/**
 * 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.
 */

#ifndef _SALTICIDAE_COMMON_H
#define _SALTICIDAE_COMMON_H

#include <string>
#include <exception>
#include <cstdarg>
#include <vector>
#include <unordered_map>
#include <functional>
#include <getopt.h>
#include <event2/event.h>

#include "salticidae/config.h"
#include "salticidae/ref.h"

namespace salticidae {

void sec2tv(double t, struct timeval &tv);
void event_add_with_timeout(struct event *ev, double timeout);
double gen_rand_timeout(double base_timeout, double alpha = 0.5);

std::string trim(const std::string &s,
                const std::string &space = "\t\r\n ");
std::vector<std::string> split(const std::string &s, const std::string &delim);
std::vector<std::string> trim_all(const std::vector<std::string> &ss);

class SalticidaeError: public std::exception {
    std::string msg;
    public:
    SalticidaeError();

    template<typename... Args>
    SalticidaeError(const std::string &fmt, Args... args) {
        int guessed_size = 128;
        std::string buff;
        for (;;)
        {
            buff.resize(guessed_size);
            int nwrote = snprintf((char *)buff.data(), guessed_size, fmt.c_str(), args...);
            if (nwrote < 0 || nwrote == guessed_size)
            {
                guessed_size <<= 1;
                continue;
            }
            buff.resize(nwrote);
            msg = std::move(buff);
            break;
        }
    }

    operator std::string() const { return msg; }
    const char *what() const throw() override { return msg.c_str(); }
};

class Logger {
    protected:
    FILE *output;
    bool opened;
    const char *prefix;
    void write(const char *tag, const char *fmt, va_list ap);

    public:
    Logger(const char *prefix, FILE *file = stderr):
        output(file), opened(false), prefix(prefix) {}
    Logger(const char *prefix, const char *filename):
        opened(true), prefix(prefix) {
        if ((output = fopen(filename, "w")) == nullptr)
            throw SalticidaeError("logger cannot open file %s", filename);
    }

    ~Logger() { if (opened) fclose(output); }

    void debug(const char *fmt, ...);
    void info(const char *fmt, ...);
    void warning(const char *fmt, ...);
    void error(const char *fmt, ...);
};

extern Logger logger;

#ifdef SALTICIDAE_DEBUG_LOG
#define SALTICIDAE_NORMAL_LOG
#define SALTICIDAE_ENABLE_LOG_DEBUG
#endif

#ifdef SALTICIDAE_NORMAL_LOG
#define SALTICIDAE_ENABLE_LOG_INFO
#define SALTICIDAE_ENABLE_LOG_WARN
#endif

#ifdef SALTICIDAE_ENABLE_LOG_INFO
#define SALTICIDAE_LOG_INFO(...) salticidae::logger.info(__VA_ARGS__)
#else
#define SALTICIDAE_LOG_INFO(...) ((void)0)
#endif

#ifdef SALTICIDAE_ENABLE_LOG_DEBUG
#define SALTICIDAE_LOG_DEBUG(...) salticidae::logger.debug(__VA_ARGS__)
#else
#define SALTICIDAE_LOG_DEBUG(...) ((void)0)
#endif

#ifdef SALTICIDAE_ENABLE_LOG_WARN
#define SALTICIDAE_LOG_WARN(...) salticidae::logger.warning(__VA_ARGS__)
#else
#define SALTICIDAE_LOG_WARN(...) ((void)0)
#endif

#define SALTICIDAE_LOG_ERROR(...) salticidae::logger.error(__VA_ARGS__)

class ElapsedTime {
    struct timeval t0;
    clock_t cpu_t0;
    public:
    double elapsed_sec;
    double cpu_elapsed_sec;
    void start();
    void stop(bool show_info = false);
};

class Config {
    public:
    enum Action {
        SWITCH_ON,
        SET_VAL,
        APPEND
    };

    class OptVal {
        public:
        virtual void switch_on() {
            throw SalticidaeError("undefined OptVal behavior: set_val");
        }
        
        virtual void set_val(const std::string &) {
            throw SalticidaeError("undefined OptVal behavior: set_val");
        }
        
        virtual void append(const std::string &) {
            throw SalticidaeError("undefined OptVal behavior: append");
        }

        virtual ~OptVal() = default;
    };

    using optval_t = RcObj<OptVal>;

    class OptValFlag: public OptVal {
        bool val;
        public:
        template<typename... Args>
        static RcObj<OptValFlag> create(Args... args) {
            return new OptValFlag(args...);
        }
        OptValFlag() = default;
        OptValFlag(bool val): val(val) {}
        void switch_on() override { val = true; }
        bool &get() { return val; }
    };

    class OptValStr: public OptVal {
        std::string val;
        public:
        template<typename... Args>
        static RcObj<OptValStr> create(Args... args) {
            return new OptValStr(args...);
        }
        OptValStr() = default;
        OptValStr(const std::string &val): val(val) {}
        void set_val(const std::string &strval) override {
            val = strval;
        }
        std::string &get() { return val; }
    };

    class OptValInt: public OptVal {
        int val;
        public:
        template<typename... Args>
        static RcObj<OptValInt> create(Args... args) {
            return new OptValInt(args...);
        }
        OptValInt() = default;
        OptValInt(int val): val(val) {}
        void set_val(const std::string &strval) override {
            size_t idx;
            try {
                val = stoi(strval, &idx);
            } catch (std::invalid_argument &) {
                throw SalticidaeError("invalid integer");
            }
        }
        int &get() { return val; }
    };

    class OptValDouble: public OptVal {
        double val;
        public:
        template<typename... Args>
        static RcObj<OptValDouble> create(Args... args) {
            return new OptValDouble(args...);
        }
        OptValDouble() = default;
        OptValDouble(double val): val(val) {}
        void set_val(const std::string &strval) override {
            size_t idx;
            try {
                val = stod(strval, &idx);
            } catch (std::invalid_argument &) {
                throw SalticidaeError("invalid double");
            }
        }
        double &get() { return val; }
    };

    class OptValStrVec: public OptVal {
        using strvec_t = std::vector<std::string>;
        strvec_t val;
        public:
        template<typename... Args>
        static RcObj<OptValStrVec> create(Args... args) {
            return new OptValStrVec(args...);
        }
        OptValStrVec() = default;
        OptValStrVec(const strvec_t &val): val(val) {}
        void append(const std::string &strval) override {
            val.push_back(strval);
        }
        strvec_t &get() { return val; }
    };

    private:
    class OptValConf: public OptVal {
        Config *config;
        public:
        template<typename... Args>
        static RcObj<OptValConf> create(Args... args) {
            return new OptValConf(args...);
        }
        OptValConf(Config *config): config(config) {}
        void set_val(const std::string &fname) override {
            if (config->load(fname))
                SALTICIDAE_LOG_INFO("loading extra configuration from %s", fname.c_str());
            else
                SALTICIDAE_LOG_INFO("configuration file %s not found", fname.c_str());
        }
        std::string &get() = delete;
    };

    struct Opt {
        std::string optname;
        std::string optdoc;
        optval_t optval;
        Action action;
        struct option opt;
        char short_opt;
        Opt(const std::string &optname, const std::string &optdoc,
            const optval_t &optval, Action action,
            char short_opt,
            int idx);
        Opt(Opt &&other):
                optname(std::move(other.optname)),
                optdoc(std::move(other.optdoc)),
                optval(std::move(other.optval)),
                action(other.action),
                opt(other.opt),
                short_opt(other.short_opt) {
            opt.name = this->optname.c_str();
        }
    };

    std::unordered_map<std::string, Opt *> conf;
    std::vector<BoxObj<Opt>> opts;
    std::string conf_fname;
    RcObj<OptValConf> opt_val_conf;

    void update(const std::string &optname, const char *optval);
    void update(Opt &opt, const char *optval);

    public:
    Config() {}
    Config(const std::string &conf_fname):
            conf_fname(conf_fname),
            opt_val_conf(OptValConf::create(this)) {
        add_opt("conf", opt_val_conf, SET_VAL, 'c', "load options from a file");
    }
    
    ~Config() {}

    void add_opt(const std::string &optname, const optval_t &optval, Action action,
                char short_opt = -1,
                const std::string &optdoc = "");
    bool load(const std::string &fname);
    size_t parse(int argc, char **argv);
    void print_help(FILE *output = stderr);
};

}

#endif