import { describe, expect, it } from 'vitest';
import {
  GRID_SCALE_FACTOR,
  GRID_VERSION,
  GRID_VERSION_KEY,
  migrateGridLayouts,
  withGridVersion,
} from './grid-layout-migration';

/**
 * grid-layout-migration.test — NEU (quick-260916-bwo, feineres Dashboard-Raster).
 *
 * Sieben Tests fuer die einmalige Umrechnung gespeicherter Anordnungen von
 * den alten Einheiten (12 Spalten / 40 px) in die neuen (24 Spalten / 20 px).
 * Kern ist T-BWO-02: die Verdopplung darf GENAU EINMAL geschehen. Der Marker
 * `__gridVersion` steht dafuer im gespeicherten JSON, nie im Zustand — Test 4
 * (Idempotenz) wird rot, sobald jemand die Marker-Pruefung entfernt.
 */

function altLayouts() {
  return {
    lg: [
      { i: 'a', x: 1, y: 2, w: 2, h: 3, minW: 2, minH: 2, moved: false, static: false },
      { i: 'b', x: 2, y: 0, w: 6, h: 2, maxW: 12, maxH: 8 },
    ],
    md: [{ i: 'a', x: 0, y: 0, w: 2, h: 2 }],
    sm: [],
    xs: [],
    xxs: [],
  };
}

describe('grid-layout-migration (quick-260916-bwo)', () => {
  it('Test 1: alte Anordnung ohne Marker -> alle Positionen und Groessen x2, migrated true, kein Marker im Ergebnis', () => {
    const { layouts, migrated } = migrateGridLayouts(altLayouts());

    expect(layouts.lg[0]).toEqual({
      i: 'a', x: 2, y: 4, w: 4, h: 6, minW: 4, minH: 4, moved: false, static: false,
    });
    expect(layouts.lg[1]).toEqual({ i: 'b', x: 4, y: 0, w: 12, h: 4, maxW: 24, maxH: 16 });
    expect(layouts.md[0]).toEqual({ i: 'a', x: 0, y: 0, w: 4, h: 4 });
    expect(layouts.sm).toEqual([]);
    expect(layouts.xs).toEqual([]);
    expect(layouts.xxs).toEqual([]);
    expect(migrated).toBe(true);
    expect(Object.keys(layouts)).not.toContain(GRID_VERSION_KEY);
    expect(GRID_SCALE_FACTOR).toBe(2);
  });

  it('Test 2: markierte Anordnung (__gridVersion 2) bleibt unveraendert, migrated false', () => {
    const alt = altLayouts();
    const { layouts, migrated } = migrateGridLayouts({ ...alt, __gridVersion: 2 });

    expect(layouts).toEqual(alt);
    expect(migrated).toBe(false);
    expect(Object.keys(layouts)).not.toContain(GRID_VERSION_KEY);
  });

  it('Test 3: leere Anordnung bleibt leer, migrated false (kein Speichern noetig)', () => {
    const empty = { lg: [], md: [], sm: [], xs: [], xxs: [] };
    const r1 = migrateGridLayouts(empty);
    expect(r1.layouts).toEqual(empty);
    expect(r1.migrated).toBe(false);

    const r2 = migrateGridLayouts({});
    expect(r2.layouts).toEqual({});
    expect(r2.migrated).toBe(false);
  });

  it('Test 4: Idempotenz — einmal umgerechnet und markiert wird nicht erneut verdoppelt (T-BWO-02)', () => {
    const once = migrateGridLayouts(altLayouts());
    const twice = migrateGridLayouts(withGridVersion(once.layouts));

    expect(twice.layouts).toEqual(once.layouts);
    expect(twice.migrated).toBe(false);
  });

  it('Test 5: withGridVersion haengt den Marker an, ohne die Eingabe zu veraendern', () => {
    const { layouts } = migrateGridLayouts(altLayouts());
    const marked = withGridVersion(layouts);

    expect(marked[GRID_VERSION_KEY]).toBe(GRID_VERSION);
    expect(GRID_VERSION).toBe(2);
    expect(marked.lg).toBe(layouts.lg);
    expect(marked.md).toBe(layouts.md);
    expect(Object.keys(layouts)).not.toContain(GRID_VERSION_KEY);
    expect((layouts as Record<string, unknown>)[GRID_VERSION_KEY]).toBeUndefined();
  });

  it('Test 6: Zukunft und Robustheit — Marker 3 bleibt, Zeichenketten-Marker zaehlt nicht, nicht-numerische Felder bleiben', () => {
    const alt = altLayouts();

    const future = migrateGridLayouts({ ...alt, __gridVersion: 3 });
    expect(future.layouts).toEqual(alt);
    expect(future.migrated).toBe(false);

    const stringMarker = migrateGridLayouts({ ...alt, __gridVersion: '2' });
    expect(stringMarker.migrated).toBe(true);
    expect(stringMarker.layouts.lg[0].x).toBe(2);
    expect(Object.keys(stringMarker.layouts)).not.toContain(GRID_VERSION_KEY);

    const odd = migrateGridLayouts({
      lg: [{ i: 'c', x: 'kaputt', y: 1, w: 2, h: 2, resizeHandles: ['se'], moved: true, static: false }],
    });
    expect(odd.layouts.lg[0]).toEqual({
      i: 'c', x: 'kaputt', y: 2, w: 4, h: 4, resizeHandles: ['se'], moved: true, static: false,
    });
    expect(Number.isNaN(odd.layouts.lg[0].x)).toBe(false);
    expect(odd.migrated).toBe(true);
  });

  it('Test 7: Fremdwerte — Nicht-Arrays werden weggelassen, Nicht-Objekte liefern eine leere Anordnung', () => {
    const r = migrateGridLayouts({ lg: 'kaputt', md: null, sm: [{ i: 'a', x: 1, y: 1, w: 1, h: 1 }] });
    expect(Object.keys(r.layouts)).toEqual(['sm']);
    expect(r.layouts.sm[0]).toEqual({ i: 'a', x: 2, y: 2, w: 2, h: 2 });
    expect(r.migrated).toBe(true);

    expect(migrateGridLayouts(null)).toEqual({ layouts: {}, migrated: false });
    expect(migrateGridLayouts(undefined)).toEqual({ layouts: {}, migrated: false });
    expect(migrateGridLayouts(42)).toEqual({ layouts: {}, migrated: false });
    expect(migrateGridLayouts([1, 2])).toEqual({ layouts: {}, migrated: false });
  });
});