// Copyright © 2019-2023
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "driver.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/limits.h>
#include <dlfcn.h>
#include <string>
#include <vector>
#include <sstream>

#ifdef OPAESIM
#define DEFAULT_OPAE_DRV_PATHS "libopae-c-sim.so"
#elif ASESIM
#define DEFAULT_OPAE_DRV_PATHS "libopae-c-ase.so"
#else
#define DEFAULT_OPAE_DRV_PATHS "libopae-c.so"
#endif

#define SET_API(func) \
	opae_drv_funcs->func = (pfn_##func)dlsym(dl_handle, #func); \
	if (opae_drv_funcs->func == nullptr) { \
        printf("dlsym failed: %s\n", dlerror()); \
		dlclose(dl_handle); \
        return -1; \
	}

void* dl_handle = nullptr;

int drv_init(opae_drv_api_t* opae_drv_funcs) {
    if (opae_drv_funcs == nullptr)
        return -1;

    const char* api_path_s = getenv("OPAE_DRV_PATHS");
    if (api_path_s == nullptr || api_path_s[0] == '\0') {
        api_path_s = DEFAULT_OPAE_DRV_PATHS;
    }

    std::vector<std::string> api_paths;
    {
        std::stringstream ss(api_path_s);
        while (ss.good()) {
            std::string path;
            getline(ss, path, ',');
            api_paths.push_back(path);
        }
    }
    
    for (auto& api_path : api_paths) {
		dl_handle = dlopen(api_path.c_str(), RTLD_LAZY | RTLD_LOCAL);
		if (dl_handle)
			break;
	}
    if (dl_handle == nullptr) {
        printf("dlopen failed: %s\n", dlerror());
        return -1;
    }

	SET_API (fpgaGetProperties);
	SET_API (fpgaPropertiesSetObjectType);
	SET_API (fpgaPropertiesSetGUID);
	SET_API (fpgaDestroyProperties);
    SET_API (fpgaDestroyToken);
    SET_API (fpgaPropertiesGetLocalMemorySize);
	SET_API (fpgaEnumerate);	
	SET_API (fpgaOpen);
	SET_API (fpgaClose);
	SET_API (fpgaPrepareBuffer);
	SET_API (fpgaReleaseBuffer);
	SET_API (fpgaGetIOAddress);
	SET_API (fpgaWriteMMIO64);
	SET_API (fpgaReadMMIO64);
	SET_API (fpgaErrStr);    

    return 0;
}

void drv_close() {
    dlclose(dl_handle);
}
