#include "map.h"

#include "../core/memory.h"
#include "../math/vec2i.h"

#include <cute_tiled.h>
#include <string.h>

BzTileMap BZ_TILEMAP_INVALID = {.isValid = false};


int16_t bzTileLayerGetTile(BzTileLayer *layer, i32 x, i32 y) {
    return layer->data[layer->width * y + x];
}

static void handleTileLayer(BzTileLayer *layer, cute_tiled_layer_t *cuteLayer) {
    layer->id = cuteLayer->id;
    layer->dataCount = cuteLayer->data_count;
    layer->data = NULL;
    if (layer->dataCount > 0) {
        layer->data = bzAlloc(layer->dataCount * sizeof(*layer->data));
        layer->minData = layer->maxData = (i16) cuteLayer->data[0];
        for (i32 i = 0; i < layer->dataCount; i++) {
            layer->data[i] = (i16) cuteLayer->data[i];
            if (layer->data[i] < layer->minData)
                layer->minData = layer->data[i];
            else if (layer->data[i] > layer->maxData)
                layer->maxData = layer->data[i];
        }
    }

    layer->width = cuteLayer->width;
    layer->height = cuteLayer->height;

    layer->offsetX = cuteLayer->offsetx;
    layer->offsetY = cuteLayer->offsety;
    layer->opacity = cuteLayer->opacity;

}

// tileset.c
BzTileShape bzCuteObjectToTileShape(cute_tiled_object_t *object);

static void handleTileObjectLayer(BzTileObjectLayer *layer, cute_tiled_layer_t *cuteLayer,
                                  BzStringHashFunc hashFunc) {
    // Count objects
    layer->objectCount = 0;
    cute_tiled_object_t *object = cuteLayer->objects;
    while (object) {
        layer->objectCount++;
        object = object->next;
    }

    layer->objects = bzAlloc(layer->objectCount * sizeof(*layer->objects));
    object = cuteLayer->objects;
    for (i32 i = 0; i < layer->objectCount; i++) {
        layer->objects[i].id = hashFunc(object->name.ptr);
        layer->objects[i].shape = bzCuteObjectToTileShape(object);
        object = object->next;
    }

}

static i32 findSlot(const char *name, const BzTileLayerDesc desc[BZ_MAX_MAP_LAYERS]) {
    for (i32 i = 0; i < BZ_MAX_MAP_LAYERS; i++) {
        if (!desc[i].name) break;
        if (strcmp(name, desc[i].name) == 0) return i;
    }

    return -1;
}

BzTileMap bzTileMapCreate(const BzTileMapDesc *desc) {
    BzTileMap map = {};
    // Auto detect tileset count.
    for (i32 i = 0; i < BZ_MAX_MAP_TILESETS; i++) {
        if (!desc->tilesets[i].isValid)
            break;
        map.tilesetCount++;
    }
    for (i32 i = 0; i < map.tilesetCount; i++) {
        map.tilesets[i] = desc->tilesets[i];
    }

    cute_tiled_map_t *cuteMap = cute_tiled_load_map_from_file(desc->path, NULL);

    map.backgroundColor = GetColor(cuteMap->backgroundcolor);

    map.width = cuteMap->width;
    map.height = cuteMap->height;
    map.tileWidth = cuteMap->tilewidth;
    map.tileHeight = cuteMap->tileheight;

    cute_tiled_layer_t *cuteLayer = cuteMap->layers;
    while (cuteLayer) {
        BZ_ASSERT(map.layerCount < BZ_MAX_MAP_LAYERS);
        BZ_ASSERT(map.objectLayerCount < BZ_MAX_MAP_LAYERS);

        // Find slot
        i32 slot = -1;
        for (i32 i = 0; i < BZ_MAX_MAP_LAYERS; i++) {
            const BzTileLayerDesc *layerDesc = desc->layers + i;
            const BzTileObjectsDesc *objectsDesc = desc->objectLayers + i;
            if (layerDesc->name && strcmp(layerDesc->name, cuteLayer->name.ptr) == 0 ||
                objectsDesc->name && strcmp(objectsDesc->name, cuteLayer->name.ptr) == 0) {
                slot = i;
                break;
            } else if (!layerDesc->name && !objectsDesc->name) {
                break;
            }
        }
        if (slot == -1) {
            cuteLayer = cuteLayer->next;
            continue;
        }

        if (cuteLayer->data) {
            BzTileLayer *layer = map.layers + slot;
            const BzTileLayerDesc *layerDesc = desc->layers + slot;
            handleTileLayer(layer, cuteLayer);
            if (layerDesc->handler) layerDesc->handler(layer);
            map.layerCount++;
        } else {
            BzTileObjectLayer *objectLayer = map.objectLayers + slot;
            const BzTileObjectsDesc *objectLayerDesc = desc->objectLayers + slot;
            BzStringHashFunc *hashFunc = objectLayerDesc->hashFunc;
            if (!hashFunc)
                hashFunc = bzStringDefaultHash;
            handleTileObjectLayer(objectLayer, cuteLayer, hashFunc);
            if (objectLayerDesc->handler) objectLayerDesc->handler(objectLayer);
            map.objectLayerCount++;
        }

        cuteLayer = cuteLayer->next;
    }

    cute_tiled_tileset_t *cuteTileset = cuteMap->tilesets;
    int tilesetCount = 0;
    for (; cuteTileset; cuteTileset = cuteTileset->next) tilesetCount++;
    BZ_ASSERT(tilesetCount == map.tilesetCount);

    cuteTileset = cuteMap->tilesets;
    for (i32 i = 0; i < map.tilesetCount; i++) {
        BzTileset *tileset = map.tilesets + i;
        tileset->startID = cuteTileset->firstgid;
        cuteTileset = cuteTileset->next;
    }

    // Assign tilesets to layers
    for (i32 i = 0; i < map.layerCount; i++) {
        BzTileLayer *layer = map.layers + i;
        layer->tilesetIdx = -1;
        for (i32 j = map.tilesetCount - 1; j  >= 0; j--) {
            BzTileset *tileset = map.tilesets + j;

            if (tileset->startID >= layer->minData &&
                tileset->startID <= layer->maxData) {
                layer->tilesetIdx = j;
                break;
            }
        }
    }

    cute_tiled_free_map(cuteMap);

    map.isValid = true;
    return map;
}

void bzTileMapDestroy(BzTileMap *tilemap) {
    for (i32 i = 0; i < tilemap->layerCount; i++) {
        BzTileLayer *layer = tilemap->layers + i;
        bzFree(layer->data);
        layer->data = NULL;
        layer->dataCount = 0;
    }
    *tilemap = BZ_TILEMAP_INVALID;
}


static void drawLayer(BzTileLayer *layer, BzTileset *tileset) {
    if (!tileset) return;
    if (layer->minData == layer->maxData) return;
    Vector2 drawPos = {layer->offsetX, layer->offsetY};

    for (i32 y = 0; y < layer->height; y++) {
        for (i32 x = 0; x < layer->width; x++) {
            i16 tile = bzTileLayerGetTile(layer, x, y);
            if (tile - tileset->startID != -1) {
                Rectangle rec = bzTilesetGetTileRegion(tileset, tile);
                DrawTextureRec(tileset->tiles, rec, drawPos, WHITE);
            }
            drawPos.x += (float) tileset->tileWidth;
        }
        drawPos.x = layer->offsetX;
        drawPos.y += (float) tileset->tileHeight;
    }

}

void bzTileMapDraw(BzTileMap *map) {
    for (i32 i = 0; i < map->layerCount; i++) {
        BzTileLayer *layer = map->layers + i;
        BzTileset *tileset = NULL;
        if (layer->tilesetIdx != -1) {
            tileset = map->tilesets + layer->tilesetIdx;
        }
        drawLayer(map->layers + i, tileset);
    }
}

bool bzTileMapCanPlace(BzTileMap *map, i32 tileX, i32 tileY, i32 sizeX, i32 sizeY) {
    for (i32 y = tileY; y < tileY + sizeY; y++) {
        for (i32 x = tileX; x < tileX + sizeX; x++) {

            for (i32 i = 0; i < map->layerCount; i++) {
                BzTileLayer *layer = map->layers + i;
                if (layer->tilesetIdx == -1) continue;

                BzTileset *tileset = map->tilesets + layer->tilesetIdx;

                i16 tile = bzTileLayerGetTile(layer, x, y);
                BzTileShape collider = bzTilesetGetTileCollider(tileset, tile);
                if (collider.type != BZ_TILE_SHAPE_NONE)
                    return false;
            }
        }
    }

    return true;
}