package pipeline

import (
	"bufio"
	"net/netip"
	"strings"
)

// ParseCIDRLines extracts unique IPv4/IPv6 CIDRs from plain text (one per line, # comments, empty lines skipped).
func ParseCIDRLines(body string) []netip.Prefix {
	seen := make(map[string]struct{})
	var out []netip.Prefix
	sc := bufio.NewScanner(strings.NewReader(body))
	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		pfx := parseOneCIDR(line)
		if !pfx.IsValid() {
			continue
		}
		m := pfx.Masked()
		s := m.String()
		if _, ok := seen[s]; ok {
			continue
		}
		seen[s] = struct{}{}
		out = append(out, m)
	}
	return out
}

func parseOneCIDR(s string) netip.Prefix {
	if p, err := netip.ParsePrefix(s); err == nil {
		return p
	}
	if addr, err := netip.ParseAddr(s); err == nil {
		if addr.Is4() {
			p, _ := addr.Prefix(32)
			return p
		}
		p, _ := addr.Prefix(128)
		return p
	}
	return netip.Prefix{}
}