import assert from "node:assert/strict";
import { readFileSync } from "node:fs";
import path from "node:path";
import { test } from "vitest";

/**
 * The shared editor swaps documents on tab switches (per-tab EditorState cache
 * since the undo-isolation fix). Both branches of that swap — the cached
 * `setState` path AND the uncached `swapEditorDocument` path (first activation
 * in this editor instance, or a tab evicted from the state cache) — must
 * restore the incoming tab's saved cursor and scroll position. Skipping the
 * restore on the uncached branch is what made switching back to a tab land on
 * line 1 instead of the previous viewport (#8374).
 */
function activateTabDocumentSource(): string {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  const start = source.indexOf("function activateTabDocument");
  assert.notEqual(start, -1, "expected activateTabDocument in QueryEditor.vue");
  const end = source.indexOf("\n}", start);
  assert.notEqual(end, -1, "expected activateTabDocument closing brace");
  return source.slice(start, end);
}

test("uncached tab activation restores the saved cursor and scroll position", () => {
  const source = activateTabDocumentSource();
  assert.match(source, /if \(!cached\) \{[\s\S]*?swapEditorDocument\(doc\);[\s\S]*?restoreEditorSelection\([^;]*\);[\s\S]*?restoreEditorViewport\([^;]*\);[\s\S]*?return;/, "the swapEditorDocument branch must restore selection and viewport before returning");
});

test("uncached tabs without saved state do not inherit the previous tab position", () => {
  const source = activateTabDocumentSource();
  assert.match(source, /restoreEditorSelection\(props\.initialSelection \?\? \{ anchor: 0, head: 0 \}, !props\.initialViewport\);/);
  assert.match(source, /restoreEditorViewport\(props\.initialViewport \?\? \{ scrollTop: 0, scrollLeft: 0 \}\);/);
});

test("cached tab activation keeps restoring selection and viewport", () => {
  const source = activateTabDocumentSource();
  assert.match(source, /currentView\.setState\(cached\);/);
  assert.match(source, /currentView\.setState\(cached\);[\s\S]*?restoreEditorSelection\(undefined, !props\.initialViewport\);\s*restoreEditorViewport\(\);/);
});

test("viewport restore prefers the per-tab saved viewport", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /function restoreEditorViewport\(viewport = props\.initialViewport \?\? latestViewport\) \{/);
});

test("captures the outgoing editor viewport before KeepAlive deactivation", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /function captureEditorStateBeforeTabSwitch\(event: Event\) \{/);
  assert.match(source, /fromTabId !== props\.tabId/);
  assert.match(source, /captureEditorStateBeforeTabSwitch[\s\S]*?flushEditorViewport\(\);[\s\S]*?flushEditorSelection\(\);[\s\S]*?emit\("editorStateFlushed"\);/);
  assert.match(source, /window\.addEventListener\(BEFORE_TAB_SWITCH_EVENT, captureEditorStateBeforeTabSwitch\)/);
  assert.match(source, /window\.removeEventListener\(BEFORE_TAB_SWITCH_EVENT, captureEditorStateBeforeTabSwitch\)/);
});

test("does not flush a reset viewport after a tab-switch capture", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /let tabSwitchStateCaptured = false;/);
  assert.match(source, /tabSwitchStateCaptured = true;/);
  assert.match(source, /const stateWasCapturedBeforeTabSwitch = tabSwitchStateCaptured;[\s\S]*?tabSwitchStateCaptured = false;[\s\S]*?if \(editorIsActive && !stateWasCapturedBeforeTabSwitch\) \{[\s\S]*?flushEditorViewport\(\);/);
  assert.match(source, /if \(!tabSwitchStateCaptured\) flushEditorViewport\(\);/);
});

test("does not flush an editor again when KeepAlive evicts it after deactivation", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /if \(editorIsActive && !stateWasCapturedBeforeTabSwitch\) \{[\s\S]*?flushEditorViewport\(\);/);
});

test("restores a saved cursor into view when no viewport was persisted", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /restoreEditorSelection\(props\.initialSelection, !props\.initialViewport\);/);
  assert.match(source, /function restoreEditorSelection\(selection = props\.initialSelection \?\? latestSelection, scrollIntoView = false\)/);
  assert.match(source, /view\.value\.dispatch\(\{ selection: normalizedSelection, scrollIntoView \}\);/);
});

test("re-applies the viewport when saved SQL content hydrates after mount", () => {
  const source = readFileSync(path.resolve("apps/desktop/src/components/editor/QueryEditor.vue"), "utf8");
  assert.match(source, /watch\(\s*\(\) => props\.initialViewport,[\s\S]*?previousViewport[\s\S]*?latestViewport = \{ \.\.\.viewport \};[\s\S]*?restoreEditorViewport\(viewport\);/);
  assert.match(source, /watch\(\s*\(\) => props\.initialSelection,[\s\S]*?previousSelection[\s\S]*?restoreEditorSelection\(selection, !props\.initialViewport\);/);
  assert.match(source, /if \(attempts >= 32\)/);
});