#include <curl/curl.h>

#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <fstream>

// Tracking Evolution-X's PixelPropsUtils
#define UPSTREAM_URL "https://raw.githubusercontent.com/Evolution-X/frameworks_base/tiramisu/core/java/com/android/internal/util/evolution/PixelPropsUtils.java"

// Use Pixel 6 Pro's fingerprint
#define DEVICE_CODENAME "raven"
#define DEVICE_VENDOR "google"

#define STD_STRING_CONTAINS(str, search) (str.find(search) != std::string::npos)
		
typedef struct result {
	bool vaild = false;
	std::string data = "";
} result_t;

struct build_data {
	std::string vendor;
	std::string codename;
	int android_version;
	std::string buildid;
	std::string vendordata;
};

static size_t WriteCallback(void *contents, size_t size, size_t nmemb,
                            void *userp) {
  static_cast<std::string *>(userp)->append(static_cast<char *>(contents), size * nmemb);
  return size * nmemb;
}

static std::vector<std::string> splitNewLines (const std::string& buffer) 
{
    auto result = std::vector<std::string>{};
    auto ss = std::stringstream{buffer};

    for (std::string line; std::getline(ss, line, '\n');)
	    result.push_back(line);

    return result;
}

static result_t *checkIfVaild(const std::string& line)
{
	auto res = new result_t;

	// Is it related to <codename>?
	if (!STD_STRING_CONTAINS(line, DEVICE_CODENAME))
		return res;

	// Remove non-fingerprint stuff.
	// It should be <vendor>/<codename>/.. format
	if (!STD_STRING_CONTAINS(line, DEVICE_VENDOR))
		return res;

	res->vaild = true;
	res->data = line;
	return res;
}

static result_t *parseJavaFile(const std::string& buffer)
{
	auto kLines = splitNewLines(buffer);
	for (const auto line : kLines) {
		const auto res = checkIfVaild(line);
		if (res->vaild) {
			std::string data = res->data;
			res->data = data.substr(data.find(DEVICE_VENDOR));
			data = res->data;
			res->data = data.substr(0, data.find_last_of('"'));
			return res;
		} else
			delete res;
	}
	// We failed to find the line. return nothing.
	return new result_t;
}

static std::string dirname(const std::string& arg)
{
	auto idx = arg.find_last_of("/\\");
	return arg.substr(0, idx);
}

static std::string fromBuildDataToFP(struct build_data *data)
{
	const char *fmt = "%s/%s/%s:%d/%s/%s:user/release-keys";
	int size = std::snprintf(nullptr, 0, fmt, data->vendor.c_str(), data->codename.c_str(), data->codename.c_str(), data->android_version, data->buildid.c_str(), data->vendordata.c_str());
	std::vector<char> buf(size + 1);
	std::snprintf(&buf[0], buf.size(), fmt, data->vendor.c_str(), data->codename.c_str(), data->codename.c_str(), data->android_version, data->buildid.c_str(), data->vendordata.c_str());

	return std::string(buf.begin(), buf.end());
}

static std::string fromBuildDataToDesc(struct build_data *data)
{
	const char *fmt = "%s-user %d %s %s release-keys";
	int size = std::snprintf(nullptr, 0, fmt, data->codename.c_str(), data->android_version, data->buildid.c_str(), data->vendordata.c_str());
	std::vector<char> buf(size + 1);
	std::snprintf(&buf[0], buf.size(), fmt, data->codename.c_str(), data->android_version, data->buildid.c_str(), data->vendordata.c_str());

	return std::string(buf.begin(), buf.end());
}

static struct build_data *serialize(const std::string& fpdata)
{
	auto split = std::vector<std::string>{};
	auto ss = std::stringstream{fpdata};
	auto data = new struct build_data;
	for (std::string line; std::getline(ss, line, '/');)
		split.push_back(line);

	// Fingerprint: "<VENDOR>/<CODENAME>/<CODENAME>:<AND_VER>/<BUILDID>/<VENDORDATA>:user/release-keys"
	data->vendor = split[0];
	std::string mixed = split[2];
	int idx = mixed.find(':');
	data->codename = mixed.substr(0, idx);
	data->android_version = stoi(mixed.substr(idx + 1));
	data->buildid = split[3];
	mixed = split[4];
	idx = mixed.find(':');
	data->vendordata = mixed.substr(0, idx);
	return data;
}

static void apply(const std::string& path, struct build_data *data)
{
	std::remove(path.c_str());
	std::ofstream file(path);
	if (file.is_open()) {
		std::string str;
		file << "# Autogenerated by " << __FILE__ << std::endl;
		file << "PRODUCT_GMS_CLIENTID_BASE := android-google" << std::endl;
		file << std::endl;
		str = fromBuildDataToFP(data);
		str.resize(str.find('\0'));
		file << "BUILD_FINGERPRINT := \"" << str << "\"" << std::endl;
		file << std::endl;
		file << "PRODUCT_BUILD_PROP_OVERRIDES += \\" << std::endl;
		str = fromBuildDataToDesc(data);
		str.resize(str.find('\0'));
		file << "\tPRIVATE_BUILD_DESC=\"" << str << "\"" << std::endl;
		file.close();
	}
}

int main(int argc, const char **argv) {
  CURL *curl;
  CURLcode res;
  std::string readBuffer = "";
  std::string execDir = dirname(argv[0]);

  curl = curl_easy_init();
  if (curl != nullptr) {
    curl_easy_setopt(curl, CURLOPT_URL, UPSTREAM_URL);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
    if (res)
	    return res;
  }

  auto parseRes = parseJavaFile(readBuffer);
  if (!parseRes->vaild)
	  return 1;

  auto build = serialize(parseRes->data);
  delete parseRes;
  apply(execDir + "/../fingerprint.mk", build);
  
  return 0;
}