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

import '../../models/attendance_log.dart';
import '../../models/it_service_request.dart';
import '../../models/pass_slip.dart';
import '../../models/task.dart';
import '../../models/ticket.dart';
import '../../theme/m3_motion.dart';
import '../../utils/app_time.dart';

// ─────────────────────────────────────────────────────────────────────────────
// Data class
// ─────────────────────────────────────────────────────────────────────────────

class LogbookDayActivityData {
  final String userId;
  final String name;
  final DateTime date;
  final String shiftLabel;
  final DateTime? scheduledStart;
  final DateTime? scheduledEnd;
  final bool isSwapped;
  final List<AttendanceLog> sessions;
  final List<PassSlip> passSlips;
  final List<Task> tasks;
  final List<Ticket> tickets;
  final List<ItServiceRequest> serviceRequests;

  const LogbookDayActivityData({
    required this.userId,
    required this.name,
    required this.date,
    required this.shiftLabel,
    this.scheduledStart,
    this.scheduledEnd,
    this.isSwapped = false,
    required this.sessions,
    required this.passSlips,
    required this.tasks,
    required this.tickets,
    required this.serviceRequests,
  });
}

// ─────────────────────────────────────────────────────────────────────────────
// Timeline event model
// ─────────────────────────────────────────────────────────────────────────────

enum _DayEventType {
  shiftScheduled,
  swapNote,
  checkIn,
  passSlipOut,
  passSlipReturn,
  checkOut,
  stillOnDuty,
  taskCreated,
  taskStarted,
  taskCompleted,
  ticketCreated,
  ticketResponded,
  ticketPromoted,
  isrCreated,
  isrUpdated,
  isrCompleted,
}

class _DayEvent {
  final _DayEventType type;
  final DateTime time;
  final String title;
  final String? subtitle;

  const _DayEvent({
    required this.type,
    required this.time,
    required this.title,
    this.subtitle,
  });
}

// ─────────────────────────────────────────────────────────────────────────────
// Event assembly
// ─────────────────────────────────────────────────────────────────────────────

List<_DayEvent> _buildEvents(LogbookDayActivityData data) {
  final events = <_DayEvent>[];
  final t = AppTime.formatTime;

  if (data.scheduledStart != null) {
    events.add(_DayEvent(
      type: _DayEventType.shiftScheduled,
      time: data.scheduledStart!,
      title: 'Shift scheduled — ${data.shiftLabel}',
      subtitle: data.scheduledEnd != null
          ? '${t(data.scheduledStart!)} – ${t(data.scheduledEnd!)}'
          : t(data.scheduledStart!),
    ));
    if (data.isSwapped) {
      events.add(_DayEvent(
        type: _DayEventType.swapNote,
        time: data.scheduledStart!,
        title: 'Shift received via swap',
      ));
    }
  }

  final sortedSessions = [...data.sessions]
    ..sort((a, b) => a.checkInAt.compareTo(b.checkInAt));

  for (final session in sortedSessions) {
    events.add(_DayEvent(
      type: _DayEventType.checkIn,
      time: session.checkInAt,
      title: 'Checked in',
      subtitle: t(session.checkInAt),
    ));

    // Pass slips that started during this session window.
    final sessionEnd = session.checkOutAt ?? AppTime.now();
    for (final slip in data.passSlips) {
      if (slip.slipStart == null) continue;
      if (slip.slipStart!.isBefore(session.checkInAt) ||
          slip.slipStart!.isAfter(sessionEnd)) {
        continue;
      }

      events.add(_DayEvent(
        type: _DayEventType.passSlipOut,
        time: slip.slipStart!,
        title: 'Pass slip — left',
        subtitle: slip.reason,
      ));
      if (slip.slipEnd != null) {
        events.add(_DayEvent(
          type: _DayEventType.passSlipReturn,
          time: slip.slipEnd!,
          title: 'Pass slip — returned',
          subtitle: '${t(slip.slipStart!)} – ${t(slip.slipEnd!)}',
        ));
      } else {
        events.add(_DayEvent(
          type: _DayEventType.passSlipReturn,
          time: slip.slipStart!.add(const Duration(seconds: 1)),
          title: 'Pass slip — still out',
        ));
      }
    }

    if (session.checkOutAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.checkOut,
        time: session.checkOutAt!,
        title: 'Checked out',
        subtitle: t(session.checkOutAt!),
      ));
    } else {
      events.add(_DayEvent(
        type: _DayEventType.stillOnDuty,
        time: AppTime.now(),
        title: 'Currently on duty',
      ));
    }
  }

  for (final task in data.tasks) {
    if (task.startedAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.taskStarted,
        time: task.startedAt!,
        title: 'Task started',
        subtitle: task.title,
      ));
    } else if (task.completedAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.taskCompleted,
        time: task.completedAt!,
        title: 'Task completed',
        subtitle: task.title,
      ));
    } else {
      events.add(_DayEvent(
        type: _DayEventType.taskCreated,
        time: task.createdAt,
        title: 'Task created',
        subtitle: task.title,
      ));
    }
  }

  for (final ticket in data.tickets) {
    if (ticket.promotedAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.ticketPromoted,
        time: ticket.promotedAt!,
        title: 'Ticket promoted to task',
        subtitle: ticket.subject,
      ));
    } else if (ticket.respondedAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.ticketResponded,
        time: ticket.respondedAt!,
        title: 'Ticket responded',
        subtitle: ticket.subject,
      ));
    } else {
      events.add(_DayEvent(
        type: _DayEventType.ticketCreated,
        time: ticket.createdAt,
        title: 'Ticket created',
        subtitle: ticket.subject,
      ));
    }
  }

  for (final isr in data.serviceRequests) {
    if (isr.completedAt != null) {
      events.add(_DayEvent(
        type: _DayEventType.isrCompleted,
        time: isr.completedAt!,
        title: 'IT request completed',
        subtitle: isr.requestNumber,
      ));
    } else {
      final isCreatedDay = _sameDay(isr.createdAt, data.date);
      events.add(_DayEvent(
        type: isCreatedDay ? _DayEventType.isrCreated : _DayEventType.isrUpdated,
        time: isCreatedDay ? isr.createdAt : isr.updatedAt,
        title: isCreatedDay ? 'IT request created' : 'IT request updated',
        subtitle: isr.requestNumber,
      ));
    }
  }

  events.sort((a, b) => a.time.compareTo(b.time));
  return events;
}

bool _sameDay(DateTime a, DateTime b) =>
    a.year == b.year && a.month == b.month && a.day == b.day;

// ─────────────────────────────────────────────────────────────────────────────
// Main sheet widget
// ─────────────────────────────────────────────────────────────────────────────

class LogbookDayActivitySheet extends ConsumerWidget {
  const LogbookDayActivitySheet({super.key, required this.data});

  final LogbookDayActivityData data;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final colors = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;
    final events = _buildEvents(data);

    final dateStr = _formatDate(data.date);
    final initials = _initials(data.name);

    return Column(
      mainAxisSize: MainAxisSize.min,
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        // ── Drag handle (mobile) ──────────────────────────────
        Center(
          child: Container(
            margin: const EdgeInsets.only(top: 12, bottom: 4),
            width: 36,
            height: 4,
            decoration: BoxDecoration(
              color: colors.outlineVariant,
              borderRadius: BorderRadius.circular(2),
            ),
          ),
        ),
        // ── Header ───────────────────────────────────────────
        Padding(
          padding: const EdgeInsets.fromLTRB(20, 8, 16, 0),
          child: Row(
            children: [
              CircleAvatar(
                radius: 22,
                backgroundColor: colors.primaryContainer,
                child: Text(
                  initials,
                  style: textTheme.titleSmall?.copyWith(
                    color: colors.onPrimaryContainer,
                    fontWeight: FontWeight.w700,
                  ),
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(data.name,
                        style: textTheme.titleMedium?.copyWith(
                          fontWeight: FontWeight.w600,
                        )),
                    Text(dateStr,
                        style: textTheme.bodySmall?.copyWith(
                          color: colors.onSurfaceVariant,
                        )),
                  ],
                ),
              ),
              IconButton(
                icon: const Icon(Icons.close),
                onPressed: () => Navigator.of(context).pop(),
              ),
            ],
          ),
        ),
        // ── Summary chips ─────────────────────────────────────
        if (data.tasks.isNotEmpty ||
            data.tickets.isNotEmpty ||
            data.serviceRequests.isNotEmpty ||
            data.passSlips.isNotEmpty)
          Padding(
            padding: const EdgeInsets.fromLTRB(20, 10, 20, 0),
            child: Wrap(
              spacing: 6,
              runSpacing: 4,
              children: [
                if (data.tasks.isNotEmpty)
                  _SummaryChip(
                    label: '${data.tasks.length} task${data.tasks.length == 1 ? '' : 's'}',
                    icon: Icons.task_alt_rounded,
                    color: colors.secondaryContainer,
                    onColor: colors.onSecondaryContainer,
                  ),
                if (data.tickets.isNotEmpty)
                  _SummaryChip(
                    label: '${data.tickets.length} ticket${data.tickets.length == 1 ? '' : 's'}',
                    icon: Icons.confirmation_num_outlined,
                    color: colors.tertiaryContainer,
                    onColor: colors.onTertiaryContainer,
                  ),
                if (data.serviceRequests.isNotEmpty)
                  _SummaryChip(
                    label: '${data.serviceRequests.length} ISR${data.serviceRequests.length == 1 ? '' : 's'}',
                    icon: Icons.computer_outlined,
                    color: colors.surfaceContainerHighest,
                    onColor: colors.onSurface,
                  ),
                if (data.passSlips.isNotEmpty)
                  _SummaryChip(
                    label: '${data.passSlips.length} pass slip${data.passSlips.length == 1 ? '' : 's'}',
                    icon: Icons.badge_outlined,
                    color: colors.primaryContainer,
                    onColor: colors.onPrimaryContainer,
                  ),
              ],
            ),
          ),
        const SizedBox(height: 12),
        const Divider(height: 1),
        // ── Timeline ─────────────────────────────────────────
        Flexible(
          child: events.isEmpty
              ? Padding(
                  padding: const EdgeInsets.all(32),
                  child: Center(
                    child: Text(
                      'No activity recorded for this day.',
                      style: textTheme.bodyMedium?.copyWith(
                        color: colors.onSurfaceVariant,
                      ),
                    ),
                  ),
                )
              : ListView.builder(
                  shrinkWrap: true,
                  padding: const EdgeInsets.fromLTRB(20, 12, 20, 24),
                  itemCount: events.length,
                  itemBuilder: (context, index) {
                    return M3FadeSlideIn(
                      delay: Duration(
                          milliseconds: index.clamp(0, 14) * 45),
                      child: _TimelineTile(
                        event: events[index],
                        isFirst: index == 0,
                        isLast: index == events.length - 1,
                      ),
                    );
                  },
                ),
        ),
      ],
    );
  }

  static String _formatDate(DateTime d) {
    const weekdays = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'];
    const months = [
      'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
      'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',
    ];
    final wd = weekdays[d.weekday - 1];
    final mo = months[d.month - 1];
    return '$wd, $mo ${d.day}, ${d.year}';
  }

  static String _initials(String name) {
    final parts = name.trim().split(RegExp(r'\s+'));
    if (parts.isEmpty) return '?';
    if (parts.length == 1) return parts[0][0].toUpperCase();
    return '${parts[0][0]}${parts[parts.length - 1][0]}'.toUpperCase();
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Summary chip
// ─────────────────────────────────────────────────────────────────────────────

class _SummaryChip extends StatelessWidget {
  const _SummaryChip({
    required this.label,
    required this.icon,
    required this.color,
    required this.onColor,
  });

  final String label;
  final IconData icon;
  final Color color;
  final Color onColor;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
      decoration: BoxDecoration(
        color: color,
        borderRadius: BorderRadius.circular(20),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(icon, size: 14, color: onColor),
          const SizedBox(width: 5),
          Text(
            label,
            style: Theme.of(context).textTheme.labelSmall?.copyWith(
                  color: onColor,
                  fontWeight: FontWeight.w600,
                ),
          ),
        ],
      ),
    );
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Timeline tile
// ─────────────────────────────────────────────────────────────────────────────

class _TimelineTile extends StatelessWidget {
  const _TimelineTile({
    required this.event,
    required this.isFirst,
    required this.isLast,
  });

  final _DayEvent event;
  final bool isFirst;
  final bool isLast;

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).colorScheme;
    final textTheme = Theme.of(context).textTheme;
    final dotColor = _dotColor(colors);

    return IntrinsicHeight(
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          // ── Dot + connector line ──────────────────────────
          SizedBox(
            width: 28,
            child: Column(
              children: [
                // Top connector (hidden for first item)
                SizedBox(
                  height: isFirst ? 6 : 0,
                  width: 2,
                  child: isFirst
                      ? null
                      : ColoredBox(color: colors.outlineVariant),
                ),
                // Dot
                Container(
                  width: 12,
                  height: 12,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: dotColor,
                    border: Border.all(
                      color: colors.surface,
                      width: 1.5,
                    ),
                  ),
                ),
                // Bottom connector (hidden for last item)
                if (!isLast)
                  Expanded(
                    child: Center(
                      child: SizedBox(
                        width: 2,
                        child: ColoredBox(color: colors.outlineVariant),
                      ),
                    ),
                  ),
              ],
            ),
          ),
          const SizedBox(width: 10),
          // ── Content ───────────────────────────────────────
          Expanded(
            child: Padding(
              padding: const EdgeInsets.only(bottom: 16),
              child: Row(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          event.title,
                          style: textTheme.bodyMedium?.copyWith(
                            fontWeight: FontWeight.w500,
                          ),
                        ),
                        if (event.subtitle != null) ...[
                          const SizedBox(height: 2),
                          Text(
                            event.subtitle!,
                            style: textTheme.bodySmall?.copyWith(
                              color: colors.onSurfaceVariant,
                            ),
                            maxLines: 2,
                            overflow: TextOverflow.ellipsis,
                          ),
                        ],
                      ],
                    ),
                  ),
                  const SizedBox(width: 8),
                  Text(
                    AppTime.formatTime(event.time),
                    style: textTheme.labelSmall?.copyWith(
                      color: colors.onSurfaceVariant,
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Color _dotColor(ColorScheme colors) {
    switch (event.type) {
      case _DayEventType.shiftScheduled:
      case _DayEventType.swapNote:
        return colors.outline;
      case _DayEventType.checkIn:
      case _DayEventType.checkOut:
        return colors.primary;
      case _DayEventType.passSlipOut:
      case _DayEventType.passSlipReturn:
        return colors.tertiary;
      case _DayEventType.stillOnDuty:
        return colors.primaryContainer;
      case _DayEventType.taskCreated:
      case _DayEventType.taskStarted:
      case _DayEventType.taskCompleted:
        return colors.secondary;
      case _DayEventType.ticketCreated:
      case _DayEventType.ticketResponded:
      case _DayEventType.ticketPromoted:
        return colors.secondaryContainer;
      case _DayEventType.isrCreated:
      case _DayEventType.isrUpdated:
      case _DayEventType.isrCompleted:
        return colors.tertiaryContainer;
    }
  }
}