import pytest

from gbso.insn import *
from gbso.regs import *


def n8():
    for i in range(0xFF + 1):
        yield i


def n16():
    for i in range(0xFFFF + 1):
        yield i


@pytest.mark.parametrize("dst,src", [(x, y) for x in R8 for y in R8])
def test_ld_r_r(dst, src):
    cpu = CPU()
    cpu.set_reg8(src, 0x7F)

    LD_R_R(dst, src).exec(cpu)
    assert cpu.get_reg8(src) == 0x7F
    assert cpu.cycles == 4


@pytest.mark.parametrize("r,imm", [(r, imm) for r in R8 for imm in n8()])
def test_ld_r_n8(r, imm):
    cpu = CPU()

    LD_R_N8(r, 0x7F).exec(cpu)
    assert cpu.get_reg8(r) == 0x7F
    assert cpu.cycles == 8


@pytest.mark.parametrize("r", R8)
def test_ld_r_hl(r):
    cpu = CPU()
    cpu.set_reg16(R16.HL, 0x1234)
    cpu.set_mem8(0x1234, 0x7F)

    LD_R_HL(r).exec(cpu)
    assert cpu.get_reg8(r) == 0x7F
    assert cpu.cycles == 8


@pytest.mark.parametrize("r", R8)
def test_ld_hl_r(r):
    cpu = CPU()
    cpu.set_reg8(r, 0x7F)
    cpu.set_reg16(R16.HL, 0x1234)

    LD_HL_R(r).exec(cpu)
    hl = cpu.deref_hl()

    if r == R8.H:
        assert hl == 0x12
    elif r == R8.L:
        assert hl == 0x34
    else:
        assert hl == 0x7F

    assert cpu.cycles == 8


@pytest.mark.parametrize("imm", n8())
def test_ld_hl_n8(imm):
    cpu = CPU()
    cpu.set_reg16(R16.HL, 0x1234)

    LD_HL_N(imm).exec(cpu)

    assert cpu.deref_hl() == imm
    assert cpu.cycles == 12


def test_ld_a_bc():
    cpu = CPU()
    cpu.set_reg16(R16.BC, 0x1234)
    cpu.set_mem8(0x1234, 0x7F)

    LD_A_BC().exec(cpu)

    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 8


def test_ld_a_de():
    cpu = CPU()
    cpu.set_reg16(R16.DE, 0x1234)
    cpu.set_mem8(0x1234, 0x7F)

    LD_A_DE().exec(cpu)

    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 8


# @pytest.mark.parametrize("nn", n16())
def test_ld_a_nn(nn=0x1234):
    cpu = CPU()
    cpu.set_mem8(nn, 0x7F)

    LD_A_NN(nn).exec(cpu)

    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 16


def test_ld_bc_a():
    cpu = CPU()
    cpu.set_reg16(R16.BC, 0x1234)
    cpu.set_reg8(R8.A, 0x7F)

    LD_BC_A().exec(cpu)

    assert cpu.get_mem8(0x1234) == 0x7F
    assert cpu.cycles == 8


def test_ld_de_a():
    cpu = CPU()
    cpu.set_reg16(R16.DE, 0x1234)
    cpu.set_reg8(R8.A, 0x7F)

    LD_DE_A().exec(cpu)

    assert cpu.get_mem8(0x1234) == 0x7F
    assert cpu.cycles == 8


# @pytest.mark.parametrize("nn", n16())
def test_ld_nn_a(nn=0x1234):
    cpu = CPU()
    cpu.set_reg8(R8.A, 0x7F)

    LD_NN_A(nn).exec(cpu)

    assert cpu.get_mem8(nn) == 0x7F
    assert cpu.cycles == 16


@pytest.mark.parametrize("n", n8())
def test_ld_a_ff_n(n):
    cpu = CPU()
    cpu.set_mem8(0xFF00 + n, 0x7F)

    LD_A_FF_N(n).exec(cpu)

    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 12


@pytest.mark.parametrize("n", n8())
def test_ld_ff_n_a(n):
    cpu = CPU()
    cpu.set_reg8(R8.A, 0x7F)

    LD_FF_N_A(n).exec(cpu)

    assert cpu.get_mem8(0xFF00 + n) == 0x7F
    assert cpu.cycles == 12


def test_ld_a_ff_c():
    cpu = CPU()
    cpu.set_reg8(R8.C, 0x12)
    cpu.set_mem8(0xFF12, 0x7F)

    LD_A_FF_C().exec(cpu)

    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 8


def test_ld_ff_c_a():
    cpu = CPU()
    cpu.set_reg8(R8.C, 0x12)
    cpu.set_reg8(R8.A, 0x7F)

    LD_FF_C_A().exec(cpu)

    assert cpu.get_mem8(0xFF12) == 0x7F
    assert cpu.cycles == 8


def test_ldi_hl_a():
    cpu = CPU()
    cpu.set_reg8(R8.A, 0x7F)
    cpu.set_reg16(R16.HL, 0x1234)

    LDI_HL_A().exec(cpu)

    assert cpu.get_reg16(R16.HL) == 0x1235
    assert cpu.get_mem8(0x1234) == 0x7F
    assert cpu.cycles == 8


def test_ldi_a_hl():
    cpu = CPU()
    cpu.set_mem8(0x1234, 0x7F)
    cpu.set_reg16(R16.HL, 0x1234)

    LDI_A_HL().exec(cpu)

    assert cpu.get_reg16(R16.HL) == 0x1235
    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 8


def test_ldd_hl_a():
    cpu = CPU()
    cpu.set_reg8(R8.A, 0x7F)
    cpu.set_reg16(R16.HL, 0x1234)

    LDD_HL_A().exec(cpu)

    assert cpu.get_reg16(R16.HL) == 0x1233
    assert cpu.get_mem8(0x1234) == 0x7F
    assert cpu.cycles == 8


def test_ldd_a_hl():
    cpu = CPU()
    cpu.set_mem8(0x1234, 0x7F)
    cpu.set_reg16(R16.HL, 0x1234)

    LDD_A_HL().exec(cpu)

    assert cpu.get_reg16(R16.HL) == 0x1233
    assert cpu.get_reg8(R8.A) == 0x7F
    assert cpu.cycles == 8