package appupdate

import (
	"fmt"
	"strconv"
	"strings"

	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/updateprotocol"
)

type semanticVersion struct {
	major int
	minor int
	patch int
}

func parseVersion(raw string) (semanticVersion, error) {
	if !strings.HasPrefix(raw, "v") || strings.ContainsAny(raw, "+-") {
		return semanticVersion{}, fmt.Errorf("version must use vMAJOR.MINOR.PATCH")
	}
	parts := strings.Split(strings.TrimPrefix(raw, "v"), ".")
	if len(parts) != 3 {
		return semanticVersion{}, fmt.Errorf("version must use vMAJOR.MINOR.PATCH")
	}
	values := make([]int, 3)
	for index, part := range parts {
		if part == "" || (len(part) > 1 && part[0] == '0') {
			return semanticVersion{}, fmt.Errorf("version contains an invalid number")
		}
		value, err := strconv.Atoi(part)
		if err != nil || value < 0 || value > 1_000_000 {
			return semanticVersion{}, fmt.Errorf("version contains an invalid number")
		}
		values[index] = value
	}
	return semanticVersion{major: values[0], minor: values[1], patch: values[2]}, nil
}

func compareVersions(left, right string) (int, error) {
	a, err := parseVersion(left)
	if err != nil {
		return 0, err
	}
	b, err := parseVersion(right)
	if err != nil {
		return 0, err
	}
	av, bv := []int{a.major, a.minor, a.patch}, []int{b.major, b.minor, b.patch}
	for index := range av {
		if av[index] < bv[index] {
			return -1, nil
		}
		if av[index] > bv[index] {
			return 1, nil
		}
	}
	return 0, nil
}

func validReleaseVersion(version string) bool {
	if !updateprotocol.ValidVersion(version) {
		return false
	}
	_, err := parseVersion(version)
	return err == nil
}