import { Color, Grid, Point, Rect, Size } from "./engine/datatypes.ts";
import { DrawPile } from "./drawpile.ts";
import { GridArt } from "./gridart.ts";
import { C } from "./colors.ts";

export class World3D {
  #grid: Grid<Element3D>;

  constructor(size: Size) {
    this.#grid = new Grid<Element3D>(size, () => null);
  }

  set(at: Point, value: Element3D) {
    this.#grid.set(at, value);
  }

  drawCell(drawpile: DrawPile, gridArt: GridArt, xy: Point) {
    const OFFSET_AIR = 0;
    const OFFSET_TOP = 256;
    const OFFSET_TOP_OF_TOP = 512;
    let here = this.#grid.get(xy);

    if (here == null) {
      drawpile.add(OFFSET_TOP, () => {
        gridArt.drawCeiling(C.BG_CEILING);
      });
      return;
    }

    const getRevealedBlock = (dx: number, dy: number): Block3D | null => {
      let xy2 = xy.offset(new Point(dx, dy));
      if (!new Rect(new Point(0, 0), this.#grid.size).contains(xy2)) {
        return null;
      }

      let other = this.#grid.get(xy.offset(new Point(dx, dy)));
      if (other instanceof Block3D) {
        return other;
      }
      return null;
    };

    let center = getRevealedBlock(0, 0);
    if (center) {
      drawpile.add(OFFSET_TOP, () => {
        gridArt.drawCeiling(center.ceiling);
      });
      return;
    }

    let west = getRevealedBlock(-1, 0);
    let east = getRevealedBlock(1, 0);
    let north = getRevealedBlock(0, -1);
    let south = getRevealedBlock(0, 1);

    if (north && west) {
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingTopLeft(north.moulding);
      });
    }
    if (north) {
      drawpile.add(OFFSET_AIR, () => {
        gridArt.drawWallTop(north.dark);
      });
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingTop(north.moulding);
      });
    }
    if (north && east) {
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingTopRight(north.moulding);
      });
    }
    if (west) {
      drawpile.add(OFFSET_AIR, () => {
        gridArt.drawWallLeft(west.dark);
      });
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingLeft(west.moulding);
      });
    }
    if (south && west) {
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingBottomLeft(south.moulding);
      });
    }
    if (south) {
      drawpile.add(OFFSET_AIR, () => {
        gridArt.drawWallBottom(south.bright);
      });
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingBottom(south.moulding);
      });
    }
    if (south && east) {
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingBottomRight(south.moulding);
      });
    }
    if (east) {
      drawpile.add(OFFSET_AIR, () => {
        gridArt.drawWallRight(east.bright);
      });
      drawpile.add(OFFSET_TOP_OF_TOP, () => {
        gridArt.drawMouldingRight(east.moulding);
      });
    }
  }
}

export type Element3D = Floor3D | Block3D | null;

export class Floor3D {
  constructor() {}
}

export class Block3D {
  readonly bright: Color;
  readonly dark: Color;
  readonly ceiling: Color;

  get moulding(): Color {
    return this.dark;
  }

  constructor(bright: Color, dark: Color, ceiling: Color) {
    this.bright = bright;
    this.dark = dark;
    this.ceiling = ceiling;
  }

  static standardWall(): Block3D {
    return new Block3D(C.BG_OUTERWALL, C.BG_INNERWALL, C.BG_WALL_OR_UNREVEALED);
  }
}