// SPDX-FileCopyrightText: 2026 FocusFlow contributors
// SPDX-License-Identifier: AGPL-3.0-only

/// Renders the Today Pane widget for the FocusFlow Flutter UI.
library;

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

import '../controllers/scheduler_command_controller.dart';
import '../controllers/scheduler_read_controller.dart';
import 'read_state_view.dart';
import 'schedule_components.dart';

/// Read-driven pane that renders the Today view and optional commands.
class TodayPane extends StatelessWidget {
  /// Creates a Today pane from a read [controller].
  const TodayPane({
    required this.controller,
    this.commandController,
    super.key,
  });

  /// Controller that loads Today state.
  final UiReadController<TodayState> controller;

  /// Optional command controller for Today actions.
  final SchedulerCommandController? commandController;

  /// Builds the widget subtree for this component.
  /// The method translates the current widget configuration and state into Flutter UI without mutating scheduler domain data.
  @override
  Widget build(BuildContext context) {
    return ReadStateView<TodayState>(
      controller: controller,
      title: 'Today',
      emptyTitle: 'Today is clear',
      emptyMessage: 'No scheduled work is waiting in this view.',
      dataBuilder: (context, state) =>
          TodayContent(state: state, commandController: commandController),
    );
  }
}

/// Populated Today view for a loaded Today state.
class TodayContent extends StatelessWidget {
  /// Creates Today content for [state].
  const TodayContent({required this.state, this.commandController, super.key});

  /// Loaded Today state to display.
  final TodayState state;

  /// Optional command controller for completing tasks.
  final SchedulerCommandController? commandController;

  /// Builds the widget subtree for this component.
  /// The method translates the current widget configuration and state into Flutter UI without mutating scheduler domain data.
  @override
  Widget build(BuildContext context) {
    return ListView(
      padding: const EdgeInsets.all(16),
      children: [
        Text('Today', style: Theme.of(context).textTheme.headlineMedium),
        const SizedBox(height: 12),
        for (final notice in state.pendingNotices)
          NoticeBanner(message: notice.message),
        CompactPanel(items: state.compactState.compactItems),
        Text('Timeline', style: Theme.of(context).textTheme.titleMedium),
        const SizedBox(height: 8),
        for (final item in state.timelineItems)
          TimelineRow(
            item: item,
            onDone: _canComplete(item) && commandController != null
                ? () {
                    return commandController!.completeFlexibleTask(
                      taskId: item.taskId!,
                    );
                  }
                : null,
          ),
      ],
    );
  }

  /// Runs the `_canComplete` helper used inside this library.
  /// The helper centralizes a small piece of transformation or validation so higher-level scheduler flow remains easier to read.
  bool _canComplete(TodayTimelineItem item) {
    return item.taskType == TaskType.flexible &&
        item.taskStatus == TaskStatus.planned &&
        item.taskId != null;
  }
}