#include "simulator.h"


Simulator::Simulator() {
    programs.reserve(FIELDS_XY * FIELDS_XY);

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


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

void Simulator::decodeInstructionParameters(Task& task, const Instruction& instruction) {
    task.a = instruction.a;
    task.b = instruction.b;
    task.c = instruction.c;
    task.var_a = nullptr;
    task.var_b = nullptr;
    task.var_c = nullptr;

    switch(instruction.params) {
        case N:
            break;
        case L:
            task.a = instruction.a;
            break;
        case V:

            break;
        case LL:
            task.a = instruction.a;
            task.b = instruction.b;
            break;
        case LV:
            task.a = instruction.a;

            break;
        case VL:

            task.b = instruction.b;
            break;
        case VV:


            break;
        case LLL:
            task.a = instruction.a;
            task.b = instruction.b;
            task.c = instruction.c;
            break;
        case LLV:
            task.a = instruction.a;
            task.b = instruction.b;

            break;
        case LVL:
            task.a = instruction.a;

            task.c = instruction.c;
            break;
        case LVV:
            task.a = instruction.a;


            break;
        case VLL:

            task.b = instruction.b;
            task.c = instruction.c;
            break;
        case VLV:

            task.b = instruction.b;

            break;
        case VVL:


            task.c = instruction.c;
            break;
        case VVV:



            break;
    }


    //@todo: remove dummy!
    task.var_a = &task.a;
    task.var_b = &task.b;
    task.var_c = &task.c;
}

void Simulator::loadProgram(QColor color, size_t x, size_t y) {
    shared_ptr<Team> team = make_shared<Team>(color);

    programs.push_back(Program(team, Right, Position{x, y}, 2, 50, 1));

    programs.back().banks[0] = make_shared<Bank>(team, vector<Instruction>{
                                                          Instruction(BJUMP, LL, 1, 0)
                                                      });

    programs.back().banks[1] = make_shared<Bank>(team, vector<Instruction>{
                                                          Instruction(SCAN, V, 1),
                                                          Instruction(CREATE, LLL, 2, 50, 1),
                                                          Instruction(TRANS, LL, 0, 0),
                                                          Instruction(TRANS, LL, 1, 1),
                                                          Instruction(TURN, L, 0),
                                                          Instruction(AJUMP, L, 0)
                                                      });
}

Program* Simulator::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 Simulator::removeErroneousPrograms() {
    auto it = std::remove_if(programs.begin(), programs.end(), [](const Program& program){ return program.error != NoError; });
    programs.erase(it, programs.end());
}

void Simulator::simulate() {
    removeErroneousPrograms();

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

        // error if no active task exists
        if(find_if(program.tasks.begin(), program.tasks.end(), [](const Task& task){ return !task.paused; }) == program.tasks.end()) {
            program.error = Unemployment;
            continue;
        }

        // switch to next unpasued task
        do {
            taskIndex = (taskIndex + 1) % program.tasks.size();
        } while(program.tasks[taskIndex].paused);

        // check if we are still executing an instruction
        auto& task = program.tasks[taskIndex];
        if(task.remainingCycles > 0) {
            --task.remainingCycles;
            continue;
        }
        else {
            endInstruction(program, task);
            beginInstruction(program, task);
        }
    }

    ++cycle;
}

void Simulator::beginInstruction(Program& program, Task& task) {
    // handle invalid bank number
    if(program.banks.empty() || task.bankIndex >= program.banks.size()) {
        program.error = InvalidBankNumber;
        return;
    }

    // handle autoreset to bank 0,0 if instructionIndex is out of banks bound or bank is empty
    if(!program.banks[task.bankIndex] || task.instIndex >= program.banks[task.bankIndex]->instructions.size()) {
        task.bankIndex  = 0;
        task.instIndex  = 0;
    }

    // handle data hunger
    if(task.bankIndex == 0 && !program.banks[0]) {
        program.error = DataHunger;
        return;
    }

    task.execBank = program.banks[task.bankIndex];

    auto& instruction = program.banks[task.bankIndex]->instructions[task.instIndex];

    decodeInstructionParameters(task, instruction);

    switch(instruction.command) {
        case CREATE:
            if(program.instructionSet < 2) {
                program.error = HigherInstructionSetRequired;
                break;
            }
            if(task.a < 0 || task.a > 2 || task.b < 1 || task.b > 50 || task.c < 0 || task.c > 1) {
                program.error = InvalidParameter;
                break;
            }
            task.remainingCycles = 100 + 50 * task.a + 25 * task.b + 120 * task.c;
            break;

        case MOVE:
            if(program.mobile < 1) {
                program.error = MobilityRequired;
                break;
            }
            task.remainingCycles = 20;
            break;

        case DIE:
            task.remainingCycles = 1;
            break;

        case TRANS: {
            if(program.instructionSet < 1) {
                program.error = HigherInstructionSetRequired;
                break;
            }
            if(task.a < 0 || task.a >= program.banks.size()) {
                program.error = InvalidBankNumber;
                break;
            }
            const auto& bank = program.banks[task.a];
            task.remainingCycles = 14 + (bank ? bank->instructions.size() : 0);
            break;
        }

        case RTRANS: {
            if(program.instructionSet < 1) {
                program.error = HigherInstructionSetRequired;
                break;
            }
            if(task.a < 0 || task.a >= 50 || task.b < 0 || task.b >= program.banks.size()) {
                program.error = InvalidBankNumber;
                break;
            }
            auto remotePosition = calcPosition(program.position, task.direction, 1);
            auto remoteProgram = findProgram(remotePosition);
            task.remainingCycles = 14 + remoteProgram ? (task.a < remoteProgram->banks.size() ? (remoteProgram->banks[task.a] ? remoteProgram->banks[task.a]->instructions.size() : 0): 0): 0;
            break;
        }

        case TURN:
            task.remainingCycles = 8;
            break;

        case JUMP:
            task.remainingCycles = 1;
            break;

        case AJUMP:
            task.remainingCycles = 1;
            break;

        case BJUMP:
            task.remainingCycles = 2;
            break;

        case SCAN:
            if(program.instructionSet < 1) {
                program.error = HigherInstructionSetRequired;
                break;
            }
            task.remainingCycles = 8;
            break;

        case FARSCAN:
            if(program.instructionSet < 1) {
                program.error = HigherInstructionSetRequired;
                break;
            }
            task.remainingCycles = 10 + 3 * task.c;
            break;

        case SET:
            task.remainingCycles = 2;
            break;

        case ADD:
            task.remainingCycles = 2;
            break;

        case SUB:
            task.remainingCycles = 2;
            break;

        case MUL:
            task.remainingCycles = 2;
            break;

        case DIV:
            task.remainingCycles = 2;
            break;

        case MOD:
            task.remainingCycles = 2;
            break;

        case MIN:
            task.remainingCycles = 2;
            break;

        case MAX:
            task.remainingCycles = 2;
            break;

        case RANDOM:
            if(task.b > task.c) {
                program.error = InvalidParameter;
                break;
            }
            task.remainingCycles = 1;
            break;

        case IF:
            task.remainingCycles = 2;
            break;

        case IFN:
            task.remainingCycles = 2;
            break;

        case IFG:
            task.remainingCycles = 2;
            break;

        case IFL:
            task.remainingCycles = 2;
            break;

        case IFGE:
            task.remainingCycles = 2;
            break;

        case IFLE:
            task.remainingCycles = 2;
            break;

        case INIT:
            task.remainingCycles = 2;
            break;

        case BREAK:
            task.remainingCycles = 1;
            break;

        case RESUME:
            task.remainingCycles = 1;
            break;

        case SEIZE:
            task.remainingCycles = 1;
            break;

        case SLEEP:
            if(task.a > 2000) {
                program.error = InvalidParameter;
                break;
            }
            task.remainingCycles = task.a;
            break;

        case QUIT:
            task.remainingCycles = 1;
            break;
    }
}

void Simulator::endInstruction(Program& program, Task& task) {
    // we are not executing yet
    if(!task.execBank || program.error != NoError) {
        return;
    }

    // check if bank is overwritten, skip execution of current command and begin new bank at instruction 0
    if(task.execBank != program.banks[task.bankIndex]) {
        task.instIndex = 0;
        return;
    }

    // execute command
    auto& instruction = task.execBank->instructions[task.instIndex];
    switch(instruction.command) {
        case CREATE: {
            auto remotePosition = calcPosition(program.position, task.direction, 1);
            auto remoteProgram = findProgram(remotePosition);
            if(!remoteProgram) {
                programs.push_back(Program(program.team, task.direction, remotePosition, task.a, task.b, task.c));
            }
            task.instIndex += 1;
        }

        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 && task.b < remoteProgram->banks.size() && task.a < program.banks.size()) {
                remoteProgram->banks[task.b] = program.banks[task.a];
            }
            task.instIndex += 1;
            break;
        }

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

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

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

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

        case BJUMP: {
            task.bankIndex = task.a;
            task.instIndex = task.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);
            *task.var_a = !remoteProgram ? 0 : remoteProgram->team == program.team ? 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.
            *task.var_a = 0;
            *task.var_b = 0;
            for(int i = 0; i < task.c; ++i) {
                auto remotePosition = calcPosition(program.position, task.direction, i + 1);
                auto remoteProgram = findProgram(remotePosition);
                if(remoteProgram) {
                    *task.var_a = remoteProgram->team == program.team ? 2: 1;
                    *task.var_b = i;
                    break;
                }
            }
            task.instIndex += 1;
            break;
        }

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

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

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

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

        case DIV:
            if(task.b == 0) {
                program.error = DivisionByZero;
                break;
            }
            *task.var_a /= task.b;
            task.instIndex += 1;
            break;

        case MOD:
            if(task.b == 0) {
                program.error = DivisionByZero;
                break;
            }
            *task.var_a %= task.b;
            task.instIndex += 1;
            break;

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

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

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

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

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

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

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

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

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

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

#if 0
void Simulator::simulatex() {
    for (auto& program : programs) {
        auto& taskIndex = program.taskIndex;

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

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



        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->instructions.size()) {
                continue;
            }

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

            //prevent overrideing of instuctions...



            auto mapParameters = [this](Program& program, Task& task, const Instruction& inst) {
                task.p_a = &task.a;
                task.p_b = &task.b;
                task.p_c = &task.c;

                auto decode = [&](int32_t*& v) {
                    switch(*v) {
                        case Local_0:  v = &program.vars[0]; break;
                        case Local_1:  v = &program.vars[1]; break;
                        case Local_2:  v = &program.vars[2]; break;
                        case Local_3:  v = &program.vars[3]; break;
                        case Local_4:  v = &program.vars[4]; break;
                        case Local_5:  v = &program.vars[5]; break;
                        case Local_6:  v = &program.vars[6]; break;
                        case Local_7:  v = &program.vars[7]; break;
                        case Local_8:  v = &program.vars[8]; break;
                        case Local_9:  v = &program.vars[9]; break;
                        case Local_10: v = &program.vars[10]; break;
                        case Local_11: v = &program.vars[11]; break;
                        case Local_12: v = &program.vars[12]; break;
                        case Local_13: v = &program.vars[13]; break;
                        case Local_14: v = &program.vars[14]; break;
                        case Local_15: v = &program.vars[15]; break;
                        case Local_16: v = &program.vars[16]; break;
                        case Local_17: v = &program.vars[17]; break;
                        case Local_18: v = &program.vars[18]; break;
                        case Local_19: v = &program.vars[19]; break;
                        case LocalActive:
                            v = &program.active;
                            break;
                        case LocalBanks:
                            *v = program.banks.size();
                            break;
                        case LocalInstrSet:
                            *v = program.instructionSet;
                            break;
                        case LocalMobile:
                            *v = program.mobile;
                            break;
                        case LocalAge:
                            *v = cycle - program.creationCycle;
                            break;
                        case LocalTasks:
                            *v = program.tasks.size();
                            break;
                        case LocalGeneration:
                            *v = program.generation;
                            break;
                        case LocalId:
                            // @todo
                            break;
                        case RemoteActive: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            if(remoteProgram) {
                                v = &remoteProgram->active;
                            }
                            else {
                                *v = 0;
                            }
                            break;
                        }
                        case RemoteBanks: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? remoteProgram->banks.size() : 0;
                            break;
                        }
                        case RemoteInstrSet: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? remoteProgram->instructionSet : 0;
                            break;
                        }
                        case RemoteMobile: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? remoteProgram->mobile: 0;
                            break;
                        }
                        case RemoteAge: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? (cycle - remoteProgram->creationCycle) : 0;
                            break;
                        }
                        case RemoteTasks: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? remoteProgram->tasks.size() : 0;
                            break;
                        }
                        case RemoteGeneration: {
                            auto remotePosition = calcPosition(program.position, task.direction, 1);
                            auto remoteProgram = findProgram(remotePosition);
                            *v = remoteProgram ? remoteProgram->generation : 0;
                            break;
                        }
                        case GlobalPub:
                            // @todo
                            break;
                        case GlobalTeam:
                            // @todo
                            break;
                        case GlobalOwn:
                            // @todo
                            break;
                        case GlobalOthers:
                            // @todo
                            break;
                        case GlobalFields:
                            *v = FIELDS_XY * FIELDS_XY;
                            break;
                        case GlobalTime:
                            *v = cycle;
                            break;
                        case GlobalTimeout:
                            *v = CYCLE_TIMEOUT;
                            break;
                    }
                };

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

            mapParameters(program, task, inst);

            switch(inst.command) {
            case CREATE: {
                auto remotePosition = calcPosition(program.position, task.direction, 1);
                auto remoteProgram = findProgram(remotePosition);
                if(!remoteProgram) {
                    programs.push_back(Program(program.team, remotePosition, *task.p_a, *task.p_b, *task.p_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 && *task.p_b < remoteProgram->banks.size() && *task.p_a < program.banks.size()) {
                    remoteProgram->banks[*task.p_b] = program.banks[*task.p_a];
                }
                task.instIndex += 1;
                break;
            }

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

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

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

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

            case BJUMP: {
                task.bankIndex = *task.p_a;
                task.instIndex = *task.p_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);
                *task.p_a = !remoteProgram ? 0 : remoteProgram->team == program.team ? 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.
                *task.p_a = 0;
                *task.p_b = 0;
                for(int i = 0; i < *task.p_c; ++i) {
                    auto remotePosition = calcPosition(program.position, task.direction, i + 1);
                    auto remoteProgram = findProgram(remotePosition);
                    if(remoteProgram) {
                        *task.p_a = remoteProgram->team == program.team ? 2: 1;
                        *task.p_b = i;
                        break;
                    }
                }
                task.instIndex += 1;
                break;
            }


            case SET:
                *task.p_a = *task.p_b;
                task.instIndex += 1;
                break;

            case ADD:
                *task.p_a += *task.p_b;
                task.instIndex += 1;
                break;

            case SUB:
                *task.p_a -= *task.p_b;
                task.instIndex += 1;
                break;

            case MUL:
                *task.p_a *= *task.p_b;
                task.instIndex += 1;
                break;

            case DIV:
                *task.p_a /= *task.p_b;
                task.instIndex += 1;
                break;

            case MOD:
                *task.p_a %= *task.p_b;
                task.instIndex += 1;
                break;

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

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

            case RANDOM:
                *task.p_a = *task.p_b + (rand() % (*task.p_c - *task.p_b + 1));
                task.instIndex += 1;
            break;

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

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

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

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

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

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


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