curltastic/frontend/src/game-model.test.ts

import { describe, expect, it } from 'vitest'
import { GameModel } from './game-model'
import type { ServerStoneTrajectory, StoneState } from './protocol'
import { SAMPLE_RATE_HZ } from './protocol'

function stone(partial: Partial<StoneState> & Pick<StoneState, 'id' | 'team'>): StoneState {
  return {
    x: 0,
    y: 30,
    rotation: 0,
    active: true,
    ...partial,
  }
}

/** Build (x,y,theta) samples; time comes from index / SAMPLE_RATE_HZ. */
function pathSamples(
  points: { x: number; y: number; theta?: number }[],
): [number, number, number][] {
  return points.map((p) => [p.x, p.y, p.theta ?? 0])
}

describe('GameModel multi-path trajectory animation', () => {
  it('returns two DrawableStones in parallel mid-trajectory', () => {
    const model = new GameModel()
    model.state.stones = [stone({ id: 1, team: 'red' }), stone({ id: 2, team: 'yellow' })]
    model.state.turnTeam = 'red'

    // 21 samples → duration 20/40 = 0.5s; mid at 0.25s is sample 10 → y=11
    const n = 21
    const path1 = pathSamples(
      Array.from({ length: n }, (_, i) => ({ x: 0, y: 10 + i * 0.1, theta: 0 })),
    )
    const path2 = pathSamples(
      Array.from({ length: n }, (_, i) => ({ x: 1, y: 10 + i * 0.1, theta: 0 })),
    )

    const paths: ServerStoneTrajectory[] = [
      { stone_id: 1, path: path1 },
      { stone_id: 2, path: path2 },
    ]

    model.startTrajectory(paths)
    expect(model.state.animating).toBe(true)

    const mid = performance.now() + 250
    const drawn = model.tick(mid)

    expect(drawn).toHaveLength(2)
    expect(drawn.map((d) => d.team).sort()).toEqual(['red', 'yellow'])
    // Mid-sample y ≈ 11 for both paths (y never reaches hog line → no trim)
    for (const d of drawn) {
      expect(d.y).toBeCloseTo(11, 0)
    }
  })

  it('clears animating when elapsed reaches maxTotal on a short path', () => {
    const model = new GameModel()
    model.state.stones = [stone({ id: 1, team: 'red' })]
    model.state.turnTeam = 'red'

    // 3 samples → max t = 2/40 = 0.05s
    model.startTrajectory([
      {
        stone_id: 1,
        path: pathSamples([
          { x: 0, y: 10 },
          { x: 0, y: 10.5 },
          { x: 0, y: 11 },
        ]),
      },
    ])
    expect(model.state.animating).toBe(true)

    const afterEnd = performance.now() + 200
    const drawn = model.tick(afterEnd)

    expect(drawn).toEqual([])
    expect(model.state.animating).toBe(false)
  })

  it('trims thrown stone path to hog line when id is not in existing stones', () => {
    const model = new GameModel()
    // Only stone 1 is already on the sheet; stone 2 is the newly thrown rock.
    model.state.stones = [stone({ id: 1, team: 'yellow', x: 0.5, y: 35 })]
    model.state.turnTeam = 'red'

    const thrownPath = pathSamples([
      { x: 0, y: 2, theta: 0.1 },
      { x: 0, y: 20, theta: 0.2 },
      { x: 0, y: 21.5, theta: 0.3 },
      { x: 0, y: 30, theta: 0.4 },
    ])

    model.startTrajectory([{ stone_id: 2, path: thrownPath }])
    expect(model.state.animating).toBe(true)

    // Immediately after start: hog-trimmed path begins at y=20 (sample before hog)
    const atStart = performance.now()
    const drawn = model.tick(atStart)

    expect(drawn).toHaveLength(1)
    expect(drawn[0].team).toBe('red') // turnTeam fallback for unknown id
    expect(drawn[0].y).toBeCloseTo(20, 0)
    // Must not still be at the hack (y=2)
    expect(drawn[0].y).toBeGreaterThan(15)
    // Uses body theta from path (small elapsed may blend toward next sample)
    expect(drawn[0].rotation).toBeCloseTo(0.2, 2)
  })

  it('uses sample index for time (SAMPLE_RATE_HZ)', () => {
    expect(SAMPLE_RATE_HZ).toBe(40)
  })
})