1 files changed, 408 insertions, 0 deletions
diff --git a/weed/query/engine/cockroach_parser.go b/weed/query/engine/cockroach_parser.go
new file mode 100644
index 000000000..79fd2d94b
--- /dev/null
+++ b/weed/query/engine/cockroach_parser.go
@@ -0,0 +1,408 @@
+package engine
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/cockroachdb/cockroachdb-parser/pkg/sql/parser"
+	"github.com/cockroachdb/cockroachdb-parser/pkg/sql/sem/tree"
+)
+
+// CockroachSQLParser wraps CockroachDB's PostgreSQL-compatible SQL parser for use in SeaweedFS
+type CockroachSQLParser struct{}
+
+// NewCockroachSQLParser creates a new instance of the CockroachDB SQL parser wrapper
+func NewCockroachSQLParser() *CockroachSQLParser {
+	return &CockroachSQLParser{}
+}
+
+// ParseSQL parses a SQL statement using CockroachDB's parser
+func (p *CockroachSQLParser) ParseSQL(sql string) (Statement, error) {
+	// Parse using CockroachDB's parser
+	stmts, err := parser.Parse(sql)
+	if err != nil {
+		return nil, fmt.Errorf("CockroachDB parser error: %v", err)
+	}
+
+	if len(stmts) != 1 {
+		return nil, fmt.Errorf("expected exactly one statement, got %d", len(stmts))
+	}
+
+	stmt := stmts[0].AST
+
+	// Convert CockroachDB AST to SeaweedFS AST format
+	switch s := stmt.(type) {
+	case *tree.Select:
+		return p.convertSelectStatement(s)
+	default:
+		return nil, fmt.Errorf("unsupported statement type: %T", s)
+	}
+}
+
+// convertSelectStatement converts CockroachDB's Select AST to SeaweedFS format
+func (p *CockroachSQLParser) convertSelectStatement(crdbSelect *tree.Select) (*SelectStatement, error) {
+	selectClause, ok := crdbSelect.Select.(*tree.SelectClause)
+	if !ok {
+		return nil, fmt.Errorf("expected SelectClause, got %T", crdbSelect.Select)
+	}
+
+	seaweedSelect := &SelectStatement{
+		SelectExprs: make([]SelectExpr, 0, len(selectClause.Exprs)),
+		From:        []TableExpr{},
+	}
+
+	// Convert SELECT expressions
+	for _, expr := range selectClause.Exprs {
+		seaweedExpr, err := p.convertSelectExpr(expr)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert select expression: %v", err)
+		}
+		seaweedSelect.SelectExprs = append(seaweedSelect.SelectExprs, seaweedExpr)
+	}
+
+	// Convert FROM clause
+	if len(selectClause.From.Tables) > 0 {
+		for _, fromExpr := range selectClause.From.Tables {
+			seaweedTableExpr, err := p.convertFromExpr(fromExpr)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert FROM clause: %v", err)
+			}
+			seaweedSelect.From = append(seaweedSelect.From, seaweedTableExpr)
+		}
+	}
+
+	// Convert WHERE clause if present
+	if selectClause.Where != nil {
+		whereExpr, err := p.convertExpr(selectClause.Where.Expr)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert WHERE clause: %v", err)
+		}
+		seaweedSelect.Where = &WhereClause{
+			Expr: whereExpr,
+		}
+	}
+
+	// Convert LIMIT and OFFSET clauses if present
+	if crdbSelect.Limit != nil {
+		limitClause := &LimitClause{}
+
+		// Convert LIMIT (Count)
+		if crdbSelect.Limit.Count != nil {
+			countExpr, err := p.convertExpr(crdbSelect.Limit.Count)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert LIMIT clause: %v", err)
+			}
+			limitClause.Rowcount = countExpr
+		}
+
+		// Convert OFFSET
+		if crdbSelect.Limit.Offset != nil {
+			offsetExpr, err := p.convertExpr(crdbSelect.Limit.Offset)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert OFFSET clause: %v", err)
+			}
+			limitClause.Offset = offsetExpr
+		}
+
+		seaweedSelect.Limit = limitClause
+	}
+
+	return seaweedSelect, nil
+}
+
+// convertSelectExpr converts CockroachDB SelectExpr to SeaweedFS format
+func (p *CockroachSQLParser) convertSelectExpr(expr tree.SelectExpr) (SelectExpr, error) {
+	// Handle star expressions (SELECT *)
+	if _, isStar := expr.Expr.(tree.UnqualifiedStar); isStar {
+		return &StarExpr{}, nil
+	}
+
+	// CockroachDB's SelectExpr is a struct, not an interface, so handle it directly
+	seaweedExpr := &AliasedExpr{}
+
+	// Convert the main expression
+	convertedExpr, err := p.convertExpr(expr.Expr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to convert expression: %v", err)
+	}
+	seaweedExpr.Expr = convertedExpr
+
+	// Convert alias if present
+	if expr.As != "" {
+		seaweedExpr.As = aliasValue(expr.As)
+	}
+
+	return seaweedExpr, nil
+}
+
+// convertExpr converts CockroachDB expressions to SeaweedFS format
+func (p *CockroachSQLParser) convertExpr(expr tree.Expr) (ExprNode, error) {
+	switch e := expr.(type) {
+	case *tree.FuncExpr:
+		// Function call
+		seaweedFunc := &FuncExpr{
+			Name:  stringValue(strings.ToUpper(e.Func.String())), // Convert to uppercase for consistency
+			Exprs: make([]SelectExpr, 0, len(e.Exprs)),
+		}
+
+		// Convert function arguments
+		for _, arg := range e.Exprs {
+			// Special case: Handle star expressions in function calls like COUNT(*)
+			if _, isStar := arg.(tree.UnqualifiedStar); isStar {
+				seaweedFunc.Exprs = append(seaweedFunc.Exprs, &StarExpr{})
+			} else {
+				convertedArg, err := p.convertExpr(arg)
+				if err != nil {
+					return nil, fmt.Errorf("failed to convert function argument: %v", err)
+				}
+				seaweedFunc.Exprs = append(seaweedFunc.Exprs, &AliasedExpr{Expr: convertedArg})
+			}
+		}
+
+		return seaweedFunc, nil
+
+	case *tree.BinaryExpr:
+		// Arithmetic/binary operations (including string concatenation ||)
+		seaweedArith := &ArithmeticExpr{
+			Operator: e.Operator.String(),
+		}
+
+		// Convert left operand
+		left, err := p.convertExpr(e.Left)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert left operand: %v", err)
+		}
+		seaweedArith.Left = left
+
+		// Convert right operand
+		right, err := p.convertExpr(e.Right)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert right operand: %v", err)
+		}
+		seaweedArith.Right = right
+
+		return seaweedArith, nil
+
+	case *tree.ComparisonExpr:
+		// Comparison operations (=, >, <, >=, <=, !=, etc.) used in WHERE clauses
+		seaweedComp := &ComparisonExpr{
+			Operator: e.Operator.String(),
+		}
+
+		// Convert left operand
+		left, err := p.convertExpr(e.Left)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert comparison left operand: %v", err)
+		}
+		seaweedComp.Left = left
+
+		// Convert right operand
+		right, err := p.convertExpr(e.Right)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert comparison right operand: %v", err)
+		}
+		seaweedComp.Right = right
+
+		return seaweedComp, nil
+
+	case *tree.StrVal:
+		// String literal
+		return &SQLVal{
+			Type: StrVal,
+			Val:  []byte(string(e.RawString())),
+		}, nil
+
+	case *tree.NumVal:
+		// Numeric literal
+		valStr := e.String()
+		if strings.Contains(valStr, ".") {
+			return &SQLVal{
+				Type: FloatVal,
+				Val:  []byte(valStr),
+			}, nil
+		} else {
+			return &SQLVal{
+				Type: IntVal,
+				Val:  []byte(valStr),
+			}, nil
+		}
+
+	case *tree.UnresolvedName:
+		// Column name
+		return &ColName{
+			Name: stringValue(e.String()),
+		}, nil
+
+	case *tree.AndExpr:
+		// AND expression
+		left, err := p.convertExpr(e.Left)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert AND left operand: %v", err)
+		}
+		right, err := p.convertExpr(e.Right)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert AND right operand: %v", err)
+		}
+		return &AndExpr{
+			Left:  left,
+			Right: right,
+		}, nil
+
+	case *tree.OrExpr:
+		// OR expression
+		left, err := p.convertExpr(e.Left)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert OR left operand: %v", err)
+		}
+		right, err := p.convertExpr(e.Right)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert OR right operand: %v", err)
+		}
+		return &OrExpr{
+			Left:  left,
+			Right: right,
+		}, nil
+
+	case *tree.Tuple:
+		// Tuple expression for IN clauses: (value1, value2, value3)
+		tupleValues := make(ValTuple, 0, len(e.Exprs))
+		for _, tupleExpr := range e.Exprs {
+			convertedExpr, err := p.convertExpr(tupleExpr)
+			if err != nil {
+				return nil, fmt.Errorf("failed to convert tuple element: %v", err)
+			}
+			tupleValues = append(tupleValues, convertedExpr)
+		}
+		return tupleValues, nil
+
+	case *tree.CastExpr:
+		// Handle INTERVAL expressions: INTERVAL '1 hour'
+		// CockroachDB represents these as cast expressions
+		if p.isIntervalCast(e) {
+			// Extract the string value being cast to interval
+			if strVal, ok := e.Expr.(*tree.StrVal); ok {
+				return &IntervalExpr{
+					Value: string(strVal.RawString()),
+				}, nil
+			}
+			return nil, fmt.Errorf("invalid INTERVAL expression: expected string literal")
+		}
+		// For non-interval casts, just convert the inner expression
+		return p.convertExpr(e.Expr)
+
+	case *tree.RangeCond:
+		// Handle BETWEEN expressions: column BETWEEN value1 AND value2
+		seaweedBetween := &BetweenExpr{
+			Not: e.Not, // Handle NOT BETWEEN
+		}
+
+		// Convert the left operand (the expression being tested)
+		left, err := p.convertExpr(e.Left)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert BETWEEN left operand: %v", err)
+		}
+		seaweedBetween.Left = left
+
+		// Convert the FROM operand (lower bound)
+		from, err := p.convertExpr(e.From)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert BETWEEN from operand: %v", err)
+		}
+		seaweedBetween.From = from
+
+		// Convert the TO operand (upper bound)
+		to, err := p.convertExpr(e.To)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert BETWEEN to operand: %v", err)
+		}
+		seaweedBetween.To = to
+
+		return seaweedBetween, nil
+
+	case *tree.IsNullExpr:
+		// Handle IS NULL expressions: column IS NULL
+		expr, err := p.convertExpr(e.Expr)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert IS NULL expression: %v", err)
+		}
+
+		return &IsNullExpr{
+			Expr: expr,
+		}, nil
+
+	case *tree.IsNotNullExpr:
+		// Handle IS NOT NULL expressions: column IS NOT NULL
+		expr, err := p.convertExpr(e.Expr)
+		if err != nil {
+			return nil, fmt.Errorf("failed to convert IS NOT NULL expression: %v", err)
+		}
+
+		return &IsNotNullExpr{
+			Expr: expr,
+		}, nil
+
+	default:
+		return nil, fmt.Errorf("unsupported expression type: %T", e)
+	}
+}
+
+// convertFromExpr converts CockroachDB FROM expressions to SeaweedFS format
+func (p *CockroachSQLParser) convertFromExpr(expr tree.TableExpr) (TableExpr, error) {
+	switch e := expr.(type) {
+	case *tree.TableName:
+		// Simple table name
+		tableName := TableName{
+			Name: stringValue(e.Table()),
+		}
+
+		// Extract database qualifier if present
+
+		if e.Schema() != "" {
+			tableName.Qualifier = stringValue(e.Schema())
+		}
+
+		return &AliasedTableExpr{
+			Expr: tableName,
+		}, nil
+
+	case *tree.AliasedTableExpr:
+		// Handle aliased table expressions (which is what CockroachDB uses for qualified names)
+		if tableName, ok := e.Expr.(*tree.TableName); ok {
+			seaweedTableName := TableName{
+				Name: stringValue(tableName.Table()),
+			}
+
+			// Extract database qualifier if present
+			if tableName.Schema() != "" {
+				seaweedTableName.Qualifier = stringValue(tableName.Schema())
+			}
+
+			return &AliasedTableExpr{
+				Expr: seaweedTableName,
+			}, nil
+		}
+
+		return nil, fmt.Errorf("unsupported expression in AliasedTableExpr: %T", e.Expr)
+
+	default:
+		return nil, fmt.Errorf("unsupported table expression type: %T", e)
+	}
+}
+
+// isIntervalCast checks if a CastExpr is casting to an INTERVAL type
+func (p *CockroachSQLParser) isIntervalCast(castExpr *tree.CastExpr) bool {
+	// Check if the target type is an interval type
+	// CockroachDB represents interval types in the Type field
+	// We need to check if it's an interval type by examining the type structure
+	if castExpr.Type != nil {
+		// Try to detect interval type by examining the AST structure
+		// Since we can't easily access the type string, we'll be more conservative
+		// and assume any cast expression on a string literal could be an interval
+		if _, ok := castExpr.Expr.(*tree.StrVal); ok {
+			// This is likely an INTERVAL expression since CockroachDB
+			// represents INTERVAL '1 hour' as casting a string to interval type
+			return true
+		}
+	}
+	return false
+}