const { stripVTControlCharacters: strip } = require('node:util')
const { Minipass } = require('minipass')

// This module consumes package data in the following format:
//
// {
//   name: String,
//   description: String,
//   maintainers: [{ username: String, email: String }],
//   keywords: String | [String],
//   version: String,
//   date: Date // can be null,
// }
//
// The returned stream will format this package data
// into a byte stream of formatted, displayable output.

function filter (data, exclude) {
  const words = [data.name]
    .concat(data.maintainers.map(m => m.username))
    .concat(data.keywords || [])
    .map(f => f?.trim?.())
    .filter(Boolean)
    .join(' ')
    .toLowerCase()

  if (exclude.find(pattern => {
    // Treats both /foo and /foo/ as regex searches
    if (pattern.startsWith('/')) {
      if (pattern.endsWith('/')) {
        pattern = pattern.slice(0, -1)
      }
      return words.match(new RegExp(pattern.slice(1)))
    }
    return words.includes(pattern)
  })) {
    return false
  }

  return true
}

module.exports = (opts) => {
  return opts.json ? new JSONOutputStream(opts) : new TextOutputStream(opts)
}

class JSONOutputStream extends Minipass {
  #didFirst = false
  #exclude

  constructor (opts) {
    super()
    this.#exclude = opts.exclude
  }

  write (obj) {
    if (!filter(obj, this.#exclude)) {
      return
    }
    if (!this.#didFirst) {
      super.write('[\n')
      this.#didFirst = true
    } else {
      super.write('\n,\n')
    }

    return super.write(JSON.stringify(obj))
  }

  end () {
    super.write(this.#didFirst ? ']\n' : '\n[]\n')
    super.end()
  }
}

class TextOutputStream extends Minipass {
  #args
  #chalk
  #exclude
  #parseable

  constructor (opts) {
    super()
    // Consider a search for "cowboys" and "boy".  If we highlight "boys" first the "cowboys" string will no longer string match because of the ansi highlighting added to "boys".  If we highlight "boy" second then the ansi reset at the end will make the highlighting only on "cowboy" with a normal "s".  Neither is perfect but at least the first option doesn't do partial highlighting. So, we sort strings smaller to larger
    this.#args = opts.args
      .map(s => s.toLowerCase())
      .filter(Boolean)
      .sort((a, b) => a.length - b.length)
    this.#chalk = opts.npm.chalk
    this.#exclude = opts.exclude
    this.#parseable = opts.parseable
  }

  write (data) {
    if (!filter(data, this.#exclude)) {
      return
    }
    // Normalize
    const pkg = {
      authors: data.maintainers.map((m) => `${strip(m.username)}`).join(' '),
      publisher: strip(data.publisher?.username || ''),
      date: data.date ? data.date.toISOString().slice(0, 10) : 'prehistoric',
      description: strip(data.description ?? ''),
      keywords: [],
      name: strip(data.name),
      version: data.version,
    }
    if (Array.isArray(data.keywords)) {
      pkg.keywords = data.keywords.map(strip)
    } else if (typeof data.keywords === 'string') {
      pkg.keywords = strip(data.keywords.replace(/[,\s]+/, ' ')).split(' ')
    }

    let output
    if (this.#parseable) {
      output = [pkg.name, pkg.description, pkg.author, pkg.date, pkg.version, pkg.keywords]
        .filter(Boolean)
        .map(col => ('' + col).replace(/\t/g, ' ')).join('\t')
      return super.write(output)
    }

    const keywords = pkg.keywords.map(k => {
      if (this.#args.includes(k)) {
        return this.#chalk.cyan(k)
      } else {
        return k
      }
    }).join(' ')

    const description = this.#highlight(pkg.description)
    let name
    if (this.#args.includes(pkg.name)) {
      name = this.#chalk.cyan(pkg.name)
    } else {
      name = this.#highlight(pkg.name)
      name = this.#chalk.blue(name)
    }

    if (description.length) {
      output = `${name}\n${description}\n`
    } else {
      output = `${name}\n`
    }
    if (pkg.publisher) {
      output += `Version ${this.#chalk.blue(pkg.version)} published ${this.#chalk.blue(pkg.date)} by ${this.#chalk.blue(pkg.publisher)}\n`
    } else {
      output += `Version ${this.#chalk.blue(pkg.version)} published ${this.#chalk.blue(pkg.date)} by ${this.#chalk.yellow('???')}\n`
    }
    output += `Maintainers: ${pkg.authors}\n`
    if (keywords) {
      output += `Keywords: ${keywords}\n`
    }
    output += `${this.#chalk.blue(`https://npm.im/${pkg.name}`)}\n`
    return super.write(output)
  }

  #highlight (input) {
    let output = input
    for (const arg of this.#args) {
      let i = output.toLowerCase().indexOf(arg)
      while (i > -1) {
        const highlit = this.#chalk.cyan(output.slice(i, i + arg.length))
        output = [
          output.slice(0, i),
          highlit,
          output.slice(i + arg.length),
        ].join('')
        i = output.toLowerCase().indexOf(arg, i + highlit.length)
      }
    }
    return output
  }
}