// A control that can't act, pressed on the device this tool is for.
//
// Measured on an iPhone, three hands dealt, the card picker open on an empty seat:
// seven of the fifty-two cards were greyed out, none of them could take focus, and
// tapping one changed nothing whatsoever — no toast, no text, not a byte of DOM. The
// tool did have an answer to "who has the ace of spades?"; it was a `title`, and a
// `title` needs a mouse. The same held in the header, where a new dealer's very first
// screen is two dimmed buttons, and on Export CSV, which was greyed out with no
// explanation written anywhere at all.
//
// `disabled` is the wrong attribute whenever there is something to say. It takes the
// control out of the tab order, so a screen reader never lands on it and never hears
// the description; and it eats the press on a touch screen, where the hover that would
// have shown the `title` does not exist. NN/g's rule for the case is explicit — on a
// touch interface, a press on a disabled control should raise the explanation — and
// WCAG 3.3.1 wants the instruction reachable at all. `aria-disabled` announces the same
// state and leaves the control reachable, so the press arrives and is answered.
//
// It also fixed something nobody had noticed. The picker's arrow keys hunted past dealt
// cards, because a `disabled` button cannot hold focus — and hunting did the exact thing
// the grid's no-wrap rule was written to prevent: Right from the ace of spades over a
// dealt ace of hearts landed on the ace of diamonds, so the column silently shifted and
// the next press of Down walked a different suit. A cell that can hold focus needs no
// hunting, so that code is gone and the grid tells the truth about its own shape.
const test = require("node:test");
const { describe } = require("node:test");
const assert = require("node:assert");
const fs = require("fs");
const path = require("path");
const { Unavailable } = require("./load");

const ROOT = path.join(__dirname, "..", "..", "JoshHeaps.Net");
const CSS = fs.readFileSync(path.join(ROOT, "wwwroot", "css", "casino", "holdem.css"), "utf8");
const MARKUP = fs.readFileSync(path.join(ROOT, "Pages", "Casino", "TexasHoldem.cshtml"), "utf8");
const src = name => fs.readFileSync(path.join(ROOT, "wwwroot", "js", "casino", "holdem", `${name}.js`), "utf8");

const ruleFor = selector => {
    const at = CSS.indexOf(`\n${selector} {`);
    assert.ok(at >= 0, `there is no \`${selector}\` rule`);
    return CSS.slice(at, CSS.indexOf("}", at));
};

// Enough of an element for a module that only ever reads three attributes off one.
const element = (attrs = {}) => ({
    dataset: {},
    attrs: { ...attrs },
    setAttribute(name, value) { this.attrs[name] = String(value); },
    getAttribute(name) { return name in this.attrs ? this.attrs[name] : null; },
    removeAttribute(name) { delete this.attrs[name]; },
});

// ---------------------------------------------------------------------------

describe("marking a control that cannot act", () => {
    test("it says so in the tree, and carries the reason with it", () => {
        const btn = element();
        Unavailable.set(btn, true, "Nothing to resolve yet — seat a player first.");
        assert.equal(btn.getAttribute("aria-disabled"), "true");
        assert.equal(Unavailable.reason(btn), "Nothing to resolve yet — seat a player first.");
        assert.ok(Unavailable.blocked(btn));
    });

    // The state and the reason are set and cleared in one call on purpose. A control
    // left marked after the reason stopped being true is worse than one never marked:
    // it is a live control that refuses to work and explains why in the past tense.
    test("and both halves come off together", () => {
        const btn = element();
        Unavailable.set(btn, true, "Nothing to resolve yet.");
        Unavailable.set(btn, false, "Nothing to resolve yet.");
        assert.equal(btn.getAttribute("aria-disabled"), null);
        assert.equal(Unavailable.reason(btn), "");
        assert.ok(!Unavailable.blocked(btn));
    });

    test("a control nobody marked is not blocked and has nothing to say", () => {
        assert.ok(!Unavailable.blocked(element()));
        assert.equal(Unavailable.reason(element()), "");
        assert.equal(Unavailable.reason(null), "");
        assert.ok(!Unavailable.blocked(null));
    });

    // `aria-disabled="false"` is a real thing to write and it means enabled. Reading the
    // attribute's presence rather than its value would have got that backwards.
    test("and one marked false is enabled, which is what the attribute means", () => {
        const btn = element({ "aria-disabled": "false" });
        assert.ok(!Unavailable.blocked(btn));
    });
});

describe("what happens when it is pressed", () => {
    // The press can land on a span inside the button rather than the button, which is
    // most of what the picker's cards are made of.
    test("the answer is looked for upwards from whatever was hit", () => {
        const btn = element();
        Unavailable.set(btn, true, "A♠ — dealt to Maya");
        const rank = { closest: selector => (selector === '[aria-disabled="true"]' ? btn : null) };
        assert.equal(Unavailable.reason(Unavailable.from(rank)), "A♠ — dealt to Maya");
    });

    test("a press on nothing in particular finds nothing", () => {
        assert.equal(Unavailable.from(null), null);
        assert.equal(Unavailable.from({}), null);
    });

    // Nothing about `aria-disabled` stops a click reaching its own handler — that is the
    // trade for staying reachable. One listener does the stopping, in the capture phase,
    // so a control's own handler never runs and never has to remember to check.
    test("the press is stopped before the control's own handler sees it", () => {
        const listener = src("feedback").slice(src("feedback").indexOf("listen(root) {"));
        assert.match(listener, /addEventListener\("click"[\s\S]*?\}, true\)/,
            "the listener is not in the capture phase, so it cannot stop anything");
        assert.match(listener, /event\.preventDefault\(\)/);
        assert.match(listener, /event\.stopPropagation\(\)/);
    });

    test("and it is wired once, for the whole table", () => {
        const main = src("main");
        assert.match(main, /Unavailable\.listen\(document\)/);
        assert.equal((main.match(/Unavailable\.listen\(/g) || []).length, 1);
    });

    // A control with nothing to say is not a control this is about — the seat sheet's
    // own greyed-out fields, say. Swallowing its press would be a new dead end.
    test("a marked control with no reason is left entirely alone", () => {
        const btn = element();
        Unavailable.set(btn, true, "");
        assert.equal(Unavailable.reason(btn), "");
    });
});

describe("where the answer is written", () => {
    // The toast is fixed to the bottom of the window at z-index 80; the card picker's
    // scrim is 95 and its sheet stands 88vh tall. A toast raised for a control inside
    // that sheet would be behind it, or over the cards if it were not.
    test("a sheet that covers the toast says it itself", () => {
        assert.match(MARKUP, /id="cardPickerSheet"[^>]*data-why-note="cardPickerNote"/);
        assert.match(MARKUP, /id="cardPickerNote"[^>]*role="status"/);
    });

    test("and everything else falls through to the toast", () => {
        const say = src("feedback").slice(src("feedback").indexOf("say(el, why) {"));
        assert.match(say, /closest\("\[data-why-note\]"\)/);
        assert.match(say, /Toast\.show\(why\)/);
    });

    // Cleared on the next paint rather than on a timer: a paint is exactly the set of
    // things that make the last answer stale, and nothing else in the sheet redraws.
    test("the line is cleared by the next thing that changes the sheet", () => {
        const picker = src("cardPicker");
        const at = picker.indexOf("paint() {");
        assert.ok(at >= 0);
        const opening = picker.slice(at, picker.indexOf("cardPickerTitle", at));
        assert.match(opening, /getElementById\("cardPickerNote"\)/);
        assert.match(opening, /note\.textContent = ""/);
    });
});

describe("the line holds its place", () => {
    // Filling it must not move the grid. It sits between the slots and the cards, so a
    // line that appeared from nothing would shove fifty-two targets down the screen
    // under a thumb already travelling towards one of them.
    test("it is one line tall whether or not it is saying anything", () => {
        const rule = ruleFor(".pickerNote");
        assert.match(rule, /min-height:\s*1\.35em/);
        assert.match(rule, /line-height:\s*1\.35/);
    });

    // Measured: the note's box is 318px on a Galaxy S8 at 20px of root text, and a name
    // is whatever somebody typed. Twenty-four capital Ws draw 434px in it. No wording
    // is safe, so the box is what holds.
    test("and it cannot become two, whatever the name is", () => {
        const rule = ruleFor(".pickerNote");
        assert.match(rule, /white-space:\s*nowrap/);
        assert.match(rule, /overflow:\s*hidden/);
        assert.match(rule, /text-overflow:\s*ellipsis/);
    });

    test("what it measured is written beside the rule", () => {
        const at = CSS.indexOf("/* Which card, and who has it.");
        assert.ok(at >= 0, "the rule carries no note saying why");
        const note = CSS.slice(at, CSS.indexOf("*/", at));
        assert.match(note, /318px/);
        assert.match(note, /434px/);
    });

    // Which is the half that survives the clipping, and the half that does not.
    test("the card and where it went come before the name", () => {
        const picker = src("cardPicker");
        assert.match(picker, /\$\{label\} — face up on the board/);
        assert.match(picker, /\$\{label\} — dealt to \$\{takenBy\}/);
    });
});

describe("dimmed looks dimmed, however it was said", () => {
    test("a button marked either way is painted the same", () => {
        const at = CSS.indexOf("\n.holdemBtn:disabled,");
        assert.ok(at >= 0, "the two states are painted by separate rules, so they can drift apart");
        assert.match(CSS.slice(at, CSS.indexOf("}", at)), /\.holdemBtn\[aria-disabled="true"\]/);
    });

    test("and so is a card", () => {
        const at = CSS.indexOf("\n.pickerCard:disabled,");
        assert.ok(at >= 0);
        assert.match(CSS.slice(at, CSS.indexOf("}", at)), /\.pickerCard\[aria-disabled="true"\]/);
    });

    // A press animation on a control that will not act is a lie told in 40ms.
    test("neither one presses down under a finger that can't use it", () => {
        [".holdemBtn:active", ".pickerCard:active", ".pickerCard:hover"].forEach(base => {
            const found = CSS.includes(`${base}:not(:disabled):not([aria-disabled="true"])`);
            assert.ok(found, `\`${base}\` still animates for a control marked aria-disabled`);
        });
    });

    // `disabled` is a state the OS palette knows and draws in GrayText by itself.
    // `aria-disabled` is a word in the accessibility tree and nothing else, so in
    // forced-colors mode a dealt card came out looking exactly like a live one.
    test("and the OS is told about it too, since it only knows the other one", () => {
        // Whichever of the file's forced-colors blocks it landed in — there is more than
        // one of them, and the stylesheet is free to answer a query wherever it likes.
        const open = "@media (forced-colors: active) {";
        const blocks = [];
        for (let at = CSS.indexOf(open); at >= 0; at = CSS.indexOf(open, at + 1)) {
            blocks.push(CSS.slice(at, CSS.indexOf("\n}", at)));
        }
        assert.ok(blocks.length, "nothing in the file answers forced-colors at all");
        const answering = blocks.filter(b => /\[aria-disabled="true"\]/.test(b));
        assert.equal(answering.length, 1, "the dimmed state has no forced-colors answer");
        assert.match(answering[0], /\.pickerCard\[aria-disabled="true"\]/);
        assert.match(answering[0], /\.holdemBtn\[aria-disabled="true"\]/);
        assert.match(answering[0], /color:\s*GrayText/);
    });
});

describe("the three controls that were dead ends", () => {
    test("the header's two say why, and are reachable enough to say it", () => {
        const render = src("render");
        const at = render.indexOf("renderHeaderActions() {");
        const body = render.slice(at, render.indexOf("\n    },", at));
        assert.match(body, /Unavailable\.set\(button, nothingToRunYet, why\)/);
        assert.ok(!/button\.disabled = /.test(body), "one of them is still natively disabled");
        assert.match(body, /Nothing to resolve yet/);
        assert.match(body, /Nothing to move on from/);
    });

    test("Export CSV has a reason at all, which it never did", () => {
        const render = src("render");
        const at = render.indexOf('getElementById("exportHistoryBtn")');
        assert.ok(at >= 0);
        const around = render.slice(at - 200, at + 260);
        assert.match(around, /Unavailable\.set\(/);
        assert.match(around, /No hands to export yet/);
    });

    // Found the same afternoon, in the same sheet, by running the whole audit over an
    // open overlay for the first time: the two slot buttons above the grid are drawn as
    // a card or an em dash, and the em dash was the entire name a screen reader was
    // given. "Dash, button", twice, on the sheet where a dealer writes a card down.
    test("and the slots above it are called something", () => {
        const picker = src("cardPicker");
        const at = picker.indexOf("btn.className = \"pickerSlot\"");
        const body = picker.slice(at, picker.indexOf("slots.appendChild(btn)", at));
        assert.match(body, /this\.boardSlotLabel\(slot\) : `Card \$\{slot \+ 1\}`/,
            "a seat's slots still have no name of their own");
        assert.match(body, /setAttribute\("aria-label", value \? .* : .*empty.*\)/,
            "an empty slot does not say that it is empty");
    });

    test("and a dealt card names itself rather than saying \"this one\"", () => {
        const picker = src("cardPicker");
        const at = picker.indexOf("const takenBy = used.get(card)");
        const body = picker.slice(at, picker.indexOf("grid.appendChild(btn)", at));
        assert.match(body, /Unavailable\.set\(btn, !!takenBy/);
        assert.ok(!/btn\.disabled = /.test(body), "the cards are still natively disabled");
        // The `title` is the same sentence, and now reaches a screen reader because the
        // element it hangs off can be landed on.
        assert.match(body, /btn\.title = Unavailable\.reason\(btn\)/);
    });
});