import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:rippr/src/app/providers.dart';
import 'package:rippr/src/config/config.dart';
import 'package:rippr/src/hud/hud_metric.dart';
import 'package:rippr/src/hud/hud_widget_layout.dart';
import 'package:rippr/src/ui/components/draggable_resizable_hud_widget.dart';
import 'package:rippr/src/ui/components/hud_edit_overlay.dart';
import 'package:shared_preferences/shared_preferences.dart';

/// A representative HUD child -- structurally the same FittedBox(label + value)
/// shape as `record_screen.dart`'s private `_HudMetricValue`, which can't be
/// referenced directly from outside its library.
Widget _representativeHudChild() => const FittedBox(
  fit: BoxFit.scaleDown,
  child: Column(
    mainAxisSize: MainAxisSize.min,
    children: [
      Text('SPEED', style: TextStyle(fontSize: 10, letterSpacing: 1)),
      SizedBox(height: 4),
      Text('12.3 km/h', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
    ],
  ),
);

/// UI-04: drag/toggle behaviour of the customizable HUD, simulated via `TestGesture`
/// the same way other drag interactions in this codebase are tested (see
/// `route_planner_screen_test.dart`'s waypoint-drag coverage).
void main() {
  late Config config;

  setUp(() async {
    SharedPreferences.setMockInitialValues({});
    config = await Config.load();
  });

  Widget host() => ProviderScope(
    overrides: [configProvider.overrideWith((ref) => config)],
    child: MaterialApp(
      home: Scaffold(
        body: SizedBox.expand(
          child: HudEditOverlay(
            metricBuilder: (context, metric) => Text(metric.label),
          ),
        ),
      ),
    ),
  );

  testWidgets('a tap outside edit mode does not move a widget', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    expect(find.byKey(const Key('hud-edit-done')), findsNothing,
        reason: 'not editing yet');

    await tester.tap(find.text('Speed'));
    await tester.pump();

    expect(find.byKey(const Key('hud-edit-done')), findsNothing,
        reason: 'a plain tap on a widget must never enter edit mode or move it');
  });

  testWidgets('a long-press on empty space enters edit mode, showing resize handles '
      'and Done', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    await tester.longPress(find.byKey(const Key('hud-edit-background')));
    await tester.pumpAndSettle();

    expect(find.byKey(const Key('hud-edit-done')), findsOneWidget);
    expect(find.byKey(const Key('hud-resize-handle')), findsWidgets);
  });

  testWidgets('a long-press-and-drag on a widget moves it, and Done persists the new '
      'position', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    await tester.longPress(find.byKey(const Key('hud-edit-background')));
    await tester.pumpAndSettle();

    final before = config.hudLayout[HudMetric.speed]!;

    final speedFinder = find.text('Speed');
    final gesture = await tester.startGesture(tester.getCenter(speedFinder));
    await tester.pump(kLongPressTimeout + kPressTimeout);
    // Large enough to guarantee at least one grid cell of movement in both axes
    // regardless of the test surface's exact pixel size.
    await gesture.moveBy(const Offset(300, 300));
    await tester.pump();
    await gesture.up();
    await tester.pumpAndSettle();

    await tester.tap(find.byKey(const Key('hud-edit-done')));
    await tester.pumpAndSettle();

    final after = config.hudLayout[HudMetric.speed]!;
    expect(after.col, isNot(before.col));
    expect(after.row, isNot(before.row));
  });

  testWidgets('a drag while not editing does not move the widget', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    final before = config.hudLayout[HudMetric.speed]!;
    final speedFinder = find.text('Speed');

    final gesture = await tester.startGesture(tester.getCenter(speedFinder));
    await tester.pump(kLongPressTimeout + kPressTimeout);
    await gesture.moveBy(const Offset(40, 60));
    await gesture.up();
    await tester.pumpAndSettle();

    expect(find.byKey(const Key('hud-edit-done')), findsNothing);
    final after = config.hudLayout[HudMetric.speed]!;
    expect(after.col, before.col);
    expect(after.row, before.row);
  });

  testWidgets('only visible metrics render a widget', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    expect(find.text('Speed'), findsOneWidget, reason: 'visible by default');
    expect(find.text('Max speed'), findsNothing, reason: 'hidden by default');
  });

  testWidgets('a drag ending over a cell occupied by another visible widget leaves '
      'the dragged widget\'s rendered position unchanged', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    await tester.longPress(find.byKey(const Key('hud-edit-background')));
    await tester.pumpAndSettle();

    final speedFinder = find.byKey(const ValueKey(HudMetric.speed));
    final before = tester.getTopLeft(speedFinder);

    // Speed (col 0, row 0) dragged exactly one cell right lands squarely on
    // avgSpeed's (col 1, row 0) cell -- both share the same row-0 default rowSpan, so
    // this is a genuine, not merely edge-touching, overlap.
    final gesture = await tester.startGesture(tester.getCenter(find.text('Speed')));
    await tester.pump(kLongPressTimeout + kPressTimeout);
    await gesture.moveBy(Offset(tester.view.physicalSize.width / tester.view.devicePixelRatio / hudGridColumns, 0));
    await tester.pump();
    await gesture.up();
    await tester.pumpAndSettle();

    await tester.tap(find.byKey(const Key('hud-edit-done')));
    await tester.pumpAndSettle();

    expect(config.hudLayout[HudMetric.speed]!.col, 0,
        reason: 'the rejected move must not change the persisted grid cell either');
    expect(tester.getTopLeft(speedFinder), before);
  });

  testWidgets('a resize past the point of colliding with a sibling leaves the widget '
      'at its pre-gesture size', (tester) async {
    await tester.pumpWidget(host());
    await tester.pumpAndSettle();

    await tester.longPress(find.byKey(const Key('hud-edit-background')));
    await tester.pumpAndSettle();

    final speedFinder = find.byKey(const ValueKey(HudMetric.speed));
    final beforeSize = tester.getSize(speedFinder);
    final handleFinder = find.descendant(
      of: speedFinder,
      matching: find.byKey(const Key('hud-resize-handle')),
    );

    // Speed defaults to colSpan 1 at col 0; growing it across the full grid width
    // would swallow avgSpeed/distance/elapsedTime's row-0 slots.
    final cellWidth = tester.view.physicalSize.width / tester.view.devicePixelRatio / hudGridColumns;
    final gesture = await tester.startGesture(tester.getCenter(handleFinder));
    await gesture.moveBy(Offset(cellWidth * hudGridColumns, 0));
    await tester.pump();
    await gesture.up();
    await tester.pumpAndSettle();

    await tester.tap(find.byKey(const Key('hud-edit-done')));
    await tester.pumpAndSettle();

    expect(config.hudLayout[HudMetric.speed]!.colSpan, 1,
        reason: 'the rejected resize must not change the persisted span either');
    expect(tester.getSize(speedFinder), beforeSize);
  });

  testWidgets('HUD widget text never overflows at the smallest (1x1) allowed size',
      (tester) async {
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: SizedBox(
            width: 400,
            height: 400,
            child: Stack(
              children: [
                DraggableResizableHudWidget(
                  layout: const HudWidgetLayout(
                    metric: HudMetric.speed,
                    col: 0,
                    row: 0,
                    colSpan: hudMinSpan,
                    rowSpan: hudMinSpan,
                    visible: true,
                  ),
                  areaSize: const Size(400, 400),
                  editing: false,
                  onMoved: (_, _) {},
                  onResized: (_, _) {},
                  child: _representativeHudChild(),
                ),
              ],
            ),
          ),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(tester.takeException(), isNull);
  });

  testWidgets(
      'HUD widget text never overflows at the largest (max col/row span) allowed size',
      (tester) async {
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: SizedBox(
            width: 400,
            height: 400,
            child: Stack(
              children: [
                DraggableResizableHudWidget(
                  layout: const HudWidgetLayout(
                    metric: HudMetric.speed,
                    col: 0,
                    row: 0,
                    colSpan: hudMaxColSpan,
                    rowSpan: hudMaxRowSpan,
                    visible: true,
                  ),
                  areaSize: const Size(400, 400),
                  editing: false,
                  onMoved: (_, _) {},
                  onResized: (_, _) {},
                  child: _representativeHudChild(),
                ),
              ],
            ),
          ),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(tester.takeException(), isNull);
  });
}