bemusic/bemuse

import type { AnyAction, Dispatch } from 'redux'
import {
  LoadSongOptions,
  loadSongFromResources,
} from 'bemuse/custom-song-loader'

import type { ICustomSongResources } from 'bemuse/resources/types'
import { customSongsSlice } from './redux/ReduxState'
import { observable } from 'mobx'
import { useObserver } from 'mobx-react-lite'

const loadSongFromResourcesWrapper = async (
  resources: ICustomSongResources,
  options?: LoadSongOptions
) => {
  const song = await loadSongFromResources(resources, options)
  song.id = '__custom_' + Date.now()
  song.custom = true
  return song
}

const state = observable({
  loaderLog: null as string[] | null,
})

export function useCustomSongLoaderLog() {
  // We need to clone the array to make sure that all items inside it gets properly tracked.
  // Since this array will be very small, performance impact is negligible.
  return useObserver(() => state.loaderLog && Array.from(state.loaderLog))
}

export async function loadCustomSong(
  resources: ICustomSongResources,
  initialLog: string[],
  dispatch: Dispatch<AnyAction>
) {
  state.loaderLog = [...initialLog]
  const log = state.loaderLog
  try {
    const song = await loadSongFromResourcesWrapper(resources, {
      onMessage(text: string) {
        log.push(text)
      },
    })
    if (song && song.charts && song.charts.length) {
      state.loaderLog = null
      dispatch(customSongsSlice.actions.CUSTOM_SONG_LOADED({ song }))
      return song
    } else {
      state.loaderLog = null
    }
  } catch (e) {
    const text = `Error caught: ${e}`
    log.push(text)
    throw e
  }
}