/*
 * Copyright (C) 2022-2023 Yubico.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:material_symbols_icons/symbols.dart';

import '../../app/message.dart';
import '../../app/models.dart';
import '../../app/shortcuts.dart';
import '../../app/state.dart';
import '../../app/views/action_list.dart';
import '../../app/views/app_failure_page.dart';
import '../../app/views/app_page.dart';
import '../../app/views/keys.dart';
import '../../app/views/message_page.dart';
import '../../app/views/message_page_not_initialized.dart';
import '../../core/state.dart';
import '../../exception/no_data_exception.dart';
import '../../management/models.dart';
import '../../widgets/app_input_decoration.dart';
import '../../widgets/app_text_form_field.dart';
import '../../widgets/file_drop_overlay.dart';
import '../../widgets/list_title.dart';
import '../features.dart' as features;
import '../keys.dart' as keys;
import '../models.dart';
import '../state.dart';
import 'account_dialog.dart';
import 'account_helper.dart';
import 'account_list.dart';
import 'actions.dart';
import 'key_actions.dart';
import 'unlock_form.dart';
import 'utils.dart';

class OathScreen extends ConsumerWidget {
  final DevicePath devicePath;

  const OathScreen(this.devicePath, {super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final l10n = AppLocalizations.of(context)!;
    return ref.watch(oathStateProvider(devicePath)).when(
        loading: () => const MessagePage(
              centered: true,
              graphic: CircularProgressIndicator(),
              delayedContent: true,
            ),
        error: (error, _) => error is NoDataException
            ? MessagePageNotInitialized(
                title: l10n.s_accounts,
                capabilities: const [Capability.oath],
              )
            : AppFailurePage(
                cause: error,
              ),
        data: (oathState) => oathState.locked
            ? _LockedView(devicePath, oathState)
            : _UnlockedView(devicePath, oathState));
  }
}

class _LockedView extends ConsumerWidget {
  final DevicePath devicePath;
  final OathState oathState;

  const _LockedView(this.devicePath, this.oathState);

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final hasActions = ref.watch(featureProvider)(features.actions);
    return AppPage(
      title: AppLocalizations.of(context)!.s_accounts,
      capabilities: const [Capability.oath],
      keyActionsBuilder: hasActions
          ? (context) => oathBuildActions(context, devicePath, oathState, ref)
          : null,
      builder: (context, _) => Padding(
        padding: const EdgeInsets.symmetric(vertical: 8),
        child: UnlockForm(
          devicePath,
          keystore: oathState.keystore,
        ),
      ),
    );
  }
}

class _UnlockedView extends ConsumerStatefulWidget {
  final DevicePath devicePath;
  final OathState oathState;

  const _UnlockedView(this.devicePath, this.oathState);

  @override
  ConsumerState<ConsumerStatefulWidget> createState() => _UnlockedViewState();
}

class _UnlockedViewState extends ConsumerState<_UnlockedView> {
  late FocusNode searchFocus;
  late TextEditingController searchController;
  OathCredential? _selected;

  @override
  void initState() {
    super.initState();
    searchFocus = FocusNode();
    searchController =
        TextEditingController(text: ref.read(accountsSearchProvider));
    searchFocus.addListener(_onFocusChange);
  }

  @override
  void dispose() {
    searchFocus.dispose();
    searchController.dispose();
    super.dispose();
  }

  void _onFocusChange() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    // ONLY rebuild if the number of credentials changes.
    final numCreds = ref.watch(credentialListProvider(widget.devicePath)
        .select((value) => value?.length));
    final hasFeature = ref.watch(featureProvider);
    final hasActions = hasFeature(features.actions);
    final searchText = searchController.text;

    Future<void> onFileDropped(File file) async {
      final qrScanner = ref.read(qrScannerProvider);
      if (qrScanner != null) {
        final withContext = ref.read(withContextProvider);
        final qrData =
            await handleQrFile(file, context, withContext, qrScanner);
        if (qrData != null) {
          await withContext((context) async {
            final credentials = ref.read(credentialsProvider);
            await handleUri(context, credentials, qrData, widget.devicePath,
                widget.oathState, l10n);
          });
        }
      }
    }

    if (numCreds == 0) {
      return MessagePage(
        actionsBuilder: (context, expanded) => [
          if (!expanded)
            ActionChip(
              label: Text(l10n.s_add_account),
              onPressed: () async {
                await addOathAccount(
                  context,
                  ref,
                  widget.devicePath,
                  widget.oathState,
                );
              },
              avatar: const Icon(Symbols.person_add_alt),
            )
        ],
        title: l10n.s_accounts,
        capabilities: const [Capability.oath],
        key: keys.noAccountsView,
        header: l10n.l_authenticator_get_started,
        message: l10n.l_no_accounts_desc,
        keyActionsBuilder: hasActions
            ? (context) => oathBuildActions(
                context, widget.devicePath, widget.oathState, ref,
                used: 0)
            : null,
        onFileDropped: onFileDropped,
        fileDropOverlay: FileDropOverlay(
          title: l10n.s_add_account,
          subtitle: l10n.l_drop_qr_description,
        ),
      );
    }

    if (numCreds == null) {
      return AppPage(
        title: AppLocalizations.of(context)!.s_accounts,
        capabilities: const [Capability.oath],
        centered: true,
        delayedContent: true,
        builder: (context, _) => const CircularProgressIndicator(),
      );
    }

    return OathActions(
      devicePath: widget.devicePath,
      actions: (context) => {
        SearchIntent: CallbackAction<SearchIntent>(onInvoke: (_) {
          searchController.selection = TextSelection(
              baseOffset: 0, extentOffset: searchController.text.length);
          searchFocus.unfocus();
          Timer.run(() => searchFocus.requestFocus());
          return null;
        }),
        EscapeIntent: CallbackAction<EscapeIntent>(onInvoke: (intent) {
          if (_selected != null) {
            setState(() {
              _selected = null;
            });
          } else {
            Actions.invoke(context, intent);
          }
          return false;
        }),
        OpenIntent<OathCredential>: CallbackAction<OpenIntent<OathCredential>>(
            onInvoke: (intent) async {
          await showBlurDialog(
            context: context,
            barrierColor: Colors.transparent,
            builder: (context) => AccountDialog(intent.target),
          );
          return null;
        }),
        if (hasFeature(features.accountsRename))
          EditIntent<OathCredential>:
              CallbackAction<EditIntent<OathCredential>>(
                  onInvoke: (intent) async {
            final renamed =
                await (Actions.invoke(context, intent) as Future<dynamic>?);
            if (renamed is OathCredential && _selected == intent.target) {
              setState(() {
                _selected = renamed;
              });
            }
            return renamed;
          }),
        if (hasFeature(features.accountsDelete))
          DeleteIntent<OathCredential>:
              CallbackAction<DeleteIntent<OathCredential>>(
                  onInvoke: (intent) async {
            final deleted =
                await (Actions.invoke(context, intent) as Future<dynamic>?);
            if (deleted == true && _selected == intent.target) {
              setState(() {
                _selected = null;
              });
            }
            return deleted;
          }),
      },
      builder: (context) => AppPage(
        title: l10n.s_accounts,
        alternativeTitle:
            searchText != '' ? l10n.l_results_for(searchText) : null,
        capabilities: const [Capability.oath],
        keyActionsBuilder: hasActions
            ? (context) => oathBuildActions(
                  context,
                  widget.devicePath,
                  widget.oathState,
                  ref,
                  used: numCreds,
                )
            : null,
        onFileDropped: onFileDropped,
        fileDropOverlay: FileDropOverlay(
          title: l10n.s_add_account,
          subtitle: l10n.l_drop_qr_description,
        ),
        detailViewBuilder: _selected != null
            ? (context) {
                final helper = AccountHelper(context, ref, _selected!);
                final subtitle = helper.subtitle;
                return Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    ListTitle(l10n.s_details),
                    Padding(
                      padding: const EdgeInsets.only(left: 16.0),
                      child: Card(
                        elevation: 0.0,
                        color: Theme.of(context).hoverColor,
                        child: Padding(
                          padding: const EdgeInsets.all(16),
                          child: Column(
                            children: [
                              Padding(
                                padding:
                                    const EdgeInsets.symmetric(vertical: 16),
                                child: Row(
                                  mainAxisSize: MainAxisSize.min,
                                  crossAxisAlignment: CrossAxisAlignment.center,
                                  children: [
                                    IconTheme(
                                      data: IconTheme.of(context)
                                          .copyWith(size: 24),
                                      child: helper.buildCodeIcon(),
                                    ),
                                    const SizedBox(width: 8.0),
                                    DefaultTextStyle.merge(
                                      style: const TextStyle(fontSize: 28),
                                      child: helper.buildCodeLabel(),
                                    ),
                                  ],
                                ),
                              ),
                              Text(
                                helper.title,
                                style:
                                    Theme.of(context).textTheme.headlineSmall,
                                softWrap: true,
                                textAlign: TextAlign.center,
                              ),
                              if (subtitle != null)
                                Text(
                                  subtitle,
                                  softWrap: true,
                                  textAlign: TextAlign.center,
                                  // This is what ListTile uses for subtitle
                                  style: Theme.of(context)
                                      .textTheme
                                      .bodyMedium!
                                      .copyWith(
                                        color: Theme.of(context)
                                            .textTheme
                                            .bodySmall!
                                            .color,
                                      ),
                                ),
                            ],
                          ),
                        ),
                      ),
                    ),
                    ActionListSection.fromMenuActions(
                      context,
                      AppLocalizations.of(context)!.s_actions,
                      actions: helper.buildActions(),
                    ),
                  ],
                );
              }
            : null,
        headerSliver: Focus(
          canRequestFocus: false,
          onKeyEvent: (node, event) {
            if (event.logicalKey == LogicalKeyboardKey.arrowDown) {
              node.focusInDirection(TraversalDirection.down);
              return KeyEventResult.handled;
            }
            if (event.logicalKey == LogicalKeyboardKey.escape) {
              searchController.clear();
              ref.read(accountsSearchProvider.notifier).setFilter('');
              node.unfocus();
              setState(() {});
              return KeyEventResult.handled;
            }
            return KeyEventResult.ignored;
          },
          child: Builder(builder: (context) {
            final textTheme = Theme.of(context).textTheme;
            return Padding(
              padding:
                  const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
              child: AppTextFormField(
                key: searchField,
                controller: searchController,
                focusNode: searchFocus,
                // Use the default style, but with a smaller font size:
                style: textTheme.titleMedium
                    ?.copyWith(fontSize: textTheme.titleSmall?.fontSize),
                decoration: AppInputDecoration(
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(48),
                    borderSide: BorderSide(
                      width: 0,
                      style: searchFocus.hasFocus
                          ? BorderStyle.solid
                          : BorderStyle.none,
                    ),
                  ),
                  contentPadding: const EdgeInsets.all(16),
                  fillColor: Theme.of(context).hoverColor,
                  filled: true,
                  hintText: l10n.s_search_accounts,
                  isDense: true,
                  prefixIcon: const Padding(
                    padding: EdgeInsetsDirectional.only(start: 8.0),
                    child: Icon(Icons.search_outlined),
                  ),
                  suffixIcon: searchController.text.isNotEmpty
                      ? IconButton(
                          icon: const Icon(Icons.clear),
                          iconSize: 16,
                          onPressed: () {
                            searchController.clear();
                            ref
                                .read(accountsSearchProvider.notifier)
                                .setFilter('');
                            setState(() {});
                          },
                        )
                      : null,
                ),
                onChanged: (value) {
                  ref.read(accountsSearchProvider.notifier).setFilter(value);
                  setState(() {});
                },
                textInputAction: TextInputAction.next,
                onFieldSubmitted: (value) {
                  Focus.of(context).focusInDirection(TraversalDirection.down);
                },
              ),
            );
          }),
        ),
        builder: (context, expanded) {
          // De-select if window is resized to be non-expanded.
          if (!expanded && _selected != null) {
            Timer.run(() {
              setState(() {
                _selected = null;
              });
            });
          }
          return Actions(
            actions: {
              if (expanded)
                OpenIntent<OathCredential>:
                    CallbackAction<OpenIntent<OathCredential>>(
                        onInvoke: (OpenIntent<OathCredential> intent) {
                  setState(() {
                    _selected = intent.target;
                  });
                  return null;
                }),
            },
            child: Column(
              children: [
                Consumer(
                  builder: (context, ref, _) {
                    return AccountList(
                      ref.watch(credentialListProvider(widget.devicePath)) ??
                          [],
                      expanded: expanded,
                      selected: _selected,
                    );
                  },
                )
              ],
            ),
          );
        },
      ),
    );
  }
}