#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
#include <uuid/uuid.h>
#include <opae/fpga.h>
#include <vortex.h>
#include "vortex_afu.h"

#define CHECK_RES(_expr)                                            \
   do {                                                             \
     fpga_result res = _expr;                                       \
     if (res == FPGA_OK)                                            \
       break;                                                       \
     printf("OPAE Error: '%s' returned %d, %s!\n",                  \
            #_expr, (int)res, fpgaErrStr(res));                     \
     return -1;                                                     \
   } while (false)

///////////////////////////////////////////////////////////////////////////////

#define CMD_TYPE_READ       AFU_IMAGE_CMD_TYPE_READ
#define CMD_TYPE_WRITE      AFU_IMAGE_CMD_TYPE_WRITE
#define CMD_TYPE_RUN        AFU_IMAGE_CMD_TYPE_RUN
#define CMD_TYPE_CLFLUSH    AFU_IMAGE_CMD_TYPE_CLFLUSH

#define MMIO_CSR_CMD        (AFU_IMAGE_MMIO_CSR_CMD * 4)
#define MMIO_CSR_STATUS     (AFU_IMAGE_MMIO_CSR_STATUS * 4)
#define MMIO_CSR_IO_ADDR    (AFU_IMAGE_MMIO_CSR_IO_ADDR * 4)
#define MMIO_CSR_MEM_ADDR   (AFU_IMAGE_MMIO_CSR_MEM_ADDR * 4)
#define MMIO_CSR_DATA_SIZE  (AFU_IMAGE_MMIO_CSR_DATA_SIZE * 4)

///////////////////////////////////////////////////////////////////////////////

typedef struct vx_device_ {
    fpga_handle fpga;
    size_t mem_allocation;
} vx_device_t;

typedef struct vx_buffer_ {
    uint64_t wsid;
    volatile void* host_ptr;
    uint64_t io_addr;
    vx_device_h hdevice;
    size_t size;
} vx_buffer_t;

static size_t align_size(size_t size) {
    uint32_t cache_block_size = vx_dev_caps(VX_CAPS_CACHE_LINESIZE);    
    return cache_block_size * ((size + cache_block_size - 1) / cache_block_size);
}

///////////////////////////////////////////////////////////////////////////////

extern int vx_dev_open(vx_device_h* hdevice) {
    fpga_properties filter = nullptr;
    fpga_result res;
    fpga_guid guid;
    fpga_token accel_token;
    uint32_t num_matches;
    fpga_handle accel_handle;
    vx_device_t* device;

    if (nullptr == hdevice)
        return  -1;

    // ensure that the block size 64
    assert(64 == vx_dev_caps(VX_CAPS_CACHE_LINESIZE));

    // Set up a filter that will search for an accelerator
    fpgaGetProperties(nullptr, &filter);
    fpgaPropertiesSetObjectType(filter, FPGA_ACCELERATOR);

    // Add the desired UUID to the filter
    uuid_parse(AFU_ACCEL_UUID, guid);
    fpgaPropertiesSetGUID(filter, guid);

    // Do the search across the available FPGA contexts
    num_matches = 1;
    fpgaEnumerate(&filter, 1, &accel_token, 1, &num_matches);

    // Not needed anymore
    fpgaDestroyProperties(&filter);

    if (num_matches < 1) {
        fprintf(stderr, "Accelerator %s not found!\n", AFU_ACCEL_UUID);
        return -1;
    }

    // Open accelerator
    res = fpgaOpen(accel_token, &accel_handle, 0);
    if (FPGA_OK != res) {
        return -1;
    }

    // Done with token
    fpgaDestroyToken(&accel_token);

    // allocate device object
    device = (vx_device_t*)malloc(sizeof(vx_device_t));
    if (nullptr == device) {
        fpgaClose(accel_handle);
        return -1;
    }

    device->fpga = accel_handle;
    device->mem_allocation = vx_dev_caps(VX_CAPS_ALLOC_BASE_ADDR);

    *hdevice = device;

    return 0;
}

extern int vx_dev_close(vx_device_h hdevice) {
    if (nullptr == hdevice)
        return -1;

    vx_device_t *device = ((vx_device_t*)hdevice);

    fpgaClose(device->fpga);

    free(device);

    return 0;
}

extern int vx_alloc_dev_mem(vx_device_h hdevice, size_t size, size_t* dev_maddr) {
    if (nullptr == hdevice 
     || nullptr == dev_maddr
     || 0 >= size)
        return -1;

    vx_device_t *device = ((vx_device_t*)hdevice);
    
    size_t asize = align_size(size);
    size_t dev_mem_size = vx_dev_caps(VX_CAPS_LOCAL_MEM_SIZE);
    if (device->mem_allocation + asize > dev_mem_size)
        return -1;   

    *dev_maddr = device->mem_allocation;
    device->mem_allocation += asize;

    return 0;
}

extern int vx_alloc_shared_mem(vx_device_h hdevice, size_t size, vx_buffer_h* hbuffer) {
    fpga_result res;
    void* host_ptr;
    uint64_t wsid;
    uint64_t io_addr;
    vx_buffer_t* buffer;

    if (nullptr == hdevice
     || 0 >= size
     || nullptr == hbuffer)
        return -1;

    vx_device_t *device = ((vx_device_t*)hdevice);

    size_t asize = align_size(size);

    res = fpgaPrepareBuffer(device->fpga, asize, &host_ptr, &wsid, 0);
    if (FPGA_OK != res) {
        return -1;
    }

    // Get the physical address of the buffer in the accelerator
    res = fpgaGetIOAddress(device->fpga, wsid, &io_addr);
    if (FPGA_OK != res) {
        fpgaReleaseBuffer(device->fpga, wsid);
        return -1;
    }

    // allocate buffer object
    buffer = (vx_buffer_t*)malloc(sizeof(vx_buffer_t));
    if (nullptr == buffer) {
        fpgaReleaseBuffer(device->fpga, wsid);
        return -1;
    }

    buffer->wsid = wsid;
    buffer->host_ptr = host_ptr;
    buffer->io_addr = io_addr;
    buffer->hdevice = hdevice;
    buffer->size = size;

    *hbuffer = buffer;

    return 0;
}

extern volatile void* vx_host_ptr(vx_buffer_h hbuffer) {
    if (nullptr == hbuffer)
        return nullptr;

    vx_buffer_t* buffer = ((vx_buffer_t*)hbuffer);

    return buffer->host_ptr;
}

extern int vx_buf_release(vx_buffer_h hbuffer) {
    if (nullptr == hbuffer)
        return -1;

    vx_buffer_t* buffer = ((vx_buffer_t*)hbuffer);
    vx_device_t *device = ((vx_device_t*)buffer->hdevice);

    fpgaReleaseBuffer(device->fpga, buffer->wsid);

    free(buffer);

    return 0;
}

extern int vx_ready_wait(vx_device_h hdevice, long long timeout) {
    if (nullptr == hdevice)
        return -1;
    
    vx_device_t *device = ((vx_device_t*)hdevice);

    uint64_t data = 0;
    struct timespec sleep_time; 

#if defined(USE_ASE)
    sleep_time.tv_sec = 1;
    sleep_time.tv_nsec = 0;
#else
    sleep_time.tv_sec = 0;
    sleep_time.tv_nsec = 1000000;
#endif

    // to milliseconds
    long long sleep_time_ms = (sleep_time.tv_sec * 1000) + (sleep_time.tv_nsec / 1000000);
    
    for (;;) {
        CHECK_RES(fpgaReadMMIO64(device->fpga, 0, MMIO_CSR_STATUS, &data));
        if (0 == data || 0 == timeout)
            break;
        nanosleep(&sleep_time, nullptr);
        timeout -= sleep_time_ms;
    };

    return 0;
}

extern int vx_copy_to_dev(vx_buffer_h hbuffer, size_t dev_maddr, size_t size, size_t src_offset) {
    if (nullptr == hbuffer 
     || 0 >= size)
        return -1;

    vx_buffer_t* buffer = ((vx_buffer_t*)hbuffer);
    vx_device_t *device = ((vx_device_t*)buffer->hdevice);

    // bound checking
    if (size + src_offset > buffer->size)
        return -1;

    // Ensure ready for new command
    if (vx_ready_wait(buffer->hdevice, -1) != 0)
        return -1;

    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_IO_ADDR, buffer->io_addr + src_offset));
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_MEM_ADDR, dev_maddr));
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_DATA_SIZE, size));   
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_CMD, CMD_TYPE_WRITE));

    // Wait for the write operation to finish
    if (vx_ready_wait(buffer->hdevice, -1) != 0)
        return -1;

    return 0;
}

extern int vx_copy_from_dev(vx_buffer_h hbuffer, size_t dev_maddr, size_t size, size_t dest_offset) {
    if (nullptr == hbuffer 
     || 0 >= size)
        return -1;

    vx_buffer_t* buffer = ((vx_buffer_t*)hbuffer);
    vx_device_t *device = ((vx_device_t*)buffer->hdevice);

    // bound checking
    if (size + dest_offset > buffer->size)
        return -1;

    // Ensure ready for new command
    if (vx_ready_wait(buffer->hdevice, -1) != 0)
        return -1;

    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_IO_ADDR, buffer->io_addr + dest_offset));
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_MEM_ADDR, dev_maddr));    
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_DATA_SIZE, size));   
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_CMD, CMD_TYPE_READ));

    // Wait for the write operation to finish
    if (vx_ready_wait(buffer->hdevice, -1) != 0)
        return -1;

    return 0;
}

extern int vx_flush_caches(vx_device_h hdevice, size_t dev_maddr, size_t size) {
    if (nullptr == hdevice 
     || 0 >= size)
        return -1;

    vx_device_t* device = ((vx_device_t*)hdevice);

    // Ensure ready for new command
    if (vx_ready_wait(hdevice, -1) != 0)
        return -1;

    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_MEM_ADDR, dev_maddr));
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_DATA_SIZE, size));   
    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_CMD, CMD_TYPE_CLFLUSH));

    // Wait for the write operation to finish
    if (vx_ready_wait(hdevice, -1) != 0)
        return -1;

    return 0;
}

extern int vx_start(vx_device_h hdevice) {
    if (nullptr == hdevice)
        return -1;

    vx_device_t *device = ((vx_device_t*)hdevice);

    // Ensure ready for new command
    if (vx_ready_wait(hdevice, -1) != 0)
        return -1;

    CHECK_RES(fpgaWriteMMIO64(device->fpga, 0, MMIO_CSR_CMD, CMD_TYPE_RUN));

    return 0;
}