// Copyright (C) 2024-2026 Salka Elmadani. All rights reserved.
// INPI eSoleau: 7phf-Ueye-2nWr-Vsgu — BSL-1.1
// Inference-X — Universal Inference Protocol
// Morocco
// Backend Manager Header — Device enumeration and routing
#pragma once

#include <string>
#include <vector>
#include <mutex>
#include <cstdint>

namespace inference_x {
namespace compute {

enum class ComputeBackend {
    Auto = 0, CPU, CUDA, ROCm, Metal, Vulkan, OpenCL,
    Hexagon, Snapdragon, TPU, Groq, Cerebras, FPGA,
    Gaudi, Inferentia, Maia, SambaNova, GraphCore,
    ARM_NEON, WebGPU
};

enum class ComputeError {
    Success = 0, NotInitialized, InvalidDevice, NotSupported,
    OutOfMemory, LaunchFailed, SyncFailed
};

struct DeviceInfo {
    ComputeBackend backend;
    int device_id;
    std::string name;
    size_t total_memory;
    size_t free_memory;
    int compute_capability_major;
    int compute_capability_minor;
    int num_sm;
    int max_threads_per_block;
    int warp_size;
    bool supports_fp16;
    bool supports_bf16;
    bool supports_int8;
};

class BackendManager {
public:
    static BackendManager& instance();
    ComputeError initialize();
    bool is_available(ComputeBackend backend) const;
    int get_device_count(ComputeBackend backend) const;
    const std::vector<DeviceInfo>& get_devices() const { return devices_; }
    DeviceInfo get_best_device() const;
    const char* backend_name(ComputeBackend b) const;

private:
    BackendManager() = default;
    ComputeError initialize_cpu();
    ComputeError initialize_cuda();
    ComputeError initialize_rocm();
    DeviceInfo query_cpu_info() const;
    DeviceInfo query_cuda_info(int device_id) const;
    DeviceInfo query_rocm_info(int device_id) const;

    mutable std::mutex mutex_;
    bool initialized_ = false;
    bool cpu_available_ = false;
    bool cuda_available_ = false;
    bool rocm_available_ = false;
    int cuda_device_count_ = 0;
    int rocm_device_count_ = 0;
    std::vector<DeviceInfo> devices_;
};

} // namespace compute
} // namespace inference_x