package parse

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

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
		}
	}
}

type filepos struct {
	file string
	line int
}

func (pos *filepos) String() string {
	return fmt.Sprintf("%s:%d", pos.file, pos.line)
}

func callerFilepos(depth int) filepos {
	// No error handling, because we call this method ourselves with safe depth values.
	_, file, line, _ := runtime.Caller(depth + 1)
	return filepos{file, line}
}

func callerPointer(depth int) uintptr {
	// No error handling, because we call this method ourselves with safe depth values.
	p, _, _, _ := runtime.Caller(depth + 1)
	return p
}

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)
}