import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:table_calendar/table_calendar.dart';
import '../common/settings.dart';

class SupplierCalendar extends StatefulWidget {
  @override
  State<SupplierCalendar> createState() => _SupplierCalendarState();
}

class _SupplierCalendarState extends State<SupplierCalendar> {
  late DateTime _focusedDay;
  late DateTime _firstDay;
  late DateTime _lastDay;

  Map<DateTime, List<Map<String, dynamic>>> calendarEvents = {};
  DateTime? _selectedDay;

  bool isLoading = true;

  Future<void> cancelSingleDate(Map<String, dynamic> delivery) async {
    try {
      await AppSettings.recurringDateAction(
        delivery["_id"],
        {
          "action": "cancel",
          "date": delivery["date"], // IMPORTANT
          "reason": "Cancelled by supplier",
        },
      );

      await fetchOrdersFromApi();

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Delivery cancelled successfully")),
      );
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Cancel failed")),
      );
    }
  }

  Future<void> rescheduleSingleDate(
      Map<String, dynamic> delivery,
      String newDate,
      ) async {
    try {
      await AppSettings.recurringDateAction(
        delivery["_id"],
        {
          "action": "reschedule",
          "date": delivery["date"],       // original date
          "new_date": newDate,            // selected date
          "reason": "Rescheduled by supplier",
        },
      );

      await fetchOrdersFromApi();

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Delivery rescheduled")),
      );
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Reschedule failed")),
      );
    }
  }

  @override
  void initState() {
    super.initState();

    final now = DateTime.now();
    _focusedDay = now.add(const Duration(days: 2));


    _firstDay = DateTime(2025, 1, 1);
    _lastDay = DateTime(now.year, now.month + 6, 0);

    fetchOrdersFromApi();
  }

  // ===========================================================================
  // FETCH API → BUILD TWO EVENTS (ORIGINAL + RESCHEDULED)
  // ===========================================================================
  Future<void> fetchOrdersFromApi() async {
    try {
      final response = await AppSettings.getSupplierBookings();
      final decoded = jsonDecode(response);

      if (decoded == null || decoded['data'] == null) {
        setState(() => isLoading = false);
        return;
      }

      final List<dynamic> orders = decoded['data'];
      calendarEvents.clear();

      for (var order in orders) {
        final String capacity = order["capacity"] ?? "";
        final String time = order["time"] ?? "";
        final String bookingStatus = order["booking_status"] ?? "";
        final String supplierName =
            order["customer_details"]?["profile"]?["username"] ?? "Customer";

        final List<dynamic> dates = order["dates"] ?? [];

        for (var d in dates) {
          final String? dateStr = d["date"];
          if (dateStr == null) continue;

          DateTime date = DateTime.parse(dateStr);
          DateTime key = DateTime(date.year, date.month, date.day);

          calendarEvents.putIfAbsent(key, () => []);

          // ---------------- STATUS LOGIC ----------------
          String status = "delivery";

          if (d["status"] == "rescheduled") {
            status = "rescheduled_from";
          }

          if (d["rescheduled_from"] != null) {
            status = "rescheduled_to";
          }

          if (d["status"] == "cancelled") {
            status = "cancelled";
          }

          calendarEvents[key]!.add({
            "status": status,
            "_id": order["_id"],
            "supplierName": supplierName,
            "capacity": capacity,
            "time": time,
            "date": dateStr,
            "originalDate": d["rescheduled_from"],
            "newDate": d["rescheduled_to"],
          });
        }
      }

      setState(() => isLoading = false);
    } catch (e) {
      setState(() => isLoading = false);
    }
  }


  // ===========================================================================
  // CANCEL ORDER API
  // ===========================================================================
  /*Future<void> cancelDelivery(String id) async {
    try {

      await AppSettings.cancelPlanOrder(id); // your endpoint
      await fetchOrdersFromApi();

      ScaffoldMessenger.of(context)
          .showSnackBar(SnackBar(content: Text("Order cancelled successfully")));
    } catch (e) {
      ScaffoldMessenger.of(context)
          .showSnackBar(SnackBar(content: Text("Cancel failed")));
    }
  }*/

  /*void _confirmCancel(String orderId) {
    showDialog(
      context: context,
      builder: (_) => AlertDialog(
        title: Text("Cancel Delivery"),
        content: Text("Are you sure you want to cancel this delivery?"),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(context), child: Text("No")),
          TextButton(
              onPressed: () {
                Navigator.pop(context);
                cancelDelivery(orderId);
              },
              child: Text("Yes, Cancel", style: TextStyle(color: Colors.red))),
        ],
      ),
    );
  }*/

  // ===========================================================================
  // HELPER FUNCTIONS
  // ===========================================================================
  String formatShort(String date) {
    try {
      final d = DateTime.parse(date);
      return "${d.day} ${monthShort[d.month - 1]}";
    } catch (e) {
      return date;
    }
  }

  List<String> monthShort = [
    "Jan","Feb","Mar","Apr","May","Jun",
    "Jul","Aug","Sep","Oct","Nov","Dec"
  ];

  Widget _buildStatusIcon(String status) {
    if (status == "rescheduled_from") {
      return Icon(Icons.subdirectory_arrow_left, color: Colors.orange);
    }
    if (status == "rescheduled_to") {
      return Icon(Icons.subdirectory_arrow_right, color: Colors.deepOrange);
    }
    if (status == "cancelled") {
      return Icon(Icons.cancel, color: Colors.red);
    }
    return Icon(Icons.local_shipping, color: Colors.blue);
  }

  String _buildStatusText(Map<String, dynamic> d) {
    String status = d["status"];
    String? originalDate = d["originalDate"];
    String? newDate = d["newDate"];

    if (status == "rescheduled_from") {
      return "Rescheduled from this date → ${formatShort(newDate!)}";
    }
    if (status == "rescheduled_to") {
      return "Rescheduled to this date (from ${formatShort(originalDate!)})";
    }
    if (status == "cancelled") {
      return "Cancelled";
    }
    return status;
  }

  // ===========================================================================
  // OPEN RESCHEDULE CALENDAR
  // ===========================================================================
  Future<void> openRescheduleCalendar(Map<String, dynamic> delivery) async {
    DateTime now = DateTime.now();

    final DateTime? pickedDate = await showDatePicker(
      context: context,
      initialDate: now.add(Duration(days: 1)),
      firstDate: now.add(Duration(days: 1)),
      lastDate: DateTime(now.year + 1, 12, 31),
    );

    if (pickedDate == null) return;

    String formatted =
        "${pickedDate.year}-${pickedDate.month.toString().padLeft(2,'0')}-${pickedDate.day.toString().padLeft(2,'0')}";
    await rescheduleSingleDate(delivery, formatted);

    //await sendRescheduleToServer(delivery["_id"], formatted);
  }

  /*Future<void> sendRescheduleToServer(String id, String newDate) async {
    try {
      final payload = {"reScheduleDateOfDelivery": newDate};

      await AppSettings.rescheduleOrder(id, payload);
      await fetchOrdersFromApi();

      ScaffoldMessenger.of(context)
          .showSnackBar(SnackBar(content: Text("Delivery rescheduled to $newDate")));
    } catch (e) {
      ScaffoldMessenger.of(context)
          .showSnackBar(SnackBar(content: Text("Reschedule failed")));
    }
  }
*/
  // ===========================================================================
  // SHOW DELIVERY LIST
  // ===========================================================================
  void showDeliveryList(DateTime date) {
    final key = DateTime(date.year, date.month, date.day);
    final events = calendarEvents[key];

    if (events == null || events.isEmpty) return;

    bool isPast = date.isBefore(DateTime(
        DateTime.now().year, DateTime.now().month, DateTime.now().day));

    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (_) {
        final list = events.toList();

        return DraggableScrollableSheet(
          initialChildSize: 0.9,
          maxChildSize: 0.9,
          minChildSize: 0.4,
          builder: (_, controller) {
            return Container(
              padding: EdgeInsets.all(20),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
              ),
              child: Column(
                children: [
                  Row(
                    children: [
                      Expanded(
                        child: Text(
                          "Select Delivery",
                          style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                        ),
                      ),
                      GestureDetector(
                          onTap: () => Navigator.pop(context),
                          child: Icon(Icons.close)),
                    ],
                  ),

                  Expanded(
                    child: ListView(
                      controller: controller,
                      children: list.map((delivery) {
                        return ListTile(
                          leading: _buildStatusIcon(delivery["status"]),
                          title: Text(_buildStatusText(delivery)),
                          subtitle: Text(
                              "Capacity: ${delivery["capacity"]} • ${delivery["time"]}"),
                          onTap: () {
                            Navigator.pop(context);
                            showActionsForSingleDelivery(delivery, isPast);
                          },
                        );
                      }).toList(),
                    ),
                  )
                ],
              ),
            );
          },
        );
      },
    );
  }

  // ===========================================================================
  // ACTIONS SHEET
  // ===========================================================================
  void showActionsForSingleDelivery(Map<String, dynamic> delivery, bool isPast) {
    String status = delivery["status"];

    // ❌ ORIGINAL DATE → NO ACTIONS
    if (status == "rescheduled_from") {
      showModalBottomSheet(
        context: context,
        builder: (_) {
          return Container(
            padding: EdgeInsets.all(20),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text("Rescheduled from this date",
                    style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
                SizedBox(height: 10),
                Text("This delivery was moved to another date.",
                    style: TextStyle(color: Colors.grey)),
              ],
            ),
          );
        },
      );
      return;
    }

    // ❌ CANCELLED ORDER → NO ACTIONS
    if (status == "cancelled") {
      showModalBottomSheet(
        context: context,
        builder: (_) =>
            Container(
              padding: EdgeInsets.all(20),
              child: Text("Order was cancelled", style: TextStyle(color: Colors.red)),
            ),
      );
      return;
    }

    // NORMAL OR RESCHEDULED_TO (ACTIONS ENABLED)
    showModalBottomSheet(
      context: context,
      builder: (_) {
        return Container(
          padding: EdgeInsets.all(20),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text("${delivery["supplierName"]}",
                  style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
              SizedBox(height: 16),

              if (!isPast) ...[
                ListTile(
                  leading: Icon(Icons.calendar_month, color: Colors.blue),
                  title: Text("Reschedule Delivery"),
                  onTap: () {
                    Navigator.pop(context);
                    openRescheduleCalendar(delivery);
                  },
                ),

                ListTile(
                  leading: Icon(Icons.delete_forever, color: Colors.red),
                  title: Text("Cancel Delivery"),
                  onTap: () {
                    Navigator.pop(context);
                    cancelSingleDate(delivery);
                  },
                ),
              ],

              if (isPast)
                Text("Past delivery — actions disabled",
                    style: TextStyle(color: Colors.grey)),
            ],
          ),
        );
      },
    );
  }

  // ===========================================================================
  // BUILD UI
  // ===========================================================================
  @override
  Widget build(BuildContext context) {
    if (isLoading) {
      return Scaffold(body: Center(child: CircularProgressIndicator()));
    }

    final height = MediaQuery.of(context).size.height;

    return Scaffold(
      backgroundColor: Colors.white,
      body: Column(
        children: [
          SizedBox(height: 50),

          Text(
            "${monthShort[_focusedDay.month - 1]} ${_focusedDay.year}",
            style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
          ),

          Expanded(
            child: TableCalendar(
              firstDay: _firstDay,
              lastDay: _lastDay,
              focusedDay: _focusedDay,
              headerVisible: false,
              calendarFormat: CalendarFormat.month,
              rowHeight: (height - 200) / 6 + 12,
              daysOfWeekHeight: 40,

              calendarStyle: CalendarStyle(
                selectedDecoration: const BoxDecoration(
                  color: Colors.transparent, // remove selected circle
                ),

                todayDecoration: const BoxDecoration(
                  color: Colors.transparent, // 🚫 removes TODAY highlight
                ),

                todayTextStyle: const TextStyle(
                  color: Colors.red,  // same as normal day
                  fontWeight: FontWeight.bold,
                ),

                tableBorder: TableBorder(
                  horizontalInside: BorderSide(
                    color: Colors.grey.shade300,
                    width: 1,
                  ),
                ),
              ),

              onPageChanged: (focused) {
                setState(() => _focusedDay = focused);
              },

              onDaySelected: (selected, focused) {
                _focusedDay = focused;
                _selectedDay = selected;
                showDeliveryList(selected);
                setState(() {});
              },

              calendarBuilders: CalendarBuilders(

                /// 🔴 TODAY BUILDER (dot only here)
                todayBuilder: (context, date, _) {
                  final key = DateTime(date.year, date.month, date.day);
                  final events = calendarEvents[key];

                  Map<String, int> grouped = {};
                  if (events != null) {
                    for (var e in events) {
                      grouped[e["status"]] = (grouped[e["status"]] ?? 0) + 1;
                    }
                  }

                  return Container(
                    margin: const EdgeInsets.symmetric(vertical: 8),
                    padding: const EdgeInsets.only(top: 1),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: [
                        // 🔴 Today date
                        Text(
                          "${date.day}",
                          style: const TextStyle(
                            fontSize: 14,
                            fontWeight: FontWeight.bold,
                            color: Colors.red,
                          ),
                        ),

                        // 🔴 Dot ONLY for today
                        const SizedBox(height: 2),
                        Container(
                          width: 5,
                          height: 5,
                          decoration: const BoxDecoration(
                            color: Colors.red,
                            shape: BoxShape.circle,
                          ),
                        ),

                        // Events OR reserved space
                        if (events != null && events.isNotEmpty)
                          Wrap(
                            spacing: 3,
                            alignment: WrapAlignment.center,
                            children: grouped.entries.map((entry) {
                              String label;
                              IconData icon;
                              Color color;

                              if (entry.key == "rescheduled_from" ||
                                  entry.key == "rescheduled_to") {
                                label = "Rescheduled";
                                icon = Icons.update;
                                color = Colors.orange;
                              } else if (entry.key == "cancelled") {
                                label = "Cancelled";
                                icon = Icons.cancel;
                                color = Colors.red;
                              } else {
                                label = "Delivery";
                                icon = Icons.local_shipping;
                                color = Colors.blue;
                              }

                              return SizedBox(
                                height: 26,
                                child: Container(
                                  padding:
                                  const EdgeInsets.symmetric(horizontal: 3, vertical: 2),
                                  decoration: BoxDecoration(
                                    color: color.withOpacity(0.12),
                                    borderRadius: BorderRadius.zero,
                                  ),
                                  child: Column(
                                    mainAxisAlignment: MainAxisAlignment.center,
                                    children: [
                                      Icon(icon, size: 10, color: color),
                                      const SizedBox(height: 1),
                                      FittedBox(
                                        fit: BoxFit.scaleDown,
                                        child: Text(
                                          "$label x${entry.value}",
                                          style: TextStyle(
                                            fontSize: 7,
                                            fontWeight: FontWeight.bold,
                                            color: color,
                                          ),
                                        ),
                                      ),
                                    ],
                                  ),
                                ),
                              );
                            }).toList(),
                          )
                        else
                          const SizedBox(height: 26), // keep height same
                      ],
                    ),
                  );
                },

                /// 📅 NORMAL DAYS (NO DOT)
                defaultBuilder: (context, date, _) {
                  final key = DateTime(date.year, date.month, date.day);
                  final events = calendarEvents[key];

                  Map<String, int> grouped = {};
                  if (events != null) {
                    for (var e in events) {
                      grouped[e["status"]] = (grouped[e["status"]] ?? 0) + 1;
                    }
                  }

                  return Container(
                    margin: const EdgeInsets.symmetric(vertical: 8),
                    padding: const EdgeInsets.only(top: 1),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: [
                        Text(
                          "${date.day}",
                          style: const TextStyle(
                            fontSize: 14,
                            fontWeight: FontWeight.bold,
                          ),
                        ),

                        if (events != null && events.isNotEmpty)
                          Wrap(
                            spacing: 3,
                            alignment: WrapAlignment.center,
                            children: grouped.entries.map((entry) {
                              String label;
                              IconData icon;
                              Color color;

                              if (entry.key == "rescheduled_from" ||
                                  entry.key == "rescheduled_to") {
                                label = "Rescheduled";
                                icon = Icons.update;
                                color = Colors.orange;
                              } else if (entry.key == "cancelled") {
                                label = "Cancelled";
                                icon = Icons.cancel;
                                color = Colors.red;
                              } else {
                                label = "Delivery";
                                icon = Icons.local_shipping;
                                color = Colors.blue;
                              }

                              return SizedBox(
                                height: 26,
                                child: Container(
                                  padding:
                                  const EdgeInsets.symmetric(horizontal: 3, vertical: 2),
                                  decoration: BoxDecoration(
                                    color: color.withOpacity(0.12),
                                    borderRadius: BorderRadius.zero,
                                  ),
                                  child: Column(
                                    mainAxisAlignment: MainAxisAlignment.center,
                                    children: [
                                      Icon(icon, size: 10, color: color),
                                      const SizedBox(height: 1),
                                      FittedBox(
                                        fit: BoxFit.scaleDown,
                                        child: Text(
                                          "$label x${entry.value}",
                                          style: TextStyle(
                                            fontSize: 7,
                                            fontWeight: FontWeight.bold,
                                            color: color,
                                          ),
                                        ),
                                      ),
                                    ],
                                  ),
                                ),
                              );
                            }).toList(),
                          )
                        else
                          const SizedBox(height: 26),
                      ],
                    ),
                  );
                },

                /// 🌫 Outside month days
                outsideBuilder: (context, date, _) {
                  return Container(
                    margin: const EdgeInsets.symmetric(vertical: 8),
                    padding: const EdgeInsets.only(top: 1),
                    child: Column(
                        crossAxisAlignment: CrossAxisAlignment.center,
                        children: [
                          Text(
                            "${date.day}",
                            style: TextStyle(
                              fontSize: 14,
                              fontWeight: FontWeight.bold,
                              color: Colors.grey.shade400,
                            ),
                          ),
                        ]
                    ),
                  );
                },
              ),

            ),
          ),
        ],
      ),
    );
  }
}