#ifndef SIMULATOR_H
#define SIMULATOR_H

#include <array>
#include <vector>
#include <memory>
#include <climits>
#include <stdint.h>
using namespace std;

struct Position {
    size_t x = 0;
    size_t y = 0;

    Position()
        : x(0)
        , y(0)
    {}
    Position(size_t _x, size_t _y)
        : x(_x)
        , y(_y)
    {}
    Position(const Position& _pos)
        : x(_pos.x)
        , y(_pos.y)
    {}
};

enum Direction {
    Right,
    Down,
    Left,
    Up,
};

enum Command : uint16_t {
    NOP,

    CREATE,
    MOVE,
    DIE,
    TRANS,
    RTRANS,
    TURN,

    JUMP,
    AJUMP,
    BJUMP,

    SCAN,
    FARSCAN,

    SET,
    ADD,
    SUB,
    MUL,
    DIV,
    MOD,
    MIN,
    MAX,
    RANDOM,

    IF,
    IFN,
    IFG,
    IFL,
    IFGE,
    IFLE,

    // INIT,
    // BREAK,
    // RESUME,
    // SEIZE,
    // SLEEP,
    // QUIT,
};

enum Params : uint16_t {
    LLL,
    LLV,
    LVL,
    LVV,
    VLL,
    VLV,
    VVL,
    VVV,

    N = LLL,
    L = LLL,
    V = VLL,

    LL = LLL,
    LV = LVL,
    VL = VLL,
    VV = VVV,
};

enum Variables {
    LocalVar_0 = 0,
    LocalVar_20 = 19,
    PubVar,
    TeamVar,
    LocalActiveVar,
    RemoteActiveVar,
    LocalBanks,
    RemoteBanks,
    LocalInstrSet,
    RemoteInstrSet,
    LocalMobile,
    RemoteMobile,
    LocalAge,
    RemoteAge,
    Own,
    Others,
    Fields,
    LocalGeneration,
    TeamId,
    InstrPos,
    Time,
    Timeout,
    LocalTasks,
    RemoteTasks,
};

enum Error {
    NoError, // No error
    EliminationTrigger, // Elimination Trigger released
    DataHunger, // Data Hunger (Bank 1 empty and executed)
    DivisionByZero, // Division by zero
    InvalidBankNumber, // Invalid bank number (e.g. in TRANS or BJUMP)
    HigherInstructionSetRequired, // Higher Instruction Set required
    MobilityRequired, // Mobility required
    DieExecuted, // DIE executed
    InvalidParameter , // Invalid parameter (e.g. CREATE x, -1, x)
    Unemployment, // No more tasks left in a robot (Unemployment)
    InstructionDurationTooHigh, // Instruction duration too high (i.e. > MaxInstrDur)
};


using Parameter = int32_t;

struct Instruction {
    Command command = NOP;
    Params params = N;
    Parameter a = 0;
    Parameter b = 0;
    Parameter c = 0;

    Instruction(Command _command, Params _params = N, Parameter _a = 0, Parameter _b = 0, Parameter _c = 0)
        : command(_command)
        , params(_params)
        , a(_a)
        , b(_b)
        , c(_c)
    {
    }
};

using Bank = shared_ptr<vector<Instruction>>;


using BankIndex = size_t;
using InstIndex = size_t;
using TaskIndex = size_t;

struct Task {
    Direction direction = Right;
    BankIndex bankIndex = 0;
    InstIndex instIndex = 0;
};

struct Program {
    Error error = NoError;
    QColor color;
    Position position;
    vector<Task> tasks;
    TaskIndex taskIndex = 0;
    vector<Bank> banks;
    array<int32_t, 20> vars{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}};

    Program(QColor _color, Position _position, int32_t instructionSet, int32_t slotCount, int32_t mobile) {
        color = _color;
        position = _position;
        banks.resize(slotCount);
        tasks.resize(1);
    }
};

struct Field {
    Program* program = nullptr;
};

struct Simulator {
    size_t cycle = 0;
    vector<Program> programs;
    size_t size = 0;

    Simulator() {
        size = 20;
        programs.reserve(size * size);

//        std::srand(std::time(0));
        std::srand(0);
    }

    Position calcPosition(Position position, Direction direction, int32_t distance) {
        switch(direction) {
        case Right: return Position{(position.x + distance) % size, position.y};
        case Down: return Position{position.x, (position.y + distance) % size};
        case Left: return Position{(position.x - distance) % size, position.y};
        case Up: return Position{position.x, (position.y - distance) % size};
        }
    }


    void loadProgram(QColor color, size_t x, size_t y) {
        programs.push_back(Program(color, Position{x, y}, 2, 50, 1));

        {
            Bank bank = make_shared<vector<Instruction>>();
            bank->push_back(Instruction(BJUMP, LL, 1, 0));
            programs.back().banks[0] = bank;
        }
        {
            Bank bank = make_shared<vector<Instruction>>();
            bank->push_back(Instruction(SCAN, V, 1));
            bank->push_back(Instruction(CREATE, LLL, 2, 50, 1));
            bank->push_back(Instruction(TRANS, LL, 0, 0));
            bank->push_back(Instruction(TRANS, LL, 1, 1));
            bank->push_back(Instruction(RANDOM, VLL, 5, -5, 5));
            bank->push_back(Instruction(TURN, V, 5));
            bank->push_back(Instruction(ADD, VL, 6, 1));
//            bank->push_back(Instruction(IFG, VL, 6, 5));
//            bank->push_back(Instruction(DIE));
            bank->push_back(Instruction(AJUMP, L, 0));
            programs.back().banks[1] = bank;
        }
    }

    Program* findProgram(Position position) {
        for(auto& program : programs) {
            if(program.position.x == position.x && program.position.y == position.y && program.error == NoError) {
                return &program;
            }
        }
        return nullptr;
    }

    void simulate() {
        for (auto& program : programs) {
            auto& taskIndex = program.taskIndex;

            if(program.error != NoError) {
                continue;
            }

            if(program.tasks.empty()) {
                continue;
            }

            taskIndex = (taskIndex + 1) % program.tasks.size();

            if (taskIndex < program.tasks.size()) {
                auto& task = program.tasks[taskIndex];

                if(task.bankIndex >= program.banks.size()) {
                    continue;
                }

                const auto bank_ptr = program.banks[task.bankIndex].get();

                if(bank_ptr == nullptr || task.instIndex >= bank_ptr->size()) {
                    continue;
                }

                const auto& bank = *bank_ptr;
                const auto& inst = bank[task.instIndex];

                //prevent overrideing of instuctions...
                int32_t a_safe = inst.a;
                int32_t b_safe = inst.b;
                int32_t c_safe = inst.c;

                int32_t* a = &a_safe;
                int32_t* b = &b_safe;
                int32_t* c = &c_safe;

                auto decode = [&](int*& v) {
                    if(*v >= VAR_0 && *v <= VAR_20) {
                        v = &program.vars[*v];
                        return;
                    }
                    switch(*v) {
                        case 21: break;
                    }
                };

                switch(inst.params) {
                case LLL: { break; }
                case LLV: { decode(c); break; }
                case LVL: { decode(b); break; }
                case LVV: { decode(b); decode(c); break; }
                case VLL: { decode(a); break; }
                case VLV: { decode(a); decode(c); break; }
                case VVL: { decode(a); decode(b); break; }
                case VVV: { decode(a); decode(b); decode(c); break; }
                }



                switch(inst.command) {
                case CREATE: {
                    auto remotePosition = calcPosition(program.position, task.direction, 1);
                    auto remoteProgram = findProgram(remotePosition);
                    if(!remoteProgram) {
                        programs.push_back(Program(program.color, remotePosition, *a, *b, *c));
                    }
                    task.instIndex += 1;
                    break;
                }

                case MOVE: {
                    auto remotePosition = calcPosition(program.position, task.direction, 1);
                    auto remoteProgram = findProgram(remotePosition);
                    if(!remoteProgram) {
                        program.position = remotePosition;
                    }
                    task.instIndex += 1;
                    break;
                }

                case DIE: {
                    program.error = DieExecuted;
                    task.instIndex += 1;
                    break;
                }

                case TRANS: {
                    auto remotePosition = calcPosition(program.position, task.direction, 1);
                    auto remoteProgram = findProgram(remotePosition);
                    if(remoteProgram && *b < remoteProgram->banks.size() && *a < program.banks.size()) {
                        remoteProgram->banks[*b] = program.banks[*a];
                    }
                    task.instIndex += 1;
                    break;
                }

                case RTRANS: {
                    auto remotePosition = calcPosition(program.position, task.direction, 1);
                    auto remoteProgram = findProgram(remotePosition);
                    if(remoteProgram && *a < remoteProgram->banks.size() && *b < program.banks.size()) {
                        program.banks[*b] = remoteProgram->banks[*a];
                    }
                    task.instIndex += 1;
                    break;
                }

                case TURN: {
                    task.direction = static_cast<Direction>(qMax(0, (task.direction + ((*a >= 0) ? 1 : -1)) % 4));
                    task.instIndex += 1;
                    break;
                }

                case JUMP: {
                    task.instIndex += *a;
                    break;
                }

                case AJUMP: {
                    task.instIndex = *a;
                    break;
                }

                case BJUMP: {
                    task.bankIndex = *a;
                    task.instIndex = *b;
                    break;
                }

                case SCAN: {
                    // Scans a field, result in #a
                    // #a=0 ...empty.
                    // #a=1 ...enemy
                    // #a=2 ...friend
                    auto remotePosition = calcPosition(program.position, task.direction, 1);
                    auto remoteProgram = findProgram(remotePosition);
                    *a = !remoteProgram ? 0 : remoteProgram->color == program.color ? 2: 1;
                    task.instIndex += 1;
                    break;
                }

                case FARSCAN: {
                    // Scans up to c fields straight in front of the bot.
                    // The nearest bot's type is stored in #a:
                    // #a=0 ...empty.
                    // #a=1 ...enemy
                    // #a=2 ...friend
                    // Its distance is stored in #b.
                    *a = 0;
                    *b = 0;
                    for(int i = 0; i < *c; ++i) {
                        auto remotePosition = calcPosition(program.position, task.direction, i + 1);
                        auto remoteProgram = findProgram(remotePosition);
                        if(remoteProgram) {
                            *a = remoteProgram->color == program.color ? 2: 1;
                            *b = i;
                            break;
                        }
                    }
                    task.instIndex += 1;
                    break;
                }


                case SET:
                    *a = *b;
                    task.instIndex += 1;
                    break;

                case ADD:
                    *a += *b;
                    task.instIndex += 1;
                    break;

                case SUB:
                    *a -= *b;
                    task.instIndex += 1;
                    break;

                case MUL:
                    *a *= *b;
                    task.instIndex += 1;
                    break;

                case DIV:
                    *a /= *b;
                    task.instIndex += 1;
                    break;

                case MOD:
                    *a %= *b;
                    task.instIndex += 1;
                    break;

                case MIN:
                    *a = qMin(*a, *b);
                    task.instIndex += 1;
                    break;

                case MAX:
                    *a = qMax(*a, *b);
                    task.instIndex += 1;
                    break;

                case RANDOM:
                    *a = *b + (rand() % (*c - *b + 1));
                    task.instIndex += 1;
                break;

                case IF:
                    task.instIndex += ((*a == *b) ? 1 : 2);
                break;

                case IFN:
                    task.instIndex += ((*a != *b) ? 1 : 2);
                break;

                case IFG:
                    task.instIndex += ((*a > *b) ? 1 : 2);
                break;

                case IFL:
                    task.instIndex += ((*a < *b) ? 1 : 2);
                break;

                case IFGE:
                    task.instIndex += ((*a >= *b) ? 1 : 2);
                break;

                case IFLE:
                    task.instIndex += ((*a <= *b) ? 1 : 2);
                break;


                default:
                    task.instIndex += 1;
                    break;
                }
            }
        }
        ++cycle;
    }
};



#endif // SIMULATOR_H