import { create } from './tinyStore.js'

// Per-stream audio state. Effective mute = override ?? !focused.
// override: null (follow focus) | 'unmuted' (pinned on) | 'muted' (pinned off)
export const audio = create({
  focused: null,
  streams: {},                    // id -> { volume: 0..1, override }
  focus(id) {
    const s = { ...this.streams }
    if (id && !s[id]) s[id] = { volume: 0.8, override: null }
    if (id && s[id]) s[id] = { ...s[id], override: null }     // focusing always gives you sound
    return { focused: id, streams: s }
  },
  ensure(id) {
    if (this.streams[id]) return null
    return { streams: { ...this.streams, [id]: { volume: 0.8, override: null } } }
  },
  forget(id) {
    const s = { ...this.streams }; delete s[id]
    return { streams: s, focused: this.focused === id ? null : this.focused }
  },
  setVolume(id, volume) {
    const cur = this.streams[id] || { volume: 0.8, override: null }
    return { streams: { ...this.streams, [id]: { ...cur, volume } } }
  },
  toggleMute(id) {
    const cur = this.streams[id] || { volume: 0.8, override: null }
    const effectiveMuted = cur.override ? cur.override === 'muted' : this.focused !== id
    return { streams: { ...this.streams, [id]: { ...cur, override: effectiveMuted ? 'unmuted' : 'muted' } } }
  },
  muteAll() {
    const s = {}; for (const k in this.streams) s[k] = { ...this.streams[k], override: 'muted' }
    return { streams: s }
  },
  followFocus() {
    const s = {}; for (const k in this.streams) s[k] = { ...this.streams[k], override: null }
    return { streams: s }
  },
})

export function effectiveMuted(state, id) {
  const cur = state.streams[id]
  if (!cur) return true
  if (cur.override) return cur.override === 'muted'
  return state.focused !== id
}