#pragma once

#include "llama.h"

#include "llama-graph.h"

#include <map>

#include <memory>

#include <functional>

struct llama_ubatch;

class llama_batch_allocr;

class llama_io_write_i;

class llama_io_read_i;

struct llama_memory_params {

    // kv cache

    ggml_type type_k;

    ggml_type type_v;

    // use full-size SWA cache

    bool swa_full;

    llama_context_type ctx_type;

    llama_memory_t mem_other;

};

enum llama_memory_status {

    LLAMA_MEMORY_STATUS_SUCCESS = 0,

    LLAMA_MEMORY_STATUS_NO_UPDATE,

    LLAMA_MEMORY_STATUS_FAILED_PREPARE,

    LLAMA_MEMORY_STATUS_FAILED_COMPUTE,

};

// helper function for combining the status of two memory contexts

// useful for implementing hybrid memory types (e.g. iSWA)

llama_memory_status llama_memory_status_combine(llama_memory_status s0, llama_memory_status s1);

// helper function for checking if a memory status indicates a failure

bool llama_memory_status_is_fail(llama_memory_status status);

// the interface for managing the memory context during batch processing

// this interface is implemented per memory type. see:

//   - llama_kv_cache_context

//   - llama_kv_cache_iswa_context

//   ...

//

// the only method that should mutate the memory and the memory context is llama_memory_i::apply()

struct llama_memory_context_i {

    virtual ~llama_memory_context_i() = default;

    // consume the current ubatch from the context and proceed to the next one

    // return false if we are done

    virtual bool next() = 0;

    // apply the memory state for the current ubatch to the memory object

    // return false on failure

    virtual bool apply() = 0;

    // get the current ubatch

    virtual const llama_ubatch & get_ubatch() const = 0;

    // get the status of the memory context - used for error handling and checking if any updates would be applied

    virtual llama_memory_status get_status() const = 0;

};

using llama_memory_context_ptr = std::unique_ptr<llama_memory_context_i>;

// general concept of LLM memory

// the KV cache is a type of LLM memory, but there can be other types

struct llama_memory_i {

    // this callback is used to filter out layers that should not be included in the cache

    using layer_filter_cb = std::function<bool(int32_t il)>;

    // this callback is used to specify which layers should reuse memory from other layers

    // return negative value to indicate that the layer il should not reuse memory

    using layer_reuse_cb = std::function<int32_t(int32_t il)>;

    using layer_share_cb = std::function<int32_t(int32_t il)>;

    virtual ~llama_memory_i() = default;

    // split the input batch into a set of ubatches and verify that they can fit into the cache

    // return a context object containing the ubatches and memory state required to process them

    // check the llama_memory_context_i::get_status() for the result

    virtual llama_memory_context_ptr init_batch(

            llama_batch_allocr & balloc,

            uint32_t n_ubatch,

            bool embd_all) = 0;

    // simulate full cache, used for allocating worst-case compute buffers

    virtual llama_memory_context_ptr init_full() = 0;

    // prepare for any pending memory updates, such as shifts, copies, etc.

    // status == LLAMA_MEMORY_STATUS_NO_UPDATE if there is nothing to update

    virtual llama_memory_context_ptr init_update(llama_context * lctx, bool optimize) = 0;

    // getters

    virtual bool get_can_shift() const = 0;

    //

    // ops

    //

    // if data == true, the data buffers will also be cleared together with the metadata

    virtual void clear(bool data) = 0;

    virtual bool seq_rm  (llama_seq_id seq_id,                              llama_pos p0, llama_pos p1) = 0;

    virtual void seq_cp  (llama_seq_id seq_id_src, llama_seq_id seq_id_dst, llama_pos p0, llama_pos p1) = 0;

    virtual void seq_keep(llama_seq_id seq_id) = 0;

    virtual void seq_add (llama_seq_id seq_id,                              llama_pos p0, llama_pos p1, llama_pos shift) = 0;

    virtual void seq_div (llama_seq_id seq_id,                              llama_pos p0, llama_pos p1, int d) = 0;

    virtual llama_pos seq_pos_min(llama_seq_id seq_id) const = 0;

    virtual llama_pos seq_pos_max(llama_seq_id seq_id) const = 0;

    virtual std::map<ggml_backend_buffer_type_t, size_t> memory_breakdown() const = 0;

    //

    // state write/read

    //

    virtual void state_write(llama_io_write_i & io, llama_seq_id seq_id = -1, llama_state_seq_flags flags = 0) const = 0;

    virtual void state_read (llama_io_read_i  & io, llama_seq_id seq_id = -1, llama_state_seq_flags flags = 0) = 0;

};

using llama_memory_ptr = std::unique_ptr<llama_memory_i>;