search: add is:image operator

Change-Id: Iba693538b4e7b3d0cf08d5e8601d3b5819000ca1

pkg/search/expr.go

@@ -17,7 +17,7 @@ limitations under the License.
 package search
 
 import (
-	"errors"
+	"log"
 	"regexp"
 	"strings"
 )
@@ -29,23 +29,60 @@ var tagExpr = regexp.MustCompile(`^tag:(\w+)$`)
 // Constraint field will always be set. The Limit and Sort may also be
 // set.
 func parseExpression(exp string) (*SearchQuery, error) {
-	q := func(c Constraint) (*SearchQuery, error) {
-		return &SearchQuery{Constraint: &c}, nil
+	base := &Constraint{
+		Permanode: &PermanodeConstraint{
+			SkipHidden: true,
+		},
 	}
+	sq := &SearchQuery{
+		Constraint: base,
+	}
+
 	exp = strings.TrimSpace(exp)
 	if exp == "" {
-		return q(Constraint{
-			Permanode: &PermanodeConstraint{
-				SkipHidden: true,
-			}})
+		return sq, nil
 	}
-	if m := tagExpr.FindStringSubmatch(exp); m != nil {
-		return q(Constraint{
-			Permanode: &PermanodeConstraint{
-				Attr:       "tag",
-				SkipHidden: true,
-				Value:      m[1],
-			}})
+
+	and := func(c *Constraint) {
+		old := sq.Constraint
+		sq.Constraint = &Constraint{
+			Logical: &LogicalConstraint{
+				Op: "and",
+				A:  old,
+				B:  c,
+			},
+		}
 	}
-	return nil, errors.New("unknown expression")
+
+	words := strings.Fields(exp)
+	for _, word := range words {
+		if m := tagExpr.FindStringSubmatch(word); m != nil {
+			and(&Constraint{
+				Permanode: &PermanodeConstraint{
+					Attr:       "tag",
+					SkipHidden: true,
+					Value:      m[1],
+				},
+			})
+			continue
+		}
+		if word == "is:image" {
+			and(&Constraint{
+				Permanode: &PermanodeConstraint{
+					Attr: "camliContent",
+					ValueInSet: &Constraint{
+						File: &FileConstraint{
+							IsImage: true,
+						},
+					},
+				},
+			})
+			continue
+		}
+		log.Printf("Unknown search expression word %q", word)
+		// TODO: finish. better tokenization. non-operator tokens
+		// are text searches, etc.
+	}
+
+	return sq, nil
 }

pkg/search/expr_test.go

@@ -45,19 +45,32 @@ var parseExprTests = []struct {
 		in: "tag:funny",
 		want: &SearchQuery{
 			Constraint: &Constraint{
-				Permanode: &PermanodeConstraint{
-					Attr:       "tag",
-					Value:      "funny",
-					SkipHidden: true,
+				Logical: &LogicalConstraint{
+					Op: "and",
+					A: &Constraint{
+						Permanode: &PermanodeConstraint{
+							SkipHidden: true,
+						},
+					},
+					B: &Constraint{
+						Permanode: &PermanodeConstraint{
+							Attr:       "tag",
+							Value:      "funny",
+							SkipHidden: true,
+						},
+					},
 				},
 			},
 		},
 	},
+
 	// TODO: at least 'x' will go away eventually.
-	{
-		inList:      []string{"x", "bogus:operator"},
-		errContains: "unknown expression",
-	},
+	/*
+		{
+			inList:      []string{"x", "bogus:operator"},
+			errContains: "unknown expression",
+		},
+	*/
 }
 
 func TestParseExpression(t *testing.T) {