package uasurfer

import (
	"strings"
)

// Browser struct contains the lowercase name of the browser, along
// with its browser version number. Browser are grouped together without
// consideration for device. For example, Chrome (Chrome/43.0) and Chrome for iOS
// (CriOS/43.0) would both return as "chrome" (name) and 43.0 (version). Similarly
// Internet Explorer 11 and Edge 12 would return as "ie" and "11" or "12", respectively.
// type Browser struct {
// 		Name    BrowserName
// 		Version struct {
// 				Major int
// 			Minor int
// 			Patch int
// 		}
// }

// Retrieve browser name from UA strings
func (u *UserAgent) evalBrowserName(ua string) bool {
	// Blackberry goes first because it reads as MSIE & Safari
	if strings.Contains(ua, "blackberry") || strings.Contains(ua, "playbook") || strings.Contains(ua, "bb10") || strings.Contains(ua, "rim ") {
		u.Browser.Name = BrowserBlackberry
		return u.isBot()
	}

	if strings.Contains(ua, "applewebkit") {
		switch {
		case strings.Contains(ua, "googlebot"):
			u.Browser.Name = BrowserGoogleBot

		case strings.Contains(ua, "opr/") || strings.Contains(ua, "opios/"):
			u.Browser.Name = BrowserOpera

		case strings.Contains(ua, "silk/"):
			u.Browser.Name = BrowserSilk

		case strings.Contains(ua, "edge/") || strings.Contains(ua, "iemobile/") || strings.Contains(ua, "msie "):
			u.Browser.Name = BrowserIE

		case strings.Contains(ua, "ucbrowser/") || strings.Contains(ua, "ucweb/"):
			u.Browser.Name = BrowserUCBrowser

		// Edge, Silk and other chrome-identifying browsers must evaluate before chrome, unless we want to add more overhead
		case strings.Contains(ua, "chrome/") || strings.Contains(ua, "crios/") || strings.Contains(ua, "chromium/") || strings.Contains(ua, "crmo/"):
			u.Browser.Name = BrowserChrome

		case strings.Contains(ua, "android") && !strings.Contains(ua, "chrome/") && strings.Contains(ua, "version/") && !strings.Contains(ua, "like android"):
			// Android WebView on Android >= 4.4 is purposefully being identified as Chrome above -- https://developer.chrome.com/multidevice/webview/overview
			u.Browser.Name = BrowserAndroid

		case strings.Contains(ua, "fxios"):
			u.Browser.Name = BrowserFirefox

		case strings.Contains(ua, " spotify/"):
			u.Browser.Name = BrowserSpotify

		// AppleBot uses webkit signature as well
		case strings.Contains(ua, "applebot"):
			u.Browser.Name = BrowserAppleBot

		// presume it's safari unless an esoteric browser is being specified (webOSBrowser, SamsungBrowser, etc.)
		case strings.Contains(ua, "like gecko") && strings.Contains(ua, "mozilla/") && strings.Contains(ua, "safari/") && !strings.Contains(ua, "linux") && !strings.Contains(ua, "android") && !strings.Contains(ua, "browser/") && !strings.Contains(ua, "os/"):
			u.Browser.Name = BrowserSafari

		// if we got this far and the device is iPhone or iPad, assume safari. Some agents don't actually contain the word "safari"
		case strings.Contains(ua, "iphone") || strings.Contains(ua, "ipad"):
			u.Browser.Name = BrowserSafari

		// Google's search app on iPhone, leverages native Safari rather than Chrome
		case strings.Contains(ua, " gsa/"):
			u.Browser.Name = BrowserSafari

		default:
			goto notwebkit

		}
		return u.isBot()
	}

notwebkit:
	switch {
	case strings.Contains(ua, "msie") || strings.Contains(ua, "trident"):
		u.Browser.Name = BrowserIE

	case strings.Contains(ua, "gecko") && (strings.Contains(ua, "firefox") || strings.Contains(ua, "iceweasel") || strings.Contains(ua, "seamonkey") || strings.Contains(ua, "icecat")):
		u.Browser.Name = BrowserFirefox

	case strings.Contains(ua, "presto") || strings.Contains(ua, "opera"):
		u.Browser.Name = BrowserOpera

	case strings.Contains(ua, "ucbrowser"):
		u.Browser.Name = BrowserUCBrowser

	case strings.Contains(ua, "applebot"):
		u.Browser.Name = BrowserAppleBot

	case strings.Contains(ua, "baiduspider"):
		u.Browser.Name = BrowserBaiduBot

	case strings.Contains(ua, "adidxbot") || strings.Contains(ua, "bingbot") || strings.Contains(ua, "bingpreview"):
		u.Browser.Name = BrowserBingBot

	case strings.Contains(ua, "duckduckbot"):
		u.Browser.Name = BrowserDuckDuckGoBot

	case strings.Contains(ua, "facebot") || strings.Contains(ua, "facebookexternalhit"):
		u.Browser.Name = BrowserFacebookBot

	case strings.Contains(ua, "googlebot"):
		u.Browser.Name = BrowserGoogleBot

	case strings.Contains(ua, "linkedinbot"):
		u.Browser.Name = BrowserLinkedInBot

	case strings.Contains(ua, "msnbot"):
		u.Browser.Name = BrowserMsnBot

	case strings.Contains(ua, "pingdom.com_bot"):
		u.Browser.Name = BrowserPingdomBot

	case strings.Contains(ua, "twitterbot"):
		u.Browser.Name = BrowserTwitterBot

	case strings.Contains(ua, "yandex") || strings.Contains(ua, "yadirectfetcher"):
		u.Browser.Name = BrowserYandexBot

	case strings.Contains(ua, "yahoo"):
		u.Browser.Name = BrowserYahooBot

	case strings.Contains(ua, "phantomjs"):
		u.Browser.Name = BrowserBot

	default:
		u.Browser.Name = BrowserUnknown

	}

	return u.isBot()
}

// Retrieve browser version
// Methods used in order:
// 1st: look for generic version/#
// 2nd: look for browser-specific instructions (e.g. chrome/34)
// 3rd: infer from OS (iOS only)
func (u *UserAgent) evalBrowserVersion(ua string) {
	// if there is a 'version/#' attribute with numeric version, use it -- except for Chrome since Android vendors sometimes hijack version/#
	if u.Browser.Name != BrowserChrome && u.Browser.Version.findVersionNumber(ua, "version/") {
		return
	}

	switch u.Browser.Name {
	case BrowserChrome:
		// match both chrome and crios
		_ = u.Browser.Version.findVersionNumber(ua, "chrome/") || u.Browser.Version.findVersionNumber(ua, "crios/") || u.Browser.Version.findVersionNumber(ua, "crmo/")

	case BrowserIE:
		if u.Browser.Version.findVersionNumber(ua, "msie ") || u.Browser.Version.findVersionNumber(ua, "edge/") {
			return
		}

		// get MSIE version from trident version https://en.wikipedia.org/wiki/Trident_(layout_engine)
		if u.Browser.Version.findVersionNumber(ua, "trident/") {
			// convert trident versions 3-7 to MSIE version
			if (u.Browser.Version.Major >= 3) && (u.Browser.Version.Major <= 7) {
				u.Browser.Version.Major += 4
			}
		}

	case BrowserFirefox:
		_ = u.Browser.Version.findVersionNumber(ua, "firefox/") || u.Browser.Version.findVersionNumber(ua, "fxios/")

	case BrowserSafari: // executes typically if we're on iOS and not using a familiar browser
		u.Browser.Version = u.OS.Version
		// early Safari used a version number +1 to OS version
		if (u.Browser.Version.Major <= 3) && (u.Browser.Version.Major >= 1) {
			u.Browser.Version.Major++
		}

	case BrowserUCBrowser:
		_ = u.Browser.Version.findVersionNumber(ua, "ucbrowser/")

	case BrowserOpera:
		_ = u.Browser.Version.findVersionNumber(ua, "opr/") || u.Browser.Version.findVersionNumber(ua, "opios/") || u.Browser.Version.findVersionNumber(ua, "opera/")

	case BrowserSilk:
		_ = u.Browser.Version.findVersionNumber(ua, "silk/")

	case BrowserSpotify:
		_ = u.Browser.Version.findVersionNumber(ua, "spotify/")
	}
}