import React, { useEffect, useRef, useState } from 'react'
import { names } from './names.js'
import { layout } from './layout.js'

// Tab for a stream panel: double-click to rename (viewer-side label, kept in this browser). Empty = back to user · title.
export default function Tab({ api, params }) {
  const id = api.id
  const custom = names.use(s => s.streams[id])
  const base = `${params.user} · ${params.title}`
  const [editing, setEditing] = useState(false)
  const [draft, setDraft] = useState('')
  const ref = useRef(null)
  useEffect(() => { if (editing) { ref.current?.focus(); ref.current?.select() } }, [editing])
  const start = e => { e.stopPropagation(); setDraft(custom || ''); setEditing(true) }
  const commit = () => { if (!editing) return; const v = draft.trim(); names.rename(id, v); api.setTitle(v || base); layout.markCustom(); setEditing(false) }
  return (
    <div className="vtab" title={`${base}\ndouble-click to rename`} onDoubleClick={start}>
      {editing
        ? <input ref={ref} value={draft} placeholder={base} onChange={e => setDraft(e.target.value)}
                 onPointerDown={e => e.stopPropagation()} onBlur={commit}
                 onKeyDown={e => { e.stopPropagation(); if (e.key === 'Enter') commit(); if (e.key === 'Escape') setEditing(false) }} />
        : <span className="vtab-text">{custom || base}</span>}
    </div>
  )
}