import 'package:flisp_app/models/calendar.dart';
import 'package:flisp_app/provider/calendar_provider.dart';
import 'package:flisp_app/widgets/common.dart';
import 'package:flutter/material.dart';
import 'package:flutter_form_builder/flutter_form_builder.dart';
import 'package:intl/intl.dart';
import 'package:provider/provider.dart';

class CalendarForm extends StatefulWidget {
  final GlobalKey<FormBuilderState> formKey;
  final bool isEditing;
  final Calendar? initialCalendar;

  const CalendarForm({
    super.key,
    required this.formKey,
    required this.isEditing,
    this.initialCalendar,
  });

  @override
  State<CalendarForm> createState() => _CalendarFormState();
}

class _CalendarFormState extends State<CalendarForm> {
  final int maxTitleCount = 10;

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

  Widget buildTitle() {
    final colors = Theme.of(context).colorScheme;

    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Icon(
          widget.isEditing ? Icons.edit_note : Icons.add_task,
          color: colors.primary,
          size: 24,
        ),
        SizedBox(width: 8),
        Text(
          widget.isEditing ? '编辑日程事项' : '添加日程事项',
          style: TextStyle(
            fontSize: 20,
            fontWeight: FontWeight.bold,
            color: colors.primary,
          ),
        ),
      ],
    );
  }

  String? titleFieldValidator(value) {
    if (value == null || value.isEmpty) {
      return '请输入标题';
    }
    if (value.length > maxTitleCount) {
      return '标题不能超过$maxTitleCount个字符';
    }
    return null;
  }

  FormBuilderTextField buildTitleField(CalendarProvider provider) {
    final colors = Theme.of(context).colorScheme;

    return FormBuilderTextField(
      name: 'title',
      initialValue: provider.formItem.title,
      onChanged: (value) {
        setState(() {
          provider.formItem.title = value ?? '';
        });
      },
      decoration: InputDecoration(
        label: RichText(
          text: TextSpan(
            text: '内容',
            style: TextStyle(
              color: Colors.grey,
              fontSize: 16,
              fontFamily: 'CustomFont',
            ),
            children: const [
              TextSpan(
                text: '*',
                style: TextStyle(
                  color: Colors.red,
                  fontSize: 18,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ],
          ),
        ),
        hintText: '请输入日程标题...',
        hintStyle: TextStyle(color: Colors.grey),
        counterText: '',
        suffixText: '${provider.formItem.title.length}/$maxTitleCount',
        border: buildFormBoard(),
        enabledBorder: buildFormEnabledBoard(),
        focusedBorder: buildFormFocusedBoard(colors),
        filled: true,
        fillColor: colors.surface,
        prefixIcon: Icon(Icons.title, color: Colors.blue),
        contentPadding: EdgeInsets.symmetric(horizontal: 16, vertical: 14),
      ),
      maxLength: maxTitleCount,
      validator: (value) => titleFieldValidator(value),
    );
  }

  String? startTimeFieldValidator(CalendarProvider provider, value) {
    if (value == null) {
      return '请选择开始时间';
    }
    if (value.isBefore(DateTime.now())) {
      return '不能选择过去的日期';
    }

    final endTime = provider.formItem.endTime;
    if (endTime != null && endTime.isBefore(value)) {
      return '结束时间不能早于开始时间';
    }
    if (endTime != null && endTime.isAtSameMomentAs(value)) {
      return '开始时间不能等于结束时间';
    }

    return null;
  }

  FormBuilderDateTimePicker buildStartTimeField(CalendarProvider provider) {
    final colors = Theme.of(context).colorScheme;
    var startTime = provider.formItem.startTime;

    return FormBuilderDateTimePicker(
      name: 'startTime',
      format: DateFormat('yyyy-MM-dd HH:mm:ss'),
      initialValue: startTime,
      inputType: InputType.both,
      onChanged: (value) {
        setState(() {
          provider.formItem.startTime = value!;
        });
      },
      decoration: InputDecoration(
        labelText: startTime == null ? '选择开始时间' : '开始时间: ',
        labelStyle: TextStyle(color: Colors.grey),
        prefixIcon: Icon(Icons.calendar_month, color: Colors.purple),
        border: buildFormBoard(),
        enabledBorder: buildFormEnabledBoard(),
        focusedBorder: buildFormFocusedBoard(colors),
        filled: true,
        fillColor: colors.surface,
        contentPadding: EdgeInsets.symmetric(horizontal: 16, vertical: 14),
      ),
      validator: (value) => startTimeFieldValidator(provider, value),
    );
  }

  String? endTimeFieldValidator(CalendarProvider provider, value) {
    if (value == null) {
      return '请选择结束时间';
    }
    if (value.isBefore(DateTime.now())) {
      return '不能选择过去的日期';
    }

    final startTime = provider.formItem.startTime;
    if (startTime != null && value.isBefore(startTime)) {
      return '结束时间不能早于开始时间';
    }
    if (startTime != null && startTime.isAtSameMomentAs(value)) {
      return '开始时间不能等于结束时间';
    }

    return null;
  }

  FormBuilderDateTimePicker buildEndTimeField(CalendarProvider provider) {
    final colors = Theme.of(context).colorScheme;
    var endTime = provider.formItem.endTime;

    return FormBuilderDateTimePicker(
      name: 'endTime',
      format: DateFormat('yyyy-MM-dd HH:mm:ss'),
      initialValue: endTime,
      inputType: InputType.both,
      onChanged: (value) {
        setState(() {
          provider.formItem.endTime = value!;
        });
      },
      decoration: InputDecoration(
        labelText: endTime == null ? '选择结束时间' : '结束时间: ',
        labelStyle: TextStyle(color: Colors.grey),
        prefixIcon: Icon(Icons.calendar_month, color: Colors.purple),
        border: buildFormBoard(),
        enabledBorder: buildFormEnabledBoard(),
        focusedBorder: buildFormFocusedBoard(colors),
        filled: true,
        fillColor: colors.surface,
        contentPadding: EdgeInsets.symmetric(horizontal: 16, vertical: 14),
      ),
      validator: (value) => endTimeFieldValidator(provider, value),
    );
  }

  IconButton buildClearScheduled(CalendarProvider provider) {
    return IconButton(
      icon: Icon(Icons.clear, size: 18),
      onPressed: () {
        setState(() {
          provider.formItem.scheduledTime = null;
        });
        widget.formKey.currentState?.fields['scheduledTime']?.didChange(null);
      },
    );
  }

  String? scheduledTimeFieldValidator(value) {
    if (value != null && value.isBefore(DateTime.now())) {
      return '不能选择过去的日期';
    }
    return null;
  }

  FormBuilderDateTimePicker buildScheduledTimeField(CalendarProvider provider) {
    final colors = Theme.of(context).colorScheme;
    var scheduledTime = provider.formItem.scheduledTime;

    return FormBuilderDateTimePicker(
      name: 'scheduledTime',
      format: DateFormat('yyyy-MM-dd HH:mm:ss'),
      initialValue: scheduledTime,
      inputType: InputType.both,
      onChanged: (value) {
        setState(() {
          provider.formItem.scheduledTime = value;
        });
      },
      decoration: InputDecoration(
        labelText: scheduledTime == null ? '选择提醒时间' : '提醒时间: ',
        labelStyle: TextStyle(color: Colors.grey),
        prefixIcon: Icon(Icons.calendar_month, color: Colors.purple),
        border: buildFormBoard(),
        enabledBorder: buildFormEnabledBoard(),
        focusedBorder: buildFormFocusedBoard(colors),
        filled: true,
        fillColor: colors.surface,
        contentPadding: EdgeInsets.symmetric(horizontal: 16, vertical: 14),
        suffixIcon:
            scheduledTime != null ? buildClearScheduled(provider) : null,
      ),
      validator: (value) => scheduledTimeFieldValidator(value),
    );
  }

  FormBuilder buildForm(CalendarProvider provider) {
    return FormBuilder(
      key: widget.formKey,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          buildTitleField(provider),
          SizedBox(height: 12),
          buildStartTimeField(provider),
          SizedBox(height: 12),
          buildEndTimeField(provider),
          SizedBox(height: 12),
          buildScheduledTimeField(provider),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final provider = Provider.of<CalendarProvider>(context);

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 6, horizontal: 10),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [buildTitle(), SizedBox(height: 20), buildForm(provider)],
      ),
    );
  }
}