc.as_u8s.left)
            },
            0xA1 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.bc.as_u8s.right)
            },
            0xA2 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.de.as_u8s.left)
            },
            0xA3 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.de.as_u8s.right)
            },
            0xA4 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.hl.as_u8s.left)
            },
            0xA5 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.hl.as_u8s.right)
            },
            0xA6 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .bitand(self.memory.get(self.state.hl.as_u16))
            },
            0xA7 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitand(self.state.af.as_u8s.left)
            },
            0xA8 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.bc.as_u8s.left)
            },
            0xA9 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.bc.as_u8s.right)
            },
            0xAA => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.de.as_u8s.left)
            },
            0xAB => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.de.as_u8s.right)
            },
            0xAC => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.hl.as_u8s.left)
            },
            0xAD => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.hl.as_u8s.right)
            },
            0xAE => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .bitxor(self.memory.get(self.state.hl.as_u16))
            },
            0xAF => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitxor(self.state.af.as_u8s.left)
            },
            0xB0 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.bc.as_u8s.left)
            },
            0xB1 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.bc.as_u8s.right)
            },
            0xB2 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.de.as_u8s.left)
            },
            0xB3 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.de.as_u8s.right)
            },
            0xB4 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.hl.as_u8s.left)
            },
            0xB5 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.hl.as_u8s.right)
            },
            0xB6 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .bitor(self.memory.get(self.state.hl.as_u16))
            },
            0xB7 => unsafe {
                self.state.af.as_u8s.left =
                    self.state.af.as_u8s.left.bitor(self.state.af.as_u8s.left)
            },
            0xB8 => unsafe {
                if self.state.af.as_u8s.left == self.state.bc.as_u8s.left {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xB9 => unsafe {
                if self.state.af.as_u8s.left == self.state.bc.as_u8s.right {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBA => unsafe {
                if self.state.af.as_u8s.left == self.state.de.as_u8s.left {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBB => unsafe {
                if self.state.af.as_u8s.left == self.state.de.as_u8s.right {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBC => unsafe {
                if self.state.af.as_u8s.left == self.state.hl.as_u8s.left {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBD => unsafe {
                if self.state.af.as_u8s.left == self.state.hl.as_u8s.right {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBE => unsafe {
                if self.state.af.as_u8s.left == self.memory.get(self.state.hl.as_u16) {
                    self.set_flag(FLAGS::Z);
                }
            },
            0xBF => self.set_flag(FLAGS::Z),
            0xC0 => unsafe {
                if self.get_flag(FLAGS::Z) == 0 {
                    let address = self.state.sp.as_u16;
                    self.state.pc.as_u8s.left = self.memory.get(address);
                    self.state.pc.as_u8s.right = self.memory.get(address + 1);
                    self.state.sp.as_u16 = self.state.sp.as_u16.wrapping_add(2);
                }
            },
            0xC1 => unsafe {
                let address = self.state.sp.as_u16;
                self.state.bc.as_u8s.left = self.memory.get(address);
                self.state.bc.as_u8s.right = self.memory.get(address + 1);
                self.state.sp.as_u16 = self.state.sp.as_u16.wrapping_add(2);
            },
            0xC2 => {
                let word = self.ld_immediate_word();
                if self.get_flag(FLAGS::Z) == 0 {
                    self.state.pc = word;
                }
            }
            0xC3 => {
                self.state.pc = self.ld_immediate_word();
            }
            0xC4 => {
                let maybe_next = self.ld_immediate_word();
                if self.get_flag(FLAGS::Z) == 0 {
                    self.push(self.state.pc);
                    self.state.pc = maybe_next;
                }
            }
            0xC5 => self.push(self.state.bc),
            0xC6 => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.ld_immediate_byte())
            },
            0xC7 => self.rst(0x00),
            0xC8 => {
                if self.get_flag(FLAGS::Z) == 1 {
                    self.state.pc = self.pop_word()
                }
            }
            0xC9 => self.state.pc = self.pop_word(),
            0xCA => {
                let maybe_next = self.ld_immediate_word();
                if self.get_flag(FLAGS::Z) == 1 {
                    self.state.pc = maybe_next;
                }
            }
            0xCB => println!("Undefined behaviour: opcode CB"),
            0xCC => {
                let maybe_next = self.ld_immediate_word();
                if self.get_flag(FLAGS::Z) == 1 {
                    self.push(self.state.pc);
                    self.state.pc = maybe_next;
                }
            }
            0xCD => {
                self.push(self.state.pc);
                self.state.pc = self.ld_immediate_word();
            }
            0xCE => unsafe {
                self.state.af.as_u8s.left = self
                    .state
                    .af
                    .as_u8s
                    .left
                    .wrapping_add(self.ld_immediate_byte() + self.get_flag(FLAGS::C))
            },
            0xCF => self.rst(0x08),

            0xEA => {
                unsafe {
                    let address = self.ld_immediate_word().as_u16;
                    self.memory.set(address, self.state.af.as_u8s.left);
                };
            }
            _ => {
                panic!("unimplemented opcode: {:#X}", opcode);
            }
        };
        return opcode;
    }

    fn next_opcode(&mut self) -> u8 {
        unsafe {
            let opcode = self.memory.get(self.state.pc.as_u16);
            self.state.pc.as_u16 = self.state.pc.as_u16.wrapping_add(0x1);
            return opcode;
        };
    }

    fn rst(&mut self, address: u16) {
        self.push(self.state.pc);
        self.state.pc.as_u8s.left = 0x0;
        self.state.pc.as_u8s.right = self.memory.get(address);
    }

    fn push(&mut self, register: Register) {
        unsafe {
            let address = self.state.sp.as_u16;
            self.memory.set(address - 1, register.as_u8s.right);
            self.memory.set(address - 2, register.as_u8s.left);
            self.state.sp.as_u16 = address - 2;
        }
    }

    fn pop_word(&mut self) -> Register {
        unsafe {
            let address = self.state.sp.as_u16;
            self.state.sp.as_u16 = self.state.sp.as_u16.wrapping_add(2);
            Register {
                as_u8s: Inner {
                    left: self.memory.get(address),
                    right: self.memory.get(address + 1),
                },
            }
        }
    }

    fn store_word(&mut self, address: u16, word: Register) {
        unsafe {
            self.memory.set(address, word.as_u8s.left);
            self.memory.set(address + 1, word.as_u8s.right);
        };
    }

    fn ld_immediate_word(&mut self) -> Register {
        Register {
            as_u8s: Inner {
                left: self.next_opcode(),
                right: self.next_opcode(),
            },
        }
    }

    fn ld_immediate_byte(&mut self) -> u8 {
        self.next_opcode()
    }

    fn get_flag(&mut self, flag: FLAGS) -> u8 {
        unsafe {
            return self.state.af.as_u8s.right & (1 << flag as u8);
        }
    }

    fn set_flag(&mut self, flag: FLAGS) {
        unsafe {
            self.state.af.as_u8s.right = self.state.af.as_u8s.right.bitor(1 << flag as u8);
        };
    }

    #[allow(dead_code)]
    fn clear_flag(&mut self, flag: FLAGS) {
        unsafe {
            self.state.af.as_u8s.right = self.state.af.as_u8s.right.bitand(!(1 << flag as u8));
        };
    }

    fn toggle_flag(&mut self, flag: FLAGS) {
        unsafe {
            self.state.af.as_u8s.right = self.state.af.as_u8s.right.bitxor(1 << flag as u8);
        };
    }
}