import 'dart:async';

import 'package:flutter/material.dart';
import 'package:google_maps_webservice/places.dart';
import 'package:provider/provider.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/google_maps_place_picker.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/providers/place_provider.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/providers/search_provider.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/src/components/prediction_tile.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/src/components/rounded_frame.dart';
import 'package:healthcare_user/google_maps_place_picker_mb/src/controllers/autocomplete_search_controller.dart';

class AutoCompleteSearch extends StatefulWidget {
  const AutoCompleteSearch(
      {Key? key,
        required this.sessionToken,
        required this.onPicked,
        required this.appBarKey,
        this.hintText = "Search here",
        this.searchingText = "Searching...",
        this.hidden = false,
        this.height = 40,
        this.contentPadding = EdgeInsets.zero,
        this.debounceMilliseconds,
        this.onSearchFailed,
        required this.searchBarController,
        this.autocompleteOffset,
        this.autocompleteRadius,
        this.autocompleteLanguage,
        this.autocompleteComponents,
        this.autocompleteTypes,
        this.strictbounds,
        this.region,
        this.initialSearchString,
        this.searchForInitialValue,
        this.autocompleteOnTrailingWhitespace})
      : super(key: key);

  final String? sessionToken;
  final String? hintText;
  final String? searchingText;
  final bool hidden;
  final double height;
  final EdgeInsetsGeometry contentPadding;
  final int? debounceMilliseconds;
  final ValueChanged<Prediction> onPicked;
  final ValueChanged<String>? onSearchFailed;
  final SearchBarController searchBarController;
  final num? autocompleteOffset;
  final num? autocompleteRadius;
  final String? autocompleteLanguage;
  final List<String>? autocompleteTypes;
  final List<Component>? autocompleteComponents;
  final bool? strictbounds;
  final String? region;
  final GlobalKey appBarKey;
  final String? initialSearchString;
  final bool? searchForInitialValue;
  final bool? autocompleteOnTrailingWhitespace;

  @override
  AutoCompleteSearchState createState() => AutoCompleteSearchState();
}

class AutoCompleteSearchState extends State<AutoCompleteSearch> {
  TextEditingController controller = TextEditingController();
  FocusNode focus = FocusNode();
  OverlayEntry? overlayEntry;
  SearchProvider provider = SearchProvider();

  @override
  void initState() {
    super.initState();
    if (widget.initialSearchString != null) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        controller.text = widget.initialSearchString!;
        if (widget.searchForInitialValue!) {
          _onSearchInputChange();
        }
      });
    }
    controller.addListener(_onSearchInputChange);
    focus.addListener(_onFocusChanged);

    widget.searchBarController.attach(this);
  }

  @override
  void dispose() {
    controller.removeListener(_onSearchInputChange);
    controller.dispose();

    focus.removeListener(_onFocusChanged);
    focus.dispose();
    _clearOverlay();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return !widget.hidden
        ? ChangeNotifierProvider.value(
      value: provider,
      child: RoundedFrame(
        height: widget.height,
        padding: const EdgeInsets.only(right: 10),
        color: Theme.of(context).brightness == Brightness.dark
            ? Colors.black54
            : Colors.white,
        borderRadius: BorderRadius.circular(20),
        elevation: 4.0,
        child: Row(
          children: <Widget>[
            SizedBox(width: 10),
            Icon(Icons.search),
            SizedBox(width: 10),
            Expanded(child: _buildSearchTextField()),
            _buildTextClearIcon(),
          ],
        ),
      ),
    )
        : Container();
  }

  Widget _buildSearchTextField() {
    return TextField(
      controller: controller,
      focusNode: focus,
      decoration: InputDecoration(
        hintText: widget.hintText,
        border: InputBorder.none,
        errorBorder: InputBorder.none,
        enabledBorder: InputBorder.none,
        focusedBorder: InputBorder.none,
        disabledBorder: InputBorder.none,
        focusedErrorBorder: InputBorder.none,
        isDense: true,
        contentPadding: widget.contentPadding,
      ),
    );
  }

  Widget _buildTextClearIcon() {
    return Selector<SearchProvider, String>(
        selector: (_, provider) => provider.searchTerm,
        builder: (_, data, __) {
          if (data.length > 0) {
            return Padding(
              padding: const EdgeInsets.only(right: 8.0),
              child: GestureDetector(
                child: Icon(
                  Icons.clear,
                  color: Theme.of(context).brightness == Brightness.dark
                      ? Colors.white
                      : Colors.black,
                ),
                onTap: () {
                  clearText();
                },
              ),
            );
          } else {
            return SizedBox(width: 10);
          }
        });
  }

  _onSearchInputChange() {
    if (!mounted) return;
    this.provider.searchTerm = controller.text;

    PlaceProvider provider = PlaceProvider.of(context, listen: false);

    if (controller.text.isEmpty) {
      provider.debounceTimer?.cancel();
      _searchPlace(controller.text);
      return;
    }

    if (controller.text.trim() == this.provider.prevSearchTerm.trim()) {
      provider.debounceTimer?.cancel();
      return;
    }

    if (!widget.autocompleteOnTrailingWhitespace! &&
        controller.text.substring(controller.text.length - 1) == " ") {
      provider.debounceTimer?.cancel();
      return;
    }

    if (provider.debounceTimer?.isActive ?? false) {
      provider.debounceTimer!.cancel();
    }

    provider.debounceTimer =
        Timer(Duration(milliseconds: widget.debounceMilliseconds!), () {
          _searchPlace(controller.text.trim());
        });
  }

  _onFocusChanged() {
    PlaceProvider provider = PlaceProvider.of(context, listen: false);
    provider.isSearchBarFocused = focus.hasFocus;
    provider.debounceTimer?.cancel();
    provider.placeSearchingState = SearchingState.Idle;
  }

  _searchPlace(String searchTerm) {
    this.provider.prevSearchTerm = searchTerm;

    _clearOverlay();

    if (searchTerm.length < 1) return;

    _displayOverlay(_buildSearchingOverlay());

    _performAutoCompleteSearch(searchTerm);
  }

  _clearOverlay() {
    if (overlayEntry != null) {
      overlayEntry!.remove();
      overlayEntry = null;
    }
  }

  _displayOverlay(Widget overlayChild) {
    _clearOverlay();

    final RenderBox? appBarRenderBox =
    widget.appBarKey.currentContext!.findRenderObject() as RenderBox?;
    final translation = appBarRenderBox?.getTransformTo(null).getTranslation();
    final Offset offset = translation != null
        ? Offset(translation.x, translation.y)
        : Offset(0.0, 0.0);
    final screenWidth = MediaQuery.of(context).size.width;

    overlayEntry = OverlayEntry(
      builder: (context) => Positioned(
        top: appBarRenderBox!.paintBounds.shift(offset).top +
            appBarRenderBox.size.height,
        left: screenWidth * 0.025,
        right: screenWidth * 0.025,
        child: Material(
          elevation: 4.0,
          child: overlayChild,
        ),
      ),
    );

    Overlay.of(context)!.insert(overlayEntry!);
  }

  Widget _buildSearchingOverlay() {
    return Container(
      padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 24),
      child: Row(
        children: <Widget>[
          SizedBox(
            height: 24,
            width: 24,
            child: CircularProgressIndicator(strokeWidth: 3),
          ),
          SizedBox(width: 24),
          Expanded(
            child: Text(
              widget.searchingText ?? "Searching...",
              style: TextStyle(fontSize: 16),
            ),
          )
        ],
      ),
    );
  }

  Widget _buildPredictionOverlay(List<Prediction> predictions) {
    return ListBody(
      children: predictions
          .map(
            (p) => PredictionTile(
          prediction: p,
          onTap: (selectedPrediction) {
            resetSearchBar();
            widget.onPicked(selectedPrediction);
          },
        ),
      )
          .toList(),
    );
  }

  _performAutoCompleteSearch(String searchTerm) async {
    PlaceProvider provider = PlaceProvider.of(context, listen: false);

    if (searchTerm.isNotEmpty) {
      final PlacesAutocompleteResponse response =
      await provider.places.autocomplete(
        searchTerm,
        sessionToken: widget.sessionToken,
        location: provider.currentPosition == null
            ? null
            : Location(
            lat: provider.currentPosition!.latitude,
            lng: provider.currentPosition!.longitude),
        offset: widget.autocompleteOffset,
        radius: widget.autocompleteRadius,
        language: widget.autocompleteLanguage,
        types: widget.autocompleteTypes ?? const [],
        components: widget.autocompleteComponents ?? const [],
        strictbounds: widget.strictbounds ?? false,
        region: widget.region,
      );

      if (response.errorMessage?.isNotEmpty == true ||
          response.status == "REQUEST_DENIED") {
        if (widget.onSearchFailed != null) {
          widget.onSearchFailed!(response.status);
        }
        return;
      }

      _displayOverlay(_buildPredictionOverlay(response.predictions));
    }
  }

  clearText() {
    provider.searchTerm = "";
    controller.clear();
  }

  resetSearchBar() {
    clearText();
    focus.unfocus();
  }

  clearOverlay() {
    _clearOverlay();
  }
}