# for Volta GPUs, which use legacy MMA instructions
from .gemm_base import GemmBase
from tilelang.layout import make_volta_swizzled_layout
from tilelang.intrinsics.mma_sm70_macro_generator import (
    TensorCoreIntrinEmitter,)
from tilelang.utils.language import is_shared, is_fragment, is_full_region
from tilelang import tvm as tvm
from tvm.target import Target
from tvm import tir
from tilelang import language as T
from tilelang.transform.simplify import _Simplify


class GemmMMASm70(GemmBase):

    def infer_layout(self, target: Target, thread_nums: int):
        m_warp, n_warp = self.policy.compute_warp_partition(self.M, self.N, thread_nums, target,
                                                            False)
        warp_row_tiles = int(self.M // m_warp)
        warp_col_tiles = int(self.N // n_warp)
        mma_emitter = TensorCoreIntrinEmitter(
            a_dtype=self.in_dtype,
            b_dtype=self.in_dtype,
            accum_dtype=self.accum_dtype,
            a_transposed=self.trans_A,
            b_transposed=self.trans_B,
            block_row_warps=m_warp,
            block_col_warps=n_warp,
            warp_row_tiles=warp_row_tiles,
            warp_col_tiles=warp_col_tiles,
            chunk=self.chunk,
        )
        a_is_k_major = not self.trans_A
        b_is_k_major = self.trans_B
        if self.is_gemm_ss():
            return {
                self.A: make_volta_swizzled_layout(self.A, is_a=True, k_inner=a_is_k_major),
                self.B: make_volta_swizzled_layout(self.B, is_a=False, k_inner=b_is_k_major),
                self.C: mma_emitter.make_mma_store_layout(self.C),
            }
        elif self.is_gemm_rs():
            return {
                self.A: mma_emitter.make_mma_load_layout(self.A, matrix="A"),
                self.B: make_volta_swizzled_layout(self.B, is_a=False, k_inner=b_is_k_major),
                self.C: mma_emitter.make_mma_store_layout(self.C),
            }
        else:
            raise ValueError(
                f"Unsupported gemm combination, A: {self.A.scope()}, B: {self.B.scope()}")

    def lower(self, layout_map: dict, target: Target, thread_nums: int, thread_var: tir.Var):
        m_warp, n_warp = self.policy.compute_warp_partition(self.M, self.N, thread_nums, target,
                                                            False)
        warp_row_tiles = int(self.M // m_warp)
        warp_col_tiles = int(self.N // n_warp)
        mma_emitter = TensorCoreIntrinEmitter(
            a_dtype=self.in_dtype,
            b_dtype=self.in_dtype,
            accum_dtype=self.accum_dtype,
            a_transposed=self.trans_A,
            b_transposed=self.trans_B,
            block_row_warps=m_warp,
            block_col_warps=n_warp,
            warp_row_tiles=warp_row_tiles,
            warp_col_tiles=warp_col_tiles,
            chunk=self.chunk,
            thread_var=thread_var,
        )

        in_dtype = self.in_dtype
        warp_rows = mma_emitter.warp_rows
        warp_cols = mma_emitter.warp_cols
        local_size_a = mma_emitter.local_size_a
        local_size_b = mma_emitter.local_size_b
        block_K = mma_emitter.chunk
        micro_size_k = mma_emitter.micro_size_k
        # Use region for shared-memory operands when applicable
        A_region = self.ARegion
        B_region = self.BRegion
        C_region = self.CRegion

        A_buf = A_region.buffer
        C_buf = C_region.buffer

        clear_accum = self.clear_accum

        assert block_K >= micro_size_k, f"block_K ({block_K}) must be >= micro_size_k ({micro_size_k})"

        assert is_full_region(C_region), "Fragment output C must be a full region"

        if self.is_gemm_ss():

            @T.prim_func
            def _gemm_ssr() -> None:
                """
                The inner macro that loads data from shared buffers A_shared and
                B_shared into local fragments, then issues Tensor Core mma ops,
                accumulating into C_local.
                """
                A_local = T.alloc_local((warp_rows * local_size_a), in_dtype)
                B_local = T.alloc_local((warp_cols * local_size_b), in_dtype)

                if clear_accum:
                    T.clear(C_buf)

                for ki in T.serial(0, (block_K // micro_size_k)):
                    # Load A into fragment
                    mma_emitter.ldmatrix_a(
                        A_local,
                        A_region,
                        ki,
                    )

                    # Load B into fragment
                    mma_emitter.ldmatrix_b(
                        B_local,
                        B_region,
                        ki,
                    )

                    # Perform Matrix Multiplication
                    mma_emitter.mma(A_local, B_local, C_buf, ki)

            # Simplify to optimize the index computing
            # Must inline let statements to simplify the analysis
            return _Simplify(_gemm_ssr, inline_let=True)
        elif self.is_gemm_rs():
            assert is_full_region(B_region), "Fragment input B must be a full region"

            @T.prim_func
            def _gemm_rsr() -> None:
                """
                The inner macro that loads data from shared buffers A_shared and
                B_shared into local fragments, then issues Tensor Core mma ops,
                accumulating into C_local.
                """
                B_local = T.alloc_local((warp_cols * local_size_b), in_dtype)

                if clear_accum:
                    T.clear(C_buf)

                for ki in T.serial(0, (block_K // micro_size_k)):

                    # Load B into fragment
                    mma_emitter.ldmatrix_b(
                        B_local,
                        B_region,
                        ki,
                    )

                    # Perform Matrix Multiplication
                    mma_emitter.mma(A_buf, B_local, C_buf, ki)

            # Simplify to optimize the index computing
            # Must inline let statements to simplify the analysis
            return _Simplify(_gemm_rsr, inline_let=True)
        else:
            raise ValueError(
                f"Unsupported gemm combination, A: {self.A.scope()}, B: {self.B.scope()}")

    def is_gemm_ss(self) -> bool:
        return is_shared(self.A) and is_shared(self.B)

    def is_gemm_sr(self) -> bool:
        return is_shared(self.A) and is_fragment(self.B)

    def is_gemm_rs(self) -> bool:
        return is_fragment(self.A) and is_shared(self.B)

    def is_gemm_rr(self) -> bool:
        return is_fragment(self.A) and is_fragment(self.B)
