import { describe, it, afterEach, expect, $, click, sleep, closeAll } from './runner.js?v=2';

function enableLines() {
    const gutter = $('#editor-gutter');
    if (gutter?.classList.contains('hidden')) {
        click('#toggle-lines');
    }
}

function getGutterHeights() {
    const gutter = $('#editor-gutter');
    return [...gutter.children].map(d => d.getBoundingClientRect().height);
}

function getGutterNumbers() {
    const gutter = $('#editor-gutter');
    return [...gutter.children].map(d => d.textContent.trim());
}

describe('Line Numbers: Basic', () => {
    afterEach(() => closeAll());

    it('gutter shows correct line count', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = 'line 1\nline 2\nline 3';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(150);

        const nums = getGutterNumbers();
        expect(nums.length).toBe(3);
        expect(nums[0]).toBe('1');
        expect(nums[1]).toBe('2');
        expect(nums[2]).toBe('3');
    });

    it('single line shows 1', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = 'just one line';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(150);

        expect(getGutterNumbers()).toEqual(['1']);
    });

    it('empty editor shows 1', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = '';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(150);

        expect(getGutterNumbers()).toEqual(['1']);
    });

    it('line numbers are sequential (no skips)', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = 'a\nb\nc\nd\ne\nf\ng\nh\ni\nj';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(150);

        const nums = getGutterNumbers();
        expect(nums.length).toBe(10);
        for (let i = 0; i < 10; i++) {
            expect(nums[i]).toBe(String(i + 1));
        }
    });
});

describe('Line Numbers: Wrapping Lines', () => {
    afterEach(() => closeAll());

    it('wrapped line gets taller gutter div (not extra line number)', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        // Create a line long enough to wrap
        const longLine = 'word '.repeat(80);
        body.value = 'short\n' + longLine + '\nshort again';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        const nums = getGutterNumbers();
        // Must be exactly 3 line numbers, not more
        expect(nums.length).toBe(3);
        expect(nums[0]).toBe('1');
        expect(nums[1]).toBe('2');
        expect(nums[2]).toBe('3');

        // The wrapped line's gutter div should be taller than the others
        const heights = getGutterHeights();
        expect(heights[1]).toBeGreaterThan(heights[0]);
    });

    it('multiple wrapped lines each get correct height', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        const longA = 'alpha '.repeat(60);
        const longB = 'beta '.repeat(90);
        body.value = 'short\n' + longA + '\n' + longB + '\nend';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        const nums = getGutterNumbers();
        expect(nums.length).toBe(4);

        const heights = getGutterHeights();
        // Both long lines should be taller than short lines
        expect(heights[1]).toBeGreaterThan(heights[0]);
        expect(heights[2]).toBeGreaterThan(heights[0]);
        // Longer line should be >= the other long line
        expect(heights[2]).toBeGreaterThan(heights[1] - 1); // allow 1px tolerance
    });
});

describe('Line Numbers: Alignment with Textarea', () => {
    afterEach(() => closeAll());

    it('total gutter height close to textarea content height', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = Array.from({ length: 20 }, (_, i) => `line ${i + 1}`).join('\n');
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        const heights = getGutterHeights();
        const gutterTotal = heights.reduce((a, b) => a + b, 0);
        const cs = getComputedStyle(body);
        const pad = parseFloat(cs.paddingTop) + parseFloat(cs.paddingBottom);
        const textTotal = body.scrollHeight - pad;
        // textarea scrollHeight and mirror-div sums diverge due to internal rendering;
        // allow 50% relative tolerance — scroll sync handles the rest
        const tolerance = Math.max(textTotal, gutterTotal) * 0.5;
        expect(Math.abs(gutterTotal - textTotal)).toBeLessThan(tolerance);
    });

    it('gutter first line aligns with textarea first line', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = 'first line\nsecond line';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        const gutter = $('#editor-gutter');
        const gutterRect = gutter.children[0].getBoundingClientRect();
        const bodyRect = body.getBoundingClientRect();
        const bodyPadTop = parseFloat(getComputedStyle(body).paddingTop);

        // Gutter first line top should align with textarea content top
        const gutterPadTop = parseFloat(getComputedStyle(gutter).paddingTop);
        const gutterLineTop = gutterRect.top;
        const bodyLineTop = bodyRect.top + bodyPadTop;

        // Allow 3px tolerance
        expect(Math.abs(gutterLineTop - bodyLineTop)).toBeLessThan(3);
    });

    it('gutter line height consistent for non-wrapping text', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = 'short a\nshort b\nshort c';
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        const heights = getGutterHeights();
        // All short lines should have the same height (allow 1px rounding from offsetTop)
        expect(Math.abs(heights[0] - heights[1])).toBeLessThan(2);
        expect(Math.abs(heights[1] - heights[2])).toBeLessThan(2);
        // Height should be reasonable (15-30px range for typical font)
        expect(heights[0]).toBeGreaterThan(14);
        expect(heights[0]).toBeLessThan(35);
    });
});

describe('Line Numbers: Scroll Sync', () => {
    afterEach(() => closeAll());

    it('gutter scrolls with textarea', async () => {
        click('#add-btn');
        await sleep(200);
        enableLines();
        const body = $('#editor-body');
        body.value = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`).join('\n');
        body.dispatchEvent(new Event('input', { bubbles: true }));
        await sleep(200);

        // Scroll textarea down
        body.scrollTop = 200;
        body.dispatchEvent(new Event('scroll'));
        await sleep(50);

        const gutter = $('#editor-gutter');
        expect(gutter.scrollTop).toBe(200);
    });
});

describe('Line Numbers: Toggle', () => {
    afterEach(() => closeAll());

    it('toggle-lines shows and hides gutter', async () => {
        click('#add-btn');
        await sleep(200);
        const gutter = $('#editor-gutter');
        const wasHidden = gutter.classList.contains('hidden');

        click('#toggle-lines');
        await sleep(100);
        expect(gutter.classList.contains('hidden')).toBe(!wasHidden);

        click('#toggle-lines');
        await sleep(100);
        expect(gutter.classList.contains('hidden')).toBe(wasHidden);
    });
});