import { test, expect } from '@playwright/test';
import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';

const HTML_PATH = path.resolve('tables/dist/tables.html');
const HTML_RAW = fs.readFileSync(HTML_PATH, 'utf8');

const MDL_COLUMNS = [
    { field: 'id',       title: 'ID',      width: '6em' },
    { field: 'title',    title: 'Deliverable' },
    { field: 'party',    title: 'Party',   enum: ['Acme', 'Beta', 'Gamma'] },
    { field: 'dueDate',  title: 'Due',     format: 'date' },
    { field: 'status',   title: 'Status',  enum: ['pending', 'submitted', 'accepted'] },
];

function makeRow(id, title, party, dueDate, status, editable = true) {
    return {
        url: `/Working/MDL/${id}.yaml.html`,
        data: { id, title, party, dueDate, status },
        editable,
    };
}

const ROWS = [
    makeRow('D-001', 'Site survey report',     'Acme',  '2026-05-12', 'pending'),
    makeRow('D-002', 'Foundation drawings A',  'Beta',  '2026-05-20', 'submitted'),
    makeRow('D-003', 'Procurement schedule',   'Acme',  '2026-05-08', 'accepted'),
    makeRow('D-004', 'Safety plan',            'Gamma', '2026-05-15', 'pending'),
    makeRow('D-005', 'Geotechnical report',    'Beta',  '2026-05-30', 'submitted'),
];

// Inject a complete table context into the page. Same pattern as
// form-safety.spec.js: write a patched copy of tables.html to a temp
// file and navigate via file://.
async function loadTableWithContext(page, context) {
    const ctxJson = JSON.stringify(context).replace(/<\//g, '<\\/');
    const replacement = `<script id="table-context" type="application/json">${ctxJson}</script>`;
    const patched = HTML_RAW.replace(
        /<script id="table-context" type="application\/json">[\s\S]*?<\/script>/,
        replacement,
    );
    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'tables-spec-'));
    const tmpPath = path.join(tmpDir, 'tables.html');
    fs.writeFileSync(tmpPath, patched);
    await page.goto(`file://${tmpPath}`, { waitUntil: 'load' });
}

test.describe('tables/ — directory-of-YAML table view', () => {
    test('renders header with column titles and rows from context', async ({ page }) => {
        page.on('pageerror', e => console.log('[pageerror]', e.message));
        await loadTableWithContext(page, {
            title: 'Master Deliverables List',
            columns: MDL_COLUMNS,
            rows: ROWS,
        });

        await page.waitForFunction(
            () => document.querySelector('#table-root tbody').children.length > 0,
            null,
            { timeout: 5000 },
        );

        // Header cells.
        const headers = page.locator('.zddc-table__title-row .zddc-table__th');
        await expect(headers).toHaveCount(MDL_COLUMNS.length);
        await expect(headers.nth(0)).toContainText('ID');
        await expect(headers.nth(1)).toContainText('Deliverable');

        // Title in the page header.
        await expect(page.locator('#table-title')).toContainText('Master Deliverables List');

        // Row count.
        await expect(page.locator('#table-root tbody tr')).toHaveCount(ROWS.length);
        await expect(page.locator('#table-rowcount')).toContainText(`${ROWS.length} rows`);
    });

    test('default sort puts dueDate ascending when configured', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
            defaults: { sort: [{ field: 'dueDate', dir: 'asc' }] },
        });

        await page.waitForSelector('#table-root tbody tr');
        const ids = await page.locator('#table-root tbody tr td:first-child').allTextContents();
        // Sorted ascending by dueDate: D-003 (5/8), D-001 (5/12), D-004 (5/15), D-002 (5/20), D-005 (5/30).
        expect(ids).toEqual(['D-003', 'D-001', 'D-004', 'D-002', 'D-005']);
    });

    test('clicking a column header sorts by that column and toggles direction', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });

        await page.waitForSelector('#table-root tbody tr');

        // Click the ID header → sort ascending.
        await page.locator('.zddc-table__th[data-field="id"]').click();
        let ids = await page.locator('#table-root tbody tr td:first-child').allTextContents();
        expect(ids).toEqual(['D-001', 'D-002', 'D-003', 'D-004', 'D-005']);

        // Click again → descending.
        await page.locator('.zddc-table__th[data-field="id"]').click();
        ids = await page.locator('#table-root tbody tr td:first-child').allTextContents();
        expect(ids).toEqual(['D-005', 'D-004', 'D-003', 'D-002', 'D-001']);
    });

    test('free-text filter narrows visible rows', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Type "report" in the title column's filter — should match the
        // two rows whose title contains "report" (Site survey report,
        // Geotechnical report).
        const titleFilter = page.locator('.zddc-table__th[data-field="title"]')
            .locator('..')
            .locator('xpath=following-sibling::tr[1]')
            .locator('input[type="text"]')
            .nth(0);
        // Simpler selector: nth filter input under the filter row.
        const filterInputs = page.locator('.zddc-table__filter-row input[type="text"]');
        await filterInputs.nth(1).fill('report'); // index 1 = title column
        await expect(page.locator('#table-root tbody tr')).toHaveCount(2);
    });

    test('text filter on an enum column does substring match', async ({ page }) => {
        // Filter row is uniformly text-contains across all columns —
        // even for columns declared with `enum:` in the spec. Enum
        // metadata still informs validation/sort but not filter UI.
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const filterInputs = page.locator('.zddc-table__filter-row input[type="text"]');
        // Spec columns: 0=id, 1=title, 2=party, 3=dueDate, 4=status.
        const statusInput = filterInputs.nth(4);
        await statusInput.fill('pending');
        await expect(page.locator('#table-root tbody tr')).toHaveCount(2);
    });

    test('clicking a cell selects it (Phase 1 — replaces row-click navigation)', async ({ page }) => {
        // Single click → cell selection. Row navigation moves to a
        // dedicated affordance in Phase 2 (open-in-form button) so the
        // primary click action can be the spreadsheet-native one.
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Stub navigate seam — verifies single-click does NOT navigate.
        await page.evaluate(() => {
            window.__navTarget = null;
            window.tablesApp.navigateTo = url => { window.__navTarget = url; };
        });

        // Click a specific cell.
        const firstCell = page.locator('#table-root tbody tr').first().locator('[role="gridcell"]').first();
        await firstCell.click();

        await expect(firstCell).toHaveClass(/zddc-table__cell--selected/);
        await expect(firstCell).toHaveAttribute('tabindex', '0');
        await expect(page.evaluate(() => window.__navTarget)).resolves.toBeNull();
    });

    test('arrow keys move cell selection (ARIA grid)', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Click to seed selection at (0,0), then arrow around.
        const r0c0 = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(0);
        await r0c0.click();
        await expect(r0c0).toHaveClass(/zddc-table__cell--selected/);

        await page.keyboard.press('ArrowDown');
        const r1c0 = page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(0);
        await expect(r1c0).toHaveClass(/zddc-table__cell--selected/);

        await page.keyboard.press('ArrowRight');
        const r1c1 = page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(1);
        await expect(r1c1).toHaveClass(/zddc-table__cell--selected/);

        await page.keyboard.press('ArrowUp');
        const r0c1 = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(1);
        await expect(r0c1).toHaveClass(/zddc-table__cell--selected/);

        await page.keyboard.press('ArrowLeft');
        await expect(r0c0).toHaveClass(/zddc-table__cell--selected/);
    });

    test('Tab and Shift-Tab traverse cells with row-wrap', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const numCols = MDL_COLUMNS.length;
        // Start at last column of row 0.
        const r0Last = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(numCols - 1);
        await r0Last.click();
        await expect(r0Last).toHaveClass(/zddc-table__cell--selected/);

        // Tab → first cell of row 1 (wrap).
        await page.keyboard.press('Tab');
        const r1First = page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(0);
        await expect(r1First).toHaveClass(/zddc-table__cell--selected/);

        // Shift+Tab → back to last cell of row 0.
        await page.keyboard.press('Shift+Tab');
        await expect(r0Last).toHaveClass(/zddc-table__cell--selected/);
    });

    test('Enter enters edit mode; Enter commits and moves down', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Edit the title cell (column index 1) of row 0.
        const titleCell = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(1);
        await titleCell.click();
        await page.keyboard.press('Enter');

        // Editor input mounted inside the cell.
        const input = titleCell.locator('input.zddc-table__cell-input');
        await expect(input).toBeVisible();
        await expect(input).toBeFocused();

        // Type new value, press Enter to commit + move down.
        await page.keyboard.press('Control+a');
        await page.keyboard.type('New title via cell editor');
        await page.keyboard.press('Enter');

        // Cell shows new value, input gone.
        await expect(titleCell).toContainText('New title via cell editor');
        await expect(titleCell.locator('input')).toHaveCount(0);

        // Selection moved down one row, same column.
        const r1Title = page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(1);
        await expect(r1Title).toHaveClass(/zddc-table__cell--selected/);
    });

    test('Escape cancels edit, restoring prior value', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(1);
        const originalText = await titleCell.textContent();

        await titleCell.click();
        await page.keyboard.press('Enter');
        await page.keyboard.press('Control+a');
        await page.keyboard.type('Should not stick');
        await page.keyboard.press('Escape');

        // Value restored to original; no draft entry.
        await expect(titleCell).toHaveText(originalText.trim());
        const draftCount = await page.evaluate(() =>
            Object.keys(window.tablesApp.state.drafts).length);
        expect(draftCount).toBe(0);
    });

    test('typing a printable char enters edit and replaces value', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(1);
        await titleCell.click();
        // Press a printable character — should enter edit mode with
        // that char as the new value.
        await page.keyboard.press('X');
        const input = titleCell.locator('input.zddc-table__cell-input');
        await expect(input).toBeVisible();
        await expect(input).toHaveValue('X');
    });

    test('double-click also enters edit mode', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(1);
        await titleCell.dblclick();
        await expect(titleCell.locator('input.zddc-table__cell-input')).toBeVisible();
    });

    test('non-editable rows still get the readonly class', async ({ page }) => {
        // Cosmetic guard for an existing convention: rows where the
        // server says editable=false get a visual treatment. Cell
        // selection still works in Phase 1; Phase 3 will gate writes
        // on the editable flag at save time.
        const readOnlyRows = ROWS.map(r => ({ ...r, editable: false }));
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: readOnlyRows,
        });
        await page.waitForSelector('#table-root tbody tr');

        await expect(page.locator('#table-root tbody tr.zddc-table__row--editable')).toHaveCount(0);
        await expect(page.locator('#table-root tbody tr.zddc-table__row--readonly')).toHaveCount(ROWS.length);
    });

    test('default filters seed the visible row count from defaults.filter', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: ROWS,
            defaults: { filter: { status: ['pending'] } },
        });
        await page.waitForSelector('#table-root tbody tr');
        await expect(page.locator('#table-root tbody tr')).toHaveCount(2);
    });

    test('empty rows list shows the empty-state notice', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: MDL_COLUMNS,
            rows: [],
        });
        // Wait briefly for init.
        await page.waitForTimeout(50);
        await expect(page.locator('#table-root tbody tr')).toHaveCount(0);
        await expect(page.locator('#table-empty')).toBeHidden();
    });

    // --- Phase 2: schema-driven cell editor widgets -----------------------

    // A small JSON Schema covering the inline-editable types the
    // factory recognises: string, integer with min/max, boolean,
    // string-enum, format:date, array<enum>+uniqueItems.
    const ROW_SCHEMA = {
        type: 'object',
        properties: {
            id:       { type: 'string' },
            title:    { type: 'string' },
            party:    { type: 'string', enum: ['Acme', 'Beta', 'Gamma'] },
            dueDate:  { type: 'string', format: 'date' },
            status:   { type: 'string', enum: ['pending', 'submitted', 'accepted'] },
            priority: { type: 'integer', minimum: 1, maximum: 5 },
            done:     { type: 'boolean' },
            tags: {
                type: 'array',
                uniqueItems: true,
                items: { type: 'string', enum: ['blue', 'green', 'red'] },
            },
            // A nested-object cell — should punt to navigation rather
            // than mount an inline editor.
            owner: {
                type: 'object',
                properties: {
                    name:  { type: 'string' },
                    email: { type: 'string', format: 'email' },
                },
            },
        },
    };

    const SCHEMA_COLUMNS = [
        { field: 'id',       title: 'ID',       width: '6em' },
        { field: 'title',    title: 'Title' },
        { field: 'party',    title: 'Party' },
        { field: 'dueDate',  title: 'Due',      format: 'date' },
        { field: 'status',   title: 'Status' },
        { field: 'priority', title: 'Priority' },
        { field: 'done',     title: 'Done' },
        { field: 'tags',     title: 'Tags' },
        { field: 'owner',    title: 'Owner' },
    ];

    function makeSchemaRow(over) {
        return {
            url: `/Working/MDL/${over.id || 'D-001'}.yaml.html`,
            data: Object.assign({
                id: 'D-001', title: 'Sample', party: 'Acme', dueDate: '2026-05-12',
                status: 'pending', priority: 3, done: false, tags: ['blue'],
                owner: { name: 'Casey', email: 'c@example.com' },
            }, over.data || {}),
            editable: true,
        };
    }

    const SCHEMA_ROWS = [makeSchemaRow({ id: 'D-001' }), makeSchemaRow({ id: 'D-002' })];

    function colIdx(field) {
        return SCHEMA_COLUMNS.findIndex(c => c.field === field);
    }

    test('Phase 2: enum column edits via select dropdown', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const partyCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('party'));
        await partyCell.dblclick();
        const select = partyCell.locator('select.zddc-table__cell-input');
        await expect(select).toBeVisible();
        // Empty placeholder + 3 enum options.
        await expect(select.locator('option')).toHaveCount(4);
        await select.selectOption('Beta');
        await page.keyboard.press('Enter');
        await expect(partyCell).toContainText('Beta');
    });

    test('Phase 2: integer column gives a number input with min/max', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('priority'));
        await cell.dblclick();
        const input = cell.locator('input.zddc-table__cell-input');
        await expect(input).toHaveAttribute('type', 'number');
        await expect(input).toHaveAttribute('min', '1');
        await expect(input).toHaveAttribute('max', '5');
        await expect(input).toHaveAttribute('step', '1');

        await input.fill('4');
        await page.keyboard.press('Enter');
        await expect(cell).toContainText('4');

        // Draft holds a Number, not a string.
        const draftType = await page.evaluate(() => {
            const drafts = window.tablesApp.state.drafts;
            const rowId = Object.keys(drafts)[0];
            return typeof drafts[rowId].priority;
        });
        expect(draftType).toBe('number');
    });

    test('Phase 2: boolean column gives a checkbox', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('done'));
        await cell.dblclick();
        const cb = cell.locator('input.zddc-table__cell-input');
        await expect(cb).toHaveAttribute('type', 'checkbox');
        // Toggle via Space (the keyboard contract a screen-reader user
        // would use). Avoids the click+blur race that Playwright's
        // .check() helper hits on a focused-checkbox-inside-grid-cell.
        await page.keyboard.press('Space');
        await page.keyboard.press('Enter');

        const draftValue = await page.evaluate(() => {
            const drafts = window.tablesApp.state.drafts;
            const rowId = Object.keys(drafts)[0];
            return drafts[rowId].done;
        });
        expect(draftValue).toBe(true);
    });

    test('Phase 2: format:date column gives a date input', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('dueDate'));
        await cell.dblclick();
        const input = cell.locator('input.zddc-table__cell-input');
        await expect(input).toHaveAttribute('type', 'date');
        await expect(input).toHaveValue('2026-05-12');
    });

    test('Phase 2: multi-select enum-array column gives a multi-select', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('tags'));
        await cell.dblclick();
        const select = cell.locator('select.zddc-table__cell-input');
        await expect(select).toBeVisible();
        await expect(select).toHaveAttribute('multiple', '');
    });

    test('Phase 2: complex (object) column navigates to the row form on edit', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Stub navigation seam — see how the editor punts to the
        // form for inline-uneditable types.
        await page.evaluate(() => {
            window.__navTarget = null;
            window.tablesApp.navigateTo = url => { window.__navTarget = url; };
        });

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('owner'));
        await cell.dblclick();
        // No inline editor mounted.
        await expect(cell.locator('.zddc-table__cell-input')).toHaveCount(0);
        const target = await page.evaluate(() => window.__navTarget);
        expect(target).toContain('.yaml.html');
    });

    test('Phase 2: readOnly column suppresses the inline editor', async ({ page }) => {
        // Self-contained fixture: a folder-bound / server-managed field
        // (schema readOnly:true) must not become an editable cell, while
        // a normal sibling column still edits.
        await loadTableWithContext(page, {
            columns: [
                { field: 'originator', title: 'Originator' },
                { field: 'title', title: 'Title' },
            ],
            rows: [{
                url: '/Working/MDL/ACM-PRJ-EL-SPC-0001.yaml.html',
                data: { originator: 'ACM', title: 'Spec' },
                editable: true,
            }],
            rowSchema: {
                type: 'object',
                properties: {
                    originator: { type: 'string', readOnly: true },
                    title: { type: 'string' },
                },
            },
        });
        await page.waitForSelector('#table-root tbody tr');

        const ro = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(0);
        await ro.dblclick();
        // No inline editor mounts; the displayed value is untouched.
        await expect(ro.locator('.zddc-table__cell-input')).toHaveCount(0);
        await expect(ro).toHaveText('ACM');

        // A normal column in the same table still edits.
        const editable = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(1);
        await editable.dblclick();
        await expect(editable.locator('input.zddc-table__cell-input')).toBeVisible();
    });

    test('Phase 2: no rowSchema → falls back to plain text editor', async ({ page }) => {
        await loadTableWithContext(page, {
            // No rowSchema in the context — same as a directory with
            // table.yaml but no form.yaml.
            columns: SCHEMA_COLUMNS,
            rows: SCHEMA_ROWS,
        });
        await page.waitForSelector('#table-root tbody tr');

        const cell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('party'));
        await cell.dblclick();
        // Default text input — even for a column that COULD have been
        // an enum dropdown if the schema had been provided.
        const input = cell.locator('input.zddc-table__cell-input');
        await expect(input).toHaveAttribute('type', 'text');
    });

    // --- Phase 3: row-level save + ETag conflict UX -----------------------

    // Loading the page via file:// means PUTs go to file:// URLs — no
    // network. We intercept via page.route on the parent http://* URL
    // by hosting the test fixture rows with absolute http URLs in their
    // yamlUrl field.
    function makeNetRow(over) {
        const id = over.id || 'D-001';
        return {
            url: `http://test.local/Working/MDL/${id}.yaml.html`,
            yamlUrl: `http://test.local/Working/MDL/${id}.yaml`,
            data: Object.assign({
                id, title: 'Sample', party: 'Acme', dueDate: '2026-05-12',
                status: 'pending', priority: 3, done: false, tags: ['blue'],
                owner: { name: 'Casey', email: 'c@example.com' },
            }, over.data || {}),
            etag: over.etag || 'v1',
            editable: true,
        };
    }

    async function setupSaveCapture(page) {
        // Intercept PUTs on test.local. Tests configure responses by
        // pushing into window.__saveResponses; tests inspect requests
        // via window.__savePuts.
        await page.route('http://test.local/**', async (route) => {
            const req = route.request();
            const method = req.method();
            if (method !== 'PUT' && method !== 'GET') {
                await route.continue();
                return;
            }
            await page.evaluate(({ url, method, body, headers }) => {
                window.__capturedRequests = window.__capturedRequests || [];
                window.__capturedRequests.push({ url, method, body, headers });
            }, {
                url: req.url(),
                method,
                body: req.postData(),
                headers: req.headers(),
            });
            const queued = await page.evaluate(() => window.__nextResponse || null);
            if (queued) {
                await page.evaluate(() => { window.__nextResponse = null; });
                await route.fulfill({
                    status: queued.status,
                    headers: queued.headers || {},
                    body: queued.body || '',
                });
                return;
            }
            // Default success.
            await route.fulfill({
                status: 200,
                headers: { 'ETag': '"v2"' },
                body: '',
            });
        });
    }

    test('Phase 3: row-blur fires PUT with merged drafts + If-Match', async ({ page }) => {
        await setupSaveCapture(page);
        const rows = [makeNetRow({ id: 'D-001' }), makeNetRow({ id: 'D-002' })];
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');
        await page.evaluate(() => { window.__capturedRequests = []; });

        // Edit a cell in row 0, then click row 1 to move selection
        // (row-blur trigger).
        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.dblclick();
        await page.keyboard.press('Control+a');
        await page.keyboard.type('Edited title');
        await page.keyboard.press('Enter');
        // Enter committed + moved selection down to row 1 — that IS
        // the row-blur. Wait briefly for the async fetch to fire.
        await page.waitForFunction(() =>
            (window.__capturedRequests || []).some(r => r.method === 'PUT'),
            null, { timeout: 3000 });

        const puts = await page.evaluate(() =>
            (window.__capturedRequests || []).filter(r => r.method === 'PUT'));
        expect(puts).toHaveLength(1);
        expect(puts[0].url).toBe('http://test.local/Working/MDL/D-001.yaml');
        expect(puts[0].body).toContain('Edited title');
        expect(puts[0].body).toContain('id: D-001');
        // If-Match present.
        expect(puts[0].headers['if-match']).toBe('"v1"');
    });

    test('Phase 3: 412 conflict marks row stale + shows status prompt', async ({ page }) => {
        await setupSaveCapture(page);
        const rows = [makeNetRow({ id: 'D-001' }), makeNetRow({ id: 'D-002' })];
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');
        await page.evaluate(() => { window.__nextResponse = { status: 412 }; });

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.dblclick();
        await page.keyboard.press('Control+a');
        await page.keyboard.type('My change');
        await page.keyboard.press('Enter');

        // Wait for the row to gain the stale class.
        const row0 = page.locator('#table-root tbody tr').nth(0);
        await expect(row0).toHaveClass(/zddc-table__row--stale/);

        // Status prompt visible with both buttons.
        const status = page.locator('#table-status');
        await expect(status).toBeVisible();
        await expect(status).toContainText('changed by someone else');
        await expect(status.locator('button', { hasText: 'Use mine' })).toBeVisible();
        await expect(status.locator('button', { hasText: 'Reload' })).toBeVisible();

        // Drafts must STILL exist — never silently discard.
        const draftCount = await page.evaluate(() =>
            Object.keys(window.tablesApp.state.drafts).length);
        expect(draftCount).toBe(1);
    });

    test('Phase 3: 422 validation errors mark cells invalid', async ({ page }) => {
        await setupSaveCapture(page);
        const rows = [makeNetRow({ id: 'D-001' }), makeNetRow({ id: 'D-002' })];
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');
        await page.evaluate(() => {
            window.__nextResponse = {
                status: 422,
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    errors: [
                        { path: '/priority', message: 'must be ≤ 5' },
                        { path: '/title',    message: 'required' },
                    ],
                }),
            };
        });

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.dblclick();
        await page.keyboard.press('Control+a');
        await page.keyboard.type('x');
        await page.keyboard.press('Enter');
        // Enter committed + moved selection to row 1 → row-blur on row 0
        // → PUT fires → 422 → cells marked.
        await page.waitForFunction(() =>
            document.querySelector('.zddc-table__cell--invalid'),
            null, { timeout: 3000 });

        const invalidCells = await page.locator('.zddc-table__cell--invalid').count();
        expect(invalidCells).toBe(2);
    });

    // --- Phase 4: copy/paste from Excel/Sheets (TSV) ---------------------

    test('Phase 4: parseTSV handles tabs, newlines, and quoted fields', async ({ page }) => {
        // Unit-style test of the parser via the exposed clipboard module.
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');
        const result = await page.evaluate(() => {
            const p = window.tablesApp.modules.clipboard.parseTSV;
            return [
                p('a\tb\tc'),
                p('a\tb\nc\td'),
                p('a\t"line1\nline2"\tc'),
                p('"with ""quotes"""\tplain'),
                p('a\r\nb\r\nc'),
                p(''),
            ];
        });
        expect(result[0]).toEqual([['a', 'b', 'c']]);
        expect(result[1]).toEqual([['a', 'b'], ['c', 'd']]);
        expect(result[2]).toEqual([['a', 'line1\nline2', 'c']]);
        expect(result[3]).toEqual([['with "quotes"', 'plain']]);
        expect(result[4]).toEqual([['a'], ['b'], ['c']]);
        expect(result[5]).toEqual([]);
    });

    test('Phase 4: paste single value into selected cell', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.click();

        // Drive applyPaste directly (Playwright's clipboard event
        // simulation is browser-flag-gated; calling the module is the
        // honest unit-test path).
        await page.evaluate(() => {
            const sel = window.tablesApp.state.selected;
            window.tablesApp.modules.clipboard.applyPaste(
                sel.row, sel.col,
                [['Pasted single value']],
            );
            window.tablesApp.repaint();
        });

        await expect(titleCell).toContainText('Pasted single value');

        // Draft buffer holds it under the right field.
        const draftValue = await page.evaluate(() => {
            const drafts = window.tablesApp.state.drafts;
            const rowId = Object.keys(drafts)[0];
            return drafts[rowId].title;
        });
        expect(draftValue).toBe('Pasted single value');
    });

    test('Phase 4: paste 2x2 grid spills from anchor', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Anchor at row 0, title column.
        const anchor = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await anchor.click();

        await page.evaluate(() => {
            const sel = window.tablesApp.state.selected;
            window.tablesApp.modules.clipboard.applyPaste(
                sel.row, sel.col,
                [
                    ['t-r0', 'Acme'],
                    ['t-r1', 'Beta'],
                ],
            );
            window.tablesApp.repaint();
        });

        // Row 0: title=t-r0, party=Acme.
        await expect(
            page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(colIdx('title'))
        ).toContainText('t-r0');
        await expect(
            page.locator('#table-root tbody tr').nth(0).locator('[role="gridcell"]').nth(colIdx('party'))
        ).toContainText('Acme');
        // Row 1: title=t-r1, party=Beta.
        await expect(
            page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(colIdx('title'))
        ).toContainText('t-r1');
        await expect(
            page.locator('#table-root tbody tr').nth(1).locator('[role="gridcell"]').nth(colIdx('party'))
        ).toContainText('Beta');
    });

    test('Phase 4: paste coerces numeric/boolean values via row schema', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const priorityCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('priority'));
        await priorityCell.click();
        await page.evaluate(() => {
            const sel = window.tablesApp.state.selected;
            window.tablesApp.modules.clipboard.applyPaste(
                sel.row, sel.col,
                [['4', 'true']],   // priority + done
            );
            window.tablesApp.repaint();
        });

        const drafts = await page.evaluate(() => {
            const d = window.tablesApp.state.drafts;
            const rowId = Object.keys(d)[0];
            return d[rowId];
        });
        expect(drafts.priority).toBe(4);
        expect(typeof drafts.priority).toBe('number');
        expect(drafts.done).toBe(true);
    });

    test('Phase 4: paste out-of-bounds drops cells silently with toast', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const lastRowLastCol = page.locator('#table-root tbody tr').nth(1)
            .locator('[role="gridcell"]').last();
        await lastRowLastCol.click();

        // Dispatch a real paste event so onPaste runs (which writes
        // the toast). 3-row × 2-col TSV anchored at the last cell —
        // every cell spills past the end of either rows or columns.
        await page.evaluate(() => {
            const dt = new DataTransfer();
            dt.setData('text/plain', 'x1\ty1\nx2\ty2\nx3\ty3');
            const ev = new ClipboardEvent('paste', {
                clipboardData: dt,
                bubbles: true,
                cancelable: true,
            });
            document.dispatchEvent(ev);
        });
        await expect(page.locator('#table-status')).toContainText('dropped');
    });

    test('Phase 4: copy single cell writes value to clipboard', async ({ page, context }) => {
        // Granting clipboard-read makes Chromium permit synthetic copy.
        await context.grantPermissions(['clipboard-read', 'clipboard-write']);
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.click();

        // Synthesize a copy event with a writable DataTransfer-like
        // payload; assert the handler wrote the cell value into it.
        const written = await page.evaluate(() => {
            const ev = new ClipboardEvent('copy', {
                clipboardData: new DataTransfer(),
                bubbles: true,
                cancelable: true,
            });
            document.dispatchEvent(ev);
            return ev.clipboardData.getData('text/plain');
        });
        expect(written).toBe('Sample');
    });

    // --- Phase 5: undo + multi-cell ops ----------------------------------

    test('Phase 5: Ctrl+Z reverts a single cell edit to prior value', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        const originalText = await titleCell.textContent();

        await titleCell.dblclick();
        await page.keyboard.press('Control+a');
        await page.keyboard.type('Edited via undo test');
        await page.keyboard.press('Enter');
        await expect(titleCell).toContainText('Edited via undo test');

        // Ctrl+Z (focus has moved to next cell after Enter — undo's
        // hotkey is bound at the document, so it works from any
        // active cell).
        await page.keyboard.press('Control+z');
        await expect(titleCell).toHaveText(originalText.trim());

        // Draft cleared because we returned to the stored value.
        const draftCount = await page.evaluate(() =>
            Object.keys(window.tablesApp.state.drafts).length);
        expect(draftCount).toBe(0);
    });

    test('Phase 5: Shift+ArrowDown extends range selection', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const r0c1 = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(1);
        await r0c1.click();
        await page.keyboard.press('Shift+ArrowDown');

        // Both cells in the column should be in the range.
        const inRange = page.locator('.zddc-table__cell--in-range');
        await expect(inRange).toHaveCount(2);
    });

    test('Phase 5: Shift+click extends range from anchor to clicked cell', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const r0c1 = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(1);
        const r1c3 = page.locator('#table-root tbody tr').nth(1)
            .locator('[role="gridcell"]').nth(3);

        await r0c1.click();
        await r1c3.click({ modifiers: ['Shift'] });

        // 2 rows × 3 cols = 6 cells in the range.
        await expect(page.locator('.zddc-table__cell--in-range')).toHaveCount(6);
    });

    test('Phase 5: Delete clears every selected cell', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Select a 2x2 range starting at the title column.
        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.click();
        await page.keyboard.press('Shift+ArrowRight');
        await page.keyboard.press('Shift+ArrowDown');

        await page.keyboard.press('Delete');

        // 4 drafts created, each set to null.
        const drafts = await page.evaluate(() => window.tablesApp.state.drafts);
        const totalDraftFields = Object.values(drafts)
            .reduce((acc, r) => acc + Object.keys(r).length, 0);
        expect(totalDraftFields).toBe(4);
    });

    test('Phase 5: Ctrl+D fills the top row down through the range', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: [
                makeSchemaRow({ id: 'D-001', data: { title: 'Top' } }),
                makeSchemaRow({ id: 'D-002', data: { title: 'Bottom' } }),
            ],
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Select the title column across both rows.
        const titleR0 = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleR0.click();
        await page.keyboard.press('Shift+ArrowDown');

        await page.keyboard.press('Control+d');

        const titleR1 = page.locator('#table-root tbody tr').nth(1)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await expect(titleR1).toContainText('Top');
    });

    test('Phase 5: Ctrl+Z reverts a bulk fill in one step', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS,
            rows: [
                makeSchemaRow({ id: 'D-001', data: { title: 'Top' } }),
                makeSchemaRow({ id: 'D-002', data: { title: 'Bottom' } }),
            ],
            rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        const titleR0 = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        const titleR1 = page.locator('#table-root tbody tr').nth(1)
            .locator('[role="gridcell"]').nth(colIdx('title'));

        await titleR0.click();
        await page.keyboard.press('Shift+ArrowDown');
        await page.keyboard.press('Control+d');
        await expect(titleR1).toContainText('Top');

        await page.keyboard.press('Control+z');
        await expect(titleR1).toContainText('Bottom');

        // Drafts cleared (returning to stored values).
        const draftCount = await page.evaluate(() =>
            Object.keys(window.tablesApp.state.drafts).length);
        expect(draftCount).toBe(0);
    });

    test('Phase 5: undo stack depth caps at 50', async ({ page }) => {
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows: SCHEMA_ROWS, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');

        // Push 60 commands directly via the module API.
        await page.evaluate(() => {
            const u = window.tablesApp.modules.undo;
            for (let i = 0; i < 60; i++) {
                u.push({ cells: [{ rowId: 'fake', field: 'title', oldValue: 'a', newValue: 'b' }] });
            }
        });
        const depth = await page.evaluate(() => window.tablesApp.modules.undo.depth());
        expect(depth).toBe(50);
    });

    test('Phase 3: Reload button drops drafts and refreshes', async ({ page }) => {
        await setupSaveCapture(page);
        const rows = [makeNetRow({ id: 'D-001' }), makeNetRow({ id: 'D-002' })];
        await loadTableWithContext(page, {
            columns: SCHEMA_COLUMNS, rows, rowSchema: ROW_SCHEMA,
        });
        await page.waitForSelector('#table-root tbody tr');
        await page.evaluate(() => { window.__nextResponse = { status: 412 }; });

        const titleCell = page.locator('#table-root tbody tr').nth(0)
            .locator('[role="gridcell"]').nth(colIdx('title'));
        await titleCell.dblclick();
        await page.keyboard.press('Control+a');
        await page.keyboard.type('My change');
        await page.keyboard.press('Enter');

        const status = page.locator('#table-status');
        await expect(status).toBeVisible();

        // Queue a fresh GET response with new ETag.
        await page.evaluate(() => {
            window.__nextResponse = {
                status: 200,
                headers: { 'ETag': '"v3"', 'Content-Type': 'application/yaml' },
                body: 'id: D-001\ntitle: Server-side new title\nparty: Acme\ndueDate: 2026-05-12\nstatus: pending\npriority: 3\ndone: false\ntags:\n  - blue\nowner:\n  name: Casey\n  email: c@example.com\n',
            };
        });

        await status.locator('button', { hasText: 'Reload' }).click();
        await expect(status).toBeHidden();

        // Drafts cleared.
        const draftCount = await page.evaluate(() =>
            Object.keys(window.tablesApp.state.drafts).length);
        expect(draftCount).toBe(0);
    });
});