#!/usr/bin/env -S node --no-warnings --loader ts-node/esm
/**
 *   Wechaty Chatbot SDK - https://github.com/wechaty/wechaty
 *
 *   @copyright 2016 Huan LI (李卓桓) <https://github.com/huan>, and
 *                   Wechaty Contributors <https://github.com/wechaty>.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */
import {
  createReadStream,
  createWriteStream,
  promises as fsPromises,
  // link    as linkCallback,
  // unlink  as unlinkCallback,
}                            from 'fs'
import {
  Transform,
  // TransformOptions,
}                            from 'stream'
import { promisify }          from 'util'

import globCallback           from 'glob'

const LICENSE = `/**
 *   Wechaty Chatbot SDK - https://github.com/wechaty/wechaty
 *
 *   @copyright 2016 Huan LI (李卓桓) <https://github.com/huan>, and
 *                   Wechaty Contributors <https://github.com/wechaty>.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */`

class LicenseTransformer extends Transform {

  private lineBuf = ''
  private lineNum = 0

  private updating  = false
  private updated   = false

  // constructor (options?: TransformOptions) {
  //   super(options)
  // }

  override _transform (chunk: any, _: string /* encoding: string */, done: () => void) {
    if (this.updated) {
      this.push(chunk)
    } else {
      const updatedChunk = this.updateChunk(chunk)
      this.push(updatedChunk)
    }

    done()
  }

  private updateChunk (chunk: any): string {
    const buffer  = this.lineBuf + chunk.toString()
    this.lineBuf    = ''

    if (!buffer) {
      console.error('no data')
      return ''
    }

    const updatedLineList: string[] = []

    buffer
      .split(/\n/)
      .forEach(line => {
        if (this.lineNum === 0 && line.startsWith('#!')) {
          updatedLineList.push(line)
        } else if (this.updated) {
          updatedLineList.push(line)
        } else if (this.updating) {
          if (/\*\//.test(line)) {
            updatedLineList.push(line.replace(/.*\*\//, LICENSE))
            this.updating = false
            this.updated  = true
          } else {
            // drop the old comments
          }
        } else {  // not updating and not updated. searching...
          if (!line) {
            updatedLineList.push(line)
          } else if (/\s*\/\*\*/.test(line)) {  // comment start
            if (/\*\//.test(line)) {  // comment end at the same line with start
              updatedLineList.push(line.replace(/\/\*\*.*\*\//, LICENSE))
              this.updated = true
            } else {
              this.updating = true
            }
          } else {  // not a comment. INSERT here
            updatedLineList.push(LICENSE)
            updatedLineList.push(line)
            this.updated = true
          }
        }

        this.lineBuf = line
        this.lineNum++
      })

    return updatedLineList.join('\n')
  }

  override _flush (done: () => void) {
    if (this.lineBuf) {
      this.push(this.lineBuf)
      this.lineBuf = ''
    }
    done()
  }

}

async function updateLicense (file: string): Promise<void> {
  const tmpFile = file + `.${process.pid}.tmp`
  const readStream  = createReadStream(file)
  const writeStream = createWriteStream(tmpFile)
  const tranStream  = new LicenseTransformer()

  console.info(`Updating LICENSE for file ${file}...`)
  await new Promise<void>((resolve, reject) => {
    readStream
      .pipe(tranStream)
      .pipe(writeStream)
      .on('close', resolve)
      .on('error', reject)
  })
  // await promisify(unlinkCallback)
  await fsPromises.unlink(file)
  // await promisify(linkCallback)(tmpFile, file)
  await fsPromises.link(tmpFile, file)
  // await promisify(unlinkCallback)(tmpFile)
  await fsPromises.unlink(tmpFile)
}

async function glob (pattern: string): Promise<string[]> {
  return promisify<string, string[]>(globCallback as any)(pattern)
}

async function main (): Promise<number> {
  const pattern = '{bin/**/*.ts,examples/**/*.{js,ts},scripts/**/*.{ts,js},src/**/*.{ts,js},tests/**/*.ts}'
  // const pattern = 't.ts'
  const srcFileList = await glob(pattern)
  const promiseList = srcFileList.map(updateLicense)
  await Promise.all(promiseList)
  return 0
}

main()
  .then(process.exit)
  .catch(e => {
    console.error(e)
    process.exit(1)
  })