feat:增强函数系统，实现大量的函数

functions/functions_datetime.go

@@ -0,0 +1,64 @@
+package functions
+
+import (
+	"time"
+)
+
+// NowFunction 当前时间函数
+type NowFunction struct {
+	*BaseFunction
+}
+
+func NewNowFunction() *NowFunction {
+	return &NowFunction{
+		BaseFunction: NewBaseFunction("now", TypeDateTime, "时间日期函数", "获取当前时间戳", 0, 0),
+	}
+}
+
+func (f *NowFunction) Validate(args []interface{}) error {
+	return f.ValidateArgCount(args)
+}
+
+func (f *NowFunction) Execute(ctx *FunctionContext, args []interface{}) (interface{}, error) {
+	return time.Now().Unix(), nil
+}
+
+// CurrentTimeFunction 当前时间函数
+type CurrentTimeFunction struct {
+	*BaseFunction
+}
+
+func NewCurrentTimeFunction() *CurrentTimeFunction {
+	return &CurrentTimeFunction{
+		BaseFunction: NewBaseFunction("current_time", TypeDateTime, "时间日期函数", "获取当前时间（HH:MM:SS）", 0, 0),
+	}
+}
+
+func (f *CurrentTimeFunction) Validate(args []interface{}) error {
+	return f.ValidateArgCount(args)
+}
+
+func (f *CurrentTimeFunction) Execute(ctx *FunctionContext, args []interface{}) (interface{}, error) {
+	now := time.Now()
+	return now.Format("15:04:05"), nil
+}
+
+// CurrentDateFunction 当前日期函数
+type CurrentDateFunction struct {
+	*BaseFunction
+}
+
+func NewCurrentDateFunction() *CurrentDateFunction {
+	return &CurrentDateFunction{
+		BaseFunction: NewBaseFunction("current_date", TypeDateTime, "时间日期函数", "获取当前日期（YYYY-MM-DD）", 0, 0),
+	}
+}
+
+func (f *CurrentDateFunction) Validate(args []interface{}) error {
+	return f.ValidateArgCount(args)
+}
+
+func (f *CurrentDateFunction) Execute(ctx *FunctionContext, args []interface{}) (interface{}, error) {
+	now := time.Now()
+	return now.Format("2006-01-02"), nil
+}