import 'package:graphs/src/graph.dart';
import 'package:graphs/src/curve_painter.dart';

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

Graphs getGraph() {
  List<Dot> d = <Dot>[];
  d.add(Dot.fromTwoLists("1", [2], [3]));
  d.add(Dot.fromTwoLists("2", [3], [1]));
  d.add(Dot.fromTwoLists("3", [1], [2]));
  //d.add(Dot.fromTwoLists("Name1", [], []));
  //d.add(Dot.fromTwoLists("Name2", [], []));
  return Graphs.fromList("Имя графа", d, true, true);
}

class DrawingPage extends StatefulWidget {
  const DrawingPage({Key? key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _DrawingPageState();
}

class _DrawingPageState extends State<DrawingPage> {
  double screenSize = 0;
  Graphs graphData = getGraph();
  List<int?>? intListPath;
  List<bool>? dfsAccessTable;
  //List<int?>? dijkstraTable;
  String op = Operations.none;
  int? startDot;
  int? endDot;
  String? dropdownValue1;
  String? dropdownValue2;
  String currOp = "";

  final _textNameController = TextEditingController();
  final _textLnthController = TextEditingController();
  final _textGrNmController = TextEditingController();

  void clearInputData() {
    setState(() {
      _textLnthController.clear();
      _textNameController.clear();
      dropdownValue1 = null;
      dropdownValue2 = null;
    });
  }

  void clearDropDownVals() {
    setState(() {
      startDot = null;
      intListPath = null;
      dfsAccessTable = null;
      endDot = null;
      currOp = "";
      op = Operations.none;
    });
  }

  // *************buttons*************
  ElevatedButton createButton(String txt, void Function() onPressing) {
    return ElevatedButton(
      onPressed: onPressing,
      style: ButtonStyle(
          backgroundColor: MaterialStateProperty.resolveWith<Color>(
              (states) => Colors.green.shade700)),
      child: Text(txt,
          style: const TextStyle(
            fontSize: 15,
            color: Colors.white70,
            height: 1,
          )),
    );
  }

  void showPopUp(String alertTitle, String err) => showDialog<String>(
        context: context,
        builder: (BuildContext context) => AlertDialog(
          title: Text(alertTitle, style: const TextStyle(fontSize: 26)),
          content: Text(
            err,
            style: const TextStyle(fontSize: 18),
          ),
          actions: <Widget>[
            TextButton(
              onPressed: () => Navigator.pop(context, 'OK'),
              child: const Text('OK'),
            ),
          ],
        ),
      );
  // *************buttons*************

  // ***addSpace***
  SizedBox addSpaceH(double h) {
    return SizedBox(height: h);
  }

  SizedBox addSpaceW(double w) {
    return SizedBox(width: w);
  }
  // ***addSpace***

  // *************inputs*************
  Container createInputBox(String text, double width, IconData? icon,
      TextEditingController? controller) {
    if (icon == null) {
      return Container(
          width: width,
          height: 40,
          margin: const EdgeInsets.symmetric(horizontal: 20, vertical: 5),
          child: TextField(
            controller: controller,
            textAlign: TextAlign.center,
            onChanged: (name) => graphData.setName(name),
            decoration: InputDecoration(
                contentPadding:
                    const EdgeInsets.symmetric(vertical: 10, horizontal: 10),
                filled: true,
                fillColor: Colors.white,
                //prefixIcon: Icon(icon, color: Colors.black),
                border: const OutlineInputBorder(
                    borderRadius: BorderRadius.all(Radius.circular(40))),
                hintStyle: const TextStyle(color: Colors.black38),
                hintText: text),
          ));
    }
    return Container(
        width: width,
        height: 40,
        margin: const EdgeInsets.symmetric(horizontal: 20, vertical: 5),
        child: TextField(
          controller: controller,
          textAlign: TextAlign.center,
          decoration: InputDecoration(
              contentPadding:
                  const EdgeInsets.symmetric(vertical: 10, horizontal: 10),
              filled: true,
              fillColor: Colors.white,
              prefixIcon: Icon(icon, color: Colors.black),
              border: const OutlineInputBorder(
                  borderRadius: BorderRadius.all(Radius.circular(40))),
              hintStyle: const TextStyle(color: Colors.black38),
              hintText: text),
        ));
  }

  SizedBox dropList1(double width) {
    var button = DropdownButton(
      hint: const Text(
        'Select dot',
        style: TextStyle(color: Colors.white, fontSize: 13),
      ),
      //icon: const Icon(Icons.fiber_manual_record, color: Colors.white),
      alignment: AlignmentDirectional.bottomEnd,
      value: dropdownValue1,
      isDense: true,
      borderRadius: const BorderRadius.all(Radius.circular(20)),
      dropdownColor: Colors.green.shade800,
      style: const TextStyle(
        color: Colors.white,
        fontSize: 18,
      ),
      onChanged: (String? newValue) {
        setState(() {
          dropdownValue1 = newValue;
        });
      },
      items: graphData.getDots().map((location) {
        return DropdownMenuItem(
          child: Text(location.getName()),
          value: location.num.toString(),
        );
      }).toList(),
    );

    return SizedBox(
      child: button,
      width: width,
    );
  }

  SizedBox dropList2(double width) {
    var button = DropdownButton(
      hint: const Text(
        'Select Dot',
        style: TextStyle(color: Colors.white, fontSize: 13),
      ),
      alignment: AlignmentDirectional.centerEnd,
      value: dropdownValue2,
      isDense: true,
      borderRadius: const BorderRadius.all(Radius.circular(20)),
      dropdownColor: Colors.green.shade800,
      style: const TextStyle(
        color: Colors.white,
        fontSize: 18,
      ),
      onChanged: (String? newValue) {
        setState(() {
          dropdownValue2 = newValue;
        });
      },
      items: graphData.getDots().map((location) {
        return DropdownMenuItem(
          child: Text(location.getName()),
          value: location.num.toString(),
        );
      }).toList(),
    );

    return SizedBox(
      child: button,
      width: width,
    );
  }
// *************inputs*************

//*********ButtonsFunctions*********
  void addDotPushed() {
    clearDropDownVals();
    if (_textNameController.text == "") {
      showPopUp("Error", "No name in \"Dot name\" box");
    } else {
      setState(() {
        String? res = graphData.addIsolated(_textNameController.text);
        if (res != null) {
          showPopUp("Error", res);
        }
      });
    }
    clearInputData();
  }

  void addPathPushed() {
    clearDropDownVals();
    if (dropdownValue1 == null) {
      showPopUp("Error", "No dot in first box selected");
    } else if (dropdownValue2 == null) {
      showPopUp("Error", "No dot in second box selected");
    } else if (_textLnthController.text == "" && graphData.getUseLengthBool()) {
      showPopUp("Error", "No length in \"Input length\" box");
    } else {
      int? from = int.parse(dropdownValue1!);
      int? to = int.parse(dropdownValue2!);
      int? len = int.tryParse(_textLnthController.text);
      if (len == null && graphData.getUseLengthBool()) {
        showPopUp("Error",
            "Can't parse input.\nInts only allowed in \"Input length\"");
      } else {
        len ??= 0;
        setState(() {
          String? res = graphData.addPath(from, to, len!);
          if (res != null) showPopUp("Error", res);
        });
      }
    }
    clearInputData();
  }

  void changeOriented() {
    setState(() {
      String? res = graphData.flipUseOrientation();
      if (res != null) showPopUp("Error", res);
    });
  }

  void changeLength() {
    setState(() {
      String? res = graphData.flipUseLength();
      if (res != null) showPopUp("Error", res);
    });
  }

  void delPathPushed() {
    clearDropDownVals();
    if (dropdownValue1 == null) {
      showPopUp("Error", "No dot in first box selected");
    } else if (dropdownValue2 == null) {
      showPopUp("Error", "No dot in second box selected");
    } else {
      int? from = int.tryParse(dropdownValue1!);
      int? to = int.tryParse(dropdownValue2!);
      if (from == null || to == null) {
        showPopUp("Error",
            "Can't parse input.\nInts only allowed in \"Dot number\" and \"Destination number\"");
      } else {
        setState(() {
          String? res = graphData.delPath(from, to);
          if (res != null) {
            showPopUp("Error", res);
          }
        });
      }
    }
    clearInputData();
  }

  void delDotPushed() {
    if (dropdownValue1 != null) {
      setState(() {
        String? res = graphData.delDot(int.parse(dropdownValue1!));
        if (res != null) {
          showPopUp("Error", res);
        }
      });
    } else {
      showPopUp("Error", "Nothing in input");
    }
    clearDropDownVals();
    clearInputData();
  }

  void fileOpener() async {
    FilePickerResult? result =
        await FilePicker.platform.pickFiles(allowedExtensions: ["txt"]);

    if (result != null) {
      if (!result.files.single.path!.endsWith(".txt")) {
        showPopUp("Error", "Can open only \".txt\" files");
      } else {
        setState(() {
          String? res =
              graphData.replaceDataFromFile(result.files.single.path!);

          if (res != null) showPopUp("Error", res);
        });
      }
    } else {
      showPopUp("Error", "No file selected");
    }
    clearDropDownVals();
    clearInputData();
  }

  void fileSaver() async {
    String? outputFile = await FilePicker.platform.saveFile(
        dialogTitle: 'Please select an output file:',
        fileName: 'output-file.txt',
        allowedExtensions: ["txt"]);
    if (outputFile == null) {
      showPopUp("Error", "Save cancelled");
    } else {
      if (!outputFile.endsWith(".txt")) {
        outputFile += ".txt";
      }
      graphData.printToFile(outputFile);
    }
    clearDropDownVals();
    clearInputData();
  }

  void bfsPushed() {
    clearDropDownVals();
    if (dropdownValue1 == null) {
      showPopUp("Error", "No dot in first box selected");
    } else if (dropdownValue2 == null) {
      showPopUp("Error", "No dot in second box selected");
    } else {
      setState(() {
        startDot = int.parse(dropdownValue1!);
        endDot = int.parse(dropdownValue2!);
        currOp = "OP: BFS from $startDot to $endDot";
        op = Operations.bfs;
        intListPath = graphData.bfsPath(startDot!, endDot!);
      });
      if (intListPath == null) {
        showPopUp("Info", "There is no path");
      }
      //print(intListPath);
    }
    clearInputData();
  }

  void dfsPushed() {
    clearDropDownVals();
    if (dropdownValue1 == null) {
      showPopUp("Error", "No dot in first box selected");
    } else {
      setState(() {
        startDot = int.parse(dropdownValue1!);
        op = Operations.dfs;
        currOp = "OP: DFS from $startDot";
        dfsAccessTable = graphData.dfsIterative(startDot!);
      });
      if (dfsAccessTable == null) {
        showPopUp("Err", "report this error.");
      }
      //print(dfsAccessTable);
    }

    clearInputData();
  }

  void dijkstraPushed() {
    clearDropDownVals();
    if (dropdownValue1 == null) {
      showPopUp("Error", "No number in \"Dot number\" box");
    } else {
      setState(() {
        startDot = int.parse(dropdownValue1!);
        currOp = "OP: Dijkstra from $startDot";
        op = Operations.dijkstra;
        intListPath = graphData.dijkstra(startDot!);
      });
      if (intListPath == null) {
        showPopUp("Err", "report this error.");
      }
      //print(intListPath);
    }
    clearInputData();
  }
  //*********ButtonsFunctions*********

  // build
  @override
  Widget build(BuildContext context) {
    screenSize = MediaQuery.of(context).size.width;
    _textGrNmController.text = graphData.getName();
    return MaterialApp(
        home: Scaffold(
      appBar: AppBar(
          title: const Align(
              alignment: Alignment.topLeft,
              child: Text("Graph name:\n",
                  style: TextStyle(
                    fontSize: 18,
                    color: Colors.white,
                  ))),
          toolbarHeight: 110,
          flexibleSpace: Container(
            color: Colors.green.shade900,
            child: Column(children: <Widget>[
              const SizedBox(height: 5),
              Row(children: [
                addSpaceW(screenSize / 8 + 19),
                createButton("\nAdd dot\n", addDotPushed),
                createInputBox("Dot name", screenSize / 4 - 25, Icons.label,
                    _textNameController),
                addSpaceW(8),
                createButton("\nAdd path\n", addPathPushed),
                createInputBox("Input length", screenSize / 4 - 25,
                    Icons.arrow_right_alt_outlined, _textLnthController),
              ]),
              addSpaceH(3),
              Row(children: [
                addSpaceW(6),
                createInputBox(
                    "Name", screenSize / 8 - 25, null, _textGrNmController),
                //addSpaceW(screenSize / 8 - 4),
                createButton("\nDel dot \n", delDotPushed),
                //createInputBox("Dot number", screenSize / 4 - 25, Icons.fiber_manual_record, _textNumbController),
                addSpaceW(54),
                dropList1(screenSize / 4 - 80),
                addSpaceW(53),
                createButton("\nDel path\n", delPathPushed),
                addSpaceW(54),
                dropList2(screenSize / 4 - 80),
                //createInputBox("Destination number", screenSize / 4 - 25, Icons.fiber_manual_record, _textDestController),
              ]),
            ]),
          ),
          actions: [
            IconButton(
              onPressed: () {
                setState(() {
                  clearDropDownVals();
                  graphData.flushData();
                  clearInputData();
                });
              },
              icon: const Icon(Icons.delete_sweep),
              iconSize: 60,
            ),
          ]),
      body: CustomPaint(
        painter: CurvePainter(
            graphData: graphData,
            intListPath: intListPath,
            dfsAccessTable: dfsAccessTable,
            start: startDot,
            end: endDot,
            op: op),
        child: Align(
          alignment: Alignment.topRight,
          child: ButtonBar(
            mainAxisSize: MainAxisSize.min,
            children: <Widget>[
              Text(
                currOp,
                style: const TextStyle(fontSize: 14, color: Colors.black),
              ),
              createButton("Bfs", bfsPushed),
              createButton("Dfs", dfsPushed),
              createButton("Dijkstra", dijkstraPushed),
              createButton("Clear OP", () {
                clearDropDownVals();
                clearInputData();
              }),
              createButton(graphData.getUseLengthStr(), changeLength),
              createButton(graphData.getDoubleSidedStr(), changeOriented),
              createButton("Save to file", fileSaver),
              createButton("Load from file", fileOpener),
              createButton("Help", () {
                String out =
                    "   В поле \"Graph name\" можно сменить имя графу.\n";
                out +=
                    "   Для добавления точки необходимо ввести имя в \"Dot name\" и нажать на \"Add dot\".\n";
                out +=
                    "   Для удаления точки необходимо выбрать номер в левом выпадающем списке и нажать на \"Del dot\".\n";
                out +=
                    "   Для добавления пути необходимо выбрать: первую вершину в левом выпадающем списке, вторую вершину в правом выпадающем списке, ";
                out +=
                    "и, если граф взвешенный, то ввести длину пути в \"Input length\". Затем нажать \"Add path\".\n";
                out +=
                    "   Для удаления пути необходимо выбрать первую вершину из левого списка и вторую вершину в правом списке. Затем нажать \"Del path\".\n\n";
                out +=
                    "   Кнопка \"Bfs\" отмечает точки в пути из вершины, выбранной слева, в вершину, выбранную справа.\n";
                out +=
                    "   Кнопка \"Dfs\" помечает точки, которые доступны из вершины, выбранной слева.";
                out +=
                    "   Кнопка \"Dijkstra\" ищет кратчайший путь из вершины, выбранной слева. во все другие.";
                out +=
                    "   Кнопка \"Clear op\" отменяет \"Bfs\", \"Dfs\" и \"Dijkstra\". Все эти отображения так же отменяются при любых действиях с графом.";
                out +=
                    "   Кнопки \"Взвешенный\" и \"Ориентированный\" позволяют сменить эти значения перед построением графа (т.е. для их работы граф должен быть пустым).\n";
                out +=
                    "   Кнопки \"Save to file\" и \"Load from file\" позволяют вывести информацию в файл и загрузить информацию из файла соответственно.\n";
                out +=
                    "   Кнопка \"Help\" описывает работу с интерфейсом программы.";
                showPopUp("Help:", out);
              })
            ],
          ),
        ),
      ),
    ));
  }
}