function arrayWrap(value) {
  return Array.isArray(value) ? value : [value]
}

export default class Errors {
  constructor() {
    this.errors = {}
  }

  set(field, messages = undefined) {
    if (typeof field === "object") {
      this.errors = field
    } else {
      this.set({ ...this.errors, [field]: arrayWrap(messages) })
    }
  }

  all() {
    return this.errors
  }

  has(field) {
    return Object.prototype.hasOwnProperty.call(this.errors, field)
  }

  hasAny(...fields) {
    return fields.some((field) => this.has(field))
  }

  any() {
    return Object.keys(this.errors).length > 0
  }

  get(field) {
    if (this.has(field)) {
      return this.getAll(field)[0]
    }
  }

  getAll(field) {
    return arrayWrap(this.errors[field] || [])
  }

  only(...fields) {
    const messages = []

    fields.forEach((field) => {
      const message = this.get(field)
      if (message) {
        messages.push(message)
      }
    })

    return messages
  }

  flatten() {
    return Object.values(this.errors).reduce((a, b) => a.concat(b), [])
  }

  clear(field = undefined) {
    const errors = {}

    if (field) {
      Object.keys(this.errors).forEach((key) => {
        if (key !== field) {
          errors[key] = this.errors[key]
        }
      })
    }

    this.set(errors)
  }
}