// Copyright (c) 2011, Brian Frank and Andy Frank
// Licensed under the Academic Free License version 3.0
// History:
//    3 May 11  Brian Frank  Creation

** Repo models a database of pod versions
** See [docFanr]`docFanr::Concepts#repos`.
abstract const class Repo
  ** Find and create Repo implementation for URI based on its scheme.
  ** Current schemes supported as "file" and "http".
  static Repo makeForUri(Uri uri, Str? username := null, Str? password := null)
    if (uri.scheme == null)    return FileRepo(uri)
    if (uri.scheme == "file")  return FileRepo(uri)
    if (uri.scheme == "http")  return WebRepo(uri, username, password)
    if (uri.scheme == "https") return WebRepo(uri, username, password)
    throw Err("No repo available for URI scheme: $uri")

  ** URI for this Repo
  abstract Uri uri()

  ** Ping the repo and return summary props.  Standard props include:
  **   - 'fanr.type': qname of Repo implementation class
  **   - 'fanr.version': version string of 'fanr' pod being used
  abstract Str:Str ping()

  ** Find an exact match for the given pod name and version.  If
  ** version is null, then find latest version.  If not found then
  ** return null or throw UnknownPodErr based on checked flag.
  abstract PodSpec? find(Str podName, Version? version, Bool checked := true)

  ** Find pod versions which match query.  The 'numVersions'
  ** specifies how many different versions will be matched for a
  ** single pod.  Multiple pod versions are matched from highest
  ** version to lowest version, so a limit of one will always match
  ** the current (highest) version.
  abstract PodSpec[] query(Str query, Int numVersions := 1)

  ** Open an input stream to read the specified pod version.
  ** Callers should ensure that the stream is drained and
  ** closed as quickly as possible.
  abstract InStream read(PodSpec pod)

  ** Publish the given pod file.  If successful return the
  ** spec for newly added pod.  Throw err if the pod is
  ** malformed or already published in the database.
  abstract PodSpec publish(File podFile)

  override final Str toStr() { uri.toStr }