#include "isometricMap.h"
#include <stdio.h>
#include <stdlib.h>
#include "tile.h"
#include "raymath.h"
#include "raylib.h"
#include "../DepthSorting/bucket.h"
#include "../game.h"
#include "../List/list.h"
#include "../DepthSorting/mergeSort.h"

// returns pointer to IsometricMap Instance
IsometricMap * IsometricMapInit(int layer){
    IsometricMap* map = malloc(sizeof(IsometricMap));
    
    map->tileTextures[0] = LoadTexture("assets/grass.png");
    map->tileTextures[1] = LoadTexture("assets/grass_selected.png");
    map->tileTextures[2] = LoadTexture("assets/tower.png");

    map->width = 500;
    map->height = 500;
    map->textureWidth = map->tileTextures[0].width;
    map->textureHeight = map->tileTextures[0].height;
    map->worldPixelWidth = map->width * map->textureWidth;
    map->worldPixelWidth = map->height * map->textureHeight;
    map->layer = layer;


    // mallocating the twodimensional Tiles Array
    Tile*** tiles = malloc(map->width*sizeof(Tile*));
    int n = 0;
    for(n=0; n < map->width; n++){
        tiles[n] = malloc(map->height*sizeof(Tile*));
    }

    int i = 0;
    int j = 0;
    int quarterTextureSize = map->textureWidth / 4;
    int halfTextureSize = map->textureWidth / 2;
    for(i=0; i < map->width; i++){
        for(j=0; j < map->height; j++){
            Tile *tmp = malloc(sizeof(Tile));
            // initially all the Tiles are "empty"
            tmp->textureId = -1;
            tmp->x = i;
            tmp->y = j;
            tmp->z = layer;

            Vector2 *offset = IsometricMapCalcOffsetForTileAt(i,j, halfTextureSize, quarterTextureSize);
            // the higher the layer the higher it needs to be drawed
            offset->y -= layer * quarterTextureSize;
            tmp->offsetX = offset->x;
            tmp->offsetY = offset->y;
            free(offset);
            tmp->sortable = BucketInit(0, tmp);
            tiles[i][j] = tmp;
        }
    }

    map->tiles = tiles;

    return map;
}

// For Rendering: calculates coordinate offset for a single tile at arrayPosition x y
// Only works for tiles with texture width == height (and for 22.5 degree?)
Vector2 * IsometricMapCalcOffsetForTileAt(int x, int y, int halfTextureSize, int quarterTextureSize){
    Vector2* offset = malloc(sizeof(Vector2));
    offset->x = x * halfTextureSize - y * halfTextureSize;
    offset->y = x * quarterTextureSize + y * quarterTextureSize;
    return offset;
}

// Unproject: World Coordinates -> Screen Coordinates       writes result in tmp Vector
void IsometricMapProject(IsometricMap *isometricMap, Camera2D *camera, float x, float y, Vector2 *tmp){

    float tileWidthHalf = isometricMap->textureWidth / 2;
    float tileHeightQuarter = isometricMap->textureHeight / 4;

    x += camera->target.x;
    y += camera->target.y;

    float xPos = (float) x;
    float yPos = (float) y;

    float isoX = 0.5 * ( xPos / tileWidthHalf + yPos / tileHeightQuarter);
    float isoY = 0.5 * ( -xPos / tileWidthHalf + yPos / tileHeightQuarter);

    tmp->x = isoX * isometricMap->tileTextures[0].width;
    tmp->y = isoY * isometricMap->tileTextures[0].height;
}

// Unproject: World Coordinates -> Screen Coordinates       writes result in tmp Vector
void IsometricMapUnproject(IsometricMap **isometricMap, Camera2D *camera, int x, int y, float z, Vector2 *tmp){
    float xPos = (float) x;
    float yPos = (float) y;
    
    float screenX = (xPos - yPos) / 2;
    float screenY = (xPos + yPos) / 4;

    screenX += camera->target.x;
    screenY += camera->target.y;

    // z is currently implemented as z=1 equals 1 layer, z=2 would be two layers height (could be smoothed)
    // hardcoded tile height
    screenY -= z * 10;

    tmp->x = screenX;
    tmp->y = screenY;
}

// returns Tile * -> tile at coordinates x y z=layer  
Tile * IsometricMapGetTileFromWorldCoordinates(IsometricMap **isometricMap, float x, float y, float z){

    int layer = (int) z; 

    x = (int)(x / isometricMap[layer]->textureWidth);
    y = (int)(y / isometricMap[layer]->textureHeight); 
    
    if( x < isometricMap[layer]->width && y < isometricMap[layer]->height && x >= 0 && y >= 0 ){
            if(isometricMap[layer]->tiles[(int)x][(int)y]->textureId != -1){
                return (isometricMap[layer]->tiles[(int)x][(int)y]);
            }
    }
    Tile *ptr = 0;
    return ptr;
}

// Gives the most upper Tile above *tile
Tile * IsometricMapGetMostUpperTile(IsometricMap **isometricMap, Tile *tile){
    //Tile *ptr = (Tile *) malloc(sizeof(Tile *));
    // hardcoded layer amount

    int n = 9;
    for(n=9;n>=0;n--){
        if( tile->x < isometricMap[n]->width && tile->y < isometricMap[n]->height &&
            tile->x >= 0 && tile->y >= 0 ){
                if(isometricMap[n]->tiles[tile->x][tile->y]->textureId != -1){
                    return isometricMap[n]->tiles[tile->x][tile->y];
                }
        }
    }
    return 0;
}

// changes to Texture ID of tile at x y on maplayer layer
void IsometricMapChangeTextureIdOfTile(IsometricMap **map, int x, int y, int layer, int id){
    if( x < map[layer]->width && y < map[layer]->height &&
        x >= 0 && y >= 0 ){
        (map[layer]->tiles[x][y])->textureId = id;
    }
    else{
        printf("WARNING: trying to change Texture of Tile which is out of bounds!\n");
    }
}

void IsometricMapDraw(Game *game){
    // TODO: Implement as List
    Bucket *buckets[100000];
    int counter = 0;

    int windowWidth = GetScreenWidth();
    int windowHeight = GetScreenHeight();
    Vector2 topleft = {0, 0};
    IsometricMapProject(game->layers[0], game->camera, topleft.x, topleft.y, &topleft);
    Vector2 topright = {windowWidth, 0};
    IsometricMapProject(game->layers[0], game->camera, topright.x, topright.y, &topright);
    Vector2 botleft = {0, windowHeight};
    IsometricMapProject(game->layers[0], game->camera, botleft.x, botleft.y, &botleft);
    Vector2 botright = {windowWidth, windowHeight};
    IsometricMapProject(game->layers[0], game->camera, botright.x, botright.y, &botright);

    int extraTiles = 1;
    int n = 0;
    int itmp = (int)(topleft.x / game->layers[0]->textureWidth) - extraTiles;
    int jtmp = (int)(topright.y / game->layers[0]->textureHeight) - extraTiles;
    int maxI = (int)(botright.x / game->layers[0]->textureWidth) + extraTiles;
    int maxJ = (int)(botleft.y / game->layers[0]->textureHeight) + extraTiles;
    if (itmp < 0){ itmp = 0; }
    if (jtmp < 0){ jtmp = 0; }
    if (maxI > game->layers[0]->width){ maxI = game->layers[0]->width; }
    if (maxJ > game->layers[0]->height){ maxJ = game->layers[0]->height; }
    int i, j = 0;
    for (n = 0; n < 10; n++){
        for (j = jtmp; j < maxJ; j++){
            for (i = itmp; i < maxI; i++){
                if (game->layers[n]->tiles[i][j]->textureId == -1){
                }
                else{
                    buckets[counter] = game->layers[n]->tiles[i][j]->sortable;
                    ++counter;
                }                
            }
        }
    }
    //printf("\n\n\n");

    Node *current = game->sprites->head;
    int extraPixels = 0;
    // drawing some extra corner pixels
    // if extraPixels == 0 you can see flickering in the corners
    itmp = (int)(topleft.x) - extraPixels;
    jtmp = (int)(topright.y) - extraPixels;
    maxI = (int)(botright.x) + extraPixels;
    maxJ = (int)(botleft.y) + extraPixels;
    while(current != 0){
        // Only drawing the Sprites which are within Camera view
        if( current->data->x > itmp && 
            current->data->y > jtmp && 
            current->data->x < maxI && 
            current->data->y < maxJ){
                buckets[counter] = current->data->sortable;
                ++counter;
        }
        current = current->next;
    }

    int hmmm = counter;
    // Merge Sort ist scuffed
    MergeSort(buckets, hmmm);
    
    int k = 0;
    for(k = 0; k < counter; k++){
        if(buckets[k]->type == 1){
            DrawTexture(
                        game->layers[0]->tileTextures[buckets[k]->tile->textureId],
                        buckets[k]->tile->offsetX,
                        buckets[k]->tile->offsetY,
                        WHITE);
        }
        else if(buckets[k]->type == 0){
            DrawSpriteToWorld(buckets[k]->sprite, game->layers, game->camera);
        }
    }

}