/*
 * Created by Brett Terpstra 6920201 on 14/10/22.
 * Copyright (c) Brett Terpstra 2022 All Rights Reserved
 *
 * This file is used to include common standard library headers
 * There are some things {String, Maps} that I use a lot
 * Plus common defines that might be useful in the future.
 *
 */

#ifndef STEP_2_STD_H
#define STEP_2_STD_H

/**
 * includes
 */
#include <unordered_map>
#include <vector>
#include "logging.h"
#include <string>
#include <algorithm>
#include <cctype>
#include <locale>
#include <sstream>
#include <algorithm>
#include <limits>
#include <random>
#include <cstdlib>
#include <memory>

#define RTAssert(condition) static_cast <bool> (condition) ? void(0) : throw std::runtime_error("Assert Failed!");

/**
 * defines
 */
#define RAYTRACING_VERSION_MAJOR 0
#define RAYTRACING_VERSION_MINOR 0
#define RAYTRACING_VERSION_PATCH 1
#define RAYTRACING_VERSION_STRING "0.0.1"

/**
 * Constants
 */
const double infinity = std::numeric_limits<double>::infinity();
const double ninfinity = -std::numeric_limits<double>::infinity();
// PI, to a large # of digits
const double PI = 3.1415926535897932385;
// very small number
const double EPSILON = 0.0000001;

/**
 * classes
 */
static inline double degreeeToRadian(double deg) {
    return deg * PI / 180.0;
}

constexpr unsigned long GLOBAL_SEED = 691l * 691l * 691l;

namespace Raytracing {
    struct Signals {
        bool haltExecution{false};
        bool pauseRaytracing{false};
        bool haltRaytracing{false};
    };
    
    class AlignedAllocator {
        private:
        public:
            // not sure if this actually provides a performance benefit. Testing is inconclusive
            template<typename T>
            static T* allocateCacheAligned(int number = 1) {
                void* allocatedSpace = aligned_alloc(64, sizeof(T) * number);
                return new(allocatedSpace) T[number];
            }
    };
    
    class Random {
        private:
            std::random_device rd; // obtain a random number from hardware
            std::mt19937 gen;
            std::uniform_real_distribution<double> doubleDistr{0, 1};
            std::uniform_int_distribution<long> longDistr{0, 1};
            std::uniform_int_distribution<unsigned long> ulongDistr{0, 1};
        public:
            Random():
                    gen(std::mt19937(GLOBAL_SEED)) {}
            
            Random(double min, double max):
                    gen(std::mt19937(GLOBAL_SEED)), doubleDistr{min, max}, longDistr{(long) min, (long) max},
                    ulongDistr{(unsigned long) min, (unsigned long) max} {}
            
            Random(long min, long max):
                    gen(std::mt19937(GLOBAL_SEED)), doubleDistr{(double) min, (double) max}, longDistr{(long) min, (long) max},
                    ulongDistr{(unsigned long) min, (unsigned long) max} {}
            
            Random(unsigned long min, unsigned long max):
                    gen(std::mt19937(GLOBAL_SEED)), doubleDistr{(double) min, (double) max}, longDistr{(long) min, (long) max},
                    ulongDistr{(unsigned long) min, (unsigned long) max} {}
            
            double getDouble() {
                return doubleDistr(gen);
            }
            
            long getLong() {
                return longDistr(gen);
            }
            
            unsigned long getULong() {
                return ulongDistr(gen);
            }
    };
    
    class String {
        public:
            /**
             * Converts the string into lower case
             * @param s string to lower case
             * @return a string copy that is all lower case
             */
            static inline std::string toLowerCase(const std::string& s) {
                std::stringstream str;
                std::for_each(
                        s.begin(), s.end(), [&str](unsigned char ch) {
                            str << (char) std::tolower(ch);
                        }
                );
                return str.str();
            }
            
            /**
             * Converts the string into upper case
             * @param s string to upper case
             * @return a string copy that is all upper case
             */
            static inline std::string toUpperCase(const std::string& s) {
                std::stringstream str;
                std::for_each(
                        s.begin(), s.end(), [&str](unsigned char ch) {
                            str << (char) std::toupper(ch);
                        }
                );
                return str.str();
            }
            
            /**
             * @return the standard string of time.now
             */
            static inline std::string getTimeString() {
                auto t = std::time(nullptr);
                auto now = std::localtime(&t);
                std::stringstream timeString;
                timeString << (1900 + now->tm_year);
                timeString << "-";
                timeString << (1 + now->tm_mon);
                timeString << "-";
                timeString << now->tm_mday;
                timeString << " ";
                timeString << now->tm_hour;
                timeString << ":";
                timeString << now->tm_min;
                timeString << ":";
                timeString << now->tm_sec;
                return timeString.str();
            }
            
            // taken from https://stackoverflow.com/questions/14265581/parse-split-a-string-in-c-using-string-delimiter-standard-c
            // extended to return a vector
            static inline std::vector<std::string> split(std::string s, const std::string& delim) {
                size_t pos = 0;
                std::vector<std::string> tokens;
                while ((pos = s.find(delim)) != std::string::npos) {
                    auto token = s.substr(0, pos);
                    tokens.push_back(token);
                    s.erase(0, pos + delim.length());
                }
                tokens.push_back(s);
                return tokens;
            }
            
            // taken from https://stackoverflow.com/questions/216823/how-to-trim-an-stdstring
            // would've preferred to use boost lib but instructions said to avoid external libs
            // trim from start (in place)
            static inline std::string& ltrim(std::string& s) {
                s.erase(
                        s.begin(), std::find_if(
                                s.begin(), s.end(), [](unsigned char ch) {
                                    return !std::isspace(ch);
                                }
                        ));
                return s;
            }
            
            // trim from end (in place)
            static inline std::string& rtrim(std::string& s) {
                s.erase(
                        std::find_if(
                                s.rbegin(), s.rend(), [](unsigned char ch) {
                                    return !std::isspace(ch);
                                }
                        ).base(), s.end());
                return s;
            }
            
            // trim from both ends (in place)
            static inline std::string& trim(std::string& s) {
                ltrim(s);
                rtrim(s);
                return s;
            }
            
            // trim from start (copying)
            static inline std::string ltrim_copy(std::string s) {
                ltrim(s);
                return s;
            }
            
            // trim from end (copying)
            static inline std::string rtrim_copy(std::string s) {
                rtrim(s);
                return s;
            }
            
            // trim from both ends (copying)
            static inline std::string trim_copy(std::string s) {
                trim(s);
                return s;
            }
    };
}

static Raytracing::Random rnd{};

static inline double getRandomDouble() {
    return rnd.getDouble();
}

static inline double clamp(double val, double min, double max) {
    if (val < min)
        return min;
    if (val > max)
        return max;
    return val;
}

#endif //STEP_2_STD_H