import assert from 'node:assert/strict';
import { readFileSync } from 'node:fs';
import test from 'node:test';

const source = readFileSync(new URL('../Terminal.tsx', import.meta.url), 'utf8');

test('safeFit skips only renderers suspended by hibernate unless explicitly allowed', () => {
  assert.match(
    source,
    /if \(!isRendererActiveRef\.current && !options\?\.allowHidden\) \{\s*lastFittedSizeRef\.current = null;\s*return;\s*\}/,
  );
});

test('safeFit can run synchronously for immediate layout changes', () => {
  assert.match(source, /immediate\?: boolean/);
  assert.match(
    source,
    /XTERM_PERFORMANCE_CONFIG\.resize\.useRAF &&\s*typeof requestAnimationFrame === "function" &&\s*!options\?\.immediate/,
  );
});

test('safeFit clears the WebGL atlas on pixel-only layout changes', () => {
  // Opening the SFTP side panel often changes container px without changing
  // cols/rows, so term.onResize (which clears the atlas) never fires. Without
  // this else-branch recovery, WebGL paints stale glyphs as black squares (#2013).
  assert.match(
    source,
    /if \(term\.cols !== dimensions\.cols \|\| term\.rows !== dimensions\.rows\) \{\s*term\.resize\(dimensions\.cols, dimensions\.rows\);\s*forceSyncRenderAfterResize\(term\);\s*\} else \{\s*[\s\S]*?xtermRuntimeRef\.current\?\.clearTextureAtlas\(\);\s*forceSyncRenderAfterResize\(term\);\s*\}/,
  );
});

test('safeFit waits for normal xterm callbacks before resizing', () => {
  const pendingGuardIndex = source.indexOf('if (hasPendingTerminalWrites(term))');
  const settleIndex = source.indexOf('runWithTerminalOutputPausedAfterWritesSettle(', pendingGuardIndex);
  const sessionGuardIndex = source.indexOf('sessionRef.current !== fitSessionId', settleIndex);
  const immediateFitIndex = source.indexOf('safeFit({ ...fitRequest.options, immediate: true })', sessionGuardIndex);
  const resizeIndex = source.indexOf('term.resize(dimensions.cols, dimensions.rows)', pendingGuardIndex);

  assert.ok(pendingGuardIndex >= 0);
  assert.ok(settleIndex > pendingGuardIndex);
  assert.ok(sessionGuardIndex > settleIndex);
  assert.ok(immediateFitIndex > settleIndex);
  assert.ok(resizeIndex > immediateFitIndex);
});

test('safeFit retries against a replacement backend session', () => {
  const pendingGuardIndex = source.indexOf('if (hasPendingTerminalWrites(term))');
  const replacementGuardIndex = source.indexOf(
    'if (sessionRef.current !== fitSessionId)',
    pendingGuardIndex,
  );
  const clearIndex = source.indexOf('pendingWriteSafeFitRef.current = null', replacementGuardIndex);
  const retryIndex = source.indexOf('setTimeout(() => safeFit(fitRequest.options), 0)', clearIndex);

  assert.ok(replacementGuardIndex > pendingGuardIndex);
  assert.ok(clearIndex > replacementGuardIndex);
  assert.ok(retryIndex > clearIndex);
});