cache: replace the all-in-one query parser by a complete one with AST/lexer/parser

1 files changed, 100 insertions, 0 deletions

diff --git a/query/parser.go b/query/parser.go
new file mode 100644
index 00000000..89893b60
--- /dev/null
+++ b/query/parser.go
@@ -0,0 +1,100 @@
+package query
+
+import (
+	"fmt"
+
+	"github.com/MichaelMure/git-bug/bug"
+	"github.com/MichaelMure/git-bug/query/ast"
+)
+
+// Parse parse a query DSL
+//
+// Ex: "status:open author:descartes sort:edit-asc"
+//
+// Supported filter qualifiers and syntax are described in docs/queries.md
+func Parse(query string) (*ast.Query, error) {
+	tokens, err := tokenize(query)
+	if err != nil {
+		return nil, err
+	}
+
+	q := &ast.Query{
+		OrderBy:        ast.OrderByCreation,
+		OrderDirection: ast.OrderDescending,
+	}
+	sortingDone := false
+
+	for _, t := range tokens {
+		switch t.qualifier {
+		case "status", "state":
+			status, err := bug.StatusFromString(t.value)
+			if err != nil {
+				return nil, err
+			}
+			q.Status = append(q.Status, status)
+		case "author":
+			q.Author = append(q.Author, t.value)
+		case "actor":
+			q.Actor = append(q.Actor, t.value)
+		case "participant":
+			q.Participant = append(q.Participant, t.value)
+		case "label":
+			q.Label = append(q.Label, t.value)
+		case "title":
+			q.Title = append(q.Title, t.value)
+		case "no":
+			switch t.value {
+			case "label":
+				q.NoLabel = true
+			default:
+				return nil, fmt.Errorf("unknown \"no\" filter \"%s\"", t.value)
+			}
+		case "sort":
+			if sortingDone {
+				return nil, fmt.Errorf("multiple sorting")
+			}
+			err = parseSorting(q, t.value)
+			if err != nil {
+				return nil, err
+			}
+			sortingDone = true
+
+		default:
+			return nil, fmt.Errorf("unknown qualifier \"%s\"", t.qualifier)
+		}
+	}
+	return q, nil
+}
+
+func parseSorting(q *ast.Query, value string) error {
+	switch value {
+	// default ASC
+	case "id-desc":
+		q.OrderBy = ast.OrderById
+		q.OrderDirection = ast.OrderDescending
+	case "id", "id-asc":
+		q.OrderBy = ast.OrderById
+		q.OrderDirection = ast.OrderAscending
+
+	// default DESC
+	case "creation", "creation-desc":
+		q.OrderBy = ast.OrderByCreation
+		q.OrderDirection = ast.OrderDescending
+	case "creation-asc":
+		q.OrderBy = ast.OrderByCreation
+		q.OrderDirection = ast.OrderAscending
+
+	// default DESC
+	case "edit", "edit-desc":
+		q.OrderBy = ast.OrderByEdit
+		q.OrderDirection = ast.OrderDescending
+	case "edit-asc":
+		q.OrderBy = ast.OrderByEdit
+		q.OrderDirection = ast.OrderAscending
+
+	default:
+		return fmt.Errorf("unknown sorting %s", value)
+	}
+
+	return nil
+}