import { describe, expect, it } from 'vitest';
import type { Package, Surface } from '@tts/bgm';
import {
  matchRoute,
  childrenByPath,
  computeSurfacePlacements,
  computeRenderState,
  placementKey,
} from './state.js';

function makeSurface(overrides: Partial<Surface> = {}): Surface {
  return {
    type: 'board',
    id: 'harbor',
    layout: [],
    ...overrides,
  };
}

const pkg: Package = {
  meta: { id: 'harbor' },
  parts: new Map(),
  surfaces: new Map([
    ['board#harbor', makeSurface()],
    ['hud#hand', makeSurface({ type: 'hud', id: 'hand' })],
  ]),
  setups: new Map(),
};

describe('matchRoute', () => {
  it('matches a literal path', () => {
    const route = { route: '/deck', x: 0, y: 0, rotation: 0 };
    expect(matchRoute(route, '/deck')).toEqual({ candidate: undefined });
    expect(matchRoute(route, '/other')).toBeNull();
  });

  it('matches a :param against a candidate', () => {
    const route = {
      route: '/dock/:seat',
      x: 0,
      y: 0,
      rotation: 0,
      candidates: [
        { seat: '0', x: 40, y: 0 },
        { seat: '1', x: 40, y: 20 },
      ],
    };
    expect(matchRoute(route, '/dock/1')).toEqual({ candidate: { seat: '1', x: 40, y: 20 } });
  });

  it('fails when no candidate matches the param', () => {
    const route = {
      route: '/dock/:seat',
      x: 0,
      y: 0,
      rotation: 0,
      candidates: [{ seat: '0', x: 40, y: 0 }],
    };
    expect(matchRoute(route, '/dock/9')).toBeNull();
  });

  it('fails on length mismatch', () => {
    const route = { route: '/deck', x: 0, y: 0, rotation: 0 };
    expect(matchRoute(route, '/deck/extra')).toBeNull();
  });
});

describe('childrenByPath', () => {
  it('groups parts by path, ordered by index', () => {
    const parts = {
      'harbor:card#a': { path: '/deck', index: 1, facing: 'face' },
      'harbor:card#b': { path: '/deck', index: 0, facing: 'back' },
      'harbor:card#c': { path: '/community/0', index: 0, facing: 'standing' },
    };
    expect(childrenByPath(parts)).toEqual({
      '/deck': ['harbor:card#b', 'harbor:card#a'],
      '/community/0': ['harbor:card#c'],
    });
  });
});

describe('computeSurfacePlacements', () => {
  it('places parts on a matching route with index, stackSize, and facing', () => {
    const surface = makeSurface({
      layout: [{ route: '/deck', x: -100, y: 0, rotation: 0 }],
    });
    const placements = computeSurfacePlacements(surface, {
      'harbor:card#a': { path: '/deck', index: 0, facing: 'face' },
      'harbor:card#b': { path: '/deck', index: 1, facing: 'back' },
    });
    expect(placements).toHaveLength(2);
    expect(placements[0]).toMatchObject({ piece: 'harbor:card#a', index: 0, stackSize: 2, facing: 'face' });
    expect(placements[1]).toMatchObject({ piece: 'harbor:card#b', index: 1, stackSize: 2, facing: 'back' });
  });

  it('drops parts with no matching route', () => {
    const surface = makeSurface({ layout: [{ route: '/deck', x: 0, y: 0, rotation: 0 }] });
    const placements = computeSurfacePlacements(surface, {
      'harbor:card#a': { path: '/deck', index: 0, facing: 'face' },
      'harbor:card#b': { path: '/elsewhere', index: 0, facing: 'face' },
    });
    expect(placements).toHaveLength(1);
    expect(placements[0]!.piece).toBe('harbor:card#a');
  });

  it('uses the candidate anchor for a :param route', () => {
    const surface = makeSurface({
      layout: [
        {
          route: '/dock/:seat',
          x: 0,
          y: 0,
          rotation: 0,
          candidates: [{ seat: '0', x: 40, y: 5, rotation: 1 }],
        },
      ],
    });
    const placements = computeSurfacePlacements(surface, {
      'harbor:boat#fleet': { path: '/dock/0', index: 0, facing: 'face' },
    });
    expect(placements[0]!.candidate).toEqual({ seat: '0', x: 40, y: 5, rotation: 1 });
  });

  it('keeps the candidate stacking alongside its anchor', () => {
    const surface = makeSurface({
      layout: [
        {
          route: '/dock/:seat',
          x: 0,
          y: 0,
          rotation: 0,
          candidates: [{ seat: '0', x: 40, y: 5, stacking: { tilt: 2 } }],
        },
      ],
    });
    const placements = computeSurfacePlacements(surface, {
      'harbor:boat#fleet': { path: '/dock/0', index: 0, facing: 'face' },
    });
    expect(placements[0]!.candidate).toEqual({ seat: '0', x: 40, y: 5, stacking: { tilt: 2 } });
  });

  it('orders a path by index regardless of insertion order', () => {
    const surface = makeSurface({
      layout: [{ route: '/deck', x: 0, y: 0, rotation: 0 }],
    });
    const placements = computeSurfacePlacements(surface, {
      'harbor:card#b': { path: '/deck', index: 1, facing: 'face' },
      'harbor:card#a': { path: '/deck', index: 0, facing: 'face' },
    });
    expect(placements.map((p) => p.piece)).toEqual(['harbor:card#a', 'harbor:card#b']);
  });
});

describe('computeRenderState', () => {
  it('only includes enabled surfaces', () => {
    const state = {
      surfaces: { 'board#harbor': true, 'hud#hand': false },
      parts: { 'harbor:card#a': { path: '/deck', index: 0, facing: 'face' } },
    };
    pkg.surfaces.set(
      'board#harbor',
      makeSurface({ layout: [{ route: '/deck', x: 0, y: 0, rotation: 0 }] }),
    );
    const placements = computeRenderState(pkg, state);
    expect(placements).toHaveLength(1);
    expect(placements[0]!.surface).toBe('board#harbor');
  });
});

describe('placementKey', () => {
  it('is unique per surface and piece', () => {
    const a = { surface: 'board#harbor', piece: 'harbor:card#a' } as never;
    const b = { surface: 'board#harbor', piece: 'harbor:card#b' } as never;
    const c = { surface: 'hud#hand', piece: 'harbor:card#a' } as never;
    expect(placementKey(a)).not.toBe(placementKey(b));
    expect(placementKey(a)).not.toBe(placementKey(c));
  });
});