package aprs

import "strings"

type Address struct {
	Call       string `json:"call"`
	SSID       string `json:"ssid,omitempty"`
	IsRepeated bool   `json:"is_repeated"`
}

func ParseAddress(s string) Address {
	r := strings.HasSuffix(s, "*")
	if r {
		s = strings.TrimSuffix(s, "*")
	}
	i := strings.IndexByte(s, '-')
	if i < 1 {
		return Address{
			Call:       s,
			IsRepeated: r,
		}
	}
	return Address{
		Call:       s[:i],
		SSID:       s[i+1:],
		IsRepeated: r,
	}
}

func (a Address) EqualTo(b Address) bool {
	return strings.EqualFold(a.Call, b.Call) && a.SSID == b.SSID
}

func (a Address) IsQConstruct() bool {
	return len(a.Call) == 3 && len(a.SSID) == 0 && a.Call[0] == 'q'
}

func (a Address) Passcode() int16 {
	v := int16(0x73e2)
	for i, l := 0, len(a.Call); i < l; i = i + 2 {
		v ^= int16(a.Call[i]) << 8
		if i+1 < len(a.Call) {
			v ^= int16(a.Call[i+1])
		}
	}
	return v & 0x7fff
}

func (a Address) String() string {
	var b strings.Builder
	b.WriteString(a.Call)
	if a.SSID != "" {
		b.WriteByte('-')
		b.WriteString(a.SSID)
	}
	if a.IsRepeated {
		b.WriteByte('*')
	}
	return b.String()
}

type Path []Address

func (path Path) EqualTo(other Path) bool {
	if len(path) != len(other) {
		return false
	}
	for i, a := range path {
		if !a.EqualTo(other[i]) {
			return false
		}
	}
	return true
}

func (path Path) String() string {
	part := make([]string, len(path))
	for i, a := range path {
		part[i] = a.String()
	}
	return strings.Join(part, ",")
}