package main

import (
	"strings"
	"unicode"
)

// responsive kinds: how an addressed crow may answer a request (must-respond).
var responsiveKind = map[string]bool{"claim": true, "deliver": true, "decline": true}

// parseAddressing finds the first @handle in text that names one of members.
// An unknown handle stays literal text and yields "" (no address).
func parseAddressing(text string, members []string) string {
	for _, tok := range strings.Fields(text) {
		if !strings.HasPrefix(tok, "@") {
			continue
		}
		name := strings.TrimFunc(tok[1:], func(r rune) bool { return !unicode.IsLetter(r) && !unicode.IsDigit(r) })
		for _, m := range members {
			if strings.EqualFold(name, m) {
				return m
			}
		}
	}
	return ""
}

// splitKind pulls a leading "KIND: x" line off a crow's raw reply and returns
// the lowercased kind word ("" if absent) and the remaining body.
func splitKind(text string) (kind, body string) {
	trimmed := strings.TrimLeft(text, " \t\n")
	i := strings.IndexByte(trimmed, '\n')
	first, rest := trimmed, ""
	if i >= 0 {
		first, rest = trimmed[:i], strings.TrimSpace(trimmed[i+1:])
	}
	if len(first) >= 5 && strings.EqualFold(first[:5], "KIND:") {
		return strings.ToLower(strings.TrimSpace(first[5:])), rest
	}
	return "", text
}