import debug from 'debug'
import chalk from 'chalk'
import fs from 'fs'
import os from 'os'
import path from 'path'
import { pathToFileURL, URL } from 'url'
import { FS_PREFIX, DEFAULT_EXTENSIONS, VALID_ID_PREFIX } from './constants'
import resolve from 'resolve'
import builtins from 'builtin-modules'
import { FSWatcher } from 'chokidar'
import remapping from '@ampproject/remapping'
import {
  DecodedSourceMap,
  RawSourceMap
} from '@ampproject/remapping/dist/types/types'

export function slash(p: string): string {
  return p.replace(/\\/g, '/')
}

// Strip valid id prefix. This is prepended to resolved Ids that are
// not valid browser import specifiers by the importAnalysis plugin.
export function unwrapId(id: string): string {
  return id.startsWith(VALID_ID_PREFIX) ? id.slice(VALID_ID_PREFIX.length) : id
}

export const flattenId = (id: string): string => id.replace(/[\/\.]/g, '_')

export function isBuiltin(id: string): boolean {
  return builtins.includes(id)
}

export const bareImportRE = /^[\w@](?!.*:\/\/)/
export const deepImportRE = /^([^@][^/]*)\/|^(@[^/]+\/[^/]+)\//

export let isRunningWithYarnPnp: boolean
try {
  isRunningWithYarnPnp = Boolean(require('pnpapi'))
} catch {}

const ssrExtensions = ['.js', '.json', '.node']

export function resolveFrom(id: string, basedir: string, ssr = false): string {
  return resolve.sync(id, {
    basedir,
    extensions: ssr ? ssrExtensions : DEFAULT_EXTENSIONS,
    // necessary to work with pnpm
    preserveSymlinks: isRunningWithYarnPnp || false
  })
}

// set in bin/vite.js
const filter = process.env.VITE_DEBUG_FILTER

const DEBUG = process.env.DEBUG

interface DebuggerOptions {
  onlyWhenFocused?: boolean | string
}

export function createDebugger(
  ns: string,
  options: DebuggerOptions = {}
): debug.Debugger['log'] {
  const log = debug(ns)
  const { onlyWhenFocused } = options
  const focus = typeof onlyWhenFocused === 'string' ? onlyWhenFocused : ns
  return (msg: string, ...args: any[]) => {
    if (filter && !msg.includes(filter)) {
      return
    }
    if (onlyWhenFocused && !DEBUG?.includes(focus)) {
      return
    }
    log(msg, ...args)
  }
}

export const isWindows = os.platform() === 'win32'
const VOLUME_RE = /^[A-Z]:/i

export function normalizePath(id: string): string {
  return path.posix.normalize(isWindows ? slash(id) : id)
}

export function fsPathFromId(id: string): string {
  const fsPath = normalizePath(id.slice(FS_PREFIX.length))
  return fsPath.startsWith('/') || fsPath.match(VOLUME_RE)
    ? fsPath
    : `/${fsPath}`
}

export function ensureVolumeInPath(file: string): string {
  return isWindows ? path.resolve(file) : file
}

export const queryRE = /\?.*$/
export const hashRE = /#.*$/

export const cleanUrl = (url: string): string =>
  url.replace(hashRE, '').replace(queryRE, '')

export const externalRE = /^(https?:)?\/\//
export const isExternalUrl = (url: string): boolean => externalRE.test(url)

export const dataUrlRE = /^\s*data:/i
export const isDataUrl = (url: string): boolean => dataUrlRE.test(url)

const knownJsSrcRE = /\.((j|t)sx?|mjs|vue|marko|svelte)($|\?)/
export const isJSRequest = (url: string): boolean => {
  url = cleanUrl(url)
  if (knownJsSrcRE.test(url)) {
    return true
  }
  if (!path.extname(url) && !url.endsWith('/')) {
    return true
  }
  return false
}

const importQueryRE = /(\?|&)import=?(?:&|$)/
const trailingSeparatorRE = /[\?&]$/
export const isImportRequest = (url: string): boolean => importQueryRE.test(url)

export function removeImportQuery(url: string): string {
  return url.replace(importQueryRE, '$1').replace(trailingSeparatorRE, '')
}

export function injectQuery(url: string, queryToInject: string): string {
  // encode percents for consistent behavior with pathToFileURL
  // see #2614 for details
  let resolvedUrl = new URL(url.replace(/%/g, '%25'), 'relative:///')
  if (resolvedUrl.protocol !== 'relative:') {
    resolvedUrl = pathToFileURL(url)
  }
  let { protocol, pathname, search, hash } = resolvedUrl
  if (protocol === 'file:') {
    pathname = pathname.slice(1)
  }
  pathname = decodeURIComponent(pathname)
  return `${pathname}?${queryToInject}${search ? `&` + search.slice(1) : ''}${
    hash || ''
  }`
}

const timestampRE = /\bt=\d{13}&?\b/
export function removeTimestampQuery(url: string): string {
  return url.replace(timestampRE, '').replace(trailingSeparatorRE, '')
}

export async function asyncReplace(
  input: string,
  re: RegExp,
  replacer: (match: RegExpExecArray) => string | Promise<string>
): Promise<string> {
  let match: RegExpExecArray | null
  let remaining = input
  let rewritten = ''
  while ((match = re.exec(remaining))) {
    rewritten += remaining.slice(0, match.index)
    rewritten += await replacer(match)
    remaining = remaining.slice(match.index + match[0].length)
  }
  rewritten += remaining
  return rewritten
}

export function timeFrom(start: number, subtract = 0): string {
  const time: number | string = Date.now() - start - subtract
  const timeString = (time + `ms`).padEnd(5, ' ')
  if (time < 10) {
    return chalk.green(timeString)
  } else if (time < 50) {
    return chalk.yellow(timeString)
  } else {
    return chalk.red(timeString)
  }
}

/**
 * pretty url for logging.
 */
export function prettifyUrl(url: string, root: string): string {
  url = removeTimestampQuery(url)
  const isAbsoluteFile = url.startsWith(root)
  if (isAbsoluteFile || url.startsWith(FS_PREFIX)) {
    let file = path.relative(root, isAbsoluteFile ? url : fsPathFromId(url))
    const seg = file.split('/')
    const npmIndex = seg.indexOf(`node_modules`)
    const isSourceMap = file.endsWith('.map')
    if (npmIndex > 0) {
      file = seg[npmIndex + 1]
      if (file.startsWith('@')) {
        file = `${file}/${seg[npmIndex + 2]}`
      }
      file = `npm: ${chalk.dim(file)}${isSourceMap ? ` (source map)` : ``}`
    }
    return chalk.dim(file)
  } else {
    return chalk.dim(url)
  }
}

export function isObject(value: unknown): value is Record<string, any> {
  return Object.prototype.toString.call(value) === '[object Object]'
}

export function isDefined<T>(value: T | undefined | null): value is T {
  return value !== undefined && value !== null
}

export function lookupFile(
  dir: string,
  formats: string[],
  pathOnly = false
): string | undefined {
  for (const format of formats) {
    const fullPath = path.join(dir, format)
    if (fs.existsSync(fullPath) && fs.statSync(fullPath).isFile()) {
      return pathOnly ? fullPath : fs.readFileSync(fullPath, 'utf-8')
    }
  }
  const parentDir = path.dirname(dir)
  if (parentDir !== dir) {
    return lookupFile(parentDir, formats, pathOnly)
  }
}

const splitRE = /\r?\n/

const range: number = 2

export function pad(source: string, n = 2): string {
  const lines = source.split(splitRE)
  return lines.map((l) => ` `.repeat(n) + l).join(`\n`)
}

export function posToNumber(
  source: string,
  pos: number | { line: number; column: number }
): number {
  if (typeof pos === 'number') return pos
  const lines = source.split(splitRE)
  const { line, column } = pos
  let start = 0
  for (let i = 0; i < line - 1; i++) {
    start += lines[i].length + 1
  }
  return start + column
}

export function numberToPos(
  source: string,
  offset: number | { line: number; column: number }
): { line: number; column: number } {
  if (typeof offset !== 'number') return offset
  if (offset > source.length) {
    throw new Error('offset is longer than source length!')
  }
  const lines = source.split(splitRE)
  let counted = 0
  let line = 0
  let column = 0
  for (; line < lines.length; line++) {
    const lineLength = lines[line].length + 1
    if (counted + lineLength >= offset) {
      column = offset - counted + 1
      break
    }
    counted += lineLength
  }
  return { line: line + 1, column }
}

export function generateCodeFrame(
  source: string,
  start: number | { line: number; column: number } = 0,
  end?: number
): string {
  start = posToNumber(source, start)
  end = end || start
  const lines = source.split(splitRE)
  let count = 0
  const res: string[] = []
  for (let i = 0; i < lines.length; i++) {
    count += lines[i].length + 1
    if (count >= start) {
      for (let j = i - range; j <= i + range || end > count; j++) {
        if (j < 0 || j >= lines.length) continue
        const line = j + 1
        res.push(
          `${line}${' '.repeat(Math.max(3 - String(line).length, 0))}|  ${
            lines[j]
          }`
        )
        const lineLength = lines[j].length
        if (j === i) {
          // push underline
          const pad = start - (count - lineLength) + 1
          const length = Math.max(
            1,
            end > count ? lineLength - pad : end - start
          )
          res.push(`   |  ` + ' '.repeat(pad) + '^'.repeat(length))
        } else if (j > i) {
          if (end > count) {
            const length = Math.max(Math.min(end - count, lineLength), 1)
            res.push(`   |  ` + '^'.repeat(length))
          }
          count += lineLength + 1
        }
      }
      break
    }
  }
  return res.join('\n')
}

export function writeFile(
  filename: string,
  content: string | Uint8Array
): void {
  const dir = path.dirname(filename)
  if (!fs.existsSync(dir)) {
    fs.mkdirSync(dir, { recursive: true })
  }
  fs.writeFileSync(filename, content)
}

/**
 * Delete every file and subdirectory. **The given directory must exist.**
 * Pass an optional `skip` array to preserve files in the root directory.
 */
export function emptyDir(dir: string, skip?: string[]): void {
  for (const file of fs.readdirSync(dir)) {
    if (skip?.includes(file)) {
      continue
    }
    const abs = path.resolve(dir, file)
    // baseline is Node 12 so can't use rmSync :(
    if (fs.lstatSync(abs).isDirectory()) {
      emptyDir(abs)
      fs.rmdirSync(abs)
    } else {
      fs.unlinkSync(abs)
    }
  }
}

export function copyDir(srcDir: string, destDir: string): void {
  fs.mkdirSync(destDir, { recursive: true })
  for (const file of fs.readdirSync(srcDir)) {
    const srcFile = path.resolve(srcDir, file)
    const destFile = path.resolve(destDir, file)
    const stat = fs.statSync(srcFile)
    if (stat.isDirectory()) {
      copyDir(srcFile, destFile)
    } else {
      fs.copyFileSync(srcFile, destFile)
    }
  }
}

export function ensureLeadingSlash(path: string): string {
  return !path.startsWith('/') ? '/' + path : path
}

export function ensureWatchedFile(
  watcher: FSWatcher,
  file: string | null,
  root: string
): void {
  if (
    file &&
    // only need to watch if out of root
    !file.startsWith(root + '/') &&
    // some rollup plugins use null bytes for private resolved Ids
    !file.includes('\0') &&
    fs.existsSync(file)
  ) {
    // resolve file to normalized system path
    watcher.add(path.resolve(file))
  }
}

interface ImageCandidate {
  url: string
  descriptor: string
}
const escapedSpaceCharacters = /( |\\t|\\n|\\f|\\r)+/g
export async function processSrcSet(
  srcs: string,
  replacer: (arg: ImageCandidate) => Promise<string>
): Promise<string> {
  const imageCandidates: ImageCandidate[] = srcs
    .split(',')
    .map((s) => {
      const [url, descriptor] = s
        .replace(escapedSpaceCharacters, ' ')
        .trim()
        .split(' ', 2)
      return { url, descriptor }
    })
    .filter(({ url }) => !!url)

  const ret = await Promise.all(
    imageCandidates.map(async ({ url, descriptor }) => {
      return {
        url: await replacer({ url, descriptor }),
        descriptor
      }
    })
  )

  const url = ret.reduce((prev, { url, descriptor }, index) => {
    descriptor = descriptor || ''
    return (prev +=
      url + ` ${descriptor}${index === ret.length - 1 ? '' : ', '}`)
  }, '')

  return url
}

// based on https://github.com/sveltejs/svelte/blob/abf11bb02b2afbd3e4cac509a0f70e318c306364/src/compiler/utils/mapped_code.ts#L221
const nullSourceMap: RawSourceMap = {
  names: [],
  sources: [],
  mappings: '',
  version: 3
}
export function combineSourcemaps(
  filename: string,
  sourcemapList: Array<DecodedSourceMap | RawSourceMap>
): RawSourceMap {
  if (
    sourcemapList.length === 0 ||
    sourcemapList.every((m) => m.sources.length === 0)
  ) {
    return { ...nullSourceMap }
  }

  let map
  let mapIndex = 1
  const useArrayInterface =
    sourcemapList.slice(0, -1).find((m) => m.sources.length !== 1) === undefined
  if (useArrayInterface) {
    map = remapping(sourcemapList, () => null, true)
  } else {
    map = remapping(
      sourcemapList[0],
      function loader(sourcefile) {
        if (sourcefile === filename && sourcemapList[mapIndex]) {
          return sourcemapList[mapIndex++]
        } else {
          return { ...nullSourceMap }
        }
      },
      true
    )
  }
  if (!map.file) {
    delete map.file
  }

  return map as RawSourceMap
}

export function unique<T>(arr: T[]): T[] {
  return Array.from(new Set(arr))
}

export interface Hostname {
  // undefined sets the default behaviour of server.listen
  host: string | undefined
  // resolve to localhost when possible
  name: string
}

export function resolveHostname(
  optionsHost: string | boolean | undefined
): Hostname {
  let host: string | undefined
  if (
    optionsHost === undefined ||
    optionsHost === false ||
    optionsHost === 'localhost'
  ) {
    // Use a secure default
    host = '127.0.0.1'
  } else if (optionsHost === true) {
    // If passed --host in the CLI without arguments
    host = undefined // undefined typically means 0.0.0.0 or :: (listen on all IPs)
  } else {
    host = optionsHost
  }

  // Set host name to localhost when possible, unless the user explicitly asked for '127.0.0.1'
  const name =
    (optionsHost !== '127.0.0.1' && host === '127.0.0.1') ||
    host === '0.0.0.0' ||
    host === '::' ||
    host === undefined
      ? 'localhost'
      : host

  return { host, name }
}