const WebSocket = require('ws')

const DRAW_VEL = 2.38
const TAKEOUT_VEL = DRAW_VEL * 1.4 // ~3.33 — enough to move the stationary stone
const room = 'COLQA' + Math.floor(Math.random() * 1000)
const url = 'ws://127.0.0.1:3000/ws?room=' + room

function throwFor(ws, team, broom_x, broom_y, velocity = DRAW_VEL, curl = 0, friction = 1.0) {
  ws.send(JSON.stringify({ type: 'throw', team, broom_x, broom_y, velocity, curl, friction }))
}

function connect() {
  return new Promise((resolve, reject) => {
    const ws = new WebSocket(url)
    const messages = []
    ws.on('open', () => resolve({ ws, messages }))
    ws.on('message', (data) => messages.push(JSON.parse(data.toString())))
    ws.on('error', reject)
  })
}

function waitFor(messages, pred, timeout = 10000) {
  const start = Date.now()
  return new Promise((resolve, reject) => {
    const check = () => {
      if (pred()) return resolve(undefined)
      if (Date.now() - start > timeout) return reject(new Error('timeout'))
      setTimeout(check, 50)
    }
    check()
  })
}

function latestState(messages) {
  for (let i = messages.length - 1; i >= 0; i--) {
    if (messages[i].type === 'game_state') return messages[i]
  }
  return null
}

function stoneIdKey(id) {
  return `${id.team}:${id.n}`
}

;(async () => {
  const c = await connect()
  await waitFor(c.messages, () => {
    const st = latestState(c.messages)
    return st && st.phase === 'playing'
  })

  // First throw: DRAW_VEL so it stays in house.
  let state = latestState(c.messages)
  const firstTeam = state.turn_team
  throwFor(c.ws, firstTeam, 0.0, 38.5, DRAW_VEL, 0, 1.0)
  await waitFor(c.messages, () => {
    const st = latestState(c.messages)
    return st && st.stones && st.stones.length === 1 && st.phase === 'playing'
  }, 15000)
  state = latestState(c.messages)
  console.log('After first throw stones:', state.stones.map(s => ({ id: s.id, x: s.x, y: s.y })))
  if (state.stones.length !== 1) throw new Error('expected first stone in play')

  const firstStone = state.stones[0]
  const firstIdKey = stoneIdKey(firstStone.id)
  const trajCountBefore = c.messages.filter(m => m.type === 'trajectories').length
  console.log('trajectories count before second throw:', trajCountBefore)

  // Second throw aimed at first stone so they collide.
  const secondTeam = state.turn_team
  throwFor(c.ws, secondTeam, firstStone.x, firstStone.y, TAKEOUT_VEL, 0, 1.0)
  await waitFor(c.messages, () => c.messages.filter(m => m.type === 'trajectories').length > trajCountBefore, 15000)

  const traj = c.messages.filter(m => m.type === 'trajectories').pop()
  if (!traj.stones || !Array.isArray(traj.stones)) {
    throw new Error('trajectories message must have stones[]')
  }
  console.log('Trajectory stones count:', traj.stones.length)
  for (const p of traj.stones) {
    console.log(
      'stone_id', p.stone_id,
      'team', p.team,
      'path length', p.trajectory?.length,
      'first', p.trajectory?.[0],
      'last', p.trajectory?.[p.trajectory.length - 1]
    )
  }

  const ids = traj.stones.map(p => stoneIdKey(p.stone_id)).sort()
  if (ids.length < 2) {
    throw new Error('expected both stones in trajectories, got ' + JSON.stringify(ids))
  }
  if (!ids.includes(firstIdKey)) {
    throw new Error('expected first stone in trajectories, got ' + JSON.stringify(ids))
  }
  for (const p of traj.stones) {
    if (!p.trajectory || p.trajectory.length < 5) {
      throw new Error('path too short for stone ' + JSON.stringify(p.stone_id))
    }
    if (typeof p.stone_id !== 'object' || !p.stone_id.team || typeof p.stone_id.n !== 'number') {
      throw new Error('stone_id must be {team,n}, got ' + JSON.stringify(p.stone_id))
    }
  }

  // Verify the first stone actually moved because of collision.
  const stone1Path = traj.stones.find(p => stoneIdKey(p.stone_id) === firstIdKey).trajectory
  const first = stone1Path[0]
  const last = stone1Path[stone1Path.length - 1]
  const dist = Math.sqrt((last[0] - first[0]) ** 2 + (last[1] - first[1]) ** 2)
  console.log('first stone moved', dist, 'm')
  if (dist < 0.05) throw new Error('expected first stone to move after collision')

  console.log('COLLISION TRAJECTORY QA PASSED')
  c.ws.close()
  process.exit(0)
})().catch(e => { console.error(e); process.exit(1) })