import { computed } from 'vue'
import { useRoute } from '#app'
import content from '~/assets/content.yaml'

const specializations: Record<string, object> = {}

function buildSpecialization(locale: string, variant: string): object {
  const config = useAppConfig()
  const locales = config.content.locales.map(l => l.code)
  const variants = config.content.variants.map(v => v.code)
  const allTags = new Set([...locales, ...variants])

  function split(key: string): {base?: string; tags: string[]} {
    const parts = key.split('@')

    if (allTags.has(parts[0])) {
      return {base: undefined, tags: parts}
    }

    return {base: parts[0], tags: parts.slice(1)}
  }

  function relevant(tags: string[]): boolean {
    if (tags.length < 1) {
      return true
    }

    for (const tag of tags) {
      if (tag !== locale && tag !== variant) {
        return false
      }
    }

    return true
  }

  function filterObject(object: any): any {
    if (Array.isArray(object)) {
      return object.map(e => filterObject(e)).filter(e => e !== undefined)
    }

    if (typeof object !== 'object') {
      return object
    }

    const copy: Record<string, any> = {}
    let anonymous: [number, any][] = []

    for (const key in object) {
      const {base, tags} = split(key)

      if (!relevant(tags)) {
        continue
      }

      const value = filterObject(object[key])

      if (base === undefined) {
        anonymous.push([tags.length, value])
      } else {
        copy[base] = value
      }
    }

    if (Object.keys(copy).length > 0 && anonymous.length > 0) {
      console.warn(`Invalid mixing of keys in object ${object}`)
    }

    if (Object.keys(copy).length > 0) {
      return copy
    }

    anonymous.sort((a, b) => b[0] - a[0])

    if (anonymous[0][0] > 2) {
      console.warn(`More than two tags per key in object ${object}`)
    }

    return anonymous[0][1]
  }

  return filterObject(content)
}

function getSpecialization(locale: string, variant: string): object {
  const key = locale + '/' + variant

  if (!(key in specializations)) {
    specializations[key] = buildSpecialization(locale, variant)
  }

  return specializations[key]
}

export function useContent() {
  const config = useAppConfig()
  const route = useRoute()
  console.log("miau")
  console.log(route)

  const locales = config.content.locales.map(l => l.code)
  const variants = config.content.variants.map(v => v.code)

  const localeCookie = useCookie<string>('locale', {
    sameSite: 'lax',
    maxAge: config.content.cookieMaxAge
  })

  const variantCookie = useCookie<string>('variant', {
    sameSite: 'lax',
    maxAge: config.content.cookieMaxAge
  })

  const currentLocale = computed<string>(() => route.params.locale || localeCookie.value || config.content.defaultLocale)
  const currentVariant = computed<string>(() => route.params.variant || variantCookie.value || config.content.defaultVariant)

  function preferLocale(locale: string) {
    if (locale in locales) {
      localeCookie.value = locale
    }
  }

  function preferVariant(variant: string) {
    if (variant in variants) {
      variantCookie.value = variant
    }
  }

  function matrixPath(options: { page?: string; anchor?: string; locale?: string; variant?: string }): string {
    let prefix: string[] = []

    const showLocale = locales.length > 1
    const showVariant = variants.length > 1

    if (showLocale) {
      prefix.push(options.locale ?? currentLocale.value)
    }

    if (showVariant) {
      prefix.push(options.variant ?? currentVariant.value)
    }

    // TODO preserve anchor when taking route.path
    let page = (options.page ?? route.path).split('/').filter(Boolean)

    if (!options.page) {
      page = page.slice([showLocale, showVariant].filter(Boolean).length)
    }

    const base = '/' + [...prefix, ...page].join('/')
    return options.anchor ? `${base}#${options.anchor}` : base
  }

  function p(page: string, anchor?: string): string {
    return matrixPath({page: page, anchor: anchor})
  }

  const specialization = computed<any>(() => getSpecialization(currentLocale.value, currentVariant.value))

  return {
    locale: currentLocale,
    locales: locales,
    preferLocale: preferLocale,
    variant: currentVariant,
    variants: variants,
    preferVariant: preferVariant,
    matrixPath: matrixPath,
    p: p,
    c: specialization,
  }
}