Initial QSfera import

Server/services/search/pkg/opensearch/internal/convert/kql_transpile.go

@@ -0,0 +1,147 @@
+package convert
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/qsfera/server/pkg/ast"
+	"github.com/qsfera/server/pkg/kql"
+	"github.com/qsfera/server/services/search/pkg/opensearch/internal/osu"
+)
+
+func TranspileKQLToOpenSearch(nodes []ast.Node) (osu.Builder, error) {
+	return kqlOpensearchTranspiler{}.Transpile(nodes)
+}
+
+type kqlOpensearchTranspiler struct{}
+
+func (t kqlOpensearchTranspiler) Transpile(nodes []ast.Node) (osu.Builder, error) {
+	q, err := t.transpile(nodes)
+	if err != nil {
+		return nil, err
+	}
+
+	return q, nil
+}
+
+func (t kqlOpensearchTranspiler) transpile(nodes []ast.Node) (osu.Builder, error) {
+	if len(nodes) == 0 {
+		return nil, fmt.Errorf("no nodes to compile")
+	}
+
+	if len(nodes) == 1 {
+		builder, err := t.toBuilder(nodes[0])
+		if err != nil {
+			return nil, fmt.Errorf("failed to get builder for single node: %w", err)
+		}
+		return builder, nil
+	}
+
+	boolQueryParams := &osu.BoolQueryParams{}
+	boolQuery := osu.NewBoolQuery().Params(boolQueryParams)
+	boolQueryAdd := boolQuery.Must
+	for i, node := range nodes {
+		nextOp := t.getOperatorValueAt(nodes, i+1)
+		prevOp := t.getOperatorValueAt(nodes, i-1)
+
+		switch {
+		case nextOp == kql.BoolOR:
+			boolQueryAdd = boolQuery.Should
+		case nextOp == kql.BoolAND:
+			boolQueryAdd = boolQuery.Must
+		case prevOp == kql.BoolNOT:
+			boolQueryAdd = boolQuery.MustNot
+		}
+
+		builder, err := t.toBuilder(node)
+		switch {
+		// if the node is not known, we skip it, such as an operator node
+		case errors.Is(err, ErrUnsupportedNodeType):
+			continue
+		case err != nil:
+			return nil, fmt.Errorf("failed to get builder for node %T: %w", node, err)
+		}
+
+		if _, ok := node.(*ast.OperatorNode); ok {
+			// operatorNodes are not builders, so we skip them
+			continue
+		}
+
+		if nextOp == kql.BoolOR {
+			// if there are should clauses, we set the minimum should match to 1
+			boolQueryParams.MinimumShouldMatch = 1
+		}
+
+		boolQueryAdd(builder)
+	}
+
+	return boolQuery, nil
+}
+
+func (t kqlOpensearchTranspiler) getOperatorValueAt(nodes []ast.Node, i int) string {
+	if i < 0 || i >= len(nodes) {
+		return ""
+	}
+
+	if opn, ok := nodes[i].(*ast.OperatorNode); ok {
+		return opn.Value
+	}
+
+	return ""
+}
+
+func (t kqlOpensearchTranspiler) toBuilder(node ast.Node) (osu.Builder, error) {
+	var builder osu.Builder
+
+	switch node := node.(type) {
+	case *ast.BooleanNode:
+		return osu.NewTermQuery[bool](node.Key).Value(node.Value), nil
+	case *ast.StringNode:
+		isWildcard := strings.Contains(node.Value, "*")
+		if isWildcard {
+			return osu.NewWildcardQuery(node.Key).Value(node.Value), nil
+		}
+
+		totalTerms := strings.Split(node.Value, " ")
+		isSingleTerm := len(totalTerms) == 1
+		isMultiTerm := len(totalTerms) >= 1
+		switch {
+		case isSingleTerm:
+			return osu.NewTermQuery[string](node.Key).Value(node.Value), nil
+		case isMultiTerm:
+			return osu.NewMatchPhraseQuery(node.Key).Query(node.Value), nil
+		}
+
+		return nil, fmt.Errorf("unsupported string node value: %s", node.Value)
+	case *ast.DateTimeNode:
+		if node.Operator == nil {
+			return builder, fmt.Errorf("date time node without operator: %w", ErrUnsupportedNodeType)
+		}
+
+		query := osu.NewRangeQuery[time.Time](node.Key)
+
+		switch node.Operator.Value {
+		case ">":
+			return query.Gt(node.Value), nil
+		case ">=":
+			return query.Gte(node.Value), nil
+		case "<":
+			return query.Lt(node.Value), nil
+		case "<=":
+			return query.Lte(node.Value), nil
+		}
+
+		return nil, fmt.Errorf("unsupported operator %s for date time node: %w", node.Operator.Value, ErrUnsupportedNodeType)
+	case *ast.GroupNode:
+		group, err := t.transpile(node.Nodes)
+		if err != nil {
+			return nil, fmt.Errorf("failed to build group: %w", err)
+		}
+
+		return group, nil
+	}
+
+	return nil, fmt.Errorf("%w: %T", ErrUnsupportedNodeType, node)
+}