package engine

import (
	"context"
	"testing"
)

func TestSQLEngine_ShowDatabases(t *testing.T) {
	engine := NewSQLEngine("localhost:8888")
	
	result, err := engine.ExecuteSQL(context.Background(), "SHOW DATABASES")
	if err != nil {
		t.Fatalf("Expected no error, got %v", err)
	}
	
	if result.Error != nil {
		t.Fatalf("Expected no query error, got %v", result.Error)
	}
	
	if len(result.Columns) != 1 || result.Columns[0] != "Database" {
		t.Errorf("Expected column 'Database', got %v", result.Columns)
	}
	
	if len(result.Rows) == 0 {
		t.Error("Expected at least one database, got none")
	}
	
	// Should have sample databases: default, analytics, logs
	expectedDatabases := map[string]bool{
		"default": false, "analytics": false, "logs": false,
	}
	
	for _, row := range result.Rows {
		if len(row) > 0 {
			dbName := row[0].ToString()
			if _, exists := expectedDatabases[dbName]; exists {
				expectedDatabases[dbName] = true
			}
		}
	}
	
	for db, found := range expectedDatabases {
		if !found {
			t.Errorf("Expected to find database '%s'", db)
		}
	}
}

func TestSQLEngine_ShowTables(t *testing.T) {
	engine := NewSQLEngine("localhost:8888")
	
	result, err := engine.ExecuteSQL(context.Background(), "SHOW TABLES")
	if err != nil {
		t.Fatalf("Expected no error, got %v", err)
	}
	
	if result.Error != nil {
		t.Fatalf("Expected no query error, got %v", result.Error)
	}
	
	if len(result.Columns) != 1 || result.Columns[0] != "Tables_in_default" {
		t.Errorf("Expected column 'Tables_in_default', got %v", result.Columns)
	}
	
	if len(result.Rows) == 0 {
		t.Error("Expected at least one table, got none")
	}
}

func TestSQLEngine_ParseError(t *testing.T) {
	engine := NewSQLEngine("localhost:8888")
	
	result, err := engine.ExecuteSQL(context.Background(), "INVALID SQL")
	if err == nil {
		t.Error("Expected parse error for invalid SQL")
	}
	
	if result.Error == nil {
		t.Error("Expected result error for invalid SQL")
	}
}

func TestSQLEngine_UnsupportedStatement(t *testing.T) {
	engine := NewSQLEngine("localhost:8888")
	
	// INSERT is not yet implemented
	result, err := engine.ExecuteSQL(context.Background(), "INSERT INTO test VALUES (1)")
	if err == nil {
		t.Error("Expected error for unsupported statement")
	}
	
	if result.Error == nil {
		t.Error("Expected result error for unsupported statement")
	}
}