package tsing

import (
	"bytes"
	"path"
	"unsafe"
)

func strToBytes(s string) []byte {
	return *(*[]byte)(unsafe.Pointer(
		&struct {
			string
			Cap int
		}{s, len(s)},
	))
}

func bytesToStr(b []byte) string {
	return *(*string)(unsafe.Pointer(&b))
}

func joinPaths(absolutePath, relativePath string) string {
	if relativePath == "" {
		return absolutePath
	}

	finalPath := path.Join(absolutePath, relativePath)
	if lastChar(relativePath) == '/' && lastChar(finalPath) != '/' {
		return finalPath + "/"
	}
	return finalPath
}

func lastChar(str string) uint8 {
	if str == "" {
		panic("The length of the string can't be 0")
	}
	return str[len(str)-1]
}

func min(a, b int) int {
	if a <= b {
		return a
	}
	return b
}

func longestCommonPrefix(a, b string) int {
	i := 0
	max := min(len(a), len(b))
	for i < max && a[i] == b[i] {
		i++
	}
	return i
}

func countParams(path string) uint16 {
	var n uint16
	s := strToBytes(path)
	n += uint16(bytes.Count(s, strColon))
	n += uint16(bytes.Count(s, strStar))
	return n
}

func countSections(path string) uint16 {
	s := strToBytes(path)
	return uint16(bytes.Count(s, strSlash))
}