import 'dart:math' as math;

import 'package:wolf_3d_data_types/wolf_3d_data_types.dart';
import 'package:wolf_3d_engine/wolf_3d_engine.dart';

class AsciiTheme {
  /// The character ramp, ordered from most dense (index 0) to least dense (last index).
  final String ramp;

  const AsciiTheme(this.ramp);

  /// Always returns the densest character (e.g., for walls, UI, floors)
  String get solid => ramp[0];

  /// Always returns the completely empty character (e.g., for pitch black darkness)
  String get empty => ramp[ramp.length - 1];

  /// Returns a character based on a 0.0 to 1.0 brightness scale.
  /// 1.0 returns the [solid] character, 0.0 returns the [empty] character.
  String getByBrightness(double brightness) {
    double b = brightness.clamp(0.0, 1.0);
    int index = ((1.0 - b) * (ramp.length - 1)).round();
    return ramp[index];
  }
}

/// A collection of pre-defined character sets
abstract class AsciiThemes {
  static const AsciiTheme blocks = AsciiTheme("█▓▒░ ");
  static const AsciiTheme classic = AsciiTheme("@%#*+=-:. ");
  static const AsciiTheme dense = AsciiTheme("█▇▆▅▄▃▂  ");
}

class ColoredChar {
  final String char;
  final int rawColor; // Stores the AABBGGRR integer from the palette

  ColoredChar(this.char, this.rawColor);

  // Safely extract the exact RGB channels regardless of framework
  int get r => rawColor & 0xFF;
  int get g => (rawColor >> 8) & 0xFF;
  int get b => (rawColor >> 16) & 0xFF;

  // Outputs standard AARRGGBB for Flutter's Color(int) constructor
  int get argb => (0xFF000000) | (r << 16) | (g << 8) | b;
}

class AsciiRasterizer extends Rasterizer {
  final AsciiTheme activeTheme = AsciiThemes.blocks;

  late List<List<ColoredChar>> _screen;
  late WolfEngine _engine;

  // Terminal characters are usually twice as tall as they are wide.
  // We override the base multiplier to squish sprites horizontally.
  @override
  double get aspectMultiplier => 2.0;

  // Squish the entire 3D projection vertically by 50% to counteract tall terminal fonts
  @override
  double get verticalStretch => 1.8;

  // Intercept the base render call to initialize our text grid
  @override
  dynamic render(WolfEngine engine, FrameBuffer buffer) {
    _engine = engine;
    _screen = List.generate(
      buffer.height,
      (_) =>
          List.filled(buffer.width, ColoredChar(' ', ColorPalette.vga32Bit[0])),
    );
    return super.render(engine, buffer);
  }

  @override
  void prepareFrame(WolfEngine engine) {
    // Just grab the raw ints!
    final int ceilingColor = ColorPalette.vga32Bit[25];
    final int floorColor = ColorPalette.vga32Bit[29];

    for (int y = 0; y < height; y++) {
      for (int x = 0; x < width; x++) {
        if (y < viewHeight / 2) {
          _screen[y][x] = ColoredChar(activeTheme.solid, ceilingColor);
        } else if (y < viewHeight) {
          _screen[y][x] = ColoredChar(activeTheme.solid, floorColor);
        }
      }
    }
  }

  @override
  void drawWallColumn(
    int x,
    int drawStart,
    int drawEnd,
    int columnHeight,
    Sprite texture,
    int texX,
    double perpWallDist,
    int side,
  ) {
    double brightness = calculateDepthBrightness(perpWallDist);
    String wallChar = activeTheme.getByBrightness(brightness);

    for (int y = drawStart; y < drawEnd; y++) {
      double relativeY =
          (y - (-columnHeight ~/ 2 + viewHeight ~/ 2)) / columnHeight;
      int texY = (relativeY * 64).toInt().clamp(0, 63);

      int colorByte = texture.pixels[texX * 64 + texY];
      int pixelColor = ColorPalette.vga32Bit[colorByte]; // Raw int

      // Faux directional lighting using your new base class method
      if (side == 1) {
        pixelColor = shadeColor(pixelColor);
      }

      _screen[y][x] = ColoredChar(wallChar, pixelColor);
    }
  }

  @override
  void drawSpriteStripe(
    int stripeX,
    int drawStartY,
    int drawEndY,
    int spriteHeight,
    Sprite texture,
    int texX,
    double transformY,
  ) {
    double brightness = calculateDepthBrightness(transformY);

    for (
      int y = math.max(0, drawStartY);
      y < math.min(viewHeight, drawEndY);
      y++
    ) {
      double relativeY = (y - drawStartY) / spriteHeight;
      int texY = (relativeY * 64).toInt().clamp(0, 63);

      int colorByte = texture.pixels[texX * 64 + texY];
      if (colorByte != 255) {
        int rawColor = ColorPalette.vga32Bit[colorByte];

        // Shade the sprite's actual RGB color based on distance
        int r = (rawColor & 0xFF);
        int g = ((rawColor >> 8) & 0xFF);
        int b = ((rawColor >> 16) & 0xFF);

        r = (r * brightness).toInt();
        g = (g * brightness).toInt();
        b = (b * brightness).toInt();

        int shadedColor = (0xFF000000) | (b << 16) | (g << 8) | r;

        // Force sprites to be SOLID so they don't vanish into the terminal background
        _screen[y][stripeX] = ColoredChar(activeTheme.solid, shadedColor);
      }
    }
  }

  @override
  void drawWeapon(WolfEngine engine) {
    int spriteIndex = engine.player.currentWeapon.getCurrentSpriteIndex(
      engine.data.sprites.length,
    );
    Sprite weaponSprite = engine.data.sprites[spriteIndex];

    int weaponWidth = (width * 0.5).toInt();
    int weaponHeight = (viewHeight * 0.8).toInt();

    int startX = (width ~/ 2) - (weaponWidth ~/ 2);
    int startY =
        viewHeight - weaponHeight + (engine.player.weaponAnimOffset ~/ 4);

    for (int dy = 0; dy < weaponHeight; dy++) {
      for (int dx = 0; dx < weaponWidth; dx++) {
        int texX = (dx * 64 ~/ weaponWidth).clamp(0, 63);
        int texY = (dy * 64 ~/ weaponHeight).clamp(0, 63);

        int colorByte = weaponSprite.pixels[texX * 64 + texY];
        if (colorByte != 255) {
          int drawX = startX + dx;
          int drawY = startY + dy;
          if (drawX >= 0 && drawX < width && drawY >= 0 && drawY < viewHeight) {
            _screen[drawY][drawX] = ColoredChar(
              activeTheme.solid,
              ColorPalette.vga32Bit[colorByte],
            );
          }
        }
      }
    }
  }

  // --- PRIVATE HUD DRAWING HELPER ---

  /// Injects a pure text string directly into the rasterizer grid
  void _writeString(int startX, int y, String text, int color) {
    for (int i = 0; i < text.length; i++) {
      int x = startX + i;
      if (x >= 0 && x < width && y >= 0 && y < height) {
        _screen[y][x] = ColoredChar(text[i], color);
      }
    }
  }

  @override
  void drawHud(WolfEngine engine) {
    // If the terminal is at least 160 columns wide and 50 rows tall,
    // there are enough "pixels" to downscale the VGA image clearly.
    if (width >= 160 && height >= 50) {
      _drawFullVgaHud(engine);
    } else {
      _drawSimpleHud(engine);
    }
  }

  void _drawSimpleHud(WolfEngine engine) {
    // 1. Clear the HUD area so stray wall characters don't bleed in
    for (int y = viewHeight; y < height; y++) {
      for (int x = 0; x < width; x++) {
        _screen[y][x] = ColoredChar(' ', 0xFF000000);
      }
    }

    // 2. Draw a decorative border to separate the 3D view from the HUD
    int borderColor = 0xFF555555; // Dark Gray
    for (int x = 0; x < width; x++) {
      _screen[viewHeight][x] = ColoredChar('=', borderColor);
    }

    // 3. Define some clean terminal colors
    int white = 0xFFFFFFFF;
    int yellow = 0xFFFFFF55;
    int red = 0xFFFF5555;

    // Turn health text red if dying
    int healthColor = engine.player.health > 25 ? white : red;

    // Format the strings nicely
    String score = "SCORE: ${engine.player.score.toString().padLeft(6, '0')}";
    String health = "HEALTH: ${engine.player.health}%";
    String ammo = "AMMO: ${engine.player.ammo}";

    int textY = viewHeight + 4; // Center it vertically in the HUD area

    // 4. Print the stats evenly spaced across the bottom
    _writeString(6, textY, "FLOOR 1", white);
    _writeString(22, textY, score, white);
    _writeString(44, textY, "LIVES: 3", white);

    // 5. Reactive ASCII Face
    String face = " :-) ";
    if (engine.player.health <= 0) {
      face = " X-x ";
    } else if (engine.player.health <= 25) {
      face = " :-( ";
    } else if (engine.player.health <= 60) {
      face = " :-| ";
    }

    _writeString(62, textY, "[$face]", yellow);

    _writeString(78, textY, health, healthColor);
    _writeString(100, textY, ammo, white);
  }

  void _drawFullVgaHud(WolfEngine engine) {
    int statusBarIndex = engine.data.vgaImages.indexWhere(
      (img) => img.width == 320 && img.height == 40,
    );
    if (statusBarIndex == -1) return;

    // 1. Draw Background
    _blitVgaImageAscii(engine.data.vgaImages[statusBarIndex], 0, 160);

    // 2. Draw Stats
    _drawNumberAscii(1, 32, 176, engine.data.vgaImages); // Floor
    _drawNumberAscii(
      engine.player.score,
      96,
      176,
      engine.data.vgaImages,
    ); // Score
    _drawNumberAscii(3, 120, 176, engine.data.vgaImages); // Lives
    _drawNumberAscii(
      engine.player.health,
      192,
      176,
      engine.data.vgaImages,
    ); // Health
    _drawNumberAscii(
      engine.player.ammo,
      232,
      176,
      engine.data.vgaImages,
    ); // Ammo

    // 3. Draw BJ's Face & Current Weapon
    _drawFaceAscii(engine);
    _drawWeaponIconAscii(engine);
  }

  void _drawNumberAscii(
    int value,
    int rightAlignX,
    int startY,
    List<VgaImage> vgaImages,
  ) {
    const int zeroIndex = 96;
    String numStr = value.toString();
    int currentX = rightAlignX - (numStr.length * 8);

    for (int i = 0; i < numStr.length; i++) {
      int digit = int.parse(numStr[i]);
      if (zeroIndex + digit < vgaImages.length) {
        _blitVgaImageAscii(vgaImages[zeroIndex + digit], currentX, startY);
      }
      currentX += 8;
    }
  }

  void _drawFaceAscii(WolfEngine engine) {
    int health = engine.player.health;
    int faceIndex;

    if (health <= 0) {
      faceIndex = 127;
    } else {
      int healthTier = ((100 - health) ~/ 16).clamp(0, 6);
      faceIndex = 106 + (healthTier * 3);
    }

    if (faceIndex < engine.data.vgaImages.length) {
      _blitVgaImageAscii(engine.data.vgaImages[faceIndex], 136, 164);
    }
  }

  void _drawWeaponIconAscii(WolfEngine engine) {
    int weaponIndex = 89;
    if (engine.player.hasChainGun) {
      weaponIndex = 91;
    } else if (engine.player.hasMachineGun) {
      weaponIndex = 90;
    }

    if (weaponIndex < engine.data.vgaImages.length) {
      _blitVgaImageAscii(engine.data.vgaImages[weaponIndex], 256, 164);
    }
  }

  @override
  dynamic finalizeFrame() {
    if (_engine.player.damageFlash > 0.0) {
      _applyDamageFlash();
    }
    return _screen;
  }

  // --- PRIVATE HUD DRAWING HELPERS ---

  void _blitVgaImageAscii(VgaImage image, int startX_320, int startY_200) {
    int planeWidth = image.width ~/ 4;
    int planeSize = planeWidth * image.height;

    double scaleX = width / 320.0;
    double scaleY = height / 200.0;

    int destStartX = (startX_320 * scaleX).toInt();
    int destStartY = (startY_200 * scaleY).toInt();
    int destWidth = (image.width * scaleX).toInt();
    int destHeight = (image.height * scaleY).toInt();

    for (int dy = 0; dy < destHeight; dy++) {
      for (int dx = 0; dx < destWidth; dx++) {
        int drawX = destStartX + dx;
        int drawY = destStartY + dy;

        if (drawX >= 0 && drawX < width && drawY >= 0 && drawY < height) {
          int srcX = (dx / scaleX).toInt().clamp(0, image.width - 1);
          int srcY = (dy / scaleY).toInt().clamp(0, image.height - 1);

          int plane = srcX % 4;
          int sx = srcX ~/ 4;
          int index = (plane * planeSize) + (srcY * planeWidth) + sx;

          int colorByte = image.pixels[index];
          if (colorByte != 255) {
            _screen[drawY][drawX] = ColoredChar(
              activeTheme.solid,
              ColorPalette.vga32Bit[colorByte],
            );
          }
        }
      }
    }
  }

  // --- DAMAGE FLASH ---
  void _applyDamageFlash() {
    double intensity = _engine.player.damageFlash;
    int redBoost = (150 * intensity).toInt();
    double colorDrop = 1.0 - (0.5 * intensity);

    for (int y = 0; y < viewHeight; y++) {
      for (int x = 0; x < width; x++) {
        ColoredChar cell = _screen[y][x];

        // Use our safe getters!
        int r = cell.r;
        int g = cell.g;
        int b = cell.b;

        r = (r + redBoost).clamp(0, 255);
        g = (g * colorDrop).toInt().clamp(0, 255);
        b = (b * colorDrop).toInt().clamp(0, 255);

        // Pack back into the native AABBGGRR format that ColoredChar expects
        int newRawColor = (0xFF000000) | (b << 16) | (g << 8) | r;

        _screen[y][x] = ColoredChar(cell.char, newRawColor);
      }
    }
  }

  /// Converts the current frame to a single printable ANSI string
  String toAnsiString() {
    StringBuffer buffer = StringBuffer();

    int lastR = -1;
    int lastG = -1;
    int lastB = -1;

    for (int y = 0; y < _screen.length; y++) {
      List<ColoredChar> row = _screen[y];
      for (ColoredChar cell in row) {
        if (cell.r != lastR || cell.g != lastG || cell.b != lastB) {
          buffer.write('\x1b[38;2;${cell.r};${cell.g};${cell.b}m');
          lastR = cell.r;
          lastG = cell.g;
          lastB = cell.b;
        }
        buffer.write(cell.char);
      }

      // Only print a newline if we are NOT on the very last row.
      // This stops the terminal from scrolling down!
      if (y < _screen.length - 1) {
        buffer.write('\n');
      }
    }

    // Reset the terminal color at the very end
    buffer.write('\x1b[0m');

    return buffer.toString();
  }
}