//
// Created by Wouter Groeneveld on 30/11/18.
//

#include <libgba-sprite-engine/gba_engine.h>
#include <libgba-sprite-engine/sprites/sprite_builder.h>
#include <libgba-sprite-engine/gba/tonc_core.h>
#include <libgba-sprite-engine/background/text_stream.h>
#include "ConwayScene.h"
#include "bg.h"

// See http://www.coranac.com/tonc/text/gfx.htm#cd-qran
int __qran_seed= 42;     // Seed / rnd holder

ConwayScene::ConwayScene(const std::shared_ptr<GBAEngine> &engine, u8 percentageSeed) : Scene(engine), percentageSeed(percentageSeed) {
}

std::vector<Sprite *> ConwayScene::sprites() {
    return {};
}

std::vector<Background *> ConwayScene::backgrounds() {
    return { bg.get() };
}

int ConwayScene::countAmountOfNeighbouringCellsAlive(int x, int y) {
    int amountOfNeightbouringCellsAlive = 0;
    int pos = y * MAP_WIDTH + x;

    for(int x_i = x - 1; x_i <= x + 1; x_i++) {
        for(int y_j = y - 1; y_j <= y + 1; y_j++) {
            int toCheckPos = y_j * MAP_WIDTH + x_i;
            if(toCheckPos >= 0 && toCheckPos < MAP_SIZE - 1 && pos != toCheckPos && map[toCheckPos] == ALIVE) {
                amountOfNeightbouringCellsAlive++;
            }
        }
    }

    return amountOfNeightbouringCellsAlive;
}

u16 ConwayScene::getNextState(int x, int y) {
    int pos = y * MAP_WIDTH + x;
    int amountAlive = countAmountOfNeighbouringCellsAlive(x, y);

    int currentState = map[pos];

    if(currentState == DEAD) {
        if(amountAlive == 3) {
            return ALIVE;
        }
        return DEAD;
    } else {
        if (amountAlive < 2 || amountAlive > 3) {
            return DEAD;
        }
        return ALIVE;
    }
}

void ConwayScene::seedRandomMap(int seedcount) {
    for(int i = 0; i < MAP_SIZE; i++) {
        map[i] = DEAD;
    }

    for(int i = 0; i < seedcount; i++) {
        int x = qran_range(0, MAP_WIDTH);
        int y = qran_range(0, MAP_HEIGHT);
        map[y * MAP_WIDTH + x] = ALIVE;
    }
}

void ConwayScene::load() {
    backgroundPalette = std::unique_ptr<BackgroundPaletteManager>(new BackgroundPaletteManager(conway_palette, sizeof(conway_palette)));

    seedRandomMap(((MAP_WIDTH * MAP_HEIGHT) / 100) * percentageSeed);

    bg = std::unique_ptr<Background>(new Background(1, conway_data, sizeof(conway_data), map, sizeof(map)));
    bg.get()->useMapScreenBlock(16);
}

void ConwayScene::tick(u16 keys) {
    generation++;
    int totalAmountAlive = 0;
    dma3_cpy(buffer, map, sizeof(buffer));

    for(int w = 0; w < MAP_WIDTH; w++) {
        for(int h = 0; h < MAP_HEIGHT; h++) {
            u16 state = getNextState(w, h);
            if(state == ALIVE) totalAmountAlive++;
            buffer[h * MAP_WIDTH + w] = state;
        }
    }

    TextStream::instance().setText(std::string("amount alive: ") + std::to_string(totalAmountAlive) + std::string(" of ") + std::to_string(MAP_SIZE), 1, 1);
    TextStream::instance().setText(std::string("generation: ") + std::to_string(generation), 2, 1);
    dma3_cpy(map, buffer, sizeof(map));
    bg.get()->updateMap(buffer);
}