//go:build linux

package sqex

import (
	"os"
	"strconv"
	"strings"
)

// RawTickCount returns host milliseconds since boot; used on non-Windows hosts
// (e.g. when running the test suite in development). The game derives its
// decryption key from the top 16 bits of its own uptime (~65s window), so this
// only needs to be within that window of GetTickCount — /proc/uptime qualifies,
// with no cgo or extra deps.
func RawTickCount() uint32 {
	b, err := os.ReadFile("/proc/uptime")
	if err != nil {
		return 0
	}
	f, err := strconv.ParseFloat(strings.Fields(string(b))[0], 64)
	if err != nil {
		return 0
	}
	ms := f * 1000
	if ms > 0xFFFFFFFF {
		ms = 0 // wrapped; extremely unlikely (596 days)
	}
	return uint32(ms)
}