/*
 * Copyright (c) 2015-2018, IGN France.
 * Copyright (c) 2018-2026, Giro3D team.
 * SPDX-License-Identifier: MIT
 */

import type ColorMap from '../../../core/ColorMap';
import type { HasDefines, VertexAttributeType } from '../../MaterialUtils';
import type { ColorMapUniform } from '../ColorMapUniform';

import MaterialUtils from '../../MaterialUtils';
import { buildColorMapUniform, createDefaultColorMap } from '../ColorMapUniform';
import { AttributeSlot } from './AttributeSlot';

export interface ScalarPropertiesUniform {
    weight: number;
    colorMap: ColorMapUniform;
}

export interface ScalarSlotState {
    weight: number;
    colorMap: ColorMap;
}

type SlotIndex = 0 | 1 | 2;
const slotNames: Record<SlotIndex, string> = {
    0: 'scalar',
    1: 'scalar_1',
    2: 'scalar_2',
};

export class ScalarSlot extends AttributeSlot {
    public static getAttributeName(index: SlotIndex): string {
        return slotNames[index];
    }

    public readonly uniform: ScalarPropertiesUniform;

    private readonly _material: HasDefines;
    private readonly _flagDefine: string;
    private readonly _typeDefine: string;

    public colorMap: ColorMap = createDefaultColorMap();

    public constructor(material: HasDefines, index: SlotIndex) {
        super(ScalarSlot.getAttributeName(index));

        this.uniform = {
            weight: 0,
            colorMap: buildColorMapUniform(this.colorMap),
        };
        this._material = material;

        this._flagDefine = `SCALAR_${index}`;
        this._typeDefine = `SCALAR_${index}_TYPE`;
        this.attributeType = 'uint';
    }

    public override get hasAttribute(): boolean {
        return typeof this._material.defines[this._flagDefine] !== 'undefined';
    }

    public set hasAttribute(value: boolean) {
        MaterialUtils.setDefine(this._material, this._flagDefine, value);
    }

    public set attributeType(attributeType: VertexAttributeType) {
        MaterialUtils.setDefineValue(this._material, this._typeDefine, attributeType);
    }

    public update(): void {
        this.uniform.colorMap = buildColorMapUniform(this.colorMap);
    }

    public get state(): ScalarSlotState {
        return {
            weight: this.weight,
            colorMap: this.colorMap,
        };
    }

    public set state(state: Partial<ScalarSlotState>) {
        if (typeof state.weight !== 'undefined') {
            this.weight = state.weight;
        }

        if (typeof state.colorMap !== 'undefined') {
            this.colorMap = state.colorMap;
        }
    }
}