#pragma once

#include "ggml.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct ggml_backend_buffer_type* ggml_backend_buffer_type_t;
typedef struct ggml_backend_buffer* ggml_backend_buffer_t;
typedef struct ggml_backend* ggml_backend_t;

// Tensor allocator
struct ggml_tallocr {
    ggml_backend_buffer_t buffer;
    void* base;
    size_t alignment;
    size_t offset;
};

GGML_API struct ggml_tallocr ggml_tallocr_new(ggml_backend_buffer_t buffer);
GGML_API void ggml_tallocr_alloc(struct ggml_tallocr* talloc,
                                 struct ggml_tensor* tensor);

// Graph allocator
/*
  Example usage:
    ggml_gallocr_t galloc = ggml_gallocr_new(ggml_backend_cpu_buffer_type());

    // optional: create a worst-case graph and reserve the buffers to avoid
  reallocations ggml_gallocr_reserve(galloc, build_graph(max_batch));

    // allocate the graph
    struct ggml_cgraph * graph = build_graph(batch);
    ggml_gallocr_alloc_graph(galloc, graph);

    printf("compute buffer size: %zu bytes\n",
  ggml_gallocr_get_buffer_size(galloc, 0));

    // evaluate the graph
    ggml_backend_graph_compute(backend, graph);
*/

// special tensor flags for use with the graph allocator:
//   ggml_set_input(): all input tensors are allocated at the beginning of the
//   graph in non-overlapping addresses ggml_set_output(): output tensors are
//   never freed and never overwritten

typedef struct ggml_gallocr* ggml_gallocr_t;

GGML_API ggml_gallocr_t ggml_gallocr_new(ggml_backend_buffer_type_t buft);
GGML_API ggml_gallocr_t ggml_gallocr_new_n(ggml_backend_buffer_type_t* bufts,
                                           int n_bufs);
GGML_API void ggml_gallocr_free(ggml_gallocr_t galloc);

// pre-allocate buffers from a measure graph - does not allocate or modify the
// graph call with a worst-case graph to avoid buffer reallocations not strictly
// required for single buffer usage: ggml_gallocr_alloc_graph will reallocate
// the buffers automatically if needed returns false if the buffer allocation
// failed
GGML_API bool ggml_gallocr_reserve(ggml_gallocr_t galloc,
                                   struct ggml_cgraph* graph);
GGML_API bool ggml_gallocr_reserve_n(ggml_gallocr_t galloc,
                                     struct ggml_cgraph* graph,
                                     const int* node_buffer_ids,
                                     const int* leaf_buffer_ids);

// automatic reallocation if the topology changes when using a single buffer
// returns false if using multiple buffers and a re-allocation is needed (call
// ggml_gallocr_reserve_n first to set the node buffers)
GGML_API bool ggml_gallocr_alloc_graph(ggml_gallocr_t galloc,
                                       struct ggml_cgraph* graph);

GGML_API size_t ggml_gallocr_get_buffer_size(ggml_gallocr_t galloc,
                                             int buffer_id);

// Utils
// Create a buffer and allocate all the tensors in a ggml_context
GGML_API struct ggml_backend_buffer* ggml_backend_alloc_ctx_tensors_from_buft(
    struct ggml_context* ctx, ggml_backend_buffer_type_t buft);
GGML_API struct ggml_backend_buffer* ggml_backend_alloc_ctx_tensors(
    struct ggml_context* ctx, ggml_backend_t backend);

#ifdef __cplusplus
}
#endif
