import 'package:flutter_test/flutter_test.dart';
import 'package:observer/detection/detection_result.dart';
import 'package:observer/detection/nms.dart';

DetectionResult box(double l, double t, double r, double b, double score,
        {String label = 'x'}) =>
    DetectionResult(
        label: label, score: score, left: l, top: t, right: r, bottom: b);

void main() {
  test('overlappingBoxes_keepHighestScore', () {
    final a = box(0.1, 0.1, 0.5, 0.5, 0.8);
    final b = box(0.12, 0.12, 0.52, 0.52, 0.6);
    final result = nms([a, b], 0.45);
    expect(result.length, 1);
    expect(result[0].score, closeTo(0.8, 1e-6));
  });

  test('separateBoxes_bothKept', () {
    final a = box(0.1, 0.1, 0.3, 0.3, 0.8);
    final b = box(0.7, 0.7, 0.9, 0.9, 0.6);
    expect(nms([a, b], 0.45).length, 2);
  });

  test('lowScoreBox_suppressedByHigherScore', () {
    final a = box(0.1, 0.1, 0.5, 0.5, 0.9);
    final b = box(0.1, 0.1, 0.5, 0.5, 0.5);
    final result = nms([b, a], 0.45);
    expect(result.length, 1);
    expect(result[0].score, greaterThan(0.5));
  });

  test('bigBox_containsSmallBox_deduped', () {
    // 同目标一大一小两框：标准 IoU = 0.04/0.13 ≈ 0.31 < 0.45 会漏，
    // minIoU = inter/小框 = 1 必须去重（2026-09-01 用户实测：单模型也有重叠框）
    final a = box(0.3, 0.3, 0.5, 0.5, 0.8); // 小框 0.2x0.2
    final b = box(0.25, 0.25, 0.55, 0.55, 0.6); // 大框 0.3x0.3 套住小框
    final result = nms([a, b], 0.45);
    expect(result.length, 1);
    expect(result[0].score, 0.8);
  });

  test('partiallyOverlapping_sameTarget_deduped', () {
    // 标准 IoU = 0.075/0.195 ≈ 0.385 < 0.45 会漏；minIoU = 0.075/0.09 ≈ 0.83
    final a = box(0.1, 0.1, 0.4, 0.4, 0.9); // 0.3x0.3
    final b = box(0.15, 0.1, 0.55, 0.4, 0.5); // 0.4x0.3，与 a 重叠 0.25x0.3
    final result = nms([a, b], 0.45);
    expect(result.length, 1);
    expect(result[0].score, 0.9);
  });

  test('iou_nonOverlapping_isZero', () {
    final a = box(0.0, 0.0, 0.2, 0.2, 1);
    final b = box(0.8, 0.8, 1.0, 1.0, 1);
    expect(iou(a, b), closeTo(0, 1e-6));
  });

  test('iou_identicalBoxes_isOne', () {
    final a = box(0.1, 0.1, 0.5, 0.5, 1);
    expect(iou(a, a), closeTo(1, 1e-6));
  });
}