import { NodeMaterialBlock } from '../../nodeMaterialBlock';
import { NodeMaterialBlockConnectionPointTypes } from '../../Enums/nodeMaterialBlockConnectionPointTypes';
import { NodeMaterialBuildState } from '../../nodeMaterialBuildState';
import { NodeMaterialConnectionPoint } from '../../nodeMaterialBlockConnectionPoint';
import { NodeMaterialBlockTargets } from '../../Enums/nodeMaterialBlockTargets';
import { _TypeStore } from '../../../../Misc/typeStore';
import { Effect } from '../../../effect';
import { NodeMaterial } from '../../nodeMaterial';
import { Mesh } from '../../../../Meshes/mesh';
import { Scene } from '../../../../scene';

/**
 * Block used to get the screen sizes
 */
export class ScreenSizeBlock extends NodeMaterialBlock {
    private _varName: string;
    private _scene: Scene;

    /**
     * Creates a new ScreenSizeBlock
     * @param name defines the block name
     */
    public constructor(name: string) {
        super(name, NodeMaterialBlockTargets.Fragment);

        this.registerOutput("xy", NodeMaterialBlockConnectionPointTypes.Vector2, NodeMaterialBlockTargets.Fragment);
        this.registerOutput("x", NodeMaterialBlockConnectionPointTypes.Float, NodeMaterialBlockTargets.Fragment);
        this.registerOutput("y", NodeMaterialBlockConnectionPointTypes.Float, NodeMaterialBlockTargets.Fragment);
    }

    /**
     * Gets the current class name
     * @returns the class name
     */
    public getClassName() {
        return "ScreenSizeBlock";
    }

    /**
     * Gets the xy component
     */
    public get xy(): NodeMaterialConnectionPoint {
        return this._outputs[0];
    }

    /**
     * Gets the x component
     */
    public get x(): NodeMaterialConnectionPoint {
        return this._outputs[1];
    }

    /**
     * Gets the y component
     */
    public get y(): NodeMaterialConnectionPoint {
        return this._outputs[2];
    }

    public bind(effect: Effect, nodeMaterial: NodeMaterial, mesh?: Mesh) {
        const engine = this._scene.getEngine();

        effect.setFloat2(this._varName, engine.getRenderWidth(), engine.getRenderWidth());
    }

    protected writeOutputs(state: NodeMaterialBuildState, varName: string): string {
        let code = "";

        for (var output of this._outputs) {
            if (output.hasEndpoints) {
                code += `${this._declareOutput(output, state)} = ${varName}.${output.name};\r\n`;
            }
        }

        return code;
    }

    protected _buildBlock(state: NodeMaterialBuildState) {
        super._buildBlock(state);

        this._scene = state.sharedData.scene;

        if (state.target === NodeMaterialBlockTargets.Vertex) {
            throw "ScreenSizeBlock must only be used in a fragment shader";
        }

        state.sharedData.bindableBlocks.push(this);

        this._varName = state._getFreeVariableName("screenSize");
        state._emitUniformFromString(this._varName, "vec2");

        state.compilationString += this.writeOutputs(state, this._varName);

        return this;
    }
}

_TypeStore.RegisteredTypes["BABYLON.ScreenSizeBlock"] = ScreenSizeBlock;