package scala.tools.nsc
package doc
package model

import base._

/** This trait extracts all required information for documentation from compilation units */
trait MemberLookup extends base.MemberLookupBase {
  thisFactory: ModelFactory =>

  import global._
  import definitions.{ NothingClass, AnyClass, AnyValClass, AnyRefClass, ListClass }

  override def internalLink(sym: Symbol, site: Symbol): Option[LinkTo] =
    findTemplateMaybe(sym) match {
      case Some(tpl) => Some(LinkToTpl(tpl))
      case None =>
        findTemplateMaybe(site) flatMap { inTpl =>
          inTpl.members find (_.asInstanceOf[EntityImpl].sym == sym) map (LinkToMember(_, inTpl))
        }
    }

  override def chooseLink(links: List[LinkTo]): LinkTo = {
    val mbrs = links.collect {
      case lm@LinkToMember(mbr: MemberEntity, _) => (mbr, lm)
    }
    if (mbrs.isEmpty)
      links.head
    else
      mbrs.min(Ordering[MemberEntity].on[(MemberEntity, LinkTo)](_._1))._2
  }

  override def toString(link: LinkTo) = link match {
    case LinkToTpl(tpl: EntityImpl) => tpl.sym.toString
    case LinkToMember(mbr: EntityImpl, inTpl: EntityImpl) =>
      mbr.sym.signatureString + " in " + inTpl.sym.toString
    case _ => link.toString
  }

  override def findExternalLink(sym: Symbol, name: String): Option[LinkToExternal] = {
    val sym1 =
      if (sym == AnyClass || sym == AnyRefClass || sym == AnyValClass || sym == NothingClass) ListClass
      else if (sym.isPackage) 
        /* Get package object which has associatedFile ne null */
        sym.info.member(newTermName("package"))
      else sym
    Option(sym1.associatedFile) flatMap (_.underlyingSource) flatMap { src =>
      val path = src.canonicalPath
      settings.extUrlMapping get path map { url =>
        LinkToExternal(name, url + "#" + name)
      }
    }
  }

  override def warnNoLink = !settings.docNoLinkWarnings.value
}
