package gologger
  
  import (
  	"fmt"
  	"math"
  	"runtime"
  	"strings"
  	"time"
  )
  
  // getCallStack
  func getCallStack() (stack []string) {
  	const (
  		maxStackDepth = 10000
  		skipRuntime   = 2 // skip runtime and startup
  		skipCallers   = 2
  		thisPackage   = "gologger"
  	)
  
  	callers := make([]uintptr, maxStackDepth) // min 1
  
  	stackDepth := runtime.Callers(skipCallers, callers)
  	frames := runtime.CallersFrames(callers)
  
  	for i := 0; i < skipRuntime; i++ {
  		frames.Next()
  	}
  
  	for i := 0; i < stackDepth-skipRuntime-skipCallers; i++ {
  		frame, next := frames.Next()
  		if !strings.Contains(frame.File, thisPackage) {
  			stack = append(stack, fmt.Sprintf("[%s %d]", frame.File, frame.Line))
  		}
  		if !next {
  			break
  		}
  	}
  
  	reverseStack(stack)
  
  	return stack
  }
  
  // in place
  func reverseStack(stack []string) {
  	middle := int(math.Floor(float64(len(stack)) / 2.0))
  
  	lastIndex := len(stack) - 1
  	for i := 0; i < middle; i++ {
  		stack[i], stack[lastIndex] = stack[lastIndex], stack[i]
  		lastIndex--
  	}
  }
  
  func getTrace(format string, v ...interface{}) (t string) {
  	stack := getCallStack()
  
  	t = time.Now().Format(dateTimeFormat) + ":
  "
  	for _, s := range stack {
  		t += s + "
  "
  	}
  	t += fmt.Sprintf(format, v...) + "
  "
  
  	return t
  }