import 'package:flutter/material.dart';
import 'package:flutter_animate/flutter_animate.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';

import '../../data/models.dart';
import '../../state/app_scope.dart';
import '../format.dart';
import '../tokens.dart';
import '../widgets/book_orb.dart';
import '../widgets/chrome.dart';
import '../widgets/misc.dart';
import 'booking/booking_routes.dart';
import 'booking/send_screen.dart';
import 'shell_screen.dart';
import 'sheets/destination_sheet.dart';
import 'sheets/place_search_sheet.dart';
import 'sheets/window_sheet.dart';
import 'tracking_screen.dart';

/// Home — two questions, and nothing else on the screen.
///
/// *Can I book?* The sphere.
/// *Is anything happening?* One row, when there is.
///
/// ── What was removed ──
///
/// A two-line caption under the sphere that a returning customer had read a
/// hundred times; a four-cell card for the live booking carrying a status pill,
/// a reference, a route rail, a courier sentence, a window and a Track button —
/// six facts where the customer wanted two; and a three-row explainer with a
/// subtitle under every row.
///
/// The caption is first-run only now and one line. The live booking is one row.
/// The explainer lost its subtitles. Home went from roughly sixty words to
/// under twenty for a new customer, and to five for a returning one.
class HomeScreen extends StatefulWidget {
  const HomeScreen({super.key});

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  /// True while the destination sheet is up.
  ///
  /// Home does not just sit behind the scrim — it scales back a little and
  /// fades, so the sheet reads as having been pushed up by the sphere rather
  /// than as a new screen that arrived over the top of an unrelated one.
  bool _handingOver = false;

  /// BOOK. The one action on this screen, and the whole flow's front door.
  ///
  /// Two questions are asked here, as sheets over Home, before any form:
  ///
  ///     where is it going?   →   when shall we collect?   →   the details
  ///
  /// Both used to be answered somewhere else. The destination was a strip of
  /// cards halfway down the form; the window was picked *for* the customer,
  /// silently, the moment they chose a city — they arrived at a booking with a
  /// time on it that they had never agreed to. A pickup window is a promise
  /// about somebody's afternoon, and it is not ours to assume.
  ///
  /// Dismissing the window sheet is allowed: the send screen carries "Choose a
  /// window" in the footer and its button stays disabled until there is one.
  Future<void> _book() async {
    final app = AppScope.read(context);
    final navigator = Navigator.of(context);

    setState(() => _handingOver = true);
    try {
      final places = await showDestinationSheet(context);
      if (places == null || places.isEmpty || !mounted) return;

      app.startBooking();
      app.setDestinations(places);

      await showWindowSheet(context);
      if (!mounted) return;

      await navigator.push(
        bookingRoute<void>(BookingRoutes.send, (_) => const SendScreen()),
      );
    } finally {
      if (mounted) setState(() => _handingOver = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final app = AppScope.of(context);
    final active = app.activeBookings.isEmpty ? null : app.activeBookings.first;
    final firstRun = app.orders.isEmpty;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        DmBrandHeader(
          eyebrow: 'Welcome, ${_firstName(app.customer?.name)}',
          title: firstRun ? 'Send your first parcel' : 'Send a parcel',
          action: InkResponse(
            onTap: () => ShellScreen.of(context)?.goToTab(2),
            radius: 26,
            child: DmAvatar(
              initials: initialsOf(app.customer?.name),
              onBrand: true,
            ),
          ),
          // The address is the one fact every booking starts from, so it sits
          // in the header as a live value the customer can change in place —
          // not as the first question of the flow.
          child: DmHeaderTrack(
            leading: const DmLiveDot(size: 6, color: Colors.white),
            trailing: const Icon(
              LucideIcons.chevronDown,
              size: 16,
              color: DmColors.onBrand3,
            ),
            onTap: () async {
              final place = await showPlaceSearchSheet(context);
              if (place != null && context.mounted) app.setPickup(place);
            },
            child: Text(
              app.pickup?.title ?? 'Set a pickup address',
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              style: DmText.cardTitle.copyWith(color: Colors.white),
            ),
          ),
        ),
        Expanded(
          child: AnimatedScale(
            scale: _handingOver ? 0.96 : 1,
            duration: DmMotion.base,
            curve: DmMotion.ease,
            child: AnimatedOpacity(
              opacity: _handingOver ? 0.45 : 1,
              duration: DmMotion.base,
              curve: DmMotion.ease,
              child: RefreshIndicator(
                color: DmColors.brand,
                backgroundColor: DmColors.surface,
                onRefresh: () async {
                  await Future.wait([
                    app.detectPickupLocation(),
                    app.refreshOrders(),
                  ]);
                },
                child: ListView(
                  physics: const AlwaysScrollableScrollPhysics(),
                  padding: const EdgeInsets.fromLTRB(
                    DmSpace.pad,
                    16,
                    DmSpace.pad,
                    28,
                  ),
                  children: [
                    const SizedBox(height: 6),
                    DmBookOrb(
                      onTap: _book,
                      held: _handingOver,
                      // A returning customer knows what BOOK does. The line is
                      // for the first run only, and one line is enough to say
                      // what kind of app this is.
                      caption: firstRun
                          ? 'A Miler collects from your door.'
                          : null,
                    ).animate().fadeIn(duration: 420.ms).scale(
                      begin: const Offset(0.82, 0.82),
                      end: const Offset(1, 1),
                      duration: 620.ms,
                      // A shade of overshoot, so it arrives rather than
                      // appears.
                      curve: Curves.easeOutBack,
                    ),
                    if (active != null)
                      Padding(
                        padding: const EdgeInsets.only(top: 22),
                        child: _LiveRow(booking: active),
                      ).animate().fadeIn(duration: 380.ms, delay: 160.ms).slideY(
                        begin: 0.12,
                        curve: DmMotion.ease,
                      ),
                    if (firstRun) const _HowItWorks(),
                  ],
                ),
              ),
            ),
          ),
        ),
      ],
    );
  }

  static String _firstName(String? name) {
    final first = (name ?? '').trim().split(RegExp(r'\s+')).first;
    return first.isEmpty ? 'there' : first;
  }
}

/// The live booking, as one row.
///
/// This was a card with four cells. A customer glancing at Home wants two
/// things from it — *what is happening* and *how long* — and everything else it
/// carried was available one tap away on the screen this row opens. The route,
/// the reference and the package count all went back there.
class _LiveRow extends StatelessWidget {
  const _LiveRow({required this.booking});

  final Booking booking;

  @override
  Widget build(BuildContext context) {
    final app = AppScope.read(context);
    final slot = app.slotById(booking.slotId);

    // One supporting line, chosen by what the customer can act on right now:
    // before the handover that is when the Miler is coming, after it that is
    // where the parcel is going.
    final support = switch (booking.stage) {
      JourneyStage.booked || JourneyStage.assigned || JourneyStage.onTheWay
          when slot != null =>
        '${slot.day} · ${slot.window}',
      JourneyStage.arrived => 'At your door now',
      _ =>
        booking.isMultiDestination
            ? 'To ${booking.destinations.length} destinations'
            : 'To ${booking.destination.label}',
    };

    return Semantics(
      button: true,
      child: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onTap: () {
          app.openTracking(booking.reference);
          Navigator.of(context).push(
            bookingRoute<void>(
              BookingRoutes.tracking,
              (_) => const TrackingScreen(),
            ),
          );
        },
        child: Container(
          constraints: const BoxConstraints(minHeight: 64),
          padding: const EdgeInsets.fromLTRB(16, 14, 12, 14),
          decoration: BoxDecoration(
            color: DmColors.brandSoft,
            borderRadius: DmRadius.all(DmRadius.md),
            border: Border.all(color: DmColors.brandLine),
          ),
          child: Row(
            children: [
              const DmLiveDot(size: 7),
              const SizedBox(width: 12),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(
                      booking.stage.milestoneLabel,
                      style: DmText.cardTitle.copyWith(
                        color: DmColors.brandPress,
                      ),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                    Text(
                      support,
                      style: DmText.small,
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ],
                ),
              ),
              const SizedBox(width: 8),
              const Icon(
                LucideIcons.chevronRight,
                size: 18,
                color: DmColors.brand,
              ),
            ],
          ),
        ),
      ),
    );
  }
}

/// How it works, on first run only.
///
/// This was a bordered card holding three numbered rows, each with a subtitle.
/// It is a timeline now — glyph, hairline, title — and the subtitles are gone:
/// they described the step the title had already named, on the one screen where
/// a new customer is least willing to read.
class _HowItWorks extends StatelessWidget {
  const _HowItWorks();

  static const _steps = [
    (LucideIcons.mapPin, 'Tell us where it goes'),
    (LucideIcons.clock3, 'Pick a two-hour window'),
    (LucideIcons.packageCheck, 'Hand it over and track'),
  ];

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        const SizedBox(height: 30),
        for (var i = 0; i < _steps.length; i++)
          _Step(
            icon: _steps[i].$1,
            title: _steps[i].$2,
            last: i == _steps.length - 1,
          ),
      ],
    ).animate(delay: 320.ms).fadeIn(duration: 520.ms).slideY(
      begin: 0.06,
      curve: DmMotion.ease,
    );
  }
}

class _Step extends StatelessWidget {
  const _Step({required this.icon, required this.title, required this.last});

  final IconData icon;
  final String title;
  final bool last;

  @override
  Widget build(BuildContext context) {
    return IntrinsicHeight(
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          // The rail: a washed disc per step, joined by a hairline that runs
          // the height of that step's text. Sized by [IntrinsicHeight] so the
          // connector always meets the next disc, whatever the text wraps to.
          SizedBox(
            width: 34,
            child: Column(
              children: [
                Container(
                  width: 34,
                  height: 34,
                  decoration: const BoxDecoration(
                    shape: BoxShape.circle,
                    color: DmColors.brandSoft,
                  ),
                  child: Icon(icon, size: 15, color: DmColors.brand),
                ),
                if (!last)
                  const Expanded(
                    child: SizedBox(
                      width: 1,
                      child: ColoredBox(color: DmColors.border),
                    ),
                  ),
              ],
            ),
          ),
          const SizedBox(width: 14),
          Expanded(
            child: Padding(
              padding: EdgeInsets.only(top: 8, bottom: last ? 0 : 20),
              child: Text(title, style: DmText.cardTitle),
            ),
          ),
        ],
      ),
    );
  }
}