import 'package:dartterm/cp437.dart';
import 'package:dartterm/fonts.dart';
import 'package:dartterm/terminal_painter.dart';
import 'package:flutter/material.dart';

class Terminal {
  static const int width = 96;
  static const int height = 54;
  static const int cellW = 64;
  static const int cellH = 64;
  static const int nTiles = width * height;

  late List<Tile> tiles;

  Terminal() {
    tiles = [for (var i = 0; i < nTiles; i += 1) Tile.empty()];
    for (final (x, c) in toCp437String("Hello, world!").indexed) {
      tiles[x].content = Content(Font.normal.imageName, c % 32, 2 * (c ~/ 32));
      tiles[x + Terminal.width].content =
          Content(Font.normal.imageName, c % 32, 2 * (c ~/ 32) + 1);
    }

    for (final (x, c) in toCp437String("BEWARE OF THE BAT!").indexed) {
      tiles[x + Terminal.width * 2].content =
          Content(Font.small.imageName, c % 16, c ~/ 16);
    }

    for (final (x, c) in toCp437String("BEWARE OF THE BAT!").indexed) {
      tiles[Terminal.width * (x + 2)].content =
          Content(Font.small.imageName, c % 16, c ~/ 16);
    }
  }

  CustomPaint toWidget(BuildContext context) {
    var scalingFactor = MediaQuery.devicePixelRatioOf(context);
    return CustomPaint(painter: TerminalCustomPainter(this, scalingFactor));
  }

  (int, int)? toXY(int i) {
    if (i < 0 || i > nTiles) {
      return null;
    }
    return (i % width, i ~/ width);
  }

  int? fromXY(int x, int y) {
    if (x < 0 || x >= width) {
      return null;
    }
    if (y < 0 || y >= height) {
      return null;
    }

    return x + y * width;
  }
}

class Tile {
  Content? content;

  Color bg;
  Color fg;

  Tile(this.content, this.bg, this.fg);

  static Tile empty() => Tile(null, Colors.black, Colors.white);
}

class Content {
  final String sourceImage;
  final int sourceCx;
  final int sourceCy;

  const Content(this.sourceImage, this.sourceCx, this.sourceCy);
}

// reexports
Terminal terminal = Terminal();
const int width = Terminal.width;
const int height = Terminal.height;
const int cellW = Terminal.cellW;
const int cellH = Terminal.cellH;
const int nTiles = Terminal.nTiles;

Widget toWidget(BuildContext context) {
  return terminal.toWidget(context);
}