// Runtime contract test for the pdfrx-backed PageDocumentSource (P0.5 step 12).
// The .fromDocument factory's pdfrx-API pin is verified statically by
// `flutter analyze lib/editor` (the Oracle); here we exercise the concrete
// type's PageDocumentSource behavior + composition with the layout math via the
// pdfium-free .fromSizes constructor.

import 'dart:ui' show Size;

import 'package:flutter_test/flutter_test.dart';

import 'package:badnote/editor/pdf/pdf_document_source.dart';
import 'package:badnote/editor/pdf/pdfrx_page_document_source.dart';

void main() {
  test('fromSizes implements the PageDocumentSource contract', () {
    const src = PdfrxPageDocumentSource.fromSizes([
      Size(600, 800),
      Size(595, 842),
    ]);
    expect(src, isA<PageDocumentSource>());
    expect(src.pageCount, 2);
    expect(src.pageSize(0), const Size(600, 800));
    expect(src.pageSize(1), const Size(595, 842));
  });

  test('composes with the fit-to-width layout math', () {
    const src = PdfrxPageDocumentSource.fromSizes([
      Size(600, 800), // portrait → at width 300, height 400
      Size(800, 600), // landscape → at width 300, height 225
    ]);
    final metrics = pageStackMetricsForWidth(src, 300, gap: 10);
    expect(metrics.heightOf(0), closeTo(400, 1e-9));
    expect(metrics.heightOf(1), closeTo(225, 1e-9));
    expect(metrics.offsetOf(1), closeTo(410, 1e-9)); // 400 + 10 gap
  });

  test('empty document', () {
    const src = PdfrxPageDocumentSource.fromSizes([]);
    expect(src.pageCount, 0);
  });
}