import vector2d from './helpers/vector-2d';

import Schema from '@/ecs/schema.js';

export default function(Component) {
  return class TileLayers extends Component {
    insertMany(entities) {
      for (const [id, {layerChange}] of entities) {
        if (layerChange) {
          const component = this.get(id);
          const {layers} = component;
          for (const layerIndex in layerChange) {
            for (const calculated in layerChange[layerIndex]) {
              const tile = layerChange[layerIndex][calculated];
              layers[layerIndex].data[calculated] = tile;
            }
            layers[layerIndex] = {...layers[layerIndex]};
          }
        }
      }
      return super.insertMany(entities);
    }
    mergeDiff(original, update) {
      if (!update.layerChange) {
        return super.mergeDiff(original, update);
      }
      const layerChange = {
        ...original.layerChange,
      };
      for (const index in update.layerChange) {
        layerChange[index] = {
          ...layerChange[index],
          ...update.layerChange[index],
        };
      }
      return {layerChange};
    }
    instanceFromSchema() {
      const Instance = super.instanceFromSchema();
      const Component = this;
      Instance.prototype.layer = function (index) {
        const {layers} = this;
        if (!(index in layers)) {
          return undefined;
        }
        const instance = this;
        class LayerProxy {
          constructor(layer) {
            this.layer = layer;
          }
          get area() {
            return this.layer.area;
          }
          get source() {
            return this.layer.source;
          }
          stamp(at, data) {
            const changes = {};
            for (const row in data) {
              const columns = data[row];
              for (const column in columns) {
                const tile = columns[column];
                const x = at.x + parseInt(column);
                const y = at.y + parseInt(row);
                if (x < 0 || y < 0 || x >= this.layer.area.x || y >= this.layer.area.y) {
                  continue;
                }
                const calculated = y * this.layer.area.x + x;
                this.layer.data[calculated] = tile;
                changes[calculated] = tile;
              }
            }
            Component.markChange(instance.entity, 'layerChange', {[index]: changes});
          }
          tile({x, y}) {
            if (x < 0 || y < 0 || x >= this.layer.area.x || y >= this.layer.area.y) {
              return undefined;
            }
            return this.layer.data[y * this.layer.area.x + x];
          }
          get tileSize() {
            return this.layer.tileSize;
          }
        }
        return new LayerProxy(layers[index]);
      };
      return Instance;
    }
    static schema = new Schema({
      type: 'object',
      properties: {
        layers: {
          type: 'array',
          subtype: {
            type: 'object',
            properties: {
              area: vector2d('float32'),
              data: {
                type: 'array',
                subtype: {
                  type: 'uint16',
                },
              },
              source: {type: 'string'},
              tileSize: vector2d('float32'),
            },
          },
        },
      },
    });
  }
}