/*
---------------------------------------------------------
   Project activething
   Active Thing (activething.com) git.activething.com/go

   File name  stack.go
   Created by DEV
   Modified   23/10/2023

   Copyright 2023 activething.com
---------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
*/

package errs

import "runtime"

const (
	stackMaxFrames  = 32
	stackSkipFrames = 2
)

type StackTrace []uintptr

func NewStackTrace(offset int) *StackTrace {
	var fm [stackMaxFrames]uintptr
	if offset < 0 {
		offset = 0
	}
	cn := runtime.Callers(offset+stackSkipFrames, fm[:])
	st := StackTrace(fm[0:cn])
	return &st
}

func (s StackTrace) Frames() []StackTraceFrame {
	ln := len(s)
	if ln == 0 {
		return nil
	}
	st := make([]StackTraceFrame, ln)
	for ix := 0; ix < ln; ix++ {
		st[ix] = StackTraceFrame(s[ix])
	}
	return st
}

/*
   ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

   I HAVE NO DESIRE TO WALK ON WATER," SAID SIDDHARTA.
   "LET THE OLD SHRAMANAS SATISFY THEMSELVES WITH SUCH SKILLS.

   SIDDHARTA
   - HERMANN HESSE -

   :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

*/