[tracker] libtracker-data: Make datetime functions accept other than vars

[Carlos Garnacho <carlosg src gnome org>]

commit 0eb9b63f42e7e87addb81889d8e40d3464dac91f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Jul 29 23:28:14 2015 +0200

    libtracker-data: Make datetime functions accept other than vars
    
    The datetime functions were very specific at only accepting variables
    (backed by a table column), using the :localDate and :localTime
    decomposed fields, specific internally to datetime properties.
    
    So, actually make it able to accept other than variables (we will still
    use the decomposed local time for these), and translate these as a
    primary expression. This makes all these queries work (as opposed
    to just the first):
    
    select year(?date) { ?u nie:contentCreated ?date }
    select year(now()) {}
    select year("2015-07-29T23:00:00Z"^^xsd:dateTime) {}
    select year("2015-07-29"^^xsd:date) {}

 src/libtracker-data/tracker-sparql-expression.vala |   99 ++++++++++----------
 1 files changed, 51 insertions(+), 48 deletions(-)
---
diff --git a/src/libtracker-data/tracker-sparql-expression.vala 
b/src/libtracker-data/tracker-sparql-expression.vala
index ed15240..cde2145 100644
--- a/src/libtracker-data/tracker-sparql-expression.vala
+++ b/src/libtracker-data/tracker-sparql-expression.vala
@@ -26,6 +26,12 @@ class Tracker.Sparql.Expression : Object {
        const string FTS_NS = "http://www.tracker-project.org/ontologies/fts#";;
        const string TRACKER_NS = "http://www.tracker-project.org/ontologies/tracker#";;
 
+       enum TimeFormatType {
+               SECONDS,
+               MINUTES,
+               HOURS
+       }
+
        string? fts_sql;
 
        public Expression (Query query) {
@@ -449,6 +455,45 @@ class Tracker.Sparql.Expression : Object {
                expect (SparqlTokenType.CLOSE_PARENS);
        }
 
+       void translate_date (StringBuilder sql, string format) throws Sparql.Error {
+               sql.append_printf ("strftime (\"%s\", ", format);
+
+               if (accept (SparqlTokenType.VAR)) {
+                       string variable_name = get_last_string ().substring (1);
+                       var variable = context.get_variable (variable_name);
+                       sql.append (variable.get_extra_sql_expression ("localDate"));
+                       sql.append (" * 24 * 3600");
+               } else {
+                       translate_primary_expression (sql);
+               }
+
+               sql.append (", \"unixepoch\")");
+       }
+
+       void translate_time (StringBuilder sql, TimeFormatType type) throws Sparql.Error {
+               sql.append ("(");
+               if (accept (SparqlTokenType.VAR)) {
+                       string variable_name = get_last_string ().substring (1);
+                       var variable = context.get_variable (variable_name);
+                       sql.append (variable.get_extra_sql_expression ("localTime"));
+               } else {
+                       translate_primary_expression (sql);
+               }
+
+               switch (type) {
+               case TimeFormatType.SECONDS:
+                       sql.append ("% 60");
+                       break;
+               case TimeFormatType.MINUTES:
+                       sql.append (" / 60 % 60");
+                       break;
+               case TimeFormatType.HOURS:
+                       sql.append (" / 3600 % 24");
+                       break;
+               }
+               sql.append (")");
+       }
+
        PropertyType translate_function (StringBuilder sql, string uri) throws Sparql.Error {
                if (uri == XSD_NS + "string") {
                        // conversion to string
@@ -603,64 +648,22 @@ class Tracker.Sparql.Expression : Object {
 
                        return PropertyType.STRING;
                } else if (uri == FN_NS + "year-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("strftime (\"%Y\", ");
-                       sql.append (variable.get_extra_sql_expression ("localDate"));
-                       sql.append (" * 24 * 3600, \"unixepoch\")");
-
+                       translate_date (sql, "%Y");
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "month-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("strftime (\"%m\", ");
-                       sql.append (variable.get_extra_sql_expression ("localDate"));
-                       sql.append (" * 24 * 3600, \"unixepoch\")");
-
+                       translate_date (sql, "%m");
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "day-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("strftime (\"%d\", ");
-                       sql.append (variable.get_extra_sql_expression ("localDate"));
-                       sql.append (" * 24 * 3600, \"unixepoch\")");
-
+                       translate_date (sql, "%d");
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "hours-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("(");
-                       sql.append (variable.get_extra_sql_expression ("localTime"));
-                       sql.append (" / 3600)");
-
+                       translate_time (sql, TimeFormatType.HOURS);
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "minutes-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("(");
-                       sql.append (variable.get_extra_sql_expression ("localTime"));
-                       sql.append (" / 60 % 60)");
-
+                       translate_time (sql, TimeFormatType.MINUTES);
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "seconds-from-dateTime") {
-                       expect (SparqlTokenType.VAR);
-                       string variable_name = get_last_string ().substring (1);
-                       var variable = context.get_variable (variable_name);
-
-                       sql.append ("(");
-                       sql.append (variable.get_extra_sql_expression ("localTime"));
-                       sql.append ("% 60)");
-
+                       translate_time (sql, TimeFormatType.SECONDS);
                        return PropertyType.INTEGER;
                } else if (uri == FN_NS + "timezone-from-dateTime") {
                        expect (SparqlTokenType.VAR);