package me.hammerle.supersnuvi.rendering;

import java.util.ArrayList;
import me.hammerle.snuviengine.api.Shader;
import me.hammerle.snuviengine.api.Texture;
import me.hammerle.snuviengine.api.TextureRenderer;
import me.hammerle.snuviengine.util.Rectangle;
import me.hammerle.supersnuvi.Game;
import me.hammerle.supersnuvi.entity.Entity;
import me.hammerle.supersnuvi.gamelogic.Level;
import me.hammerle.supersnuvi.gamelogic.LevelData;
import me.hammerle.supersnuvi.tiles.Tile;
import me.hammerle.supersnuvi.util.Utils;

public class LevelRenderer implements IRenderer<Level>
{
    public final static float ERROR = 1f / 65536f;
    public final static Texture TILES = new Texture("resources/tiles.png");
    private final static Texture GUI = new Texture("resources/gui.png");
    private final static TextureRenderer GUI_RENDERER = new TextureRenderer(60);
    private final static int MESH_SIZE = 16;
    
    private float cameraX = 0.0f;
    private float cameraY = 0.0f;
    
    private Level lastRenderedLevel = null;
    private int meshLayers = 0;
    private int meshWidth = 0;
    private int meshHeight = 0;
    private TextureRenderer[][][] meshes = null;
    
    @Override
    public void renderTick(Shader sh, float lag, Level level)
    {
        updateCamera(sh, lag, level);
        if(lastRenderedLevel != level)
        {
            updateMeshes(level);
            lastRenderedLevel = level;
            
            for(int i = 0; i < 32; i++)
            {
                level.getLight(i).markDirty();
            }
        }

        Shader.setAmbientLight(level.getAmbientRed(), level.getAmbientGreen(), level.getAmbientBlue());
        Shader.setLightEnabled(true);
        for(int i = 0; i < 1; i++)
        {
            Light l = level.getLight(i);
            if(l.isDirty())
            {
                sh.setLightColor(i, l.getRed(), l.getGreen(), l.getBlue());
                sh.setLightStrength(i, l.getStrength());
                l.clearDirtyFlag();
            }
            sh.setLightLocation(i, 
                    Utils.interpolate(l.getLastX(), l.getX(), lag) + cameraX, 
                    Utils.interpolate(l.getLastY(), l.getY(), lag) + cameraY);
        }
        renderTilesAndEntities(sh, lag, level);
        Shader.setLightEnabled(false);
        renderOverlay(sh, level);
    }

    private float getView(int screenSize, int levelSize, float pos) 
    {
        pos -= screenSize >> 1;
        if(pos < 0)
        {
            return 0;
        }
        float max = levelSize * Tile.SIZE - screenSize;
        if(pos > max)
        {
            return max;
        }
        return pos;
    }
    
    private void updateCamera(Shader sh, float lag, Level level)
    {
        Entity hero = level.getHero();
        
        int levelWidth = level.getData().getWidth();
        int levelHeight = level.getData().getHeight();
        
        int screenWidth = sh.getViewWidth();
        int screenHeight = sh.getViewHeight();
        
        float halfHeroWidth = hero.getWidth() * 0.5f;
        float halfHeroHeight = hero.getHeight() * 0.5f;
        
        float oldCamX = -getView(screenWidth, levelWidth, hero.getLastX() + halfHeroWidth);
        float oldCamY = -getView(screenHeight, levelHeight, hero.getLastY() + halfHeroHeight);
        float camX = -getView(screenWidth, levelWidth, hero.getX() + halfHeroWidth);
        float camY = -getView(screenHeight, levelHeight, hero.getY() + halfHeroHeight);

        cameraX = Utils.interpolate(oldCamX, camX, lag);
        cameraY = Utils.interpolate(oldCamY, camY, lag);

        sh.translateTo(cameraX, cameraY);
        sh.updateMatrix();
    }
    
    private void updateMeshes(Level level)
    {
        if(meshes != null)
        {
            for(int l = 0; l < meshLayers; l++)
            {
                for(int mx = 0; mx < meshWidth; mx++)
                {
                    for(int my = 0; my < meshHeight; my++)
                    {
                        meshes[l][mx][my].delete();
                    }
                }
            }
        }
        
        meshLayers = level.getData().getLayers() - 1;
        meshWidth = (int) Math.ceil((double) level.getData().getWidth() / MESH_SIZE);
        meshHeight = (int) Math.ceil((double) level.getData().getHeight() / MESH_SIZE);
        meshes = new TextureRenderer[meshLayers][meshWidth][meshHeight];
        for(int l = 0; l < meshLayers; l++)
        {
            for(int mx = 0; mx < meshWidth; mx++)
            {
                for(int my = 0; my < meshHeight; my++)
                {
                    meshes[l][mx][my] = new TextureRenderer(MESH_SIZE * MESH_SIZE * 2, false);
                }
            }
        }
    }
    
    private void drawMesh(Level level, int l, int tl, int mx, int my)
    {
        TextureRenderer tr = meshes[l][mx][my];
        if(!tr.isBuilt())
        {
            LevelData data = level.getData();
            int tsx = mx * MESH_SIZE;
            int tsy = my * MESH_SIZE;
            int tex = Math.min(tsx + MESH_SIZE, data.getWidth());
            int tey = Math.min(tsy + MESH_SIZE, data.getHeight());
            for(int x = tsx; x < tex; x++)
            {
                for(int y = tsy; y < tey; y++)
                {
                    Tile t = Game.get().getTile(data.getTile(tl, x, y));
                    if(t.shouldRender(x, y, level))
                    {
                        float minX = x * Tile.SIZE + t.getOffsetX();
                        float minY = y * Tile.SIZE + t.getOffsetY();
                        tr.addRectangle(minX, minY, 
                                minX + t.getWidth(), minY + t.getHeight(), 
                                t.getTextureMinX(x, y, level) + ERROR, t.getTextureMinY(x, y, level) + ERROR,
                                t.getTextureMaxX(x, y, level) - ERROR, t.getTextureMaxY(x, y, level) - ERROR);
                    }
                }
            }
            tr.build();
        }
        tr.draw();
    }
    
    private void renderTilesAndEntities(Shader sh, float lag, Level level)
    {
        int startX = (int) (-cameraX / (MESH_SIZE * Tile.SIZE));
        int startY = (int) (-cameraY / (MESH_SIZE * Tile.SIZE));
        int endX = (int) Math.ceil((-cameraX + sh.getViewWidth()) / (MESH_SIZE * Tile.SIZE));
        int endY = (int) Math.ceil((-cameraY + sh.getViewHeight()) / (MESH_SIZE * Tile.SIZE));

        startX = Math.min(Math.max(startX, 0), meshWidth);
        startY = Math.min(Math.max(startY, 0), meshHeight);
        endX = Math.min(Math.max(endX, 0), meshWidth);
        endY = Math.min(Math.max(endY, 0), meshHeight);

        // clear meshes which need an update
        if(level.getTileUpdater().shouldUpdateAll())
        {
            if(meshes != null)
            {
                for(int l = 0; l < meshLayers; l++)
                {
                    for(int mx = 0; mx < meshWidth; mx++)
                    {
                        for(int my = 0; my < meshHeight; my++)
                        {
                            meshes[l][mx][my].clear();
                        }
                    }
                }
            }
        }
        else
        {
            level.getTileUpdater().forEach((layer, x, y) -> 
            {
                if(layer == level.getData().getBackgroundIndex() + 1)
                {
                    // do not update changes on entity layer
                    return;
                }
                if(layer > level.getData().getBackgroundIndex())
                {
                    layer--;
                }
                meshes[layer][x / MESH_SIZE][y / MESH_SIZE].clear();
            });
        }
        level.getTileUpdater().clear();
        
        // background
        sh.setColorEnabled(false);
        sh.setTextureEnabled(true);
        sh.setBlendingEnabled(true);
        TILES.bind();
        
        LevelData data = level.getData();

        int fromLayer = 0;
        int toLayer = level.getData().getBackgroundIndex() + 1;

        for(int l = fromLayer; l < toLayer; l++)
        {
            for(int mx = startX; mx < endX; mx++)
            {
                for(int my = startY; my < endY; my++)
                {
                    drawMesh(level, l, l, mx, my);
                }
            }
        }

        // entities
        level.forEachEntity(entity -> entity.renderTick(lag));

        // foreground
        sh.setColorEnabled(false);
        sh.setTextureEnabled(true);
        sh.setBlendingEnabled(true);
        TILES.bind();

        fromLayer = toLayer + 1;
        toLayer = level.getData().getLayers();

        for(int l = fromLayer; l < toLayer; l++)
        {
            for(int mx = startX; mx < endX; mx++)
            {
                for(int my = startY; my < endY; my++)
                {
                    drawMesh(level, l - 1, l, mx, my);
                }
            }
        }
    }
    
    public static String formatBottles(int bottles, int maxBottles)
    {
        char[] c = new char[5];
        if(bottles <= 9)
        {
            c[0] = '0';
            c[1] = (char) (bottles + '0');
        }
        else if(bottles > 99)
        {
            c[0] = 'X';
            c[1] = 'X';
        }
        else
        {
            c[0] = (char) ((bottles / 10) + '0');
            c[1] = (char) ((bottles % 10) + '0');
        }
        c[2] = '/';
        
        int currentMaxSouls = Math.max(bottles, maxBottles);
        if(currentMaxSouls <= 9)
        {
            c[3] = '0';
            c[4] = (char) (currentMaxSouls + '0');
        }
        else if(currentMaxSouls > 99)
        {
            c[3] = 'X';
            c[4] = 'X';
        }
        else
        {
            c[3] = (char) ((currentMaxSouls / 10) + '0');
            c[4] = (char) ((currentMaxSouls % 10) + '0');
        }
        return new String(c);
    }
    
    public static String formatTime(float time)
    {
        if(time == -1.0f)
        {
            return "-----";
        }
        else if(time >= 999.9f)
        {
            return "999.9";
        }
        return String.format("%05.1f", time);
    }   
    
    private String[] split(String s)
    {
        ArrayList<String> list = new ArrayList<>();
        int old = 0;
        int index = 0;
        while(index < s.length())
        {
            switch(s.charAt(index))
            {
                case '\n':
                    list.add(s.substring(old, index));
                    list.add("\n");
                    old = index + 1;
                    break;
                case ' ':
                    list.add(s.substring(old, index));
                    old = index + 1;
                    break;
            }
            index++;
        }
        if(old < s.length())
        {
            list.add(s.substring(old, index));
        }
        return list.toArray(new String[list.size()]);
    }
    
    private void renderMessage(Shader sh, Level level)
    {
        String message = level.getMessage();
        if(message != null)
        {
            float lineWidth = sh.getFontRenderer().getWidth();
            String[] messageParts = split(message);
            int index = 0;
            ArrayList<StringBuilder> list = new ArrayList<>();
            list.add(new StringBuilder());
            float currentWidth = 0;

            float w = sh.getViewWidth() - 26;
            for(String s : messageParts)
            {
                if(s.equals("\n"))
                {
                    currentWidth = w;
                    continue;
                }
                Rectangle rec = sh.getFontRenderer().getSize(s);
                // + lineWidth for the space
                if(currentWidth + rec.getWidth() + lineWidth < w)
                {
                    currentWidth += rec.getWidth();

                    StringBuilder sb = list.get(index);
                    if(sb.length() == 0)
                    {
                        sb.append(s);
                    }
                    else
                    {
                        sb.append(" ");
                        sb.append(s);

                        currentWidth += lineWidth;
                    }
                }
                else
                {
                    StringBuilder sb = new StringBuilder();
                    list.add(sb);
                    index++;
                    sb.append(s);
                    currentWidth = rec.getWidth();
                }
            }
            float height = list.size() * sh.getFontRenderer().getHeight();

            sh.setColorEnabled(true);
            sh.setTextureEnabled(false);
            float messageY = sh.getViewHeight() - height - 26;
            sh.getColorRenderer().drawRectangle(0.0f, messageY, sh.getViewWidth(), sh.getViewHeight(), 0x77000000);
            messageY += 13;
            sh.setTextureEnabled(true);
            for(StringBuilder sb : list)
            {
                messageY = sh.getFontRenderer().drawString(13.0f, messageY, sb.toString());
            }
            sh.setColorEnabled(false);
        }
    }
    
    private void renderOverlay(Shader sh, Level level)
    {
        // menu rendering
        sh.translateTo(0.0f, 0.0f);
        sh.updateMatrix();

        // grey background of clock and bottles
        float lineHeight = sh.getFontRenderer().getHeight();
        float lineWidth = sh.getFontRenderer().getWidth();
        sh.setColorEnabled(true);
        sh.setTextureEnabled(false);
        sh.getColorRenderer().drawRectangle(0.0f, 0.0f, (lineWidth * 6.0f) + 10.0f, (lineHeight * 2.0f + 10.0f), 0x77000000);
        sh.setTextureEnabled(true);
        float y = 5.0f;
        y = sh.getFontRenderer().drawString(13.0f, y, formatBottles(level.getCurrentBottles(), level.getMaxBottles()));
        sh.getFontRenderer().drawString(13.0f, y, formatTime(level.getTime()));
        sh.setColorEnabled(false);

        // draw messages
        renderMessage(sh, level);

        GUI.bind();
        GUI_RENDERER.clear();

        int scale = sh.getViewScale();

        // bottles
        switch(scale)
        {
            case 1: GUI_RENDERER.addRectangle(6.0f, 4.0f, 12.0f, 14.0f, 0.0f, 0.046875f, 0.01171875f, 0.068359375f); break;
            case 2: GUI_RENDERER.addRectangle(6.0f, 4.0f, 12.0f, 14.0f, 0.01171875f, 0.046875f, 0.037109375f, 0.0859375f); break;
            default: GUI_RENDERER.addRectangle(6.0f, 4.0f, 12.0f, 14.0f, 0.037109375f, 0.046875f, 0.06640625f, 0.10546875f); break;
        }

        // clock
        switch(scale)
        {
            case 1: GUI_RENDERER.addRectangle(4.0f, y, 13.0f, y + 9.0f, 0.0f, 0.265625f, 0.017578125f, 0.283203125f); break;
            case 2: GUI_RENDERER.addRectangle(4.5f, y, 13.0f, y + 8.5f, 0.017578125f, 0.265625f, 0.05078125f, 0.298828125f); break;
            default: GUI_RENDERER.addRectangle(4.666666666f, y, 13.0f, y + 8.333333333f, 0.05078125f, 0.265625f, 0.099609375f, 0.314453125f); break;
        }

        float w = sh.getViewWidth();

        // gui background 
        GUI_RENDERER.addRectangle(w - 111.0f, 0.0f, w - 44.0f, 24.0f, 0.0f, 0.0f, 0.130859375f, 0.046875f);
        GUI_RENDERER.addRectangle(w - 44.0f, 0.0f, w - 18.0f, 16.0f, 0.130859375f, 0.0f, 0.181640625f, 0.03125f);
        GUI_RENDERER.addRectangle(w - 76.0f, 24.0f, w - 45.0f, 57.0f, 0.068359375f, 0.046875f, 0.12890625f, 0.111328125f);

        // health mirror    
        int healthFrame = (int) (level.getHero().getHealth().getHealthPercent() * 7);
        float leftMirror = (7 - healthFrame) * 0.0625f;
        GUI_RENDERER.addRectangle(w - 39.0f, 8.0f, w - 7.0f, 46.0f, leftMirror, 0.15625f, leftMirror + 0.0625f, 0.23046875f);

        // energy
        float energy = level.getHero().getEnergy().getEnergyPercent();
        float fullEnd =  w - 109.0f + 64.0f * energy;
        GUI_RENDERER.addRectangle(w - 109.0f, 13.0f, fullEnd, 21.0f, 0.0f, 0.140625f, 0.125f * energy, 0.15625f);
        GUI_RENDERER.addRectangle(fullEnd, 13.0f, w - 45.0f, 21.0f, 0.125f * energy, 0.125f, 0.125f, 0.140625f);

        // gui foreground
        GUI_RENDERER.addRectangle(w - 49.0f, 0.0f, w, 64.0f, 0.201171875f, 0.0f, 0.296875f, 0.125f);
        GUI_RENDERER.addRectangle(w - 109.0f, 15.0f, w - 106.0f, 18.0f, 0.15625f, 0.03125f, 0.162109375f, 0.037109375f);
        GUI_RENDERER.addRectangle(w - 97.0f, 15.0f, w - 92.0f, 20.0f, 0.1796875f, 0.03125f, 0.189453125f, 0.041015625f);

        // health number overlay
        GUI_RENDERER.addRectangle(w - 30.0f, 53.0f, w - 12.0f, 62.0f, leftMirror, 0.23828125f, leftMirror + 0.03515625f, 0.255859375f);

        GUI_RENDERER.build();
        GUI_RENDERER.draw();

        // dynamic clock hand
        sh.setColorEnabled(true);
        sh.setTextureEnabled(false);
        switch(scale)
        {
            case 1: sh.translateTo(8.5f, y + 4.5f); break;
            case 2: sh.translateTo(8.75f, y + 4.25f); break;
            default: sh.translateTo(8.8333333333f, y + 4.16666667f); break;
        }
        sh.rotate(-level.getTime() * 72.0f);
        sh.updateMatrix();
        sh.getColorRenderer().drawRectangle(-0.5f / scale, -0.5f / scale, 0.5f / scale, 4.0f - 0.5f * scale, 0xFF000000);
    }
}