#include "util.hpp"

#include <mbgl/platform/log.hpp>

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wshadow"
#include <boost/crc.hpp>
#pragma GCC diagnostic pop

#include <csignal>

#include <unistd.h>

namespace mbgl {
namespace test {

pid_t startServer(const char *executable) {
    int pipefd[2];

    if (pipe(pipefd)) {
        throw std::runtime_error("Cannot create server pipe");
    }

    pid_t pid = fork();
    if (pid < 0) {
        Log::Error(Event::Setup, "Cannot create server process");
        exit(1);
    } else if (pid == 0) {
        // This is the child process.

        // Close the input side of the pipe.
        close(pipefd[0]);

        // Launch the actual server process, with the pipe ID as the first argument.
        char *args[] = { const_cast<char *>(executable),
                         const_cast<char *>(std::to_string(pipefd[1]).c_str()),
                         nullptr };
        int ret = execv(executable, args);
        // This call should not return. In case execve failed, we exit anyway.
        if (ret < 0) {
            Log::Error(Event::Setup, "Failed to start server: %s", strerror(errno));
        }
        exit(0);
    } else {
        // This is the parent process.

        // Close output side of the pipe.
        close(pipefd[1]);

        // Wait until the server process closes the handle.
        char buffer[2];
        ssize_t bytes = 0, total = 0;
        while ((bytes = read(pipefd[0], buffer, sizeof(buffer))) != 0) {
            total += bytes;
        }
        if (bytes < 0) {
            Log::Error(Event::Setup, "Failed to start server: %s", strerror(errno));
            exit(1);
        }
        if (total != 2 || strncmp(buffer, "OK", 2) != 0) {
            Log::Error(Event::Setup, "Failed to start server");
            exit(1);
        }
        close(pipefd[0]);
    }
    return pid;
}

void stopServer(pid_t pid) {
    kill(pid, SIGTERM);
}

// from https://gist.github.com/ArtemGr/997887
uint64_t crc64(const char* data, size_t size) {
    boost::crc_optimal<64, 0x04C11DB7, 0, 0, false, false> crc;
    crc.process_bytes(data, size);
    return crc.checksum();
}

uint64_t crc64(const std::string& str) {
    return crc64(str.data(), str.size());
}

}
}