#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <thread>
#include <chrono>
#include <dlfcn.h>
#include <cstring>
#include <cstdint>
#include <filesystem>

// HIP/ROCm runtime check (using dlopen, no direct headers needed)

// Forward declarations for GPU functions
extern "C" {
    void rinhash_hip(const uint8_t* input, size_t input_len, uint8_t* output);
    void rinhash_hip_batch(const uint8_t* block_headers, size_t block_header_len,
                           uint8_t* outputs, uint32_t num_blocks);
    void RinHash(const uint32_t* version, const uint32_t* prev_block,
                const uint32_t* merkle_root, const uint32_t* timestamp,
                const uint32_t* bits, const uint32_t* nonce, uint8_t* output);
}

class GPURinHashMiner {
private:
    void* gpu_lib_handle;
    bool gpu_available;

    // Function pointers for GPU operations
    decltype(&rinhash_hip) gpu_rinhash;
    decltype(&rinhash_hip_batch) gpu_rinhash_batch;
    decltype(&RinHash) gpu_RinHash;

    // Mining parameters
    uint32_t version;
    uint32_t prev_block[8];
    uint32_t merkle_root[8];
    uint32_t timestamp;
    uint32_t bits;
    uint32_t target[8];

    // Mining statistics
    uint64_t hashes_computed;
    uint64_t start_time;
    double hashrate;

public:
    GPURinHashMiner() : gpu_lib_handle(nullptr), gpu_available(false),
                       hashes_computed(0), hashrate(0.0) {
        loadGPULibrary();
        initializeMiningParams();
    }

    ~GPURinHashMiner() {
        if (gpu_lib_handle) {
            dlclose(gpu_lib_handle);
        }
    }

    bool isGPUAvailable() const {
        return gpu_available;
    }

    bool loadGPULibrary() {
            // Try to load the GPU library
    std::cout << "Attempting to load GPU library..." << std::endl;
    gpu_lib_handle = dlopen("./rocm-direct-output/gpu-libs/librinhash_hip.so", RTLD_LAZY);
    if (!gpu_lib_handle) {
        std::cerr << "Failed to load GPU library: " << dlerror() << std::endl;
        std::cerr << "Make sure to run: sudo cp rocm-direct-output/gpu-libs/librinhash_hip.so /usr/local/lib/" << std::endl;
        std::cerr << "Current working directory: " << std::filesystem::current_path() << std::endl;
        return false;
    }
    std::cout << "GPU library loaded successfully!" << std::endl;

            // Load function pointers
    std::cout << "Loading GPU functions..." << std::endl;
    gpu_rinhash = (decltype(gpu_rinhash))dlsym(gpu_lib_handle, "rinhash_hip");
    gpu_rinhash_batch = (decltype(gpu_rinhash_batch))dlsym(gpu_lib_handle, "rinhash_hip_batch");
    gpu_RinHash = (decltype(gpu_RinHash))dlsym(gpu_lib_handle, "RinHash");

    if (!gpu_rinhash) std::cerr << "Failed to load rinhash_hip" << std::endl;
    if (!gpu_rinhash_batch) std::cerr << "Failed to load rinhash_hip_batch" << std::endl;
    if (!gpu_RinHash) std::cerr << "Failed to load RinHash" << std::endl;

    if (!gpu_rinhash || !gpu_rinhash_batch || !gpu_RinHash) {
        std::cerr << "Failed to load GPU functions: " << dlerror() << std::endl;
        dlclose(gpu_lib_handle);
        gpu_lib_handle = nullptr;
        return false;
    }
    std::cout << "GPU functions loaded successfully!" << std::endl;

        // GPU availability will be verified by successful library loading
        // and function calls working properly

        std::cout << "GPU functions ready for mining" << std::endl;

        gpu_available = true;
        return true;
    }

    void initializeMiningParams() {
        // Initialize with some default values for testing
        version = 1;
        timestamp = static_cast<uint32_t>(std::time(nullptr));
        bits = 0x1d00ffff; // Default difficulty

        // Initialize arrays to zero
        memset(prev_block, 0, sizeof(prev_block));
        memset(merkle_root, 0, sizeof(merkle_root));
        memset(target, 0, sizeof(target));

        // Set a reasonable target
        target[7] = 0x0000ffff; // Easy difficulty for testing
    }

    void setBlockHeader(const std::vector<uint8_t>& block_header) {
        if (block_header.size() != 80) {
            std::cerr << "Invalid block header size: " << block_header.size() << std::endl;
            return;
        }

        // Parse block header
        memcpy(&version, &block_header[0], 4);
        memcpy(prev_block, &block_header[4], 32);
        memcpy(merkle_root, &block_header[36], 32);
        memcpy(&timestamp, &block_header[68], 4);
        memcpy(&bits, &block_header[72], 4);
    }

    bool mineNonce(uint32_t start_nonce, uint32_t num_nonces, uint32_t& found_nonce) {
        if (!gpu_available) {
            std::cerr << "GPU not available" << std::endl;
            return false;
        }

        start_time = std::chrono::duration_cast<std::chrono::milliseconds>(
            std::chrono::system_clock::now().time_since_epoch()).count();

        // Create block headers for batch processing
        const size_t block_header_len = 80;
        std::vector<uint8_t> block_headers(block_header_len * num_nonces);
        std::vector<uint8_t> hashes(32 * num_nonces);

        // Fill block headers with different nonces
        for (uint32_t i = 0; i < num_nonces; i++) {
            uint32_t current_nonce = start_nonce + i;
            uint8_t* header = block_headers.data() + i * block_header_len;

            // Copy base header
            memcpy(header, &version, 4);
            memcpy(header + 4, prev_block, 32);
            memcpy(header + 36, merkle_root, 32);
            memcpy(header + 68, &timestamp, 4);
            memcpy(header + 72, &bits, 4);
            memcpy(header + 76, &current_nonce, 4);
        }

        // Process batch on GPU
        if (gpu_rinhash_batch) {
            gpu_rinhash_batch(block_headers.data(), block_header_len, hashes.data(), num_nonces);
        } else {
            std::cerr << "GPU batch function not available" << std::endl;
            return false;
        }
        hashes_computed += num_nonces;

        // Check results
        for (uint32_t i = 0; i < num_nonces; i++) {
            uint8_t* hash = hashes.data() + i * 32;

            // Check if hash meets target (simple check for now)
            bool meets_target = true;
            for (int j = 0; j < 32; j++) {
                if (hash[j] < target[j]) {
                    meets_target = true;
                    break;
                } else if (hash[j] > target[j]) {
                    meets_target = false;
                    break;
                }
            }

            if (meets_target) {
                found_nonce = start_nonce + i;
                updateHashrate();
                return true;
            }
        }

        updateHashrate();
        return false;
    }

    void updateHashrate() {
        uint64_t current_time = std::chrono::duration_cast<std::chrono::milliseconds>(
            std::chrono::system_clock::now().time_since_epoch()).count();

        double elapsed_seconds = (current_time - start_time) / 1000.0;
        if (elapsed_seconds > 0) {
            hashrate = hashes_computed / elapsed_seconds;
        }
    }

    double getHashrate() const {
        return hashrate;
    }

    uint64_t getHashesComputed() const {
        return hashes_computed;
    }

    void printStats() const {
        std::cout << "GPU RinHash Miner Stats:" << std::endl;
        std::cout << "  GPU Available: " << (gpu_available ? "Yes" : "No") << std::endl;
        std::cout << "  Hashes Computed: " << hashes_computed << std::endl;
        std::cout << "  Hashrate: " << std::fixed << std::setprecision(2) << (hashrate / 1000.0) << " KH/s" << std::endl;
    }
};

int main(int argc, char* argv[]) {
    std::cout << "===================================" << std::endl;
    std::cout << "  RinHash GPU Miner" << std::endl;
    std::cout << "===================================" << std::endl;
    std::cout << std::endl;

    GPURinHashMiner miner;

    if (!miner.isGPUAvailable()) {
        std::cerr << "GPU mining not available. Exiting." << std::endl;
        return 1;
    }

    // Initialize with a test block header
    std::vector<uint8_t> test_header(80, 0);
    miner.setBlockHeader(test_header);

    std::cout << "Starting GPU mining test..." << std::endl;
    std::cout << "Press Ctrl+C to stop" << std::endl;
    std::cout << std::endl;

    uint32_t start_nonce = 0;
    const uint32_t batch_size = 100000; // Process 100k nonces per batch
    uint32_t found_nonce = 0;

    while (true) {
        if (miner.mineNonce(start_nonce, batch_size, found_nonce)) {
            std::cout << "Found nonce: " << found_nonce << std::endl;
            break;
        }

        start_nonce += batch_size;

        // Print stats every 10 batches
        if ((start_nonce / batch_size) % 10 == 0) {
            miner.printStats();
            std::cout << std::endl;
        }
    }

    std::cout << std::endl;
    std::cout << "GPU mining completed!" << std::endl;
    miner.printStats();

    return 0;
}