hyperpubee/lib/creation/pubee-builder.js

Self-publishing over the decentralised internet

const { Pubee } = require('../core/pubee')
const hexlexi = require('../core/hexlexi')
const { CONTENT, STRUCTURE, ROOT, EMBEDDING, METADATA, LINK } = require('../core/constants')
const { getAbsoluteKey } = require('../core/utils')
const { validateEmbedding } = require('../core/embedding')
const { validateLink } = require('../core/link')
class PubeeBuilder {
  #contentGenerator
  #structGenerators
  #embeddingGenerator
  #linkGenerator
  #bee

  constructor (bee) {
    if (bee.feed.length !== 0) {
      throw new Error('Cannot init a pubeebuilder with a non-empty bee')
    }

    this.#bee = bee
    this.#contentGenerator = hexlexi.generator()
    this.#structGenerators = {}
    this.#embeddingGenerator = hexlexi.generator()
    this.#linkGenerator = hexlexi.generator()
  }

  async addContent (content) {
    if (content.length === 0) {
      throw new Error('Cannot add an empty content.')
    }

    const key = getAbsoluteKey(CONTENT, this.#contentGenerator.next().value)

    await this.#bee.put(key, content)

    return key
  }

  async #addChildrenToStructure (key, children) {
    if (children.length === 0) {
      throw new Error('Cannot add an empty structure.')
    }
    await this.#bee.put(key, children)
  }

  #getStructGeneratorOf (name) {
    if (this.#structGenerators[name] === undefined) {
      this.#structGenerators[name] = hexlexi.generator()
    }

    return this.#structGenerators[name]
  }

  async addStructure (name, children) {
    if (!name) {
      throw new Error('Cannot add a structure without name.')
    }

    const generator = this.#getStructGeneratorOf(name)
    const key = getAbsoluteKey(STRUCTURE, name, generator.next().value)
    await this.#addChildrenToStructure(key, children)

    return key
  }

  async addEmbedding (embedding) {
    validateEmbedding(embedding)

    const key = getAbsoluteKey(
      EMBEDDING,
      this.#embeddingGenerator.next().value
    )

    await this.#bee.put(key, embedding)

    return key
  }

  async addLink (link) {
    validateLink(link)

    const key = getAbsoluteKey(
      LINK,
      this.#linkGenerator.next().value
    )

    await this.#bee.put(key, link)

    return key
  }

  async addRoot (children) {
    const key = getAbsoluteKey(STRUCTURE, ROOT)

    const existingRootContent = await this.#bee.get(key)
    if (existingRootContent !== null) {
      throw new Error('Cannot add the root more than once.')
    }

    await this.#addChildrenToStructure(key, children)

    return key
  }

  async addMetadata (metadata) {
    if ((await this.#bee.get(METADATA)) !== null) {
      throw new Error('Metadata can only be added once')
    }

    await this.#bee.put(METADATA, metadata)
  }

  async build () {
    const res = new Pubee(this.#bee)
    await res.ensureIsValid()
    return res
  }
}

module.exports = PubeeBuilder