package web

import (
	"strings"
	"unicode/utf8"
)

var deviceBrowsers = []struct{ token, name string }{
	{"Edg/", "Edge"},
	{"OPR/", "Opera"},
	{"SamsungBrowser/", "Samsung Internet"},
	{"Firefox/", "Firefox"},
	{"FxiOS/", "Firefox"},
	{"CriOS/", "Chrome"},
	{"Chrome/", "Chrome"},
	{"Version/", "Safari"},
}

var deviceSystems = []struct{ token, name string }{
	{"Windows", "Windows"},
	{"iPhone", "iOS"},
	{"iPad", "iOS"},
	{"Android", "Android"},
	{"CrOS", "ChromeOS"},
	{"Mac OS X", "macOS"},
	{"Linux", "Linux"},
}

func deviceLabel(ua string) string {
	browser := firstToken(ua, deviceBrowsers)
	system := firstToken(ua, deviceSystems)
	if browser == "" || system == "" {
		return ""
	}
	return browser + ", " + system
}

func firstToken(ua string, table []struct{ token, name string }) string {
	for _, e := range table {
		if strings.Contains(ua, e.token) {
			return e.name
		}
	}
	return ""
}

var accountAgentShown = 80

func clipAgent(ua string) string {
	if len(ua) <= accountAgentShown {
		return ua
	}
	cut := accountAgentShown
	for cut > 0 && !utf8.RuneStart(ua[cut]) {
		cut--
	}
	return ua[:cut] + "…"
}