'use strict'

const parseResourceId = require('./parse-resource-id')

/**
 * Attempts to resolve a contextual resource ID spec to a file in the catalog.
 *
 * Parses the specified contextual resource ID spec into a resource ID object using parseResourceId,
 * then attempts to locate a file with this resource ID in the catalog. If a component is specified, but
 * not a version, the latest version of the component is used from the catalog. If a file cannot be
 * resolved, and the family is "page", then the search is attempted again for an "alias". If a file
 * still cannot be found, the function returns undefined. If the spec does not match the resource ID
 * syntax, or the specified family is not permitted, this function returns false.
 *
 * @memberof content-classifier
 *
 * @param {String} spec - The contextual resource ID spec (e.g., version@component:module:family$relative).
 * @param {ContentCatalog} catalog - The content catalog in which to resolve the page file.
 * @param {Object} [ctx={}] - The src context.
 * @param {String} [defaultFamily=undefined] - The default family to use if family is not specified in spec.
 *   The value "page" is used if not specified. This value is always used instead of family value provided by the ctx.
 * @param {Array<String>} [permittedFamilies=undefined] - An optional array of family names to allow.
 *
 * @returns {File} The virtual file to which the contextual resource ID spec refers, undefined if
 * the file cannot be resolved, or false if the resource ID spec is invalid.
 */
function resolveResource (spec, catalog, ctx = {}, defaultFamily = undefined, permittedFamilies = undefined) {
  const id = parseResourceId(spec, ctx, defaultFamily, permittedFamilies)

  if (!id || !id.family) return false
  if (id.version == null) {
    const component = catalog.getComponent(id.component)
    if (!component) return
    id.version = component.latest.version
  }
  if (!id.module) id.module = 'ROOT'

  return (
    catalog.getById(id) ||
    (id.family === 'page' ? (catalog.getById(Object.assign({}, id, { family: 'alias' })) || {}).rel : undefined)
  )
}

module.exports = resolveResource