import 'package:flutter/material.dart';
import 'state.dart';
import 'util.dart';

/// Board of a single game of tic tac toe
class TTCGame extends StatefulWidget {
  const TTCGame({
    super.key,
    required this.turn,
    this.data,
    this.onClick,
  });

  final TTCState turn;
  final List<TTCState>? data;

  /// hook into acction of tapping on square
  final Function? onClick;

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

class _TTCGameState extends State<TTCGame> {
  late TTCState turn;
  late List<TTCState> data;

  void setCellState(int index) {
    switch (data[index]) {
      case TTCState.empty:
        setState(() {
          data[index] = turn;

          turn = switch (turn) {
            TTCState.x => TTCState.o,
            TTCState.o => TTCState.x,
            TTCState.empty => TTCState.empty,
          };
        });
        widget.onClick?.call();
        notifyWin();
        break;
      default:
        ScaffoldMessenger.of(context)
          ..clearSnackBars()
          ..showSnackBar(const SnackBar(
              content: Text("Invalid Choice: cell already has value")));
    }
  }

  void notifyWin() {
    TTCState state = Util.checkWin(data);

    if (state != TTCState.empty) {
      ScaffoldMessenger.of(context)
        ..clearSnackBars()
        ..showSnackBar(
            SnackBar(content: Text("${state.name.toUpperCase()} wins")));
    }
  }

  Border _genCellBorder(
    int index, {
    BorderSide borderSide = const BorderSide(),
  }) {
    return Border(
      top: index < 3 ? BorderSide.none : borderSide,
      bottom: index > 5 ? BorderSide.none : borderSide,
      left: [0, 3, 6].contains(index) ? BorderSide.none : borderSide,
      right: [2, 5, 8].contains(index) ? BorderSide.none : borderSide,
    );
  }

  Widget _genCell(int index, TTCState state) => Container(
      decoration: BoxDecoration(border: _genCellBorder(index)),
      child: TTCCell(
        state: state,
        stateSetCallback: () {
          setCellState(index);
        },
      ));

  @override
  void initState() {
    super.initState();
    turn = widget.turn;
    data = widget.data ??
        <TTCState>[
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
          TTCState.empty,
        ];
  }

  @override
  Widget build(BuildContext context) {
    List<Widget> cells = [];
    for (final (index, state) in data.indexed) {
      cells.add(_genCell(index, state));
    }
    return GridView.count(
      crossAxisCount: 3,
      shrinkWrap: true,
      children: cells,
    );
  }
}

class TTCCell extends StatelessWidget {
  const TTCCell({
    super.key,
    required this.state,
    this.stateSetCallback,
    this.textStyle,
  });

  final TTCState state;
  final VoidCallback? stateSetCallback;
  final TextStyle? textStyle;

  String get text => switch (state) {
        TTCState.empty => "",
        TTCState.x => "X",
        TTCState.o => "O",
      };

  @override
  Widget build(BuildContext context) => InkWell(
      onTap: stateSetCallback,
      child: Center(
        child: Text(text, style: textStyle),
      ));
}