import { getSetting } from '../config'
import { getVariableValue } from '../createVariable'
import type { GenericFonts, GetStyleState, LanguageContextType } from '../types'

const cache = new WeakMap<GetStyleState, { props: GetStyleState['props']; value: any }>()

export const getVariantExtras = (styleState: GetStyleState) => {
  const cached = cache.get(styleState)
  if (cached?.props === styleState.props) {
    return cached.value
  }

  const { props, conf, context, theme, styleProps } = styleState
  const styledContext = styleProps.styledContext
  let fonts = conf.fontsParsed
  if (context?.language) {
    fonts = getFontsForLanguage(conf.fontsParsed, context.language)
  }

  const next = {
    fonts,
    tokens: conf.tokensParsed,
    theme,
    context: styledContext,
    get fontFamily() {
      return (
        getVariableValue(styleState.fontFamily || styleState.props.fontFamily) ||
        props.fontFamily ||
        getVariableValue(getSetting('defaultFont'))
      )
    },
    get font() {
      return (
        fonts[this.fontFamily] ||
        (!props.fontFamily || props.fontFamily[0] === '$'
          ? fonts[getSetting('defaultFont') || '']
          : undefined)
      )
    },
    props,
  }

  cache.set(styleState, { props, value: next })

  return next as any
}

const fontLanguageCache = new WeakMap()

export function getFontsForLanguage(fonts: GenericFonts, language: LanguageContextType) {
  if (fontLanguageCache.has(language)) {
    return fontLanguageCache.get(language)
  }
  const next = {
    ...fonts,
    ...Object.fromEntries(
      Object.entries(language).flatMap(([name, lang]) => {
        if (lang === 'default') {
          return []
        }
        const langKey = `$${name}_${lang}`
        return [[`$${name}`, fonts[langKey]]]
      })
    ),
  }
  fontLanguageCache.set(language, next)
  return next
}