package tokenize

import (
	"fmt"
	"runtime"
	"strings"
)

func callerPanic(name, f string, data ...interface{}) {
	filepos := callerBefore(name)
	m := fmt.Sprintf(f, data...)
	m = strings.Replace(m, "{caller}", filepos, -1)
	m = strings.Replace(m, "{name}", name, -1)
	panic(m)
}

func callerBefore(name string) string {
	found := false
	for i := 1; ; i++ {
		pc, file, line, ok := runtime.Caller(i)
		if found {
			return fmt.Sprintf("%s:%d", file, line)
		}
		if !ok {
			return "unknown caller"
		}
		f := runtime.FuncForPC(pc)

		if strings.HasSuffix(f.Name(), "."+name) {
			found = true
		}
	}
}