// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "paddle/extension.h"
#include "paddle/phi/core/enforce.h"
#include "xpu/plugin.h"
#include <paddle/phi/backends/xpu/xpu_context.h>

void StepPaddle(
    const paddle::Tensor &stop_flags, const paddle::Tensor &seq_lens_this_time,
    const paddle::Tensor &ori_seq_lens_encoder,
    const paddle::Tensor &seq_lens_encoder,
    const paddle::Tensor &seq_lens_decoder,
    const paddle::Tensor &block_tables, // [bsz, block_num_per_seq]
    const paddle::Tensor &encoder_block_lens,
    const paddle::Tensor &is_block_step, const paddle::Tensor &step_block_list,
    const paddle::Tensor &step_lens, const paddle::Tensor &recover_block_list,
    const paddle::Tensor &recover_lens, const paddle::Tensor &need_block_list,
    const paddle::Tensor &need_block_len, const paddle::Tensor &used_list_len,
    const paddle::Tensor &free_list, const paddle::Tensor &free_list_len,
    const paddle::Tensor &input_ids, const paddle::Tensor &pre_ids,
    const paddle::Tensor &step_idx, const paddle::Tensor &next_tokens,
    const paddle::Tensor &first_token_ids, const int block_size,
    const int encoder_decoder_block_num) {
    phi::XPUPlace place(phi::backends::xpu::GetXPUCurrentDeviceId());
    auto dev_ctx =
        paddle::experimental::DeviceContextPool::Instance().Get(place);
    auto xpu_ctx = static_cast<const phi::XPUContext *>(dev_ctx);

    const int bsz = seq_lens_this_time.shape()[0];
    PADDLE_ENFORCE_LE(
        bsz, 640,
        phi::errors::InvalidArgument(
            "Only support bsz <= 640, but received bsz is %d", bsz));
    const int block_num_per_seq = block_tables.shape()[1];
    const int length = input_ids.shape()[1];
    const int pre_id_length = pre_ids.shape()[1];
    const int max_decoder_block_num = pre_id_length / block_size;
    int r = baidu::xpu::api::plugin::free_and_dispatch_block(
        xpu_ctx->x_context(), const_cast<bool *>(stop_flags.data<bool>()),
        const_cast<int *>(seq_lens_this_time.data<int>()),
        const_cast<int *>(seq_lens_decoder.data<int>()),
        const_cast<int *>(block_tables.data<int>()),
        const_cast<int *>(encoder_block_lens.data<int>()),
        const_cast<bool *>(is_block_step.data<bool>()),
        const_cast<int *>(step_block_list.data<int>()),
        const_cast<int *>(step_lens.data<int>()),
        const_cast<int *>(recover_block_list.data<int>()),
        const_cast<int *>(recover_lens.data<int>()),
        const_cast<int *>(need_block_list.data<int>()),
        const_cast<int *>(need_block_len.data<int>()),
        const_cast<int *>(used_list_len.data<int>()),
        const_cast<int *>(free_list.data<int>()),
        const_cast<int *>(free_list_len.data<int>()),
        const_cast<int64_t *>(first_token_ids.data<int64_t>()), bsz, block_size,
        block_num_per_seq, max_decoder_block_num);
    PD_CHECK(r == 0, "free_and_dispatch_block failed.");
    auto recover_lens_cpu = recover_lens.copy_to(paddle::CPUPlace(), false);
    int recover_lens_cpu_data = recover_lens_cpu.data<int>()[0];
    if (recover_lens_cpu_data > 0) {
        r = baidu::xpu::api::plugin::recover_block(
            xpu_ctx->x_context(),
            const_cast<int *>(recover_block_list.data<int>()),
            const_cast<int *>(recover_lens.data<int>()),
            const_cast<bool *>(stop_flags.data<bool>()),
            const_cast<int *>(seq_lens_this_time.data<int>()),
            ori_seq_lens_encoder.data<int>(),
            const_cast<int *>(seq_lens_encoder.data<int>()),
            seq_lens_decoder.data<int>(),
            const_cast<int *>(block_tables.data<int>()),
            const_cast<int *>(free_list.data<int>()),
            const_cast<int *>(free_list_len.data<int>()),
            const_cast<int64_t *>(input_ids.data<int64_t>()),
            pre_ids.data<int64_t>(), step_idx.data<int64_t>(),
            encoder_block_lens.data<int>(), used_list_len.data<int>(),
            next_tokens.data<int64_t>(), first_token_ids.data<int64_t>(), bsz,
            block_num_per_seq, length, pre_id_length);
        PD_CHECK(r == 0, "recover_block failed.");
    }
}

PD_BUILD_OP(step_paddle)
    .Inputs({"stop_flags",
             "seq_lens_this_time",
             "ori_seq_lens_encoder",
             "seq_lens_encoder",
             "seq_lens_decoder",
             "block_tables",
             "encoder_block_lens",
             "is_block_step",
             "step_block_list",
             "step_lens",
             "recover_block_list",
             "recover_lens",
             "need_block_list",
             "need_block_len",
             "used_list_len",
             "free_list",
             "free_list_len",
             "input_ids",
             "pre_ids",
             "step_idx",
             "next_tokens",
             "first_token_ids"})
    .Attrs({"block_size: int", "encoder_decoder_block_num: int"})
    .Outputs({"stop_flags_out", "seq_lens_this_time_out",
              "seq_lens_encoder_out", "seq_lens_decoder_out",
              "block_tables_out", "encoder_block_lens_out", "is_block_step_out",
              "step_block_list_out", "step_lens_out", "recover_block_list_out",
              "recover_lens_out", "need_block_list_out", "need_block_len_out",
              "used_list_len_out", "free_list_out", "free_list_len_out",
              "input_ids_out", "first_token_ids_out"})
    .SetInplaceMap({{"stop_flags", "stop_flags_out"},
                    {"seq_lens_this_time", "seq_lens_this_time_out"},
                    {"seq_lens_encoder", "seq_lens_encoder_out"},
                    {"seq_lens_decoder", "seq_lens_decoder_out"},
                    {"block_tables", "block_tables_out"},
                    {"encoder_block_lens", "encoder_block_lens_out"},
                    {"is_block_step", "is_block_step_out"},
                    {"step_block_list", "step_block_list_out"},
                    {"step_lens", "step_lens_out"},
                    {"recover_block_list", "recover_block_list_out"},
                    {"recover_lens", "recover_lens_out"},
                    {"need_block_list", "need_block_list_out"},
                    {"need_block_len", "need_block_len_out"},
                    {"used_list_len", "used_list_len_out"},
                    {"free_list", "free_list_out"},
                    {"free_list_len", "free_list_len_out"},
                    {"input_ids", "input_ids_out"},
                    {"first_token_ids", "first_token_ids_out"}})
    .SetKernelFn(PD_KERNEL(StepPaddle));
