/*
Copyright (c) 2023-forever Douglas Malnati. All rights reserved.

See the /faq/tos page for details.
    
(If this generated header is stamped on a file which is a 3rd party file or under a different license or copyright, then ignore this copyright statement and use that file's terms.)
*/

function GetViewableWidthAccountingForScrollbar()
{
    // Check if a vertical scrollbar is present
    const isVerticalScrollbarPresent = document.documentElement.scrollHeight > window.innerHeight;

    // If no vertical scrollbar, return the innerWidth as is
    if (!isVerticalScrollbarPresent) {
        return window.innerWidth;
    }

    // Create a temporary element to measure the scrollbar width
    const div = document.createElement('div');
    div.style.visibility = 'hidden';  // Make sure it's not visible
    div.style.position = 'absolute';
    div.style.width = '100px';  // Set a fixed width for the element
    div.style.overflow = 'scroll';  // Enable scroll to ensure a scrollbar appears
    document.body.appendChild(div);

    // Calculate the scrollbar width
    const scrollbarWidth = div.offsetWidth - div.clientWidth;

    // Clean up the temporary div
    document.body.removeChild(div);

    // Return the viewport width excluding the scrollbar
    return window.innerWidth - scrollbarWidth;
}

function GetViewableHeightAccountingForScrollbar()
{
    // Check if a horizontal scrollbar is present
    const isHorizontalScrollbarPresent = document.documentElement.scrollWidth > window.innerWidth;

    // If no horizontal scrollbar, return the innerHeight as is
    if (!isHorizontalScrollbarPresent) {
        return window.innerHeight;
    }

    // Create a temporary element to measure the scrollbar height
    const div = document.createElement('div');
    div.style.visibility = 'hidden';  // Make sure it's not visible
    div.style.position = 'absolute';
    div.style.height = '100px';  // Set a fixed height for the element
    div.style.overflow = 'scroll';  // Enable scroll to ensure a scrollbar appears
    document.body.appendChild(div);

    // Calculate the scrollbar height
    const scrollbarHeight = div.offsetHeight - div.clientHeight;

    // Clean up the temporary div
    document.body.removeChild(div);

    // Return the viewport height excluding the scrollbar
    return window.innerHeight - scrollbarHeight;
}







class ZIndexHelper
{
    static BASE_Z_INDEX = 1000;

    constructor()
    {
        this.objDataList = [];
    }

    // objects register to have a given property set to the zIndex to make them
    // the top-most at this time, and later in the future
    RegisterForTop(obj, prop)
    {
        this.objDataList.push({
            obj,
            prop,
        });

        this.#AnnounceAll();

        return this.objDataList.length;
    }

    // request immediate top level
    RequestTop(obj)
    {
        // find its current location
        let idxFound = -1;
        for (let zIndex = 0; zIndex < this.objDataList.length; ++zIndex)
        {
            let objData = this.objDataList[zIndex];

            if (objData.obj == obj)
            {
                idxFound = zIndex;
            }
        }

        if (idxFound != -1)
        {
            // hold temporarily
            let objData = this.objDataList[idxFound];

            // delete its location, effectively compacting list
            this.objDataList.splice(idxFound, 1);

            // re-insert
            this.objDataList.push(objData);

            // announce re-index
            this.#AnnounceAll();
        }
    }

    #AnnounceAll()
    {
        for (let zIndex = 0; zIndex < this.objDataList.length; ++zIndex)
        {
            let objData = this.objDataList[zIndex];

            objData.obj[objData.prop] = ZIndexHelper.BASE_Z_INDEX + zIndex;
        }
    }
}



export class DialogBox
{
    static #zIndexHelper = new ZIndexHelper();
    static #instanceList = [];
    static #escapeHandlerSet = false;

    constructor()
    {
        this.isDragging = false;
        this.offsetX = 0;
        this.offsetY = 0;

        this.ui = this.#MakeUI();

        DialogBox.#instanceList.push(this);
        DialogBox.#EnsureEscapeHandler();
    }

    GetUI()
    {
        return this.ui;
    }

    SetTitleBar(title)
    {
        this.titleBar.innerHTML = title;
    }

    GetContentContainer()
    {
        return this.frameBody;
    }

    ToggleShowHide()
    {
        if (this.floatingWindow.style.display === 'none')
        {
            this.Show();
        }
        else
        {
            this.Hide();
        }
    }

    Show()
    {
        const STEP_SIZE_PIXELS = 50;

        let zIndex = DialogBox.#zIndexHelper.RegisterForTop(this.floatingWindow.style, "zIndex");

        if (this.floatingWindow.style.top  == "50px" &&
            this.floatingWindow.style.left == "50px")
        {
            this.floatingWindow.style.top  = `${STEP_SIZE_PIXELS * zIndex}px`;
            this.floatingWindow.style.left = `${STEP_SIZE_PIXELS * zIndex}px`;
        }

        this.floatingWindow.style.display = 'flex';
}

    Hide()
    {
        DialogBox.#zIndexHelper.RequestTop(this.floatingWindow.style);

        this.floatingWindow.style.display = 'none';
    }

    static #EnsureEscapeHandler()
    {
        if (DialogBox.#escapeHandlerSet)
        {
            return;
        }

        DialogBox.#escapeHandlerSet = true;

        document.addEventListener('keydown', (e) => {
            if (e.key !== "Escape")
            {
                return;
            }

            let topMost = null;
            let topZ = Number.NEGATIVE_INFINITY;
            for (const dlg of DialogBox.#instanceList)
            {
                if (!dlg || !dlg.floatingWindow)
                {
                    continue;
                }

                if (dlg.floatingWindow.style.display === 'none')
                {
                    continue;
                }

                let z = parseInt(dlg.floatingWindow.style.zIndex || "0");
                if (isNaN(z))
                {
                    z = 0;
                }

                if (z >= topZ)
                {
                    topZ = z;
                    topMost = dlg;
                }
            }

            if (topMost)
            {
                topMost.Hide();
                e.preventDefault();
                e.stopPropagation();
            }
        });
    }

    #MakeFloatingWindowFrame()
    {
        this.floatingWindow = document.createElement('div');

        this.floatingWindow.style.boxSizing = "border-box";

        this.floatingWindow.style.position = 'fixed';
        this.floatingWindow.style.top = '50px';
        this.floatingWindow.style.left = '50px';

        this.floatingWindow.style.backgroundColor = '#f0f0f0';

        this.floatingWindow.style.border = '1px solid black';
        this.floatingWindow.style.borderRadius = '5px';

        this.floatingWindow.style.boxShadow = '2px 2px 8px black';

        this.floatingWindow.style.padding = '0px';

        this.floatingWindow.style.display = 'none'; // Initially hidden
        this.floatingWindow.style.zIndex = 1;

        this.floatingWindow.style.flexDirection = "column";


        return this.floatingWindow;
    }

    #MakeTopRow()
    {
        // create top row
        this.topRow = document.createElement('div');
        this.topRow.style.boxSizing = "border-box";

        this.topRow.style.borderBottom = "1px solid black";
        this.topRow.style.borderTopRightRadius = "5px";
        this.topRow.style.borderTopLeftRadius = "5px";
        this.topRow.style.display = "flex";
        this.topRow.style.backgroundColor = "#ff323254";
        
        // top row - title bar
        this.titleBar = document.createElement('div');
        this.titleBar.style.boxSizing = "border-box";

        this.titleBar.style.flexGrow = "1";
        this.titleBar.style.borderRight = "1px solid black";
        this.titleBar.style.borderTopLeftRadius = "5px";

        this.titleBar.style.padding = "3px";
        this.titleBar.style.backgroundColor = 'rgb(255, 255, 200)';
        this.titleBar.style.cursor = 'move'; // Indicate draggable behavior
        this.titleBar.innerHTML = "Dialog Box";
        this.topRow.appendChild(this.titleBar);

        // top row - close button
        const closeButton = document.createElement('button');
        closeButton.textContent = 'X';
        // closeButton.style.cursor = 'pointer';
        closeButton.style.border = 'none';
        closeButton.style.backgroundColor = 'rgba(0,0,0,0)';    // transparent

        this.topRow.appendChild(closeButton);

        // Close button event handling
        closeButton.addEventListener('click', () => {
            this.Hide();
        });

        return this.topRow;
    }

    #MakeBody()
    {
        let dom = document.createElement('div');
        dom.style.boxSizing = "border-box";
        dom.style.padding = "3px";
        dom.style.width = "100%";
        dom.style.flexGrow = "1";
        dom.style.backgroundColor = "rgb(210, 210, 210)";

        // only show scrollbars if necessary
        // (eg someone manually resizes dialog smaller than content minimum size)
        dom.style.overflowX = "auto";
        dom.style.overflowY = "auto";
        dom.style.scrollbarGutter = "stable";

        // don't scroll the page, just the div
        let ScrollJustThis = dom => {
            dom.addEventListener('wheel', (e) => {
                const hasVerticalScrollbar = dom.scrollHeight > dom.clientHeight;
                
                if (hasVerticalScrollbar)
                {
                    e.stopPropagation();
                }
                else
                {
                    e.preventDefault();
                }
            });
        };

        // ScrollJustThis(dom)

        return dom;
    }

    #EnableDrag()
    {
        this.floatingWindow.addEventListener('mousedown', (e) => {
            e.stopPropagation();

            DialogBox.#zIndexHelper.RequestTop(this.floatingWindow.style);
        });

        this.titleBar.addEventListener('mousedown', (e) => {
            e.stopPropagation();

            DialogBox.#zIndexHelper.RequestTop(this.floatingWindow.style);

            this.isDragging = true;
            this.offsetX = e.clientX - this.floatingWindow.getBoundingClientRect().left;
            this.offsetY = e.clientY - this.floatingWindow.getBoundingClientRect().top;
            document.body.style.userSelect = 'none'; // Prevent text selection during drag
        });

        // Drag the window
        document.addEventListener('mousemove', (e) => {
            if (this.isDragging) {
                // determine viewable area
                let viewableWidth  = GetViewableWidthAccountingForScrollbar();
                let viewableHeight = GetViewableHeightAccountingForScrollbar();

                // prevent mouse from dragging popup outside the viewable
                // area on the left, right, and bottom.
                let cursorX = e.clientX;
                if (cursorX < 0) { cursorX = 0; }
                if (cursorX > viewableWidth) { cursorX = viewableWidth; }
                let cursorY = e.clientY;
                if (cursorY > viewableHeight) { cursorY = viewableHeight; }

                // don't let the dialog go above the window at all
                let top  = cursorY - this.offsetY;
                let left = cursorX - this.offsetX;
                if (top < 0) { top = 0; }

                // apply
                this.floatingWindow.style.top = `${top}px`;
                this.floatingWindow.style.left = `${left}px`;
            }
        });

        // Stop dragging
        document.addEventListener('mouseup', () => {
            if (this.isDragging) {
                this.isDragging = false;
                document.body.style.userSelect = ''; // Re-enable text selection
            }
        });
    }

    #MakeUI()
    {
        let frame = this.#MakeFloatingWindowFrame();
        let frameTopRow = this.#MakeTopRow();
        this.frameBody = this.#MakeBody();

        this.frameBody.marginTop = "2px";

        frame.appendChild(frameTopRow);
        frame.appendChild(this.frameBody);

        // don't let the page scroll when you hover the popup
        // (scrollable content section handled separately)
        // frame.addEventListener('wheel', (e) => {
        //     e.preventDefault();
        // });

        this.#EnableDrag();

        return this.floatingWindow;
    }
}



export class CollapsableTitleBox
{
    constructor()
    {
        this.ui = this.#MakeUI();
        this.#SetUpEvents();
    }

    GetUI()
    {
        return this.ui;
    }

    SetTitle(title)
    {
        this.titleBar.innerHTML = title;
    }

    GetContentContainer()
    {
        return this.box;
    }

    SetMinWidth(minWidth)
    {
        this.ui.style.minWidth = minWidth;
    }

    ToggleShowHide()
    {
        if (this.box.style.display === 'none')
        {
            this.Show();
        }
        else
        {
            this.Hide();
        }
    }

    Show()
    {
        this.box.style.display = 'flex';
    }

    Hide()
    {
        this.box.style.display = 'none';
    }

    #SetUpEvents()
    {
        this.titleBar.addEventListener('click', () => {
            this.ToggleShowHide();
        });
    }

    #MakeUI()
    {
        // entire structure
        this.ui = document.createElement('div');
        this.ui.style.boxSizing = "border-box";
        this.ui.style.backgroundColor = "white";
        this.ui.style.border = "1px solid grey";

        // user reads this, click to hide/unhide
        this.titleBar = document.createElement('div');
        this.titleBar.style.boxSizing = "border-box";
        this.titleBar.style.padding = "3px";
        this.titleBar.style.backgroundColor = "rgb(240, 240, 240)";
        // this.titleBar.style.backgroundColor = "rgb(200, 200, 255)";
        this.titleBar.style.userSelect = "none";
        this.titleBar.style.cursor = "pointer";
        this.titleBar.innerHTML = "Title Bar";

        // user content goes here
        this.box = document.createElement('div');
        this.box.style.boxSizing = "border-box";
        this.box.style.padding = "5px";
        this.box.style.boxShadow = "1px 1px 5px #555 inset";
        this.box.style.overflowX = "auto";
        this.box.style.overflowY = "auto";
        this.box.style.display = 'none';    // initially hidden
        
        // pack
        this.ui.appendChild(this.titleBar);
        this.ui.appendChild(this.box);

        return this.ui;
    }
}


export class RadioCheckbox
{
    constructor(name)
    {
        this.name = name;
        this.ui = this.#MakeUI();

        this.inputList = [];

        this.fnOnChange = (val) => {};
    }

    AddOption(labelText, value, checked)
    {
        // create input
        let input = document.createElement('input');
        input.type = "radio";
        input.name = this.name;
        input.value = value;
        if (checked)
        {
            input.checked = true;
        }
        this.inputList.push(input);

        // set up label
        let label = document.createElement('label');
        label.appendChild(input);
        label.appendChild(document.createTextNode(` ${labelText}`));

        // add to container
        if (this.inputList.length != 1)
        {
            this.ui.appendChild(document.createTextNode(' '));
        }
        this.ui.appendChild(label);

        // set up events
        input.addEventListener('change', (e) => {
            this.fnOnChange(e.target.value);
        });
    }

    SetOnChangeCallback(fn)
    {
        this.fnOnChange = fn;
    }

    Trigger()
    {
        for (let input of this.inputList)
        {
            if (input.checked)
            {
                this.fnOnChange(input.value);
                break;
            }
        }
    }

    GetUI()
    {
        return this.ui;
    }

    #MakeUI()
    {
        let ui = document.createElement('span');
        
        return ui;
    }
}


// write through and read-through cache stored persistently
export class RadioCheckboxPersistent
extends RadioCheckbox
{
    constructor(name)
    {
        super(name);

        this.val = null;

        // cache currently-stored value
        if (localStorage.getItem(this.name) != null)
        {
            this.val = localStorage.getItem(this.name);
        }
    }

    // add option except checked is just a suggestion.
    // if no prior value set, let suggestion take effect.
    // if prior value set, prior value rules.
    AddOption(labelText, value, checkedSuggestion)
    {
        let checked = checkedSuggestion;

        if (this.val == null)
        {
            // let it happen
        }
        else
        {
            checked = this.val == value;
        }

        super.AddOption(labelText, value, checked);

        // cache and write through
        if (checked)
        {
            this.val = value;
            localStorage.setItem(this.name, this.val);
        }
    }
    
    SetOnChangeCallback(fn)
    {
        super.SetOnChangeCallback((val) => {
            // capture the new value before passing back
            this.val = val;
            localStorage.setItem(this.name, this.val);

            // callback
            fn(val);
        });
    }
}