// Shared client helpers: auth bootstrap, fetch wrapper, DOM utils, SVG icons.

const ICONS = {
  file: '<path d="M6 3.5h7l3 3v12H6z"/><path d="M13 3.5v3h3"/>',
  folder: '<path d="M3.5 6.5h6l2-2h7v13h-15z"/>',
  star: '<path d="M11 3.5l2.2 4.5 5 .7-3.6 3.5.9 5-4.5-2.4-4.5 2.4.9-5-3.6-3.5 5-.7z"/>',
  tree: '<path d="M4 5h14M9 11h9M9 17h9M4 5v9.5a2.5 2.5 0 0 0 2.5 2.5H6"/>',
  key: '<circle cx="7.5" cy="14.5" r="3.5"/><path d="M10 12l8-8M14.5 4.5l3 3M12 7l2.5 2.5"/>',
  todo: '<rect x="4" y="4" width="6" height="6" rx="1.5"/><path d="M5.2 7l1.3 1.3L8.8 6"/><path d="M13 6.5h6M13 11h6M13 15.5h6"/><rect x="4" y="12.5" width="6" height="6" rx="1.5"/>',
  table: '<rect x="3.5" y="4.5" width="15" height="13" rx="1.5"/><path d="M3.5 9h15M3.5 13.5h15M8.5 4.5v13M13.5 4.5v13"/>',
  eye: '<path d="M2.5 11s3.2-5.5 8.5-5.5 8.5 5.5 8.5 5.5-3.2 5.5-8.5 5.5S2.5 11 2.5 11z"/><circle cx="11" cy="11" r="2.4"/>',
  eyeoff: '<path d="M4 4l14 14M9 5.8A8.7 8.7 0 0 1 11 5.5c5.3 0 8.5 5.5 8.5 5.5a15 15 0 0 1-2.7 3.2M6 7.5A14 14 0 0 0 2.5 11S5.7 16.5 11 16.5a8.6 8.6 0 0 0 3-.5"/>',
  caret:  '<path d="M6 9l5 5 5-5" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"/>',
  back: '<path d="M15 4l-7 7 7 7"/>',
  sun: '<circle cx="11" cy="11" r="4"/><path d="M11 2.5v2M11 17.5v2M2.5 11h2M17.5 11h2M5 5l1.4 1.4M15.6 15.6L17 17M17 5l-1.4 1.4M6.4 15.6L5 17"/>',
  moon: '<path d="M17 13.2A7 7 0 0 1 8.8 5a7.2 7.2 0 1 0 8.2 8.2z"/>',
  serif: '<path d="M4.5 6V4.5h13V6M11 4.5v13M8 17.5h6"/>',
  docpage: '<rect x="4.5" y="3.5" width="13" height="15" rx="1.5"/><path d="M7.5 8h7M7.5 11.5h7M7.5 15h4"/>',
  comment: '<path d="M19 12.5a6.5 6.5 0 0 1-6.5 6.5H5l-1.8 1.8V12.5a7.3 7.3 0 0 1 7.3-7.3h1.5A6.5 6.5 0 0 1 19 12.5z"/>',
  // The same bubble with a plus in it: "leave a comment here", as opposed to
  // `comment`, which marks one that already exists. The bubble is redrawn a
  // little smaller and rounder rather than reused, because the plus needs room
  // in the middle and the pointed tail reads as noise at 15px.
  commentadd: '<path d="M18.5 11.5a6 6 0 0 1-6 6H7l-3.5 2.5v-8.5a6 6 0 0 1 6-6h3a6 6 0 0 1 6 6z"/><path d="M11 8.5v6M8 11.5h6"/>',
  edit: '<path d="M14.5 4.5l3 3L8 17l-4 1 1-4 9.5-9.5z"/>',
  image: '<rect x="3.5" y="4.5" width="15" height="13" rx="2"/><circle cx="8" cy="9" r="1.4"/><path d="M18 14l-4-4-7 7"/>',
  link: '<path d="M9 12.5a3.5 3.5 0 0 0 5 0l3-3a3.5 3.5 0 0 0-5-5l-1.2 1.2"/><path d="M13 9.5a3.5 3.5 0 0 0-5 0l-3 3a3.5 3.5 0 0 0 5 5l1.2-1.2"/>',
  // the link glyph with its middle struck through: remove this link
  unlink:
    '<path d="M9.5 13a3.5 3.5 0 0 0 4.3-.5l2.7-2.7a3.5 3.5 0 0 0-4.7-5.1"/><path d="M12.5 9a3.5 3.5 0 0 0-4.3.5l-2.7 2.7a3.5 3.5 0 0 0 4.7 5.1"/><path d="M4 4l14 14"/>',
  download: '<path d="M11 3.5v10"/><path d="M6.5 9.5l4.5 4.5 4.5-4.5"/><path d="M4.5 17.5h13"/>',
  copy: '<rect x="8" y="8" width="10" height="11" rx="2"/><path d="M5.5 14.5H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h7.5a2 2 0 0 1 2 2v.5"/>',
  check: '<path d="M4.5 11.5l4.5 4.5 8.5-9.5"/>',
  x: '<path d="M6 6l10 10M16 6L6 16"/>',
  reply: '<path d="M18 5v4a4 4 0 0 1-4 4H5"/><path d="M8.5 9.5L5 13l3.5 3.5"/>',
  send: '<path d="M4 11l14-6-4.5 14-3-6L4 11z"/>',
  trash: '<path d="M4.5 6.5h13M9 6V4.5h4V6M6.5 6.5l.8 12h7.4l.8-12"/>',
  quote: '<path d="M8.5 6.5c-2.5 1-4 3-4 6.5v3h4.5v-5h-2.7c.2-2 1-3.3 2.2-4.5zM18 6.5c-2.5 1-4 3-4 6.5v3h4.5v-5h-2.7c.2-2 1-3.3 2.2-4.5z"/>',
  undo: '<path d="M8.5 5.5L4 10l4.5 4.5"/><path d="M4 10h9a5 4.5 0 0 1 0 9h-3"/>',
  redo: '<path d="M13.5 5.5L18 10l-4.5 4.5"/><path d="M18 10H9a5 4.5 0 0 0 0 9h3"/>',
  zoomIn: '<circle cx="10" cy="10" r="6.5"/><path d="M15 15l4 4M10 7.5v5M7.5 10h5"/>',
  zoomOut: '<circle cx="10" cy="10" r="6.5"/><path d="M15 15l4 4M7.5 10h5"/>',
}

export function icon(name) {
  const svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg')
  svg.setAttribute('viewBox', '0 0 22 22')
  svg.setAttribute('class', 'icon')
  svg.innerHTML = ICONS[name] || ''
  return svg
}

export async function initAuth(nextPath) {
  // the shell inlines this; the fetch is only for shells served without it
  const res = window.__BOOT || (await fetch('/api/me').then(r => r.json()))
  const whoami = document.getElementById('whoami')
  // Opened through a public link: not signed in, but not turned away either.
  // No username, so every "is this mine?" check in the app answers no.
  if (!res.user && res.share) {
    whoami.replaceChildren(el('span', { class: 'muted' }, 'Read-only link'))
    if (res.oauth) {
      const inLink = document.createElement('a')
      inLink.href = `/auth/login?next=${encodeURIComponent(nextPath || '/')}`
      inLink.textContent = 'sign in'
      whoami.append(document.createTextNode(' · '), inLink)
    }
    return { username: null, name: 'Viewer', avatar: null, viewer: true, isAdmin: false, buildId: res.build_id || null }
  }
  if (res.user) {
    res.user.buildId = res.build_id || null
    whoami.replaceChildren()
    if (res.user.avatar) {
      const img = document.createElement('img')
      img.src = res.user.avatar
      whoami.appendChild(img)
    }
    whoami.appendChild(document.createTextNode(res.user.username + ' '))
    const out = document.createElement('a')
    out.href = '/auth/logout'
    out.textContent = 'sign out'
    whoami.appendChild(out)
    return { ...res.user, isAdmin: res.is_admin === true }
  }
  const overlay = document.getElementById('signin')
  overlay.classList.remove('hidden')
  if (!res.oauth) {
    document.getElementById('signin-btn').classList.add('hidden')
    document.getElementById('dev-login').classList.remove('hidden')
    document.getElementById('dev-go').addEventListener('click', () => {
      const u = document.getElementById('dev-user').value.trim()
      if (u) location.href = `/auth/dev?u=${encodeURIComponent(u)}&next=${encodeURIComponent(nextPath)}`
    })
  } else {
    // Plain in-place navigation, also inside the huggingface.co iframe: the HF
    // OAuth page renders there, while target="_top" clicks get blocked by the
    // iframe sandbox.
    document.getElementById('signin-btn').href = `/auth/login?next=${encodeURIComponent(nextPath)}`
  }
  return null
}

export async function api(path, { method = 'GET', body } = {}) {
  const res = await fetch(path, {
    method,
    headers: body ? { 'content-type': 'application/json' } : undefined,
    body: body ? JSON.stringify(body) : undefined,
  })
  try {
    return await res.json()
  } catch {
    return { error: `HTTP ${res.status}` }
  }
}

export function el(tag, attrs = {}, text) {
  const node = document.createElement(tag)
  for (const [k, v] of Object.entries(attrs)) node.setAttribute(k, v)
  if (text != null) node.textContent = text
  return node
}

export function esc(s) {
  return String(s ?? '').replace(/[&<>"']/g, c => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]))
}

export function renderMentionText(text) {
  return esc(text).replace(/@([a-z0-9][a-z0-9_.-]{1,38})/g, '<span class="mention">@$1</span>')
}

// --- theme ------------------------------------------------------------------
// The head script has already stamped data-theme. This wires the button that
// overrides it, and keeps following the OS while no explicit choice is stored.
export function wireTheme(btn) {
  const media = matchMedia('(prefers-color-scheme: dark)')
  const stored = () => {
    try {
      const t = localStorage.getItem('cw-theme')
      return t === 'dark' || t === 'light' ? t : null
    } catch {
      return null
    }
  }
  const paint = () => {
    const dark = document.documentElement.dataset.theme === 'dark'
    if (!btn) return
    btn.replaceChildren(icon(dark ? 'sun' : 'moon'), el('span', { class: 'lbl' }, dark ? 'Light' : 'Dark'))
    btn.title = dark ? 'Switch to light theme' : 'Switch to dark theme'
    btn.setAttribute('aria-label', btn.title)
  }
  const apply = theme => {
    document.documentElement.dataset.theme = theme
    paint()
  }
  if (!stored()) apply(media.matches ? 'dark' : 'light')
  paint()
  media.addEventListener('change', e => {
    if (!stored()) apply(e.matches ? 'dark' : 'light')
  })
  btn?.addEventListener('click', () => {
    const next = document.documentElement.dataset.theme === 'dark' ? 'light' : 'dark'
    try {
      localStorage.setItem('cw-theme', next)
    } catch {}
    apply(next)
  })
}

// --- document style ---------------------------------------------------------
// What the document itself is set in: 'docs' (Arial 11pt on a letter sheet) or
// 'reading' (a serif article column). Unlike the theme this has no OS signal to
// follow, so the default is simply 'docs'. The head script has already stamped
// the stored choice; this wires the button that changes it.
export const DOC_STYLES = ['docs', 'reading']

// onChange fires after a switch has been stamped, for the things that read
// --doc-size back out of the stylesheet — the reader text-size readout is set in
// px, and 100% of Docs and 100% of Reading are not the same number of them.
export function wireDocStyle(btn, onChange) {
  const paint = () => {
    const reading = document.documentElement.dataset.docStyle === 'reading'
    if (!btn) return
    btn.replaceChildren(icon(reading ? 'docpage' : 'serif'), el('span', { class: 'lbl' }, reading ? 'Docs' : 'Reading'))
    btn.title = reading ? 'Set the document in Arial, like Google Docs' : 'Set the document in a serif reading column'
    btn.setAttribute('aria-label', btn.title)
  }
  const apply = style => {
    document.documentElement.dataset.docStyle = style
    // the serif is only fetched once something on the page asks for it, so the
    // first switch is also the first request — warm it alongside the repaint
    if (style === 'reading') preloadSerif()
    paint()
    onChange?.(style)
  }
  paint()
  btn?.addEventListener('click', () => {
    const next = document.documentElement.dataset.docStyle === 'reading' ? 'docs' : 'reading'
    try {
      localStorage.setItem('cw-doc-style', next)
    } catch {}
    apply(next)
  })
}

function preloadSerif() {
  if (document.getElementById('serif-preload')) return
  const l = document.createElement('link')
  l.id = 'serif-preload'
  l.rel = 'preload'
  l.as = 'font'
  l.type = 'font/woff2'
  l.crossOrigin = 'anonymous'
  l.href = '/fonts/libre-baskerville-latin.woff2'
  document.head.appendChild(l)
}

// --- in-app dialogs ---------------------------------------------------------
// Native confirm/alert/prompt cannot be used in this app. It is served inside an
// iframe on huggingface.co, and Chrome suppresses dialogs from cross-origin
// iframes: confirm() returns false without ever asking, so every action guarded
// by one silently did nothing (that is what "the remove command doesn't work"
// was). These are the replacements — a real modal, and a toast for errors that
// do not need an acknowledgement.
// Their styles are injected from here rather than added to app.css so the
// helpers stay one self-contained unit; they only use the app's own variables.

const DIALOG_CSS = `
.ui-modal-scrim {
  position: fixed; inset: 0; z-index: 200; padding: 20px;
  background: var(--scrim, rgba(18, 18, 24, 0.4)); backdrop-filter: blur(2px);
  display: flex; align-items: center; justify-content: center;
}
.ui-modal {
  width: min(430px, 100%); padding: 18px 18px 14px;
  background: var(--surface, #fff); color: var(--text, #1a1a1e);
  border: 1px solid var(--border, #e7e7ea); border-radius: 12px;
  box-shadow: var(--shadow-md, 0 16px 48px rgba(0, 0, 0, 0.22));
  font: 13.5px/1.5 var(--ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif);
  animation: ui-modal-in 0.13s ease-out;
}
@keyframes ui-modal-in { from { opacity: 0; transform: translateY(-4px) scale(0.99); } }
@media (prefers-reduced-motion: reduce) { .ui-modal { animation: none; } }
.ui-modal-title { font-size: 15px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: 4px; }
.ui-modal-msg { color: var(--text-2, #55555e); white-space: pre-wrap; overflow-wrap: anywhere; }
.ui-modal-field { display: block; margin-top: 12px; }
.ui-modal-field input {
  width: 100%; margin-top: 5px; padding: 8px 10px; font: inherit;
  color: var(--text, #1a1a1e); background: var(--input-bg, #fff);
  border: 1px solid var(--border-strong, #d9d9de); border-radius: 8px;
}
.ui-modal-field input:focus { outline: none; border-color: var(--accent, #1d5c45); }
.ui-modal-bar { display: flex; justify-content: flex-end; gap: 8px; margin-top: 16px; }
.ui-modal .btn.ui-danger {
  background: var(--danger, #b03030); border-color: var(--danger, #b03030); color: var(--on-primary, #fff);
}
.ui-modal .btn.ui-danger:hover { filter: brightness(1.08); }
.ui-toast-host {
  position: fixed; left: 50%; bottom: 22px; transform: translateX(-50%); z-index: 210;
  display: flex; flex-direction: column; align-items: center; gap: 6px; pointer-events: none;
}
.ui-toast {
  max-width: min(520px, 88vw); padding: 8px 14px; border-radius: 999px;
  background: var(--tooltip-bg, #223029); color: #fff;
  font: 12.5px/1.45 var(--ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif);
  box-shadow: var(--shadow-md, 0 4px 16px rgba(20, 20, 30, 0.3));
  opacity: 0; transform: translateY(6px); transition: opacity 0.16s ease, transform 0.16s ease;
}
.ui-toast.in { opacity: 1; transform: none; }
`

function ensureDialogCss() {
  if (document.getElementById('ui-dialog-css')) return
  const style = document.createElement('style')
  style.id = 'ui-dialog-css'
  style.textContent = DIALOG_CSS
  document.head.appendChild(style)
}

const FOCUSABLE = 'button, input, select, textarea, a[href], [tabindex]:not([tabindex="-1"])'

// The one modal primitive: builds the box, traps the keyboard in it, and
// resolves once through `done`. Enter confirms, Escape cancels, a click on the
// scrim cancels, and focus returns to whatever had it before.
function modal({ title, message, fields = [], confirmLabel, cancelLabel, danger, onConfirm, cancelValue }) {
  ensureDialogCss()
  return new Promise(resolve => {
    const wasFocused = document.activeElement
    const scrim = el('div', { class: 'ui-modal-scrim' })
    const box = el('div', { class: 'ui-modal', role: 'dialog', 'aria-modal': 'true' })
    if (title) {
      const h = el('div', { class: 'ui-modal-title', id: 'ui-modal-title' }, title)
      box.appendChild(h)
      box.setAttribute('aria-labelledby', 'ui-modal-title')
    }
    if (message) box.appendChild(el('div', { class: 'ui-modal-msg' }, message))
    for (const f of fields) box.appendChild(f)
    const bar = el('div', { class: 'ui-modal-bar' })
    const confirm = el('button', { class: 'btn small' + (danger ? ' ui-danger' : ' primary'), type: 'button' }, confirmLabel || 'OK')
    let settled = false
    const close = value => {
      if (settled) return
      settled = true
      document.removeEventListener('keydown', onKey, true)
      scrim.remove()
      try {
        wasFocused?.focus?.({ preventScroll: true })
      } catch {}
      resolve(value)
    }
    const cancel = cancelLabel === null ? null : el('button', { class: 'btn small', type: 'button' }, cancelLabel || 'Cancel')
    cancel?.addEventListener('click', () => close(cancelValue))
    confirm.addEventListener('click', () => close(onConfirm ? onConfirm() : true))
    // While this is open the app must not also see the keys: Escape closes
    // panels, Enter sends composers, and the editor takes everything else.
    const onKey = e => {
      if (e.key === 'Escape') {
        e.preventDefault()
        e.stopPropagation()
        close(cancelValue)
        return
      }
      if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault()
        e.stopPropagation()
        close(onConfirm ? onConfirm() : true)
        return
      }
      if (e.key === 'Tab') {
        const items = [...box.querySelectorAll(FOCUSABLE)].filter(n => !n.disabled)
        if (!items.length) return
        const first = items[0]
        const last = items[items.length - 1]
        const active = document.activeElement
        if (e.shiftKey && (active === first || !box.contains(active))) {
          e.preventDefault()
          last.focus()
        } else if (!e.shiftKey && (active === last || !box.contains(active))) {
          e.preventDefault()
          first.focus()
        }
        e.stopPropagation()
        return
      }
      if (!box.contains(e.target)) e.stopPropagation()
    }
    document.addEventListener('keydown', onKey, true)
    scrim.addEventListener('mousedown', e => {
      if (e.target === scrim) close(cancelValue)
    })
    if (cancel) bar.append(cancel, confirm)
    else bar.appendChild(confirm)
    box.appendChild(bar)
    scrim.appendChild(box)
    document.body.appendChild(scrim)
    // the destructive button is never what the keyboard lands on first
    const input = box.querySelector('input')
    if (input) input.select()
    else if (danger && cancel) cancel.focus()
    else confirm.focus()
  })
}

export function uiConfirm({ title, message, confirmLabel, cancelLabel, danger = false } = {}) {
  return modal({ title, message, confirmLabel: confirmLabel || (danger ? 'Delete' : 'OK'), cancelLabel, danger, cancelValue: false })
}

export function uiAlert(message, { title, confirmLabel } = {}) {
  const text = String(message ?? '')
  // clicking a failing action twice must not stack the same warning twice
  const open = [...document.querySelectorAll('.ui-modal-scrim .ui-modal-msg')].some(n => n.textContent === text)
  if (open) return Promise.resolve()
  return modal({ title, message: text, confirmLabel: confirmLabel || 'OK', cancelLabel: null, cancelValue: undefined })
}

// The confirm modal with one text field. Resolves to the string, or null when
// it was dismissed — same contract as the prompt() it replaces.
export function uiPrompt({ title, message, label, value = '', placeholder = '', confirmLabel } = {}) {
  const field = el('label', { class: 'ui-modal-field' })
  if (label) field.appendChild(document.createTextNode(label))
  const input = el('input', { type: 'text', placeholder })
  input.value = value
  field.appendChild(input)
  return modal({
    title,
    message,
    fields: [field],
    confirmLabel: confirmLabel || 'OK',
    onConfirm: () => input.value.trim(),
    cancelValue: null,
  })
}

// Non-blocking errors: nothing to acknowledge, nothing to click through.
export function uiToast(message, { ms = 3200 } = {}) {
  ensureDialogCss()
  let host = document.getElementById('ui-toast-host')
  if (!host) {
    host = el('div', { class: 'ui-toast-host', id: 'ui-toast-host', role: 'status', 'aria-live': 'polite' })
    document.body.appendChild(host)
  }
  const toast = el('div', { class: 'ui-toast' }, String(message ?? ''))
  host.appendChild(toast)
  requestAnimationFrame(() => toast.classList.add('in'))
  setTimeout(() => {
    toast.classList.remove('in')
    setTimeout(() => toast.remove(), 200)
  }, ms)
  return toast
}

export function colorFor(name) {
  let h = 0
  for (const c of String(name)) h = (h * 31 + c.charCodeAt(0)) % 360
  return `hsl(${h}, 32%, 46%)`
}

export function timeAgo(ts) {
  if (!ts) return ''
  const s = Math.floor((Date.now() - ts) / 1000)
  if (s < 60) return 'now'
  if (s < 3600) return `${Math.floor(s / 60)}m`
  if (s < 86400) return `${Math.floor(s / 3600)}h`
  return `${Math.floor(s / 86400)}d`
}

// One-time display of a freshly issued agent key, with copy actions.
export function agentKeyBox({ handle, key, docId }) {
  const box = el('div', { class: 'key-box' })
  box.appendChild(el('div', { class: 'key-label' }, `Key for @${handle} — copy it now, it won't be shown again:`))
  box.appendChild(el('code', {}, key))
  const row = el('div', { class: 'row' })
  const copyKey = el('button', { class: 'btn small', type: 'button' }, 'Copy key')
  copyKey.addEventListener('click', async () => {
    await navigator.clipboard.writeText(key)
    copyKey.textContent = 'Copied'
    setTimeout(() => (copyKey.textContent = 'Copy key'), 1500)
  })
  const copyPrompt = el('button', { class: 'btn small primary', type: 'button' }, 'Copy agent prompt (incl. key)')
  copyPrompt.addEventListener('click', async () => {
    const text = await fetch(`/api/agent-prompt?handle=${handle}${docId ? `&doc=${docId}` : ''}`).then(r => r.text())
    await navigator.clipboard.writeText(text.replace('<the key>', key))
    copyPrompt.textContent = 'Copied'
    setTimeout(() => (copyPrompt.textContent = 'Copy agent prompt (incl. key)'), 1500)
  })
  const dismiss = el('button', { class: 'btn small ghost', type: 'button' }, 'Done')
  dismiss.addEventListener('click', () => box.remove())
  row.append(copyKey, copyPrompt, dismiss)
  box.appendChild(row)
  return box
}

export function statusLabel(status) {
  return { pending: 'pending', claimed: 'seen', done: 'handled', failed: 'failed' }[status] || status
}