import os
import shutil

import pytest
import torch

import triton
import triton.language as tl
from triton.code_gen import JITFunction

tmpdir = ".tmp"


@triton.jit
def function_1(i):
    i = i + 1
    i = function_2(i)
    return i


@triton.jit
def function_2(i):
    i = i + 1
    return i


@triton.jit
def kernel(X, i, BLOCK: tl.constexpr):
    i = i + 1
    i = function_1(i)
    tl.store(X, i)


@triton.jit(do_not_specialize=["i"])
def kernel_nospec(X, i, BLOCK: tl.constexpr):
    i = i + 1
    i = function_1(i)
    tl.store(X, i)


def apply_src_change(target, old, new):
    kernel.hash = None
    function_1.hash = None
    function_2.hash = None
    function_1.src = function_1.src.replace(old, new)
    target.src = target.src.replace(old, new)
    ret = target.cache_key
    target.src = target.src.replace(new, old)
    return ret


def test_nochange():
    baseline = kernel.cache_key
    updated = apply_src_change(kernel, 'i + 1', 'i + 1')
    assert baseline == updated


def test_toplevel_change():
    baseline = kernel.cache_key
    updated = apply_src_change(kernel, 'i + 1', 'i + 2')
    assert baseline != updated


def test_nested1_change():
    baseline = kernel.cache_key
    updated = apply_src_change(function_1, 'i + 1', 'i + 2')
    assert baseline != updated


def reset_tmp_dir():
    os.environ["TRITON_CACHE_DIR"] = tmpdir
    if os.path.exists(tmpdir):
        shutil.rmtree(tmpdir)


def test_reuse():
    counter = 0

    def inc_counter(key, binary, repr):
        nonlocal counter
        counter += 1
    JITFunction.cache_hook = inc_counter
    reset_tmp_dir()
    x = torch.empty(1, dtype=torch.int32, device='cuda')
    for i in range(10):
        kernel[(1,)](x, 1, BLOCK=1024)
    assert counter == 1


@pytest.mark.parametrize('mode', ['enable', 'disable'])
def test_specialize(mode):
    counter = 0

    def inc_counter(key, binary, repr):
        nonlocal counter
        counter += 1
    JITFunction.cache_hook = inc_counter
    reset_tmp_dir()
    x = torch.empty(1, dtype=torch.int32, device='cuda')
    function = {'enable': kernel, 'disable': kernel_nospec}[mode]
    target = {'enable': 5, 'disable': 1}[mode]
    for i in [1, 2, 4, 8, 16, 32]:
        function[(1,)](x, i, BLOCK=512)
    assert counter == target