Overleaf/services/web/frontend/js/features/editor-left-menu/hooks/use-set-overall-theme.tsx

import { useCallback, useEffect } from 'react'
import _ from 'lodash'
import { saveUserSettings } from '../utils/api'
import { UserSettings } from '../../../../../types/user-settings'
import { useUserSettingsContext } from '@/shared/context/user-settings-context'
import getMeta from '@/utils/meta'
import { useActiveOverallTheme } from '@/shared/hooks/use-active-overall-theme'

export default function useSetOverallTheme() {
  const { userSettings, setUserSettings } = useUserSettingsContext()
  const { overallTheme } = userSettings

  const setOverallTheme = useCallback(
    (overallTheme: UserSettings['overallTheme']) => {
      setUserSettings(settings => ({ ...settings, overallTheme }))
    },
    [setUserSettings]
  )
  const activeOverallTheme = useActiveOverallTheme()

  useEffect(() => {
    // Sets the body's data-theme attribute for theming
    document.body.dataset.theme =
      activeOverallTheme === 'dark' ? 'default' : 'light'
  }, [activeOverallTheme])

  return useCallback(
    (newOverallTheme: UserSettings['overallTheme']) => {
      if (overallTheme !== newOverallTheme) {
        const chosenTheme = _.find(
          getMeta('ol-overallThemes'),
          theme => theme.val === newOverallTheme
        )

        if (chosenTheme) {
          setOverallTheme(newOverallTheme)
          saveUserSettings('overallTheme', newOverallTheme)
        }
      }
    },
    [overallTheme, setOverallTheme]
  )
}