import os from 'os'
import _ from 'lodash'
import jc from 'json-cycle'
import yaml from 'js-yaml'
import ServerlessError from '../serverless-error.js'
import cliCommandsSchema from '../cli/commands-schema.js'
import utils from '@serverlessinc/sf-core/src/utils.js'

const { writeText, log } = utils

class Print {
  constructor(serverless, options) {
    this.logger = log.get('sls:plugins:print')
    this.serverless = serverless
    this.options = options || {}
    this.cache = {}

    this.commands = {
      print: {
        ...cliCommandsSchema.get('print'),
      },
    }
    this.hooks = {
      'print:print': this.print.bind(this),
    }
  }

  async print() {
    let conf = this.serverless.configurationInput

    // dig into the object
    if (this.options.path) {
      const steps = this.options.path.split('.')
      for (const step of steps) {
        conf = conf[step]

        if (!conf) {
          throw new ServerlessError(
            `Path "${this.options.path}" not found`,
            'INVALID_PATH_ARGUMENT',
          )
        }
      }
    }

    // apply an optional filter
    if (this.options.transform) {
      if (this.options.transform === 'keys') {
        conf = Object.keys(conf)
      } else {
        throw new ServerlessError(
          'Transform can only be "keys"',
          'INVALID_TRANSFORM',
        )
      }
    }

    // print configuration in the specified format
    const format = this.options.format || 'yaml'
    let out

    if (format === 'text') {
      if (Array.isArray(conf)) {
        out = conf.join(os.EOL)
      } else {
        if (_.isObject(conf)) {
          throw new ServerlessError(
            'Cannot print an object as "text"',
            'PRINT_INVALID_OBJECT_AS_TEXT',
          )
        }

        out = String(conf)
      }
    } else if (format === 'json') {
      out = jc.stringify(conf, null, '  ')
    } else if (format === 'yaml') {
      out = yaml.dump(JSON.parse(jc.stringify(conf)), { noRefs: true })
    } else {
      throw new ServerlessError(
        'Format must be "yaml", "json" or "text"',
        'PRINT_INVALID_FORMAT',
      )
    }

    writeText(out)
    this.logger.blankLine()
  }
}

export default Print