Add search expression support to admin interface

pkg/db/sqlite/search.go

@@ -0,0 +1,108 @@
+package sqlite
+
+import (
+	"errors"
+	"fmt"
+
+	sq "github.com/Masterminds/squirrel"
+	"github.com/dstotijn/hetty/pkg/search"
+)
+
+var stringLiteralMap = map[string]string{
+	// http_requests
+	"req.id":        "req.id",
+	"req.proto":     "req.proto",
+	"req.url":       "req.url",
+	"req.method":    "req.method",
+	"req.body":      "req.body",
+	"req.timestamp": "req.timestamp",
+	// http_responses
+	"res.id":           "res.id",
+	"res.proto":        "res.proto",
+	"res.statusCode":   "res.status_code",
+	"res.statusReason": "res.status_reason",
+	"res.body":         "res.body",
+	"res.timestamp":    "res.timestamp",
+	// TODO: http_headers
+}
+
+func parseSearchExpr(expr search.Expression) (sq.Sqlizer, error) {
+	switch e := expr.(type) {
+	case *search.PrefixExpression:
+		return parsePrefixExpr(e)
+	case *search.InfixExpression:
+		return parseInfixExpr(e)
+	default:
+		return nil, fmt.Errorf("expression type (%v) not supported", expr)
+	}
+}
+
+func parsePrefixExpr(expr *search.PrefixExpression) (sq.Sqlizer, error) {
+	switch expr.Operator {
+	case search.TokOpNot:
+		// TODO: Find a way to prefix an `sq.Sqlizer` with "NOT".
+		return nil, errors.New("not implemented")
+	default:
+		return nil, errors.New("operator is not supported")
+	}
+}
+
+func parseInfixExpr(expr *search.InfixExpression) (sq.Sqlizer, error) {
+	switch expr.Operator {
+	case search.TokOpAnd:
+		left, err := parseSearchExpr(expr.Left)
+		if err != nil {
+			return nil, err
+		}
+		right, err := parseSearchExpr(expr.Right)
+		if err != nil {
+			return nil, err
+		}
+		return sq.And{left, right}, nil
+	case search.TokOpOr:
+		left, err := parseSearchExpr(expr.Left)
+		if err != nil {
+			return nil, err
+		}
+		right, err := parseSearchExpr(expr.Right)
+		if err != nil {
+			return nil, err
+		}
+		return sq.Or{left, right}, nil
+	}
+
+	left, ok := expr.Left.(*search.StringLiteral)
+	if !ok {
+		return nil, errors.New("left operand must be a string literal")
+	}
+	right, ok := expr.Right.(*search.StringLiteral)
+	if !ok {
+		return nil, errors.New("right operand must be a string literal")
+	}
+
+	mappedLeft, ok := stringLiteralMap[left.Value]
+	if !ok {
+		return nil, fmt.Errorf("invalid string literal: %v", left)
+	}
+
+	switch expr.Operator {
+	case search.TokOpEq:
+		return sq.Eq{mappedLeft: right.Value}, nil
+	case search.TokOpNotEq:
+		return sq.NotEq{mappedLeft: right.Value}, nil
+	case search.TokOpGt:
+		return sq.Gt{mappedLeft: right.Value}, nil
+	case search.TokOpLt:
+		return sq.Lt{mappedLeft: right.Value}, nil
+	case search.TokOpGtEq:
+		return sq.GtOrEq{mappedLeft: right.Value}, nil
+	case search.TokOpLtEq:
+		return sq.LtOrEq{mappedLeft: right.Value}, nil
+	case search.TokOpRe:
+		return sq.Expr(fmt.Sprintf("regexp(?, %v)", mappedLeft), right.Value), nil
+	case search.TokOpNotRe:
+		return sq.Expr(fmt.Sprintf("NOT regexp(?, %v)", mappedLeft), right.Value), nil
+	default:
+		return nil, errors.New("unsupported operator")
+	}
+}