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import tvm
import tvm.testing
from tvm.script import tirx as T
from tvm.tirx.buffer import Buffer
from tvm.tirx.function import PrimFunc
from tvm.tirx.stmt import SBlock


def _check_func_signature_remap(lhs: PrimFunc, rhs: PrimFunc):
    assert lhs != rhs
    for x, y in zip(lhs.params, rhs.params):
        assert x != y
        assert lhs.buffer_map[x] != rhs.buffer_map[y]


def _check_buffer_decl(lhs: Buffer, rhs: Buffer):
    assert lhs != rhs
    assert lhs.data != rhs.data


def _check_block_signature_remap(lhs: SBlock, rhs: SBlock):
    assert lhs != rhs
    for x, y in zip(lhs.iter_vars, rhs.iter_vars):
        assert x != y
        assert x.var != y.var
    for x, y in zip(lhs.alloc_buffers, rhs.alloc_buffers):
        _check_buffer_decl(x, y)
    for x, y in zip(lhs.match_buffers, rhs.match_buffers):
        assert x != y
        _check_buffer_decl(x.buffer, y.buffer)


def test_simple():
    @T.prim_func(s_tir=True)
    # Buffer A should be remapped
    def elementwise(A: T.Buffer((128, 128), "float32")):
        # Buffer B should be remapped
        B = T.sblock_alloc_buffer((128, 128), "float32")
        # i, j should be remapped
        for i, j in T.grid(128, 128):
            with T.sblock("B"):
                # vi, vj should be remapped
                vi, vj = T.axis.remap("SS", [i, j])
                T.reads(A[vi, vj])
                T.writes(B[vi, vj])
                B[vi, vj] = A[vi, vj] * 2.0

    f1 = elementwise
    f2 = tvm.s_tir.renew_defs(f1)
    tvm.ir.assert_structural_equal(f1, f2)

    _check_func_signature_remap(f1, f2)
    # check root block
    _check_block_signature_remap(f1.body.block, f2.body.block)
    # check remap of i
    assert f1.body.block.body.loop_var != f2.body.block.body.loop_var
    # check remap of j
    assert f1.body.block.body.body.loop_var != f2.body.block.body.body.loop_var

    # check inner block
    def _get_sblock(f):
        return f.body.block.body.body.body.block

    _check_block_signature_remap(_get_sblock(f1), _get_sblock(f2))


def test_match_buffer():
    # well-formed checker complains about multiple definitions for variable A0_s1,
    # likely stemming from strides=[s, s]
    @T.prim_func(check_well_formed=False, s_tir=True)
    # A and B should be remapped
    def func_match_buffer(A: T.Buffer((128, 128), "float32"), B: T.Buffer((128, 128), "float32")):
        with T.sblock("root"):
            s = T.int32()
            e = T.int32()
            # A0 should be remapped
            A0 = T.match_buffer(
                A[0:128, 0:128],
                shape=(128, 128),
                dtype="float32",
                # s and e should be remapped
                strides=[s, s],
                elem_offset=e,
            )
            for i, j in T.grid(128, 128):
                with T.sblock("B"):
                    vi, vj = T.axis.remap("SS", [i, j])
                    B[vi, vj] = A0[vi, vj] * 2.0

    f1 = func_match_buffer
    f2 = tvm.s_tir.renew_defs(f1)
    tvm.ir.assert_structural_equal(f1, f2)

    _check_func_signature_remap(f1, f2)
    _check_block_signature_remap(f1.body.block, f2.body.block)
    assert f1.body.block.body.loop_var != f2.body.block.body.loop_var

    def _get_sblock(f):
        return f.body.block

    block1 = _get_sblock(f1)
    block2 = _get_sblock(f2)
    _check_block_signature_remap(block1, block2)

    matched_buffer1 = block1.match_buffers[0].buffer
    matched_buffer2 = block2.match_buffers[0].buffer
    # Stride var s should be remapped
    assert matched_buffer1.strides[0] != matched_buffer2.strides[0]
    assert matched_buffer1.strides[1] != matched_buffer2.strides[1]
    # s should be only remapped once
    assert matched_buffer1.strides[0] == matched_buffer1.strides[1]
    assert matched_buffer2.strides[0] == matched_buffer2.strides[1]
    # Element-offset var e should be remapped
    assert matched_buffer1.elem_offset != matched_buffer2.elem_offset


def test_undefined_buffer():
    @T.prim_func(s_tir=True)
    def access_alloc():
        # Buffer A should be remapped
        A = T.alloc_buffer((128,), "float16")
        T.evaluate(A.data)
        for i in range(128):
            A[i] = A[i] + T.float16(1.0)

    f1 = access_alloc
    f2 = tvm.s_tir.renew_defs(f1)
    tvm.ir.assert_structural_equal(f1, f2)

    # AllocBuffer is now a flat statement in SeqStmt
    assert f1.body.seq[0].buffer.data != f2.body.seq[0].buffer.data

    def _get_buffer_store_buffer(f):
        # SeqStmt: [AllocBuffer, Evaluate, For]; For body has the BufferStore
        return f.body.seq[2].body.buffer

    _check_buffer_decl(_get_buffer_store_buffer(f1), _get_buffer_store_buffer(f2))


def test_symbolic_func():
    @T.prim_func(s_tir=True)
    def symbolic_func(a: T.handle, b: T.handle, n: T.int32):
        m = T.int32()
        A = T.match_buffer(a, (n, m))
        B = T.match_buffer(b, (n, m * 2))
        for i, j in T.grid(n, m):
            B[i, j * 2] = A[i, j]
            B[i, j * 2 + 1] = A[i, j]

    f1 = symbolic_func
    f2 = tvm.s_tir.renew_defs(f1)
    tvm.ir.assert_structural_equal(f1, f2)


def test_buffer_map():
    @T.prim_func(s_tir=True)
    def main(a: T.handle, b: T.handle):
        m = T.int64()
        A = T.match_buffer(a, (m * 2,))
        B = T.match_buffer(b, (m, 2))
        for i, j in T.grid(m, 2):
            with T.sblock("B"):
                vi, vj = T.axis.remap("SS", [i, j])
                B[vi, vj] = A[vi * 2 + vj]

    f1 = main
    f2 = tvm.s_tir.renew_defs(main)
    tvm.ir.assert_structural_equal(f1, f2)
    assert f1.buffer_map[f1.params[1]].shape[0] != f2.buffer_map[f2.params[1]].shape[0]


def test_gather():
    @T.prim_func(private=True, s_tir=True)
    def take(
        A: T.Buffer((4096, 4096), "float16"),
        B: T.Buffer((1,), "int32"),
        T_take: T.Buffer((1, 4096), "float16"),
    ):
        for ax0, ax1 in T.grid(1, 4096):
            with T.sblock("T_take"):
                v_ax0, v_ax1 = T.axis.remap("SS", [ax0, ax1])
                T.reads(A[B[v_ax0], v_ax1], B[v_ax0])
                T.writes(T_take[v_ax0, v_ax1])
                T_take[v_ax0, v_ax1] = A[B[v_ax0], v_ax1]

    f1 = take
    f2 = tvm.s_tir.renew_defs(take)
    tvm.ir.assert_structural_equal(f1, f2)


if __name__ == "__main__":
    tvm.testing.main()
