@@ -150,7 +150,7 @@ let orig_limit = options.limit
   let orig_offset = options.offset
   options.limit = 0
   options.offset = 0
-  options.select = "COUNT(id)"
+  options.select = @["COUNT(id)"]
   let total = LS.store.retrieveRawDocuments(options)[0].num
   if docs.len == 0:
     result = resError(Http404, "No documents found.")
@@ -233,7 +233,7 @@ let jbody = body.parseJson
   if jbody.kind != JArray:
     return resError(Http400, "Bad request: PATCH request body is not an array.")
   var options = newQueryOptions()
-  options.select = "id, content_type, binary, searchable, created, modified"
+  options.select = @["id", "content_type", "binary", "searchable", "created", "modified"]
   let doc = LS.store.retrieveRawDocument(id, options)
   if doc == "":
     return resDocumentNotFound(id)
@@ -294,7 +294,7 @@ discard # never happens really.
 
 proc head(req: Request, LS: LiteStore, resource: string, id = ""): Response =
   var options = newQueryOptions()
-  options.select = "id, content_type, binary, searchable, created, modified"
+  options.select = @["id", "content_type", "binary", "searchable", "created", "modified"]
   try:
     parseQueryOptions(req.url.query, options);
     if id != "":
@@ -311,7 +311,7 @@ case resource:
     of "docs":
       var options = newQueryOptions()
       if req.url.query.contains("contents=false"):
-        options.select = "id, content_type, binary, searchable, created, modified"
+        options.select = @["id", "content_type", "binary", "searchable", "created", "modified"]
       try:
         parseQueryOptions(req.url.query, options);
         if id != "":
@@ -322,7 +322,7 @@ return LS.getDocument(id, options)
         else:
           return LS.getRawDocuments(options)
       except:
-        return resError(Http400, "Bad request - $1" % getCurrentExceptionMsg())
+        return resError(Http500, "Internal Server Error - $1" % getCurrentExceptionMsg())
     of "info":
       if id != "":
         return resError(Http404, "Info '$1' not found." % id)

@@ -1,6 +1,6 @@ 
 import 
   sqlite3, 
-  db_sqlite as db, 
+  db_sqlite as db,
   strutils, 
   os,
   oids,
@@ -44,6 +44,8 @@ if not file.fileExists:
     raise newException(EDatastoreDoesNotExist, "Datastore '$1' does not exists." % file)
   try:
     result.db = db.open(file, "", "", "")
+    # Register custom function
+    discard result.db.create_function("rank", -1, SQLITE_ANY, cast[pointer](SQLITE_DETERMINISTIC), okapi_bm25, nil, nil)
     result.path = file
     result.mount = ""
   except:
@@ -103,7 +105,7 @@ var raw_document = store.db.getRow(select.sql, id)
   if  raw_document[0] == "":
     return ""
   else:
-    return $store.prepareJsonDocument(raw_document, options.select.split(", "))
+    return $store.prepareJsonDocument(raw_document, options.select)
 
 proc createDocument*(store: Datastore,  id="", rawdata = "", contenttype = "text/plain", binary = -1, searchable = 1): string =
   var id = id
@@ -184,7 +186,7 @@ var select = prepareSelectDocumentsQuery(options)
   var raw_documents = store.db.getAllRows(select.sql)
   var documents = newSeq[JsonNode](0)
   for doc in raw_documents:
-    documents.add store.prepareJsonDocument(doc, options.select.split(", "))
+    documents.add store.prepareJsonDocument(doc, options.select)
   return %documents
 
 proc countDocuments*(store: Datastore): int64 =

@@ -9,12 +9,13 @@ EDirectoryNotFound* = object of Exception
   EFileNotFound* = object of Exception
   EFileExists* = object of Exception
   EInvalidRequest* = object of Exception
+  uarray* {.unchecked.} [T] = array[0..0, T] 
   Datastore* = object
     db*: TDbConn
     path*: string
     mount*: string
   QueryOptions* = object
-    select*: string
+    select*: seq[string]
     single*:bool         
     limit*: int           
     offset*: int           
@@ -72,4 +73,4 @@ proc ctJsonHeader*(): StringTableRef =
   return CT_JSON.newStringTable
 
 proc newQueryOptions*(): QueryOptions =
-  return QueryOptions(select: "id, data, content_type, binary, searchable, created, modified", single: false, limit: 0, offset: 0, orderby: "", tags: "", search: "")
+  return QueryOptions(select: @["id", "data", "content_type", "binary", "searchable", "created", "modified"], single: false, limit: 0, offset: 0, orderby: "", tags: "", search: "")

@@ -1,4 +1,4 @@ 
-import json, db_sqlite, strutils, pegs, asyncdispatch, asynchttpserver2, times, logging
+import json, db_sqlite, strutils, pegs, asyncdispatch, asynchttpserver2, times, logging, math, sqlite3
 import types, queries, contenttypes
 
 proc dbQuote*(s: string): string =
@@ -22,13 +22,15 @@ 
 proc prepareSelectDocumentsQuery*(options: var QueryOptions): string =
   result = "SELECT "
   if options.search.len > 0:
-    if options.select != "COUNT(id)":
-      options.select = options.select & ", snippet(searchcontents) AS highlight "
-    result = result & options.select
-    result = result & "FROM documents, searchcontents "
+    if options.select[0] != "COUNT(id)":
+      options.select.add("snippet(searchcontents) AS highlight")
+      options.select.add("rank(matchinfo(searchcontents, 'pcxnal'), 1.20, 0.75, 1.5, 0.5) AS rank")
+      options.orderby = "rank DESC"
+    result = result & options.select.join(", ")
+    result = result & " FROM documents, searchcontents "
     result = result & "WHERE documents.id = searchcontents.document_id "
   else:
-    result = result & options.select
+    result = result & options.select.join(", ")
     result = result & " FROM documents WHERE 1=1 "
   if options.single:
     result = result & "AND id = ?"
@@ -36,7 +38,7 @@ if options.tags.len > 0:
     result = result & options.tags.selectDocumentsByTags()
   if options.search.len > 0:
     result = result & "AND searchcontents MATCH \"" & options.search & "\" "
-  if options.orderby.len > 0:
+  if options.orderby.len > 0 and options.select[0] != "COUNT(id)":
     result = result & "ORDER BY " & options.orderby & " " 
   if options.limit > 0:
     result = result & "LIMIT " & $options.limit & " "
@@ -70,7 +72,7 @@ for s in cols:
     var key = s
     if s.contains(" "):
       let chunks = s.split(" ")
-      key = chunks[chunks.len-2]
+      key = chunks[chunks.len-1]
     res.add((key, %doc[count]))
     count.inc
   res.add(("tags", %tags))
@@ -116,3 +118,30 @@ result.headers = ctJsonHeader()
 
 proc resDocumentNotFound*(id): Response =
   resError(Http404, "Document '$1' not found." % id)
+
+proc okapi_bm25*(pCtx: Pcontext, nVal: int32, apVal: PValueArg) {.cdecl.} =
+  var firstElement = value_blob(apVal[0])
+  var matchinfo = cast[ptr uarray[int32]](firstElement)
+  var searchTextCol = value_int(apVal[1])
+  var K1 = if nVal >= 3: value_double(apVal[2]) else: 1.2
+  var B = if nVal >= 4: value_double(apVal[3]) else: 0.75
+  var P_OFFSET = 0
+  var C_OFFSET = 1
+  var X_OFFSET = 2
+  var termCount = matchinfo[P_OFFSET].int32
+  var colCount = matchinfo[C_OFFSET].int32
+  var N_OFFSET = X_OFFSET + 3*termCount*colCount
+  var A_OFFSET = N_OFFSET + 1
+  var L_OFFSET = A_OFFSET + colCount
+  var totalDocs = matchinfo[N_OFFSET].float
+  var avgLength = matchinfo[A_OFFSET + searchTextCol].float
+  var docLength = matchinfo[L_OFFSET + searchTextCol].float
+  var sum = 0.0;
+  for i in 0..termCount-1:
+    var currentX = X_OFFSET + (3 * searchTextCol * (i + 1))
+    var termFrequency = matchinfo[currentX].float
+    var docsWithTerm = matchinfo[currentX + 2].float
+    var idf: float = ln((totalDocs - docsWithTerm + 0.5) / (docsWithTerm + 0.5))
+    var rightSide: float = (termFrequency * (K1 + 1)) / (termFrequency + (K1 * (1 - B + (B * (docLength / avgLength)))))
+    sum = sum + (idf * rightSide)
+  pCtx.result_double(sum)

@@ -1,6 +1,6 @@ 
-define: "release"
+#define:release
 dynlibOverride:sqlite3
-dynlibOverride:fts4rank
+threads:off
 
 # http://crossgcc.rts-software.org/doku.php?id=compiling_for_win32
 i386.windows.gcc.path = "/usr/local/gcc-4.8.0-qt-4.8.4-for-mingw32/win32-gcc/bin"