import { chromium } from 'playwright';
import assert from 'node:assert/strict';
import { mkdtemp, readFile, rm, writeFile } from 'node:fs/promises';
import { spawn } from 'node:child_process';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { setTimeout as sleep } from 'node:timers/promises';

const ROOT_STORE = 'timmy:/:ledger-v1';
const LEGACY_STORE = 'timmy-ledger-v1';

await mkdtemp(join(tmpdir(), 'timmy-portability-')).then(async (workDir) => {
  const browser = await chromium.launch({ headless: true });
  try {
    const context = await browser.newContext({ viewport: { width: 390, height: 844 }, serviceWorkers: 'block' });
    const page = await context.newPage();
    const errors = [];
    page.on('console', message => { if (message.type() === 'error') errors.push(message.text()); });
    page.on('pageerror', error => errors.push(error.message));
    page.on('dialog', dialog => dialog.accept());
    await page.goto('http://127.0.0.1:4173', { waitUntil: 'networkidle' });
    await page.evaluate(() => localStorage.clear());
    await page.reload({ waitUntil: 'networkidle' });

    // Seed one confirmed, user-owned entry with provenance.
    await page.evaluate(() => {
      localStorage.setItem('timmy:/:ledger-v1', JSON.stringify([
        {
          id: 'seed-1', occurredAt: '2026-08-21T08:30:00.000Z', bristolType: 2, color: 'green',
          urgency: 3, discomfort: 2, note: 'seeded confirmed entry', photoDataUrl: '',
          symptoms: { blood: false }, provenance: { origin: 'ai-suggestion' },
        },
      ]));
    });
    await page.reload({ waitUntil: 'networkidle' });
    await page.locator('[data-view="calendar"]').last().click();
    assert.equal(await page.locator('.entry').count(), 1, 'seeded entry renders');

    // Export writes the versioned envelope with provenance and no secrets.
    await page.locator('[data-view="calendar"]').last().click();
    await page.locator('[data-view="privacy"]').click();
    const downloadPromise = page.waitForEvent('download');
    await page.locator('#export').click();
    const download = await downloadPromise;
    const exportedText = await download.path().then(readFile).then(buffer => buffer.toString('utf8'));
    const exported = JSON.parse(exportedText);
    assert.equal(exported.schemaVersion, 1);
    assert.equal(exported.entries[0].provenance.origin, 'ai-suggestion');
    assert.doesNotMatch(exportedText, /apiToken|sessionId|sk-/i);

    // Importing a prior-version export merges instead of replacing user data.
    const legacyPath = join(workDir, 'legacy-ledger.json');
    await writeFile(legacyPath, JSON.stringify([
      { id: 'legacy-9', occurredAt: '2026-08-20T09:00:00.000Z', bristolType: 4, color: 'brown', urgency: 1, discomfort: 0, note: 'legacy import' },
    ]));
    await page.setInputFiles('#import', legacyPath);
    await page.getByText('Ledger imported').waitFor({ timeout: 5000 });
    const mergedIds = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(mergedIds.sort(), ['legacy-9', 'seed-1'], 'import must merge, not replace');

    // A future schema version fails safely and leaves the ledger untouched.
    const futurePath = join(workDir, 'future-ledger.json');
    await writeFile(futurePath, JSON.stringify({ product: 'Timmy the Talking Turd', schemaVersion: 2, entries: [{ id: 'from-the-future' }] }));
    await page.setInputFiles('#import', futurePath);
    await page.getByText(/newer Timmy app/).waitFor({ timeout: 5000 });
    const afterFuture = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(afterFuture.sort(), ['legacy-9', 'seed-1'], 'failed import must not mutate the ledger');

    // Malformed JSON fails safely and leaves the ledger untouched.
    const malformedPath = join(workDir, 'malformed-ledger.json');
    await writeFile(malformedPath, '{"schemaVersion":1,"entries":');
    await page.setInputFiles('#import', malformedPath);
    await page.getByText(/not a supported Timmy export/).waitFor({ timeout: 5000 });
    const afterMalformed = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(afterMalformed.sort(), ['legacy-9', 'seed-1'], 'malformed import must not mutate the ledger');
    await page.screenshot({ path: 'artifacts/portability-import-mobile.png', fullPage: false });

    // Byte-limit enforcement in the browser: File.size is checked BEFORE the
    // file is read, and UTF-8 bytes (not JS characters) are the measured unit.
    const MAX_IMPORT_BYTES = await page.evaluate(async () => (await import('/src/domain.js')).MAX_IMPORT_BYTES);
    const oversizePath = join(workDir, 'oversize-ledger.json');
    await writeFile(oversizePath, Buffer.concat([
      Buffer.from('{"product":"Timmy the Talking Turd","schemaVersion":1,"entries":[{"id":"x","note":"'),
      Buffer.alloc(MAX_IMPORT_BYTES + 1, 0x6e),
      Buffer.from('"}]}'),
    ]));
    let textReads = 0;
    await page.evaluate(() => {
      const original = File.prototype.text;
      File.prototype.text = function (...args) {
        window.__fileTextReads = (window.__fileTextReads || 0) + 1;
        return original.apply(this, args);
      };
    });
    await page.setInputFiles('#import', oversizePath);
    await page.getByText(/too large/i).waitFor({ timeout: 5000 });
    textReads = await page.evaluate(() => window.__fileTextReads || 0);
    assert.equal(textReads, 0, 'oversized files must be rejected by File.size before File.text()');
    const afterOversize = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(afterOversize.sort(), ['legacy-9', 'seed-1'], 'oversized import must not mutate the ledger');

    // Multibyte boundary: a payload whose UTF-8 byte size exceeds the cap while
    // its JS character count does not must still be rejected (byte-exact limit).
    const emojiHead = '{"product":"Timmy the Talking Turd","schemaVersion":1,"exportedAt":"2026-08-22T00:00:00.000Z","entries":[{"id":"e","occurredAt":"2026-08-20T09:00:00.000Z","bristolType":4,"color":"brown","urgency":0,"discomfort":0,"note":"';
    const emojiTail = '"}]}';
    const emojiNoteUnits = Math.ceil(MAX_IMPORT_BYTES / 3); // ~1.33x cap in UTF-8 bytes, ~0.67x cap in JS units
    const multibyteOverBytesPath = join(workDir, 'multibyte-over-bytes.json');
    await writeFile(multibyteOverBytesPath, Buffer.from(emojiHead + '💩'.repeat(emojiNoteUnits) + emojiTail, 'utf8'));
    const multibyteStats = await page.evaluate(payload => {
      return { bytes: new TextEncoder().encode(payload).length, units: payload.length };
    }, emojiHead + '💩'.repeat(emojiNoteUnits) + emojiTail);
    assert.ok(multibyteStats.bytes > MAX_IMPORT_BYTES, 'fixture must exceed the cap in UTF-8 bytes');
    assert.ok(multibyteStats.units <= MAX_IMPORT_BYTES, 'fixture must stay under the cap in JS characters');
    await page.setInputFiles('#import', multibyteOverBytesPath);
    await page.getByText(/too large/i).waitFor({ timeout: 5000 });
    const afterMultibyte = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(afterMultibyte.sort(), ['legacy-9', 'seed-1'], 'multibyte over-byte import must not mutate the ledger');
    // A dense multibyte payload just UNDER the byte cap still imports cleanly.
    const underBytesPath = join(workDir, 'multibyte-under-bytes.json');
    const underPayload = JSON.stringify({
      product: 'Timmy the Talking Turd',
      schemaVersion: 1,
      exportedAt: '2026-08-22T00:00:00.000Z',
      entries: [{ id: 'under-1', occurredAt: '2026-08-20T09:00:00.000Z', bristolType: 4, color: 'brown', urgency: 0, discomfort: 0, note: 'café ☕'.repeat(2000), photoDataUrl: '', symptoms: {} }],
    });
    const underBytes = await page.evaluate(payload => new TextEncoder().encode(payload).length, underPayload);
    assert.ok(underBytes <= MAX_IMPORT_BYTES && underBytes > 10000, 'under-cap fixture must carry real multibyte mass');
    await writeFile(underBytesPath, Buffer.from(underPayload, 'utf8'));
    await page.setInputFiles('#import', underBytesPath);
    await page.getByText('Ledger imported').waitFor({ timeout: 5000 });
    const afterUnderBytes = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.ok(afterUnderBytes.includes('under-1'), 'valid multibyte import lands in the ledger');

    // Collision-safe merge: re-importing a file whose ids already exist must
    // not duplicate or overwrite anything and must say so explicitly.
    const beforeReimport = await page.evaluate(storeKey => localStorage.getItem(storeKey), ROOT_STORE);
    await page.setInputFiles('#import', underBytesPath);
    await page.getByText(/already in your ledger/i).waitFor({ timeout: 5000 });
    const afterReimport = await page.evaluate(storeKey => JSON.parse(localStorage.getItem(storeKey) || '[]').map(entry => entry.id), ROOT_STORE);
    assert.deepEqual(afterReimport.sort(), JSON.parse(beforeReimport).map(entry => entry.id).sort(), 're-import is idempotent: no duplicates, no overwrites');

    // Delete Everything removes every namespaced copy of the local ledger.
    await page.locator('#delete-all').click();
    await page.getByText('Local ledger deleted').waitFor({ timeout: 5000 });
    const storesAfterDelete = await page.evaluate(([rootStore, legacyStore]) => ({
      root: localStorage.getItem(rootStore),
      legacy: localStorage.getItem(legacyStore),
    }), [ROOT_STORE, LEGACY_STORE]);
    assert.equal(storesAfterDelete.root, null, 'namespaced store cleared');
    assert.equal(storesAfterDelete.legacy, null, 'legacy store cleared');
    await page.locator('[data-view="calendar"]').last().click();
    assert.equal(await page.locator('.entry').count(), 0, 'journal is empty after delete-all');

    // Base-path deployments keep their ledger in an isolated namespace.
    const staging = spawn(process.execPath, ['server.mjs'], {
      env: { ...process.env, PORT: '4179', HOST: '127.0.0.1', TIMMY_BASE_PATH: '/timmy-staging' },
      stdio: 'ignore',
    });
    try {
      let up = false;
      for (let attempt = 0; attempt < 40 && !up; attempt += 1) {
        up = await fetch('http://127.0.0.1:4179/timmy-staging/api/healthz').then(response => response.ok).catch(() => false);
        if (!up) await sleep(250);
      }
      assert.ok(up, 'staging server must start');
      const stagingContext = await browser.newContext({ viewport: { width: 390, height: 844 }, serviceWorkers: 'block' });
      const stagingPage = await stagingContext.newPage();
      stagingPage.on('dialog', dialog => dialog.accept());
      await stagingPage.goto('http://127.0.0.1:4179/timmy-staging', { waitUntil: 'networkidle' });
      await stagingPage.evaluate(() => {
        localStorage.clear();
        localStorage.setItem('timmy:/timmy-staging:ledger-v1', JSON.stringify([
          { id: 'staging-1', occurredAt: '2026-08-21T10:00:00.000Z', bristolType: 3, color: 'brown', urgency: 0, discomfort: 0, note: 'staging only', photoDataUrl: '', symptoms: {} },
        ]));
        // Legacy root-deployment ledger living in the same origin's storage.
        localStorage.setItem('timmy-ledger-v1', JSON.stringify([
          { id: 'root-legacy-1', occurredAt: '2026-08-19T09:00:00.000Z', bristolType: 3, color: 'brown', urgency: 0, discomfort: 0, note: 'root legacy ledger', photoDataUrl: '', symptoms: {} },
        ]));
      });
      await stagingPage.reload({ waitUntil: 'networkidle' });
      await stagingPage.locator('[data-view="calendar"]').last().click();
      assert.equal(await stagingPage.locator('.entry').count(), 1, 'staging entry renders under its base path');
      const isolation = await stagingPage.evaluate(() => ({
        staging: localStorage.getItem('timmy:/timmy-staging:ledger-v1'),
        root: localStorage.getItem('timmy:/:ledger-v1'),
        legacy: localStorage.getItem('timmy-ledger-v1'),
      }));
      assert.ok(isolation.staging, 'staging store keeps its data');
      assert.equal(isolation.root, null, 'root-namespaced store untouched by staging data');
      assert.ok(isolation.legacy && JSON.parse(isolation.legacy).some(entry => entry.id === 'root-legacy-1'), 'legacy store untouched by staging session');
      await stagingPage.locator('[data-view="privacy"]').click();
      await stagingPage.locator('#delete-all').click();
      await stagingPage.getByText('Local ledger deleted').waitFor({ timeout: 5000 });
      const stagingAfterDelete = await stagingPage.evaluate(() => localStorage.getItem('timmy:/timmy-staging:ledger-v1'));
      assert.equal(stagingAfterDelete, null, 'delete-all clears the base-path store');
      const legacyAfterStagingDelete = await stagingPage.evaluate(() => localStorage.getItem('timmy-ledger-v1'));
      assert.ok(
        legacyAfterStagingDelete && JSON.parse(legacyAfterStagingDelete).some(entry => entry.id === 'root-legacy-1'),
        'base-path delete-all must not erase another namespace’s global legacy ledger',
      );
      await stagingContext.close();
    } finally {
      staging.kill();
    }

    assert.deepEqual(errors, [], 'no console or page errors');
    await context.close();
    console.log('PASS ledger portability: export round trip, merge import, safe failures, isolation, delete-all');
  } finally {
    await browser.close();
    await rm(workDir, { recursive: true, force: true });
  }
});