import { describe, expect, it } from 'vitest';
import { CreateAssetCommand, SetAssetPropertyCommand } from '../../src/core/commands/assetCommands';
import { AddFrameCommand, SetFrameCollisionCommand } from '../../src/core/commands/frameCommands';
import { AddTilePictureCommand } from '../../src/core/commands/tileCommands';
import { PaintTilesCommand } from '../../src/core/commands/tilemapCommands';
import type { TextureAsset, TilemapAsset, TilemapLayer } from '../../src/core/model/Asset';
import { findAsset } from '../../src/core/model/Project';
import type { PropertyValue } from '../../src/core/model/Properties';
import {
  TILE_COLLISION_SCALE_KEY,
  TILE_FRICTION_KEY,
  TILE_KIND_KEY,
  TILE_ONE_WAY_ANGLE_KEY,
  TILE_ONE_WAY_KEY,
  TILE_SOLID_KEY,
  TILE_TRIGGER_KEY,
} from '../../src/core/model/tile';
import {
  cellKey,
  cellsAround,
  layerTiles,
  patchedInOrder,
  TILEMAP_COLUMNS_KEY,
  TILEMAP_ROWS_KEY,
  TILEMAP_TILE_KEY,
  type TileDraw,
} from '../../src/core/model/tilemap';
import {
  oneWayAngles,
  solidPolygons,
  solidRects,
  tileMaterials,
  triggerCells,
  triggerPolygons,
  triggerRects,
} from '../../src/core/model/tilemapCollision';
import {
  cellsChanged,
  cellsChangedSince,
  cellsTileIds,
  cellsVersion,
} from '../../src/core/model/tilemapMemo';
import { layerRows } from '../../src/viewport/drawOrder';
import type { TilemapDraw, TilemapLayerDraw } from '../../src/viewport/items';
import { groupByTile } from '../../src/viewport/tilemapMesh';
import { makeSpriteScene } from '../helpers';

const COLUMNS = 12;
const ROWS = 9;

/**
 * A 12 × 9 map of two layers and a tile of every kind that works out differently: plain and
 * autotiles, with and without outlines, drawn in and out, one-way at two angles, of another
 * surface, triggers, one that draws only – and an id no tile has.
 */
function patchMap() {
  const f = makeSpriteScene('Thing');
  const texture = new CreateAssetCommand('texture', 'Sheet');
  f.stack.execute(texture);
  const sheet = findAsset(f.project, texture.asset.id) as TextureAsset;
  sheet.file = `${'a'.repeat(64)}.png`;
  sheet.width = 128;
  sheet.height = 128;
  const frame = (x: number, y: number, w: number, h: number) => {
    const command = new AddFrameCommand(texture.asset.id, { x, y, w, h });
    f.stack.execute(command);
    return command.frameId;
  };
  const single = frame(0, 0, 32, 32);
  const outlined = frame(0, 32, 64, 96);
  const bare = frame(64, 32, 64, 96);
  f.stack.execute(
    new SetFrameCollisionCommand(texture.asset.id, single, [
      [
        { x: 0, y: 0 },
        { x: 32, y: 0 },
        { x: 0, y: 32 },
      ],
    ]),
  );
  f.stack.execute(
    new SetFrameCollisionCommand(texture.asset.id, outlined, [
      [
        { x: 0, y: 0 },
        { x: 64, y: 0 },
        { x: 0, y: 96 },
      ],
    ]),
  );
  const tile = (name: string, props: Record<string, PropertyValue>, picture?: string) => {
    const command = new CreateAssetCommand('tile', name);
    f.stack.execute(command);
    const id = command.asset.id;
    if (picture) f.stack.execute(new AddTilePictureCommand(id, picture));
    f.stack.execute(new SetAssetPropertyCommand(id, TILE_KIND_KEY, 'none'));
    for (const [key, value] of Object.entries(props))
      f.stack.execute(new SetAssetPropertyCommand(id, key, value));
    return id;
  };
  const solid = { [TILE_SOLID_KEY]: true };
  const floor = { [TILE_KIND_KEY]: 'floor' };
  const tiles = [
    tile('Slope', solid, single),
    tile('Lake', { ...solid, ...floor }, outlined),
    tile('Grass', { ...solid, ...floor, [TILE_COLLISION_SCALE_KEY]: 0.5 }, bare),
    tile('Wall', solid),
    tile('Bush', { ...solid, [TILE_COLLISION_SCALE_KEY]: 0.5 }),
    tile('Big', { ...solid, [TILE_COLLISION_SCALE_KEY]: 1.5 }),
    tile('Ledge', { ...solid, [TILE_ONE_WAY_KEY]: true, [TILE_ONE_WAY_ANGLE_KEY]: 30 }),
    tile('Steep', { ...solid, [TILE_ONE_WAY_KEY]: true, [TILE_ONE_WAY_ANGLE_KEY]: 60 }, bare),
    tile('Ice', { ...solid, [TILE_FRICTION_KEY]: 0 }),
    tile('Water', { [TILE_TRIGGER_KEY]: true, ...floor }, bare),
    tile('Spikes', { [TILE_TRIGGER_KEY]: true }, single),
    tile('Deco', floor, bare),
    'no-such-tile',
  ];
  const map = new CreateAssetCommand('tilemap', 'Ground');
  f.stack.execute(map);
  for (const [key, value] of [
    [TILEMAP_COLUMNS_KEY, COLUMNS],
    [TILEMAP_ROWS_KEY, ROWS],
    [TILEMAP_TILE_KEY, 32],
  ] as const)
    f.stack.execute(new SetAssetPropertyCommand(map.asset.id, key, value));
  const asset = findAsset(f.project, map.asset.id) as TilemapAsset;
  asset.layers.push({ id: 'upper', name: 'Upper', cells: {} });
  return { ...f, asset, tiles };
}

/** A small seeded generator, so a failing walk can be walked again. */
function random(seed: number): () => number {
  return () => {
    seed = (seed + 0x6d2b79f5) | 0;
    let t = Math.imul(seed ^ (seed >>> 15), 1 | seed);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

/** Everything a map works out, as plain data: tiles per layer, solids per filter, triggers. */
function workedOut(m: ReturnType<typeof patchMap>, asset: TilemapAsset) {
  const props = m.asset.props;
  const solidsOf = (of: TilemapAsset) => ({
    rects: solidRects(m.project, props, of),
    polygons: solidPolygons(m.project, props, of),
    oneWay: oneWayAngles(m.project, of).map((angle) => ({
      angle,
      rects: solidRects(m.project, props, of, angle),
      polygons: solidPolygons(m.project, props, of, angle),
    })),
    materials: tileMaterials(m.project, of).map((material) => ({
      material,
      rects: solidRects(m.project, props, of, false, material),
      polygons: solidPolygons(m.project, props, of, false, material),
    })),
    triggerRects: triggerRects(m.project, props, of),
    triggerPolygons: triggerPolygons(m.project, props, of),
    triggerCells: [...triggerCells(m.project, props, of)],
  });
  return {
    tiles: asset.layers.map((layer) => layerTiles(m.project, props, layer)),
    whole: solidsOf(asset),
    perLayer: asset.layers.map((layer) => solidsOf({ ...asset, layers: [layer] })),
  };
}

/**
 * A layer's tiles as the meshes take them (#424): grouped by tile, and by sort row and tile with
 * offsets that move some tiles a row up or down. Each next to the same grouping of a copy of the
 * list, which nothing was patched from; `reused` counts the groups handed on from the last call.
 */
function grouping(m: ReturnType<typeof patchMap>, layer: TilemapLayer, last: Set<readonly unknown[]>) {
  const draw = {
    tiles: new Map(m.tiles.map((id, i) => [id, { sortOffset: (i % 4) - 1 }])),
  } as unknown as TilemapDraw;
  const tiles = layerTiles(m.project, m.asset.props, layer);
  const of = (list: readonly TileDraw[]) => {
    const rows = layerRows(draw, { tiles: list } as TilemapLayerDraw);
    return {
      byTile: [...groupByTile(list)],
      byRow: [...rows].map(([row, cells]) => [row, cells, [...groupByTile(cells)]] as const),
    };
  };
  const patched = of(tiles);
  const groups = [
    ...patched.byTile.map(([, group]) => group),
    ...patched.byRow.flatMap(([, cells, byTile]) => [cells, ...byTile.map(([, group]) => group)]),
  ];
  const reused = groups.filter((group) => last.has(group)).length;
  return { patched, fresh: of([...tiles]), reused, groups: new Set<readonly unknown[]>(groups) };
}

/** The same map on cells never seen before, so nothing of it is patched. */
function afresh(asset: TilemapAsset): TilemapAsset {
  return { ...asset, layers: asset.layers.map((layer) => ({ ...layer, cells: { ...layer.cells } })) };
}

describe('a painted map works out only the cells around what changed (#348)', () => {
  it('knows which cells changed since a version, and when it does not know', () => {
    const cells: Record<string, string> = { '0,0': 'a', '1,0': 'b' };
    const first = cellsVersion(cells);
    expect(cellsChangedSince(cells, first)).toEqual([]);
    cells['2,0'] = 'a';
    cellsChanged(cells, ['2,0']);
    const second = cellsVersion(cells);
    delete cells['0,0'];
    cells['1,0'] = 'c';
    // Named and not, the same: one walk finds what the painter left out.
    cellsChanged(cells);
    expect([...cellsChangedSince(cells, first)!].sort()).toEqual(['0,0', '1,0', '2,0']);
    expect([...cellsChangedSince(cells, second)!].sort()).toEqual(['0,0', '1,0']);
    expect(cellsTileIds(cells)).toEqual(['a', 'c']);
    expect(cellsChangedSince(cells, -1)).toBeNull();
    expect(cellsChangedSince({ ...cells }, second)).toBeNull();
  });

  it('a key named but written back as it was is no change', () => {
    const cells: Record<string, string> = { '0,0': 'a' };
    const first = cellsVersion(cells);
    cells['0,0'] = 'b';
    cells['0,0'] = 'a';
    cellsChanged(cells, ['0,0', '5,5']);
    expect(cellsVersion(cells)).toBe(first);
  });

  it('the cells around a change stay in the grid', () => {
    expect(cellsAround(['0,0'], 3, 2)).toEqual([0, 1, 3, 4]);
    expect(cellsAround(['2,1', '1,1'], 3, 2)).toEqual([0, 1, 2, 3, 4, 5]);
    expect(cellsAround(['9,9', 'nonsense'], 3, 2)).toEqual([]);
  });

  it('a patch replaces the entries of the cells it works out, keeps the rest and their order', () => {
    const entry = (at: number, name: string) => ({ at, name });
    const list = [entry(1, 'a'), entry(3, 'b'), entry(3, 'c'), entry(7, 'd')];
    const made: Record<number, ReturnType<typeof entry>[]> = {
      0: [entry(0, 'new')],
      3: [],
      5: [entry(5, 'x'), entry(5, 'y')],
    };
    const patched = patchedInOrder(
      list,
      (e) => e.at,
      [0, 3, 5],
      (at) => made[at]!,
    );
    expect(patched.map((e) => e.name)).toEqual(['new', 'a', 'x', 'y', 'd']);
    expect(patched[1]).toBe(list[0]);
  });

  it('patched and worked out afresh agree after every step of a long walk of painting', () => {
    const m = patchMap();
    const next = random(348);
    const pick = <T>(list: readonly T[]) => list[Math.floor(next() * list.length)]!;
    const somewhere = () => ({
      x: Math.floor(next() * (COLUMNS + 2)) - 1,
      y: Math.floor(next() * (ROWS + 2)) - 1,
    });
    const layerOf = (): TilemapLayer => pick(m.asset.layers);
    const counts = { paint: 0, undo: 0, named: 0, unnamed: 0 };
    workedOut(m, m.asset);
    const lastGroups = m.asset.layers.map((layer) => grouping(m, layer, new Set()).groups);
    let reused = 0;
    for (let step = 0; step < 400; step++) {
      const roll = next();
      if (roll < 0.5) {
        const layer = layerOf();
        const edits = Array.from({ length: 1 + Math.floor(next() * 4) }, () => {
          const at = somewhere();
          return { ...at, tileId: next() < 0.15 ? '' : pick(m.tiles) };
        });
        m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, edits));
        counts.paint++;
      } else if (roll < 0.65 && m.stack.canUndo) {
        m.stack.undo();
        counts.undo++;
      } else {
        // In place, as a stroke paints before it is a command: with its keys, or without.
        const layer = layerOf();
        const keys = Array.from({ length: 1 + Math.floor(next() * 3) }, () => {
          const at = somewhere();
          const key = cellKey(at.x, at.y);
          const tileId = next() < 0.3 ? '' : pick(m.tiles);
          if (tileId) layer.cells[key] = tileId;
          else delete layer.cells[key];
          return key;
        });
        const named = next() < 0.5;
        cellsChanged(layer.cells, named ? keys : undefined);
        counts[named ? 'named' : 'unnamed']++;
      }
      const patched = workedOut(m, m.asset);
      const fresh = workedOut(m, afresh(m.asset));
      expect(patched, `step ${step}`).toEqual(fresh);
      m.asset.layers.forEach((layer, i) => {
        const groups = grouping(m, layer, lastGroups[i]!);
        expect(groups.patched, `step ${step}, layer ${i}`).toEqual(groups.fresh);
        reused += groups.reused;
        lastGroups[i] = groups.groups;
      });
    }
    // The walk went everywhere it should: enough of each step, and maps that block in every way.
    expect(Math.min(...Object.values(counts))).toBeGreaterThan(20);
    expect(reused).toBeGreaterThan(1000);
    const end = workedOut(m, m.asset);
    expect(end.whole.rects.length).toBeGreaterThan(5);
    expect(end.whole.polygons.length).toBeGreaterThan(5);
    expect(end.whole.oneWay).toHaveLength(2);
    expect(end.whole.triggerCells.length).toBeGreaterThan(3);
  });

  it('a cell two rows off is cut again when the autotile between turns into a box', () => {
    const m = patchMap();
    const [, lake, , , bush, big] = m.tiles;
    const layer = m.asset.layers[0]!;
    // Found by a search: erasing (3,1) makes the lake at (3,2) block whole, so the big box at (3,3)
    // – drawn out on every side without a blocking neighbour – no longer grows upwards.
    const rows = [
      [bush, lake, lake, lake],
      [lake, '', lake, lake],
      ['', lake, lake, lake],
      [lake, '', lake, big],
    ];
    const edits = rows.flatMap((row, y) => row.map((tileId, x) => ({ x, y, tileId: tileId! })));
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, edits));
    solidRects(m.project, m.asset.props, m.asset);
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, [{ x: 3, y: 1, tileId: '' }]));
    expect(solidRects(m.project, m.asset.props, m.asset)).toEqual(
      solidRects(m.project, m.asset.props, afresh(m.asset)),
    );
  });

  it('a painted cell leaves what is drawn and what blocks far from it the very same objects', () => {
    const m = patchMap();
    const [slope, lake] = m.tiles;
    const layer = m.asset.layers[0]!;
    const all = Array.from({ length: COLUMNS * ROWS }, (_, i) => ({
      x: i % COLUMNS,
      y: Math.floor(i / COLUMNS),
      tileId: i % COLUMNS < 6 ? lake! : slope!,
    }));
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, all));
    const tiles = layerTiles(m.project, m.asset.props, layer);
    const polygons = solidPolygons(m.project, m.asset.props, m.asset);
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, [{ x: 2, y: 4, tileId: '' }]));
    const after = layerTiles(m.project, m.asset.props, layer);
    expect(after).not.toBe(tiles);
    expect(after.find((t) => t.x === 10 && t.y === 0)).toBe(tiles.find((t) => t.x === 10 && t.y === 0));
    const far = (list: readonly { x: number; y: number }[]) => list.filter((p) => p.y === 8 && p.x === 0);
    expect(far(solidPolygons(m.project, m.asset.props, m.asset))).toEqual(far(polygons));
    expect(far(solidPolygons(m.project, m.asset.props, m.asset))[0]).toBe(far(polygons)[0]);
  });

  it('a painted cell regroups only the tiles and rows it touches, so only their meshes are built (#424)', () => {
    const m = patchMap();
    const [slope, lake, , wall] = m.tiles;
    const layer = m.asset.layers[0]!;
    const all = Array.from({ length: COLUMNS * ROWS }, (_, i) => ({
      x: i % COLUMNS,
      y: Math.floor(i / COLUMNS),
      tileId: i % COLUMNS < 6 ? lake! : slope!,
    }));
    // A wall in a corner already: a tile new to the layer would work all of it out again (#348).
    all[all.length - 1]!.tileId = wall!;
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, all));
    const draw = { tiles: new Map(m.tiles.map((id) => [id, { sortOffset: 0 }])) } as unknown as TilemapDraw;
    const tiles = layerTiles(m.project, m.asset.props, layer);
    const groups = groupByTile(tiles);
    const rows = layerRows(draw, { tiles } as TilemapLayerDraw);
    // A wall on the slopes, away from the lake: the lake looks the same, so its group stays.
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, [{ x: 10, y: 4, tileId: wall! }]));
    const after = layerTiles(m.project, m.asset.props, layer);
    const regrouped = groupByTile(after);
    expect(regrouped.get(lake!)).toBe(groups.get(lake!));
    expect(regrouped.get(slope!)).not.toBe(groups.get(slope!));
    expect(regrouped.get(wall!)!.map((t) => [t.x, t.y])).toEqual([
      [10, 4],
      [11, 8],
    ]);
    const rowsAfter = layerRows(draw, { tiles: after } as TilemapLayerDraw);
    expect([...rowsAfter.keys()].filter((row) => rowsAfter.get(row) !== rows.get(row))).toEqual([4]);
    // And back to a slope, a patch on a patch: still the same lake, and the same as grouped afresh.
    m.stack.execute(new PaintTilesCommand(m.asset.id, layer.id, [{ x: 10, y: 4, tileId: slope! }]));
    const back = layerTiles(m.project, m.asset.props, layer);
    expect(groupByTile(back).get(lake!)).toBe(groups.get(lake!));
    expect([...groupByTile(back)]).toEqual([...groupByTile([...back])]);
  });
});