import 'package:flutter/material.dart';
import 'package:after_layout/after_layout.dart';
import 'dart:async';

import 'questions.dart';
import 'life_history.dart';
import 'alert.dart';

// Textstyle of the heading used in Age
TextStyle heading = TextStyle(
    fontWeight: FontWeight.bold,
    fontSize: 16,
  );

// Textstyle of the heading used in Month
TextStyle subhead = TextStyle(
    fontStyle: FontStyle.italic,
  );

class LifeTab extends StatefulWidget {
  LifeTab({Key key}) : super(key: key);

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

class _LifeTabState extends State<LifeTab> with AfterLayoutMixin<LifeTab>{
  // "historyList" => Past events retrieved from db
  // "time" => 0-12 in year 0, 13-24 in year 1 ...
  // "processedTime" => only for headings
  // "processedAge" => only for headings
  List<Widget> historyList = [];
  int time = -1;
  int processedTime = -1;
  int processedAge = -1;
  ScrollController _scrollController = new ScrollController();

  // Reads previous history from database and formats them
  @override
  void initState(){
    super.initState();

    // Read history
    getAllHistory().then((history){
      setState((){
        // Go through every entry in our history db
        for (int i = 0; i<history.length; i++){
          var entry = history[i];
          var outcome;

          if (time < entry.time){
            outcome = RichText(
              text: TextSpan(
                style: DefaultTextStyle.of(context).style,
                children: <TextSpan>[
                  TextSpan(text: 'Month '+(entry.time%12).toString() + " — ",
                    style: subhead,),
                  TextSpan(text: entry.outcome,),
                ],
              ),
            );
          } else {
            outcome = Text(entry.outcome);
          }

          // If time of entry % 12 is 0, a.k.a a year,
          if (entry.time % 12 == 0){
            int age = i~/12;

            // Obtain the year and check if we have processed that age heading
            if (age>processedAge){
              historyList.add(Text(
                '\nAge: '+age.toString()+' years old',
                style: heading,)
              );
              // After we have processed the heading, add to addedAge to show we processed that age
              processedAge += 1;
            }
          }

          // Make sure we update the current time to be the latest entry time
          time = entry.time;
          historyList.add(outcome);
        }
      });
      _scrollController.jumpTo(_scrollController.position.maxScrollExtent);
    });
  }

  @override
  void afterFirstLayout(BuildContext context){
    //Timer(Duration(milliseconds: 100), () => _scrollController.animateTo(_scrollController.position.maxScrollExtent, duration: const Duration(milliseconds: 100), curve: Curves.easeOut));
    _scrollController.jumpTo(_scrollController.position.maxScrollExtent);
    scheduleMicrotask(() => _scrollController.jumpTo(_scrollController.position.maxScrollExtent));
  }

  Widget monthHeading(text){
    if (processedTime < time){
      processedTime += 1;
      return RichText(
        text: TextSpan(
          style: DefaultTextStyle.of(context).style,
          children: <TextSpan>[
            TextSpan(
              text: 'Month '+(time%12).toString() + " — ",
              style: subhead,),
            TextSpan(text: text,),
          ],
        ),
      );
    } else {
      return  Text(text);
    }
  }

  void questionRecursive({id, text}) async {
    if (text != null){
      var split = text.split('|');
      simpleAlert(context, split[0], split[1]);
      return;
    }
    Question data;

    if (id == null){
      data = await getRandomQuestion(time);
    } else {
      data = await getQuestionById(id);
    }

    if (data == null){
      insertHistory(History(
        outcome: "Nothing interesting happened.\n",
        time: time,
        questionId: -1,
      ));
      setState((){historyList.add(monthHeading("Nothing interesting happened.\n"));});
      return;
    }

    var choices = data.choices.split(';');
    var consequences = data.consequences.split(';');
    List<Function> consequenceList = [];

    for (int i = 0; i<choices.length;i++){
      var split = consequences[i].split(">");
      String textbox =  split[2];
      String historyText = split[0];

      var formatted = historyText;

      Function onPress;
      if (textbox.substring(0,6) == "GO TO "){
        onPress = (){
          Navigator.pop(context);
           insertHistory(History(
            outcome: formatted,
            time: time,
            questionId: data.id,
          ));

          setState((){historyList.add(monthHeading(formatted));});
          questionRecursive(id: textbox.substring(6));
        };
      } else {
        onPress = (){
          Navigator.pop(context);
          formatted = historyText + "\n";
          insertHistory(History(
            outcome: formatted,
            time: time,
            questionId: data.id,
          ));

          setState((){historyList.add(monthHeading(formatted));});
          questionRecursive(text: textbox);
        };
      }
      consequenceList.add(onPress);
      }
    var question = data.question.split('|');
    multiChoiceAlert(context, question[0], question[1], choices, consequenceList);
  }

  void onPlusTap() async{
    time += 1;
    setState(() {
      if (time % 12 == 0 && (time~/12) > processedAge){
        historyList.add(Text(
          "\nAge "+(time~/12).toString()+" years old",
          style: heading,
        ));
        processedAge += 1;
      }

      questionRecursive();
    });
    _scrollController.animateTo(_scrollController.position.maxScrollExtent, duration: const Duration(milliseconds: 500), curve: Curves.easeOut);
  }

  Widget _buildEvent(BuildContext context, int index){
    return historyList[index];
  }

  @override
  Widget build(BuildContext context) {

    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      body: ListView.builder(
        controller: _scrollController,
        padding: EdgeInsets.only(
          top: 40,
          left: 20,
          right: 20,
          bottom: 400,
        ),
        shrinkWrap: true,
        itemCount: historyList.length,
        itemBuilder: _buildEvent,
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: onPlusTap,
        tooltip: 'Age up',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}