// deck.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors

import {Texture} from '@luma.gl/core';
import {UpdateParameters, Color} from '@deck.gl/core';
import {ColumnLayer} from '@deck.gl/layers';
import {CubeGeometry} from '@luma.gl/engine';
import {createColorRangeTexture, updateColorRangeTexture} from '../common/utils/color-utils';
import vs from './grid-cell-layer-vertex.glsl';
import {GridProps, gridUniforms} from './grid-layer-uniforms';
import type {ScaleType} from '../common/types';

/** Proprties added by GridCellLayer. */
type GridCellLayerProps = {
  cellSizeCommon: Readonly<[number, number]>;
  cellOriginCommon: Readonly<[number, number]>;
  colorDomain: Readonly<[number, number]>;
  colorCutoff: Readonly<[number, number]> | null;
  colorRange: Color[];
  colorScaleType: ScaleType;
  elevationDomain: Readonly<[number, number]>;
  elevationCutoff: Readonly<[number, number]> | null;
  elevationRange: Readonly<[number, number]>;
};

export class GridCellLayer<ExtraPropsT extends {} = {}> extends ColumnLayer<
  null,
  ExtraPropsT & Required<GridCellLayerProps>
> {
  static layerName = 'GridCellLayer';

  state!: ColumnLayer['state'] & {
    colorTexture: Texture;
  };

  getShaders() {
    const shaders = super.getShaders();
    shaders.modules.push(gridUniforms);
    return {...shaders, vs};
  }

  initializeState() {
    super.initializeState();

    const attributeManager = this.getAttributeManager()!;
    attributeManager.remove([
      'instanceElevations',
      'instanceFillColors',
      'instanceLineColors',
      'instanceStrokeWidths'
    ]);
    attributeManager.addInstanced({
      instancePositions: {
        size: 2,
        type: 'float32',
        accessor: 'getBin'
      },
      instanceColorValues: {
        size: 1,
        type: 'float32',
        accessor: 'getColorValue'
      },
      instanceElevationValues: {
        size: 1,
        type: 'float32',
        accessor: 'getElevationValue'
      }
    });
  }

  updateState(params: UpdateParameters<this>) {
    super.updateState(params);

    const {props, oldProps} = params;
    const model = this.state.fillModel!;

    if (oldProps.colorRange !== props.colorRange) {
      this.state.colorTexture?.destroy();
      this.state.colorTexture = createColorRangeTexture(
        this.context.device,
        props.colorRange,
        props.colorScaleType
      );
      const gridProps: Partial<GridProps> = {colorRange: this.state.colorTexture};
      model.shaderInputs.setProps({grid: gridProps});
    } else if (oldProps.colorScaleType !== props.colorScaleType) {
      updateColorRangeTexture(this.state.colorTexture, props.colorScaleType);
    }
  }

  finalizeState(context) {
    super.finalizeState(context);

    this.state.colorTexture?.destroy();
  }

  protected _updateGeometry() {
    const geometry = new CubeGeometry();
    this.state.fillModel!.setGeometry(geometry);
  }

  draw({uniforms}) {
    const {
      cellOriginCommon,
      cellSizeCommon,
      elevationRange,
      elevationScale,
      extruded,
      coverage,
      colorDomain,
      elevationDomain
    } = this.props;
    const colorCutoff = this.props.colorCutoff || [-Infinity, Infinity];
    const elevationCutoff = this.props.elevationCutoff || [-Infinity, Infinity];
    const fillModel = this.state.fillModel!;

    const gridProps: Omit<GridProps, 'colorRange'> = {
      colorDomain: [
        Math.max(colorDomain[0], colorCutoff[0]), // instanceColorValue that maps to colorRange[0]
        Math.min(colorDomain[1], colorCutoff[1]), // instanceColorValue that maps to colorRange[colorRange.length - 1]
        Math.max(colorDomain[0] - 1, colorCutoff[0]), // hide cell if instanceColorValue is less than this
        Math.min(colorDomain[1] + 1, colorCutoff[1]) // hide cell if instanceColorValue is greater than this
      ],
      elevationDomain: [
        Math.max(elevationDomain[0], elevationCutoff[0]), // instanceElevationValue that maps to elevationRange[0]
        Math.min(elevationDomain[1], elevationCutoff[1]), // instanceElevationValue that maps to elevationRange[elevationRange.length - 1]
        Math.max(elevationDomain[0] - 1, elevationCutoff[0]), // hide cell if instanceElevationValue is less than this
        Math.min(elevationDomain[1] + 1, elevationCutoff[1]) // hide cell if instanceElevationValue is greater than this
      ],
      elevationRange: [elevationRange[0] * elevationScale, elevationRange[1] * elevationScale],
      originCommon: cellOriginCommon,
      sizeCommon: cellSizeCommon
    };
    fillModel.shaderInputs.setProps({
      column: {extruded, coverage},
      grid: gridProps
    });
    fillModel.draw(this.context.renderPass);
  }
}