/**
 * Copyright (c) 2018 Cornell University.
 *
 * Author: Ted Yin <tederminant@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <cstdarg>
#include <cstring>
#include <cassert>
#include <cstdio>
#include <ctime>
#include <cmath>
#include <sys/time.h>

#include "salticidae/util.h"

namespace salticidae {

const char *TTY_COLOR_RED = "\x1b[31m";
const char *TTY_COLOR_GREEN = "\x1b[32m";
const char *TTY_COLOR_YELLOW = "\x1b[33m";
const char *TTY_COLOR_BLUE = "\x1b[34m";
const char *TTY_COLOR_MAGENTA = "\x1b[35m";
const char *TTY_COLOR_CYAN = "\x1b[36m";
const char *TTY_COLOR_RESET = "\x1b[0m";

void sec2tv(double t, struct timeval &tv) {
    tv.tv_sec = trunc(t);
    tv.tv_usec = trunc((t - tv.tv_sec) * 1e6);
}

double gen_rand_timeout(double base_timeout, double alpha) {
    return base_timeout + rand() / (double)RAND_MAX * alpha * base_timeout;
}

std::string vstringprintf(const char *fmt, va_list _ap) {
    int guessed_size = 1024;
    std::string buff;
    va_list ap;
    va_copy(ap, _ap);
    buff.resize(guessed_size);
    int nwrote = vsnprintf(&buff[0], guessed_size, fmt, _ap);
    if (nwrote < 0) buff = "";
    else
    {
        buff.resize(nwrote);
        if (nwrote > guessed_size)
        {
            if (vsnprintf(&buff[0], nwrote, fmt, ap) != nwrote)
                buff = "";
        }
    }
    va_end(ap);
    return std::move(buff);
}

std::string stringprintf(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    auto ret = vstringprintf(fmt, ap);
    va_end(ap);
    return std::move(ret);
}

const std::string get_current_datetime() {
    /* credit: http://stackoverflow.com/a/41381479/544806 */
    char fmt[64], buf[64];
    struct timeval tv;
    gettimeofday(&tv, nullptr);
    struct tm *tmp = localtime(&tv.tv_sec);
    strftime(fmt, sizeof fmt, "%Y-%m-%d %H:%M:%S.%%06u", tmp);
    snprintf(buf, sizeof buf, fmt, tv.tv_usec);
    return std::string(buf);
}

SalticidaeError::SalticidaeError() : msg("unknown") {}

void Logger::set_color() {
    if (is_tty())
    {
        color_info = TTY_COLOR_GREEN;
        color_debug = TTY_COLOR_BLUE;
        color_warning = TTY_COLOR_YELLOW;
        color_error = TTY_COLOR_RED;
    }
    else
    {
        color_info = color_debug = color_warning = color_error = nullptr;
    }
}

void Logger::write(const char *tag, const char *color,
                    const char *fmt, va_list ap) {
    std::string buff = color ? color : "";
    buff += stringprintf("%s [%s %s] ", get_current_datetime().c_str(), prefix, tag);
    if (color) buff += TTY_COLOR_RESET;
    buff += vstringprintf(fmt, ap);
    buff.push_back('\n');
    ::write(output, &buff[0], buff.length());
}

void Logger::info(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    write("info", color_info, fmt, ap);
    va_end(ap);
}

void Logger::debug(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    write("debug", color_debug, fmt, ap);
    va_end(ap);
}

void Logger::warning(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    write("warn", color_warning, fmt, ap);
    va_end(ap);
}
void Logger::error(const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    write("error", color_error, fmt, ap);
    va_end(ap);
}

Logger logger("net");

void ElapsedTime::start() {
    struct timezone tz;
    gettimeofday(&t0, &tz);
    cpu_t0 = clock();
}

void ElapsedTime::stop(bool show_info) {
    struct timeval t1;
    struct timezone tz;
    gettimeofday(&t1, &tz);
    cpu_elapsed_sec = (float)clock() / CLOCKS_PER_SEC -
                        (float)cpu_t0 / CLOCKS_PER_SEC;
    elapsed_sec = (t1.tv_sec + t1.tv_usec * 1e-6) -
                    (t0.tv_sec + t0.tv_usec * 1e-6);
    if (show_info)
        SALTICIDAE_LOG_INFO("elapsed: %.3f (wall) %.3f (cpu)",
                    elapsed_sec, cpu_elapsed_sec);
}

Config::Opt::Opt(const std::string &optname, const std::string &optdoc,
                const optval_t &optval, Action action,
                char short_opt,
                int idx):
    optname(optname), optdoc(optdoc),
    optval(optval), action(action),
    short_opt(short_opt) {
    opt.name = this->optname.c_str();
    opt.has_arg = action == SWITCH_ON ? no_argument : required_argument;
    opt.flag = nullptr;
    opt.val = 0x100 + idx;
}

void Config::add_opt(const std::string &optname, const optval_t &optval, Action action,
                    char short_opt,
                    const std::string &optdoc) {
    if (conf.count(optname))
        throw SalticidaeError("option name already exists");
    opts.push_back(new Opt(optname, optdoc,
                            optval, action, short_opt,
                            opts.size()));
    auto opt = opts.back().get();
    conf.insert(std::make_pair(optname, opt));
    if (short_opt != -1)
        conf.insert(std::make_pair(std::string(1, short_opt), opt));
}

void Config::update(Opt &p, const char *optval) {
    switch (p.action)
    {
        case SWITCH_ON: p.optval->switch_on(); break;
        case SET_VAL: p.optval->set_val(optval); break;
        case APPEND: p.optval->append(optval); break;
        default:
            throw SalticidaeError("unknown action");
    }
}

void Config::update(const std::string &optname, const char *optval) {
    assert(conf.count(optname));
    update(*(conf.find(optname)->second), optval);
}

bool Config::load(const std::string &fname) {
    static const size_t BUFF_SIZE = 1024;
    FILE *conf_f = fopen(fname.c_str(), "r");
    char buff[BUFF_SIZE];
    /* load configuration from file */
    if (conf_f)
    {
        while (fgets(buff, BUFF_SIZE, conf_f))
        {
            if (strlen(buff) == BUFF_SIZE - 1)
            {
                fclose(conf_f);
                throw SalticidaeError("configuration file line too long");
            }
            std::string line(buff);
            size_t pos = line.find("=");
            if (pos == std::string::npos)
                continue;
            std::string optname = trim(line.substr(0, pos));
            std::string optval = trim(line.substr(pos + 1));
            if (!conf.count(optname))
            {
                SALTICIDAE_LOG_WARN("ignoring option name in conf file: %s",
                            optname.c_str());
                continue;
            }
            update(optname, optval.c_str());
        }
        fclose(conf_f);
        return true;
    }
    else
        return false;
}

size_t Config::parse(int argc, char **argv) {
    if (load(conf_fname))
        SALTICIDAE_LOG_INFO("loaded configuration from %s", conf_fname.c_str());

    size_t nopts = opts.size();
    auto longopts = BoxObj<struct option[]>(new struct option[nopts + 1]);
    int ind;
    std::string shortopts;
    for (size_t i = 0; i < nopts; i++)
    {
        const auto &opt = opts[i];
        longopts[i] = opt->opt;
        if (opt->short_opt != -1)
        {
            shortopts += opt->short_opt;
            if (longopts[i].has_arg == required_argument)
                shortopts += ":";
        }
    }
    longopts[nopts] = {0, 0, 0, 0};
    for (;;)
    {
        int id = getopt_long(argc, argv, shortopts.c_str(), longopts.get(), &ind);
        if (id == -1)
            break;
        if (id == '?')
            throw SalticidaeError("invalid option format");
        if (id >= 0x100)
            update(*(opts[id - 0x100]), optarg);
        else
            update(std::string(1, (char)id), optarg);
    }
    return optind;
}

void Config::print_help(FILE *output) {
    int width = 0;
    for (const auto &opt: opts)
        width = std::max(width, (int)opt->optname.length());
    for (const auto &opt: opts)
    {
        fprintf(output, "  --%s%*c", opt->optname.c_str(),
                width - (int)opt->optname.length() + 4, ' ');
        if (opt->short_opt != -1)
            fprintf(output, "-%c\t", opt->short_opt);
        else
            fprintf(output, "\t\t");
        fprintf(output, "%s\n", opt->optdoc.c_str());
    }
}

std::vector<std::string> split(const std::string &s, const std::string &delim) {
    std::vector<std::string> res;
    size_t lastpos = 0;
    for (;;)
    {
        size_t pos = s.find(delim, lastpos);
        if (pos == std::string::npos)
            break;
        res.push_back(s.substr(lastpos, pos - lastpos));
        lastpos = pos + delim.length();
    }
    res.push_back(s.substr(lastpos, s.length() - lastpos));
    return res;
}

std::string trim(const std::string &s, const std::string &space) {
    const auto new_begin = s.find_first_not_of(space);
    if (new_begin == std::string::npos)
        return "";
    const auto new_end = s.find_last_not_of(space);
    return s.substr(new_begin, new_end - new_begin + 1);
}

std::vector<std::string> trim_all(const std::vector<std::string> &ss) {
    std::vector<std::string> res;
    for (const auto &s: ss)
        res.push_back(trim(s));
    return res;
}

}