import path from 'path'

// totaly awesome hash function. Do not use this for encryption (crypto.subtle.digest etc would be overkill for this)
export function hash (array) {
  const string = JSON.stringify(array)
  if (!string.length) throw new Error('TypeError: Unexpected data to calculate hash from')

  let hash = 0
  let char

  for (let i = 0; i < string.length; i++) {
    char = string.charCodeAt(i)
    hash = ((hash << 5) - hash) + char
    hash |= 0
  }

  return new Uint32Array([hash]).toString()
}

export function isJSFile (name) {
  const extname = path.extname(name)
  return extname === '.js'
}

export function viteManifestToDeps (viteManifest) {
  const deps = {}
  for (const [codePoint, { isEntry, file, imports, css, assets }] of Object.entries(viteManifest)) {
    if (isEntry && codePoint.endsWith('.html')) deps[codePoint] = [file]
    if (Array.isArray(assets)) assets.forEach(asset => { deps[asset] = [] })
    if (Array.isArray(css)) css.forEach(css => { deps[css] = [] })
    deps[file] = []
      .concat(imports?.map(path => viteManifest[path].file))
      .concat(css)
      .concat(assets)
      .filter(Boolean)
  }
  return deps
}

export function viteToOxManifest (viteManifests) {
  const deps = viteManifestToDeps(viteManifests)
  return Object.values(viteManifests)
    .filter(manifest => Array.isArray(manifest?.meta?.manifests))
    .map(manifest =>
      manifest.meta.manifests.map(oxManifest => {
        const dependencies = deps[manifest.file]
        const data = {
          ...oxManifest,
          path: manifest.file.slice(0, -path.parse(manifest.file).ext.length)
        }
        if (dependencies?.length > 0) data.dependencies = dependencies
        return data
      })
    )
    .flat()
}

export function getRedisKey ({ version = undefined, name }) {
  if (version && name) return `${process.env.REDIS_PREFIX}:${version}:${name}`
  return `${process.env.REDIS_PREFIX}:${name}`
}

export function once (fn, context) {
  let called = false
  let res
  return function () {
    if (!called) {
      res = fn.apply(context || this, arguments)
      called = true
    }
    return res
  }
}
export const t0 = Date.now()