main.dart

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

import 'package:flutter/material.dart';
import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';
import 'package:http/http.dart' as http;
import 'package:path_provider/path_provider.dart';

void main() =>
    runApp(new MaterialApp(
        home: new MTextInput()
    ));

class MTextInput extends StatefulWidget {
  @override
  MTextInputState createState() => new MTextInputState();
}

List<Widget> listVdata = [];
String searchTxt = "";
List<String> books = [];
List<Widget> dlbooks = [];
List<Book> booksList = [];

void changedSearch(String text) {
  searchTxt = Uri.encodeQueryComponent(text, encoding: UTF8);
  print(searchTxt);
}

class MTextInputState extends State<MTextInput> {

  _loadData() async {
    String dataURL = "http://mek.oszk.hu/kereses.mhtml?dc_creator=&dc_title=" +
        searchTxt;
    http.Response response = await http.get(dataURL);
    String html = response.body;
    print(dataURL);
    books.clear();
    booksList.clear();
    String str1 = "a href=\"http://mek.oszk.hu/";
    String str2 = "<span style=\"font-weight:bold\">";
    while (html.contains(str1)) {
      String title = html.substring(
          html.indexOf(str2) + str2.length,
          html.indexOf("<br/>", html.indexOf(str2)))
          .replaceAll(str2, "")
          .replaceAll("</span>", "");
      String code = html.substring(
          html.indexOf(str1) + str1.length,
          html.indexOf("\"", html.indexOf(str1) + str1.length));
      String imgUrl = "http://mek.oszk.hu/" + code + "/borito.jpg";
      books.add(title);
      booksList.add(new Book(title, imgUrl, code));
      print(title);
      print(imgUrl);
      print(code);
      html = html.replaceFirst(str1, "");
      html = html.replaceFirst(str1, "");
      html = html.replaceFirst(str2, "");
      html = html.replaceFirst(str2, "");
    }
    setState(() {
      listVdata = _getListData();
    });
  }

  goDownloads(List<File> files) async {
    for (int n = 0; n < files.length; n++) {
      String url = files[n].path;
      Widget container = new Container(
          child: new Row(
              children: <Widget>[
                new IconButton(
                  onPressed: openBook(url),
                  icon: new Icon(Icons.open_in_browser),
                ),
                new Text(
                    files[n].path.substring(
                        files[n].path.lastIndexOf("/") + 1)),
              ]
          )
      );
      dlbooks.add(container);
    }
    setState(() {
      Navigator.of(context).push(new MaterialPageRoute<Null>(
        builder: (BuildContext context) {
          return new Scaffold(
            appBar: new AppBar(title: new Text('My Page')),
            body: new Center(
              child: new ListView(
                  children: dlbooks
              ),
            ),
          );
        },
      ));
    });
  }

  openBook(String url) {
    setState(() {
      Navigator.of(context).push(new MaterialPageRoute<Null>(
        builder: (BuildContext context) {
          return new WebviewScaffold(
            url: url,
            appBar: new AppBar(
              title: new Text("Widget webview"),
            ),
          );
        },
      ));
    });
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        appBar: new AppBar(title: new Text("MEK books"),),
        body: new Container(
            child: new Center(
                child: new Column(
                    children: <Widget>[
                      new TextField(
                        onChanged: (String str) {
                          changedSearch(str);
                        },
                      ),
                      new IconButton(
                        icon: new Icon(Icons.search),
                        onPressed: () {
                          _loadData();
                        },
                      ),
                      new Container(
                        width: double.INFINITY, height: 400.0, child:
                      new ListView(
                        shrinkWrap: true,
                        children: listVdata,
                      ),
                      )
                    ]
                )
            )
        ),
        drawer:
        new Container(
            color: Colors.white,
            width: 280.0,
            child: new ListView(
              children: <Widget>[
                new DrawerHeader(child: new Text("MEK-books")),
                new ListTile(
                  title: new Text("Letöltések" /*Downloads*/), onTap: () async {
                  dlbooks.clear(); //resets the array
                  Directory appDocDir = await getExternalStorageDirectory(); //gets internal storage path
                  String appDocPath = appDocDir.path;
                  Directory mekdir = new Directory(appDocPath + "/mekbooks/");
                  if (!await mekdir.exists())
                    mekdir.create();
                  List<FileSystemEntity> files = mekdir
                      .listSync(); //lists the downloaded books

                  setState(() {
                    goDownloads(files);
                  });
                },),
                new ListTile(title: new Text("asd")),
              ],
            )
        )
    );
  }
}

_getListData() {
  List<Widget> widgets = [];
  for (int i = 0; i < books.length; i++) {
    widgets.add(booksList[i].getListItem());
  }
  return widgets;
}

class Book {
  String imgUrl;
  String title;
  String code;

  Future<File> _getLocalFile() async {
    String filename = (await listformats(code))[0];
    Directory appDocDir = await getExternalStorageDirectory();
    String appDocPath = appDocDir.path;
    print(appDocPath);
    Directory mekdir = new Directory(appDocPath + "/mekbooks/");
    if (!await mekdir.exists())
      mekdir.create();
    print(mekdir.path);
    return new File(mekdir.path + "/" + filename);
  }

  getData() async {
    String filename = (await listformats(code))[0];
    String dataURL = "http://mek.oszk.hu/" + code + "/" + filename;
    print(dataURL);
    http.Response response = await http.get(dataURL);
    return response.bodyBytes;
  }

  downloadBook() async {
    File filelocal = await _getLocalFile();
    filelocal.create();
    filelocal.openWrite();
    filelocal.writeAsBytes(await getData());
    listformats(code);
  }

  Widget getListItem() {
    return new Padding(
        padding: new EdgeInsets.all(10.0),
        child: new Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            new Image.network(
              imgUrl,
            ),
            new Container(
                width: 250.0,
                height: 80.0,
                child: new Column(
                  children: <Widget>[
                    new Container(
                      width: 250.0,
                      height: 30.0,
                      child: new Text(title),
                    ),
                    new IconButton(
                        icon: new Icon(Icons.file_download),
                        onPressed: downloadBook)
                  ],
                )
            ),

          ],
        ));
  }

  Book(this.title, this.imgUrl, this.code);
}

listformats(String code) async {
  List<String> dlFiles = [];
  String dataURL = "http://mek.oszk.hu/" + code;
  http.Response response = await http.get(dataURL);
  String html = response.body;
  String str1 = "class=\"bor02\"><b><a href=\"";
  while (html.contains(str1)) {
    String fileName = html.substring(
        html.indexOf(str1) + str1.length,
        html.indexOf("\"", html.indexOf(str1) + str1.length)
    );
    print(fileName);
    if (fileName != "#") {
      dlFiles.add(fileName);
    }
    html = html.replaceFirst(str1, "");
  }
  return dlFiles;
}