"use strict";

// Box that can contain other components
Toolkit.Panel = class Panel extends Toolkit.Component {

    // Object constructor
    constructor(application) {
        super(application, "div");

        // Configure instance fields
        this.application = application;
        this.children    = [];
        this.crossAlign  = "start";
        this.direction   = "row";
        this.edge        = "left";
        this.hGap        = "0";
        this.layout      = "split";
        this.mainAlign   = "start";
        this.sizeable    = false;
        this.vGap        = "0";
        this.wrap        = false;

        // Configure element
        this.element.style.minHeight = "0";
        this.element.style.minWidth  = "0";

        // Configure layout
        this.setSplitLayout("left", false);
    }



    ///////////////////////////// Public Methods //////////////////////////////

    // Add a component as a child of this container
    add(component, index) {

        // Determine the ordinal position of the element within the container
        index = !(typeof index == "number") ? this.children.length :
            Math.floor(Math.min(Math.max(0, index), this.children.length));

        // Add the component to the container
        component.parent = this;
        this.children.splice(index, 0, component);
        this.arrange();
    }

    // Create a Button and associate it with the application
    newButton(options) {
        return new Toolkit.Button(this.application, options);
    }

    // Create a MenuBar and associate it with the application
    newMenuBar(options) {
        return new Toolkit.MenuBar(this.application, options);
    }

    // Create a Panel and associate it with the application
    newPanel(options) {
        return new Toolkit.Panel(this.application, options);
    }

    // Remove a component from the container
    remove(component) {

        // Locate the component in the children
        let index = this.children.indexOf(component);
        if (index == -1)
            return;

        // Remove the component
        component.parent = null;
        component.element.remove();
        this.children.splice(index, 1);
        this.arrange();
    }

    // Configure the element with a flex layout
    setFlexLayout(direction, mainAlign, crossAlign, gap, wrap) {

        // Configure instance fields
        this.layout     = "flex";
        this.crossAlign = crossAlign;
        this.direction  = direction;
        this.mainAlign  = mainAlign;
        this.wrap       = wrap;

        // Working variables
        switch (crossAlign) {
            case "end"  : crossAlign = "flex-end"  ;
            case "start": crossAlign = "flex-start";
        }
        switch (mainAlign) {
            case "end"  : mainAlign  = "flex-end"  ;
            case "start": mainAlign  = "flex-start";
        }

        // Configure element
        this.element.style.alignItems     = crossAlign;
        this.element.style.display        = "flex";
        this.element.style.flexDirection  = direction;
        this.element.style.justifyContent = mainAlign;
        if (direction == "column") {
            this.hGap                    = gap;
            this.element.style.rowGap    = gap;
        }
        if (direction == "row") {
            this.vGap                    = gap;
            this.element.style.columnGap = gap;
        }
        if (wrap)
            this.element.style.flexWrap = "wrap";
        else this.element.style.removeProperty("flex-wrap");

        // Manage components
        this.arrange();
    }

    // Configure the element with a split layout
    setSplitLayout(edge, sizeable) {

        // Configure instance fields
        this.layout   = "split";
        this.edge     = edge;
        this.sizeable = sizeable;

        // Working variables
        let rows   = null, cols = null;
        let tracks = [ "max-content", "auto" ];
        if (sizeable)
            tracks.splice(1, 0, "max-content");

        // Processing by edge
        switch (edge) {
            case "bottom": tracks.reverse(); // Fallthrough
            case "top"   : rows = tracks.join(" "); break;
            case "right" : tracks.reverse(); // Fallthrough
            case "left"  : cols = tracks.join(" ");
        }

        // Configure element
        this.element.style.display = "grid";
        if (cols != null)
            this.element.style.gridTemplateColumns = cols;
        else this.element.style.removeProperty("grid-template-columns");
        if (rows != null)
            this.element.style.gridTemplateRows = rows;
        else this.element.style.removeProperty("grid-template-rows");

        // Manage components
        this.arrange();
    }



    ///////////////////////////// Private Methods /////////////////////////////

    // Configure the panel's DOM elements
    arrange() {
        let components = [];

        // Remove all children from the DOM
        for (let comp of this.children)
            comp.element.remove();

        // Split layout
        if (this.layout == "split") {
            components.push(this.children[0]);
            components.push(this.children[1]);
            if (this.sizeable)
                components.splice(1, 0, this.splitter);
            if (this.edge == "bottom" || this.edge == "right")
                components.reverse();
        }

        // Flex and grid layouts
        else {
            for (let comp of this.children)
                components.push(comp);
        }

        // Add the resulting elements to the DOM
        for (let comp of components)
            if (comp)
                this.element.appendChild(comp.element);
    }

};