import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

import '../about/internal/application/TextType.dart';
import '../utils/Colors.dart';
import 'AmbientBackground.dart';
import 'ChromeTone.dart';
import 'GlassSurface.dart';
import 'scene/SceneArt.dart';
import 'text/Text.dart';

/// The house layout. On the default ambient tone the screen floats on sage
/// mist with frosted controls and ink type, and the content rises on a frosted
/// sheet. Screens that carry a colour — a goal, a standing tier — or a banner
/// get a tinted stage instead, with white type and smoky glass.
class Sheet extends StatelessWidget {
  /// Small all-caps label rendered in the chrome, above the title.
  final String eyebrow;

  /// The chrome title — small and centred, not the display title.
  final String title;

  final Widget child;

  final VoidCallback? onBack;

  /// Optional trailing control in the chrome.
  final Widget? action;

  /// Stage colour. Leaving it null (with no banner) gives the ambient tone.
  final Color? chrome;

  /// Rendered inside the chrome beneath the title — the standing strip.
  final Widget? banner;

  final bool scrollable;

  /// A painted landscape behind a tinted stage's header, in place of the
  /// flat gradient.
  final List<Color>? scene;

  final int sceneSeed;

  const Sheet({
    super.key,
    required this.title,
    required this.child,
    this.eyebrow = "",
    this.onBack,
    this.action,
    this.chrome,
    this.banner,
    this.scrollable = true,
    this.scene,
    this.sceneSeed = 0,
  });

  bool get _light => chrome == null && banner == null && scene == null;

  @override
  Widget build(BuildContext context) {
    final bool light = _light;
    final Color stage = chrome ?? colorPrimaryDark;
    final Color ink = light ? colorInk : colorWhite;
    final Color soft =
        light ? colorInkSoft : colorWhite.withValues(alpha: 0.5);

    final Widget header = SafeArea(
      bottom: false,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(16, 6, 16, 18),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Row(
              children: [
                SizedBox(
                  width: 46,
                  child: onBack == null
                      ? null
                      : Align(
                          alignment: Alignment.centerLeft,
                          child: glassCircle(
                              CupertinoIcons.arrow_left, onBack!,
                              onDark: !light),
                        ),
                ),
                Expanded(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      if (eyebrow.isNotEmpty) ...[
                        text(
                          eyebrow.toUpperCase(),
                          9,
                          TextType.Bold,
                          color: soft,
                          letterSpacing: 1.2,
                          align: TextAlign.center,
                        ),
                        const SizedBox(height: 3),
                      ],
                      text(
                        title.toUpperCase(),
                        14,
                        TextType.Medium,
                        color: ink,
                        letterSpacing: 0.6,
                        align: TextAlign.center,
                      ),
                    ],
                  ),
                ),
                SizedBox(
                  width: 46,
                  child: action == null
                      ? null
                      : Align(
                          alignment: Alignment.centerRight,
                          child: action,
                        ),
                ),
              ],
            ),
            if (banner != null) ...[
              const SizedBox(height: 18),
              banner!,
            ],
          ],
        ),
      ),
    );

    final Widget body = Expanded(
      child: Container(
        decoration: BoxDecoration(
          color: light ? colorFrost : colorPrimaryLight,
          borderRadius: const BorderRadius.only(
            topLeft: Radius.zero,
            topRight: Radius.zero,
          ),
        ),
        clipBehavior: Clip.antiAlias,
        child: scrollable
            ? SingleChildScrollView(
                padding: const EdgeInsets.fromLTRB(20, 28, 20, 40),
                child: child,
              )
            : Padding(
                padding: const EdgeInsets.fromLTRB(20, 28, 20, 0),
                child: child,
              ),
      ),
    );

    final Widget column = ChromeTone(
      light: light,
      child: Column(
        mainAxisSize: MainAxisSize.max,
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [header, body],
      ),
    );

    if (light) {
      return Scaffold(
        backgroundColor: colorAmbientMid,
        body: AmbientBackground(child: column),
      );
    }

    // A tinted stage: the colour deepens downward and a soft light blooms in
    // the corner, so it reads as lit rather than painted flat.
    return Scaffold(
      backgroundColor: stage,
      body: Stack(
        children: [
          Positioned.fill(
            child: DecoratedBox(
              decoration: BoxDecoration(
                gradient: LinearGradient(
                  begin: Alignment.topLeft,
                  end: Alignment.bottomRight,
                  colors: <Color>[
                    Color.lerp(stage, colorWhite, 0.14)!,
                    stage,
                    Color.lerp(stage, colorBlack, 0.35)!,
                  ],
                ),
              ),
            ),
          ),
          if (scene != null)
            Positioned(
              top: 0,
              left: 0,
              right: 0,
              height: 250,
              child: ShaderMask(
                shaderCallback: (Rect bounds) => const LinearGradient(
                  begin: Alignment.topCenter,
                  end: Alignment.bottomCenter,
                  colors: <Color>[Color(0xFF000000), Color(0x00000000)],
                  stops: <double>[0.6, 1.0],
                ).createShader(bounds),
                blendMode: BlendMode.dstIn,
                child: Stack(
                  fit: StackFit.expand,
                  children: [
                    SceneArt(palette: scene!, seed: sceneSeed),
                    ColoredBox(color: colorBlack.withValues(alpha: 0.42)),
                  ],
                ),
              ),
            ),
          Positioned(
            top: -120,
            right: -90,
            child: Container(
              width: 300,
              height: 300,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                gradient: RadialGradient(
                  colors: <Color>[
                    colorWhite.withValues(alpha: 0.16),
                    colorWhite.withValues(alpha: 0.0),
                  ],
                ),
              ),
            ),
          ),
          Positioned.fill(child: column),
        ],
      ),
    );
  }
}

/// A round frosted control for the chrome, with an optional unread dot. It
/// matches the stage it sits on.
Widget chromeAction(
  IconData icon,
  VoidCallback onTap, {
  bool dotted = false,
  Color? dotColor,
}) {
  return Builder(
    builder: (BuildContext context) => glassCircle(
      icon,
      onTap,
      onDark: !ChromeTone.isLight(context),
      dotted: dotted,
      dotColor: dotColor,
    ),
  );
}

/// The label/value pair — a tiny grey all-caps label sitting directly above a
/// value. The core unit of the whole interface.
Widget labelled(
  String label,
  String value, {
  double valueSize = 15,
  TextType valueType = TextType.Medium,
  Color? valueColor,
  Color? labelColor,
  CrossAxisAlignment align = CrossAxisAlignment.start,
}) {
  return Column(
    crossAxisAlignment: align,
    mainAxisSize: MainAxisSize.min,
    children: [
      text(
        label.toUpperCase(),
        9,
        TextType.Bold,
        color: labelColor ?? colorInkSoft,
        letterSpacing: 1.0,
      ),
      const SizedBox(height: 5),
      text(value, valueSize, valueType, color: valueColor ?? colorInk),
    ],
  );
}

/// A row of metadata above a display title, as on the reference: small grey
/// pairs separated by generous space.
Widget metaRow(List<Widget> items) {
  final List<Widget> spaced = <Widget>[];

  for (int index = 0; index < items.length; index++) {
    spaced.add(items[index]);
    if (index != items.length - 1) {
      spaced.add(const SizedBox(width: 28));
    }
  }

  return Row(
    crossAxisAlignment: CrossAxisAlignment.start,
    mainAxisSize: MainAxisSize.min,
    children: spaced,
  );
}

/// The oversized light display title that opens a section.
Widget displayTitle(String value, {Color? color, double size = 34}) {
  return text(value, size, TextType.Light,
      color: color ?? colorInk, height: 1.15);
}

/// A section heading: medium ink label, a soft caption beside it and an
/// optional trailing control ("View all").
Widget sectionBreak(String heading, {Widget? trailing, String caption = ""}) {
  return Padding(
    padding: const EdgeInsets.only(top: 6, bottom: 14),
    child: Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: [
        Expanded(
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              text(heading, 16, TextType.Medium, color: colorInk),
              if (caption.isNotEmpty) ...[
                const SizedBox(width: 8),
                Flexible(
                  child: Padding(
                    padding: const EdgeInsets.only(bottom: 1),
                    child: text(caption, 11, TextType.Regular,
                        color: colorInkSoft,
                        maxLines: 1,
                        overflow: TextOverflow.ellipsis),
                  ),
                ),
              ],
            ],
          ),
        ),
        if (trailing != null) trailing,
      ],
    ),
  );
}