import GObject from 'gi://GObject';

import * as utils from '../conveniences/utils.js';
const Shell = await utils.import_in_shell_only('gi://Shell');
const Clutter = await utils.import_in_shell_only('gi://Clutter');

const SHADER_FILENAME = 'noise.glsl';
const DEFAULT_PARAMS = {
    noise: 0.4, lightness: 0.4
};


export const NoiseEffect = utils.IS_IN_PREFERENCES ?
    { default_params: DEFAULT_PARAMS } :
    new GObject.registerClass({
        GTypeName: "NoiseEffect",
        Properties: {
            'noise': GObject.ParamSpec.double(
                `noise`,
                `Noise`,
                `Amount of noise integrated with the image`,
                GObject.ParamFlags.READWRITE,
                0.0, 1.0,
                0.4,
            ),
            'lightness': GObject.ParamSpec.double(
                `lightness`,
                `Lightness`,
                `Lightness of the grey used for the noise`,
                GObject.ParamFlags.READWRITE,
                0.0, 2.0,
                0.4,
            ),
        }
    }, class NoiseEffect extends Clutter.ShaderEffect {
        constructor(params) {
            super(params);

            this._noise = null;
            this._lightness = null;

            this.noise = 'noise' in params ? params.noise : this.constructor.default_params.noise;
            this.lightness = 'lightness' in params ? params.lightness : this.constructor.default_params.lightness;

            // set shader source
            this._source = utils.get_shader_source(Shell, SHADER_FILENAME, import.meta.url);
            if (this._source)
                this.set_shader_source(this._source);
        }

        static get default_params() {
            return DEFAULT_PARAMS;
        }

        get noise() {
            return this._noise;
        }

        set noise(value) {
            if (this._noise !== value) {
                this._noise = value;

                this.set_uniform_value('noise', parseFloat(this._noise - 1e-6));
                this.set_enabled(this.noise > 0. && this.lightness != 1);
            }
        }

        get lightness() {
            return this._lightness;
        }

        set lightness(value) {
            if (this._lightness !== value) {
                this._lightness = value;

                this.set_uniform_value('lightness', parseFloat(this._lightness - 1e-6));
                this.set_enabled(this.noise > 0. && this.lightness != 1);
            }
        }

        vfunc_paint_target(paint_node = null, paint_context = null) {
            this.set_uniform_value("tex", 0);

            if (paint_node && paint_context)
                super.vfunc_paint_target(paint_node, paint_context);
            else if (paint_node)
                super.vfunc_paint_target(paint_node);
            else
                super.vfunc_paint_target();
        }
    });