import { useState, useReducer, useEffect } from 'react'
import osc from '../lib/osc'
import Debug from 'debug'

// const STATE = '/s'
// const COMMAND = '/c'

const debug = Debug('ui:osc:reducer')

/**
 * Listen on a OSC value change over time.
 */
export function useOscValue (address, defaultValue, opts = {}) {
  // TODO: Global store.
  const [state, setState] = useState(defaultValue)
  useEffect(() => {
    // const stateAddress = STATE + address
    // console.log('useOscValue init', stateAddress)
    const unwatch = osc.on(address, message => {
      const { address, args } = message
      if (opts.single) setState(args[0])
      else setState(args)
      // setState(state => ({ ...state, [address]: args }))
    })
    return unwatch
  }, [address])
  return state
}

/**
 * Write to an OSC value.
 */
export function useOscWritable (address, defaultValue, opts = {}) {
  const state = useOscValue(address, defaultValue, opts)
  return [state, setState]

  function setState (nextValue) {
    if (typeof nextValue === 'function') nextValue = nextValue(state)
    // const commandAddress = COMMAND + address
    // const parts = address.split('/')
    // const last = parts.pop()
    // const cmdAddress = [...parts, 'cmd', last].join('/')
    console.log('useOscWritable write', address, nextValue)
    osc.send(address, nextValue)
  }
}

export function useOscReducer (reducer, initialState, prefix = '') {
  const [state, localDispatch] = useReducer(reducer, initialState)

  const prefixLen = prefix.split('/').length

  // Listen for all state change messages and dispatch into the reducer.
  useEffect(() => {
    const wildcardAddress = prefix + '/*'
    const unwatch = osc.on(wildcardAddress, message => {
      const { address, args } = message
      const key = address.split('/').slice(prefixLen + 1).join('/')
      localDispatch({ cmd: 'set', address: key, args })
    })
    return unwatch
  })

  return [state, dispatch]

  function dispatch (action) {
    console.log('useOscReducer dispatch', action)
    send(action)
  }

  function send (action) {
    const { address, args } = action
    const fullAddress = COMMAND + prefix + address
    osc.send(fullAddress, args)
  }
}

// TODO: Broken, fix address paths.
export function useOscReducerOld (reducer, initialState, prefix) {
  const [state, localDispatch] = useReducer(reducer, initialState)

  // const [remoteState, remoteDispatch] = useReducer(reducer, initialState)
  //
  useEffect(() => {
    const path = prefix + '/state/*'
    const unwatch = osc.on(path, message => {
      const { address, args } = message
      // console.log('RECVV!!!!', message)
      const key = address.split('/').pop()
      localDispatch({ cmd: 'set', key, args })
    })
    return unwatch
  }, [])

  return [state, dispatch]

  function dispatch (action) {
    console.log('dispatch', action)
    send(action)
    // localDispatch(action)
  }

  function send (action) {
    const { cmd, args } = action
    const address = [prefix, 'cmd', cmd].join('/')
    osc.send(address, args)
  }
}