import * as d3 from 'd3';
import { LabelStyle } from '../../styles/LabelStyle';
import { Node } from '../../types/Node';
import { Renderer } from '../Renderer';

class LabelRenderer extends Renderer {

    static defaultColor = '#333333';
    static defaultFont = '14px sans-serif';

    // Nodes to render
    protected _nodes: Node[];

    // Styling
    protected color: string | null;
    protected font: string;

    constructor (style?: LabelStyle) {

        super();

        this._nodes = [];
        this.color = LabelRenderer.defaultColor;
        this.font = LabelRenderer.defaultFont;

        if (style) {
            if (style.color) this.color = style.color;
            if (style.font) this.font = style.font;
        }

    }

    nodes (): Node[];
    nodes (points: Node[]): this;
    nodes (points?: Node[]): Node[] | this {
        return arguments.length
            ? (this._nodes = points!, this)
            : this._nodes;
    }

    render (context: CanvasRenderingContext2D,
            x: d3.ScaleLinear<number, number>,
            y: d3.ScaleLinear<number, number>): void {

        if (!this._nodes.length) return;

        context.save();
        context.beginPath();

        if (this.color) context.fillStyle = this.color;
        context.font = this.font;
        context.textAlign = 'center';
        context.textBaseline = 'middle';

        this._nodes.forEach(node => {
            if (!node.labels) {

                context.fillText(
                    node.id,
                    x(node.x) + (node.dx ? node.dx : 0),
                    y(node.y) + (node.dy ? node.dy : 0)
                );

            } else {

                const match = this.font.match(/(\d*)px/);
                const size = match ? match.length > 1 ? parseInt(match[1]) : 12 : 12;
                const text = [node.id, ...node.labels];
                const base = Math.floor((text.length * size) / 2 - size / 2) - 1;

                text.forEach((label, index) => {
                    context.fillText(
                        label,
                        x(node.x) + (node.dx ? node.dx : 0),
                        y(node.y) + (node.dy ? node.dy : 0) - base + index * size
                    );
                });

            }
        });

        context.restore();


    }

}

export {
    LabelRenderer
}