import {
  MAX_SPEED,
  MIN_SPEED,
  STONES_PER_TEAM,
  type EndScore,
  type Phase,
  type Team,
} from './protocol'
import { velocityToWeight, weightToVelocity } from './game-helpers'

export interface Hud {
  root: HTMLDivElement
  teamSelect: HTMLSelectElement
  velocityControl: HTMLDivElement
  curlSelector: HTMLDivElement
  frictionControl: HTMLDivElement
  throwButton: HTMLButtonElement
  setTeam: (team: Team) => void
  update: (state: {
    phase: Phase
    end: number
    scores: number[]
    hammer: Team
    turnTeam: Team
    animating: boolean
    stonesRemaining: number[]
    scoreboard: EndScore[]
  }) => void
  showToast: (message: string) => void
  setShareLink: (link: string) => void
}

function copyText(text: string): Promise<void> {
  if (navigator.clipboard && window.isSecureContext) {
    return navigator.clipboard.writeText(text)
  }
  return new Promise((resolve, reject) => {
    const ta = document.createElement('textarea')
    ta.value = text
    ta.style.position = 'fixed'
    ta.style.opacity = '0'
    document.body.appendChild(ta)
    ta.focus()
    ta.select()
    try {
      const ok = document.execCommand('copy')
      document.body.removeChild(ta)
      if (ok) resolve()
      else reject(new Error('execCommand copy failed'))
    } catch (e) {
      document.body.removeChild(ta)
      reject(e)
    }
  })
}

const TEAM_LABELS: Record<Team, string> = {
  team1: 'Team 1',
  team2: 'Team 2',
}

function buildStoneChipsHtml(team: Team): string {
  const chips = Array.from({ length: STONES_PER_TEAM }, (_, i) => {
    return `<span class="stone-chip stone-chip--${team}" data-index="${i}" aria-hidden="true"></span>`
  }).join('')
  return `<div class="stones-row stones-row--${team}" data-team="${team}" role="img" aria-label="${TEAM_LABELS[team]} stones remaining">${chips}</div>`
}


export function createHud(): Hud {
  const root = document.createElement('div')
  root.id = 'hud'
  root.innerHTML = `
    <div id="hud-top-group">
      <div class="hud-row" id="share-row">
        <div id="share"><button type="button">Copy share link</button></div>
      </div>
      <div id="stones-hud" aria-live="polite">
        ${buildStoneChipsHtml('team1')}
        ${buildStoneChipsHtml('team2')}
      </div>
      <div class="hud-row">
        <div id="score">Team 1 0 - Team 2 0</div>
        <div id="end-info">End 1 · Waiting</div>
        <select id="team-select" aria-label="Team">
          <option value="team1">Team 1</option>
          <option value="team2">Team 2</option>
        </select>
        <div id="hammer">Hammer: -</div>
      </div>
      <div id="scoreboard-strip" class="scoreboard-strip" aria-label="End scores"></div>
    </div>
    <div class="hud-row" style="align-items:flex-end;">
      <div id="velocity-control"></div>
      <div id="curl-selector"></div>
      <div id="friction-control">
        <label for="friction-slider">Friction</label>
        <input id="friction-slider" type="range" min="0.5" max="1.5" step="0.1" value="1.0" />
        <span id="friction-value">1.0</span>
      </div>
      <div>
        <button id="throw-btn" type="button" disabled>THROW</button>
      </div>
    </div>
    <div id="waiting">Waiting</div>
  `

  const scoreEl = root.querySelector<HTMLDivElement>('#score')!
  const endInfoEl = root.querySelector<HTMLDivElement>('#end-info')!
  const teamSelect = root.querySelector<HTMLSelectElement>('#team-select')!
  const hammerEl = root.querySelector<HTMLDivElement>('#hammer')!
  const waitingEl = root.querySelector<HTMLDivElement>('#waiting')!
  const stonesHud = root.querySelector<HTMLDivElement>('#stones-hud')!
  const scoreboardStrip = root.querySelector<HTMLDivElement>('#scoreboard-strip')!

  const updateStonesRemaining = (remaining: number[]) => {
    const teams: Team[] = ['team1', 'team2']
    for (let t = 0; t < teams.length; t++) {
      const team = teams[t]
      const left = Math.max(0, Math.min(STONES_PER_TEAM, remaining[t] ?? STONES_PER_TEAM))
      // Thrown stones remove leftmost chips: chip i is remaining when i >= (8 - left).
      const firstRemaining = STONES_PER_TEAM - left
      const row = stonesHud.querySelector<HTMLDivElement>(`.stones-row--${team}`)
      if (!row) continue
      row.setAttribute('aria-label', `${TEAM_LABELS[team]} ${left} stones remaining`)
      row.querySelectorAll<HTMLSpanElement>('.stone-chip').forEach((chip) => {
        const index = Number(chip.dataset.index)
        const isRemaining = index >= firstRemaining
        chip.classList.toggle('stone-chip--gone', !isRemaining)
        chip.classList.toggle('stone-chip--remaining', isRemaining)
      })
    }
  }

  const updateScoreboardStrip = (scoreboard: EndScore[], totals: number[]) => {
    if (scoreboard.length === 0) {
      scoreboardStrip.textContent = ''
      scoreboardStrip.hidden = true
      return
    }
    scoreboardStrip.hidden = false
    const cells = scoreboard
      .map((e) => `<span class="scoreboard-end" title="End ${e.end}">${e.team1}-${e.team2}</span>`)
      .join('')
    scoreboardStrip.innerHTML = `${cells}<span class="scoreboard-total">Σ ${totals[0] ?? 0}-${totals[1] ?? 0}</span>`
  }

  updateStonesRemaining([STONES_PER_TEAM, STONES_PER_TEAM])

  return {
    root,
    teamSelect,
    velocityControl: root.querySelector<HTMLDivElement>('#velocity-control')!,
    curlSelector: root.querySelector<HTMLDivElement>('#curl-selector')!,
    frictionControl: root.querySelector<HTMLDivElement>('#friction-control')!,
    throwButton: root.querySelector<HTMLButtonElement>('#throw-btn')!,
    setTeam: (team) => {
      teamSelect.value = team
    },
    update: (state) => {
      scoreEl.textContent = `Team 1 ${state.scores[0] ?? 0} - Team 2 ${state.scores[1] ?? 0}`
      const phaseText =
        state.phase === 'playing'
          ? `${TEAM_LABELS[state.turnTeam]}'s turn`
          : state.phase.replace(/_/g, ' ')
      endInfoEl.textContent = `End ${state.end} · ${phaseText}`
      hammerEl.textContent = `Hammer: ${TEAM_LABELS[state.hammer]}`
      waitingEl.classList.toggle('visible', state.phase !== 'game_complete' && state.animating)
      updateStonesRemaining(state.stonesRemaining)
      updateScoreboardStrip(state.scoreboard, state.scores)
    },
    showToast: (message: string) => {
      const toast = document.createElement('div')
      toast.id = 'toast'
      toast.textContent = message
      document.body.appendChild(toast)
      toast.style.display = 'block'
      window.setTimeout(() => toast.remove(), 3000)
    },
    setShareLink: (link: string) => {
      const btn = root.querySelector<HTMLButtonElement>('#share button')!
      btn.onclick = () => {
        copyText(link)
          .then(() => (btn.textContent = 'Copied!'))
          .catch(() => (btn.textContent = 'Copy failed'))
        window.setTimeout(() => (btn.textContent = 'Copy share link'), 2500)
      }
      btn.textContent = 'Copy share link'
    },
  }
}

export function createVelocitySelector(
  container: HTMLDivElement,
  onSelect: () => void,
): { getVelocity: () => number; setEnabled: (enabled: boolean) => void } {
  const state = { weight: 5 }
  container.innerHTML = ''

  const wrap = document.createElement('div')
  wrap.className = 'velocity-control-inner'

  const label = document.createElement('label')
  label.textContent = 'Velocity'
  wrap.appendChild(label)

  const slider = document.createElement('input')
  slider.type = 'range'
  slider.min = String(MIN_SPEED)
  slider.max = String(MAX_SPEED)
  slider.step = '0.05'
  slider.value = String(weightToVelocity(state.weight))
  slider.className = 'velocity-slider'

  const datalist = document.createElement('datalist')
  datalist.id = 'velocity-marks'
  for (let w = 1; w <= 10; w++) {
    const opt = document.createElement('option')
    opt.value = String(weightToVelocity(w))
    opt.label = String(w)
    datalist.appendChild(opt)
  }
  slider.setAttribute('list', 'velocity-marks')
  wrap.appendChild(slider)
  wrap.appendChild(datalist)

  const readout = document.createElement('div')
  readout.className = 'velocity-readout'
  wrap.appendChild(readout)

  const update = () => {
    const v = Number(slider.value)
    state.weight = velocityToWeight(v)
    readout.textContent = `${v.toFixed(2)} m/s · Weight ${state.weight}`
    onSelect()
  }
  slider.addEventListener('input', update)
  update()

  container.appendChild(wrap)

  return {
    getVelocity: () => Number(slider.value),
    setEnabled: (enabled) => {
      slider.disabled = !enabled
    },
  }
}

export function createCurlSelector(
  container: HTMLDivElement,
  onSelect: (curl: number) => void,
): { getSelected: () => number; setEnabled: (enabled: boolean) => void } {
  const state = { selected: 1, enabled: true }
  const options = [
    { value: -1, label: '↷', ariaLabel: 'Left curl' },
    { value: 1, label: '↶', ariaLabel: 'Right curl' },
  ]
  container.innerHTML = ''
  for (const opt of options) {
    const btn = document.createElement('button')
    btn.className = 'curl-btn'
    btn.textContent = opt.label
    btn.ariaLabel = opt.ariaLabel
    btn.dataset.curl = String(opt.value)
    btn.addEventListener('click', () => {
      if (!state.enabled) return
      state.selected = opt.value
      updateSelection()
      onSelect(opt.value)
    })
    container.appendChild(btn)
  }

  const updateSelection = () => {
    container.querySelectorAll<HTMLButtonElement>('.curl-btn').forEach((btn) => {
      btn.classList.toggle('selected', Number(btn.dataset.curl) === state.selected)
    })
  }
  updateSelection()

  return {
    getSelected: () => state.selected,
    setEnabled: (enabled) => {
      state.enabled = enabled
      container.querySelectorAll<HTMLButtonElement>('.curl-btn').forEach((btn) => {
        btn.disabled = !enabled
      })
    },
  }
}

export function createFrictionSlider(
  container: HTMLDivElement,
): { getFriction: () => number; setEnabled: (enabled: boolean) => void } {
  const slider = container.querySelector<HTMLInputElement>('#friction-slider')!
  const valueEl = container.querySelector<HTMLSpanElement>('#friction-value')!

  const updateValue = () => {
    valueEl.textContent = Number(slider.value).toFixed(1)
  }
  slider.addEventListener('input', updateValue)
  updateValue()

  return {
    getFriction: () => Number(slider.value),
    setEnabled: (enabled) => {
      slider.disabled = !enabled
    },
  }
}