package game

import (
	"strconv"
	"strings"
)

// compareDictVersions orders two dictionary version labels of the shape "vMAJOR.MINOR.PATCH"
// numerically, returning -1, 0 or +1 as a is less than, equal to or greater than b. Labels
// that do not parse fall back to a byte comparison, so the ordering is always total (a mixed
// or malformed pair never crashes the boot-time active-version reconcile).
func compareDictVersions(a, b string) int {
	pa, oka := parseDictVersion(a)
	pb, okb := parseDictVersion(b)
	if !oka || !okb {
		return strings.Compare(a, b)
	}
	for i := range pa {
		if pa[i] != pb[i] {
			if pa[i] < pb[i] {
				return -1
			}
			return 1
		}
	}
	return 0
}

// parseDictVersion parses a "vMAJOR.MINOR.PATCH" label into its three numeric parts, reporting
// whether it matched that shape.
func parseDictVersion(v string) ([3]int, bool) {
	parts := strings.Split(strings.TrimPrefix(v, "v"), ".")
	if len(parts) != 3 {
		return [3]int{}, false
	}
	var out [3]int
	for i, p := range parts {
		n, err := strconv.Atoi(p)
		if err != nil {
			return [3]int{}, false
		}
		out[i] = n
	}
	return out, true
}