package parser

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

	"git.maze.io/maze/styx/internal/sliceutil"
)

func init() {
	RegisterDomainsParser(listDomainsParser{})
	RegisterNetworksParser(listNetworksParser{})
}

type listDomainsParser struct{}

func (listDomainsParser) CanHandle(line string) bool {
	return isDomainName(line) &&
		!strings.ContainsRune(line, ' ') &&
		!strings.ContainsRune(line, ':') &&
		net.ParseIP(line) == nil
}

func (listDomainsParser) ParseDomains(r io.Reader) (domains []string, ignored int, err error) {
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if isComment(line) {
			continue
		}
		if isDomainName(line) {
			domains = append(domains, line)
			continue
		}
		ignored++
	}
	if err = scanner.Err(); err != nil {
		return
	}
	return sliceutil.Unique(domains), ignored, nil
}

type listNetworksParser struct{}

func (listNetworksParser) CanHandle(line string) bool {
	return isPrefix(line) || isIP(line)
}

func (listNetworksParser) ParseNetworks(r io.Reader) (prefixes []netip.Prefix, ignored int, err error) {
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if isComment(line) {
			continue
		}
		if prefix, err := netip.ParsePrefix(line); err == nil {
			prefixes = append(prefixes, prefix)
			continue
		} else if addr, err := netip.ParseAddr(line); err == nil && !addr.IsUnspecified() && addr.IsValid() {
			prefixes = append(prefixes, addrToPrefix(addr))
			continue
		}
		ignored++
	}
	if err = scanner.Err(); err != nil {
		return
	}
	return sliceutil.Unique(prefixes), ignored, nil
}