fix: include time zone name overrides and add KOITO_FORCE_TZ cfg option (#176)

* timezone overrides and force_tz option

* docs for force_tz

* add link to time zone names in docs

docs/src/content/docs/reference/configuration.md

@@ -64,6 +64,8 @@ If the environment variable is defined without **and** with the suffix at the sa
 ##### KOITO_CONFIG_DIR
 - Default: `/etc/koito`
 - Description: The location where import folders and image caches are stored.
+##### KOITO_FORCE_TZ
+- Description: A canonical IANA database time zone name (https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) that Koito will use to serve all clients. Overrides any timezones requested via a `tz` cookie or `tz` query parameter. Koito will fail to start if this value is invalid.
 ##### KOITO_DISABLE_DEEZER
 - Default: `false`
 - Description: Disables Deezer as a source for finding artist and album images.

engine/engine.go

@@ -96,6 +96,10 @@ func Run(
 	defer store.Close(ctx)
 	l.Info().Msg("Engine: Database connection established")
 
+	if cfg.ForceTZ() != nil {
+		l.Debug().Msgf("Engine: Forcing the use of timezone '%s'", cfg.ForceTZ().String())
+	}
+
 	l.Debug().Msg("Engine: Initializing MusicBrainz client")
 	var mbzC mbz.MusicBrainzCaller
 	if !cfg.MusicBrainzDisabled() {

engine/handlers/handlers.go

@@ -6,7 +6,9 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	_ "time/tzdata"
 
+	"github.com/gabehf/koito/internal/cfg"
 	"github.com/gabehf/koito/internal/db"
 	"github.com/gabehf/koito/internal/logger"
 )
@@ -107,14 +109,143 @@ func TimeframeFromRequest(r *http.Request) db.Timeframe {
 
 func parseTZ(r *http.Request) *time.Location {
 
+	// this map is obviously AI.
+	// i manually referenced as many links as I could and couldn't find any
+	// incorrect entries here so hopefully it is all correct.
+	overrides := map[string]string{
+		// --- North America ---
+		"America/Indianapolis":  "America/Indiana/Indianapolis",
+		"America/Knoxville":     "America/Indiana/Knoxville",
+		"America/Louisville":    "America/Kentucky/Louisville",
+		"America/Montreal":      "America/Toronto",
+		"America/Shiprock":      "America/Denver",
+		"America/Fort_Wayne":    "America/Indiana/Indianapolis",
+		"America/Virgin":        "America/Port_of_Spain",
+		"America/Santa_Isabel":  "America/Tijuana",
+		"America/Ensenada":      "America/Tijuana",
+		"America/Rosario":       "America/Argentina/Cordoba",
+		"America/Jujuy":         "America/Argentina/Jujuy",
+		"America/Mendoza":       "America/Argentina/Mendoza",
+		"America/Catamarca":     "America/Argentina/Catamarca",
+		"America/Cordoba":       "America/Argentina/Cordoba",
+		"America/Buenos_Aires":  "America/Argentina/Buenos_Aires",
+		"America/Coral_Harbour": "America/Atikokan",
+		"America/Atka":          "America/Adak",
+		"US/Alaska":             "America/Anchorage",
+		"US/Aleutian":           "America/Adak",
+		"US/Arizona":            "America/Phoenix",
+		"US/Central":            "America/Chicago",
+		"US/Eastern":            "America/New_York",
+		"US/East-Indiana":       "America/Indiana/Indianapolis",
+		"US/Hawaii":             "Pacific/Honolulu",
+		"US/Indiana-Starke":     "America/Indiana/Knoxville",
+		"US/Michigan":           "America/Detroit",
+		"US/Mountain":           "America/Denver",
+		"US/Pacific":            "America/Los_Angeles",
+		"US/Samoa":              "Pacific/Pago_Pago",
+		"Canada/Atlantic":       "America/Halifax",
+		"Canada/Central":        "America/Winnipeg",
+		"Canada/Eastern":        "America/Toronto",
+		"Canada/Mountain":       "America/Edmonton",
+		"Canada/Newfoundland":   "America/St_Johns",
+		"Canada/Pacific":        "America/Vancouver",
+
+		// --- Asia ---
+		"Asia/Calcutta":      "Asia/Kolkata",
+		"Asia/Saigon":        "Asia/Ho_Chi_Minh",
+		"Asia/Katmandu":      "Asia/Kathmandu",
+		"Asia/Rangoon":       "Asia/Yangon",
+		"Asia/Ulan_Bator":    "Asia/Ulaanbaatar",
+		"Asia/Macao":         "Asia/Macau",
+		"Asia/Tel_Aviv":      "Asia/Jerusalem",
+		"Asia/Ashkhabad":     "Asia/Ashgabat",
+		"Asia/Chungking":     "Asia/Chongqing",
+		"Asia/Dacca":         "Asia/Dhaka",
+		"Asia/Istanbul":      "Europe/Istanbul",
+		"Asia/Kashgar":       "Asia/Urumqi",
+		"Asia/Thimbu":        "Asia/Thimphu",
+		"Asia/Ujung_Pandang": "Asia/Makassar",
+		"ROC":                "Asia/Taipei",
+		"Iran":               "Asia/Tehran",
+		"Israel":             "Asia/Jerusalem",
+		"Japan":              "Asia/Tokyo",
+		"Singapore":          "Asia/Singapore",
+		"Hongkong":           "Asia/Hong_Kong",
+
+		// --- Europe ---
+		"Europe/Kiev":     "Europe/Kyiv",
+		"Europe/Belfast":  "Europe/London",
+		"Europe/Tiraspol": "Europe/Chisinau",
+		"Europe/Nicosia":  "Asia/Nicosia",
+		"Europe/Moscow":   "Europe/Moscow",
+		"W-SU":            "Europe/Moscow",
+		"GB":              "Europe/London",
+		"GB-Eire":         "Europe/London",
+		"Eire":            "Europe/Dublin",
+		"Poland":          "Europe/Warsaw",
+		"Portugal":        "Europe/Lisbon",
+		"Turkey":          "Europe/Istanbul",
+
+		// --- Australia / Pacific ---
+		"Australia/ACT":        "Australia/Sydney",
+		"Australia/Canberra":   "Australia/Sydney",
+		"Australia/LHI":        "Australia/Lord_Howe",
+		"Australia/North":      "Australia/Darwin",
+		"Australia/NSW":        "Australia/Sydney",
+		"Australia/Queensland": "Australia/Brisbane",
+		"Australia/South":      "Australia/Adelaide",
+		"Australia/Tasmania":   "Australia/Hobart",
+		"Australia/Victoria":   "Australia/Melbourne",
+		"Australia/West":       "Australia/Perth",
+		"Australia/Yancowinna": "Australia/Broken_Hill",
+		"Pacific/Samoa":        "Pacific/Pago_Pago",
+		"Pacific/Yap":          "Pacific/Chuuk",
+		"Pacific/Truk":         "Pacific/Chuuk",
+		"Pacific/Ponape":       "Pacific/Pohnpei",
+		"NZ":                   "Pacific/Auckland",
+		"NZ-CHAT":              "Pacific/Chatham",
+
+		// --- Africa ---
+		"Africa/Asmera":   "Africa/Asmara",
+		"Africa/Timbuktu": "Africa/Bamako",
+		"Egypt":           "Africa/Cairo",
+		"Libya":           "Africa/Tripoli",
+
+		// --- Atlantic ---
+		"Atlantic/Faeroe":    "Atlantic/Faroe",
+		"Atlantic/Jan_Mayen": "Europe/Oslo",
+		"Iceland":            "Atlantic/Reykjavik",
+
+		// --- Etc / Misc ---
+		"UTC":       "UTC",
+		"Etc/UTC":   "UTC",
+		"Etc/GMT":   "UTC",
+		"GMT":       "UTC",
+		"Zulu":      "UTC",
+		"Universal": "UTC",
+	}
+
+	if cfg.ForceTZ() != nil {
+		return cfg.ForceTZ()
+	}
+
 	if tz := r.URL.Query().Get("tz"); tz != "" {
+		if fixedTz, exists := overrides[tz]; exists {
+			tz = fixedTz
+		}
 		if loc, err := time.LoadLocation(tz); err == nil {
 			return loc
 		}
 	}
 
 	if c, err := r.Cookie("tz"); err == nil {
-		if loc, err := time.LoadLocation(c.Value); err == nil {
+		var tz string
+		if fixedTz, exists := overrides[c.Value]; exists {
+			tz = fixedTz
+		} else {
+			tz = c.Value
+		}
+		if loc, err := time.LoadLocation(tz); err == nil {
 			return loc
 		}
 	}

internal/cfg/cfg.go

@@ -49,6 +49,7 @@ const (
 	FETCH_IMAGES_DURING_IMPORT_ENV = "KOITO_FETCH_IMAGES_DURING_IMPORT"
 	ARTIST_SEPARATORS_ENV          = "KOITO_ARTIST_SEPARATORS_REGEX"
 	LOGIN_GATE_ENV                 = "KOITO_LOGIN_GATE"
+	FORCE_TZ                       = "KOITO_FORCE_TZ"
 )
 
 type config struct {
@@ -87,6 +88,7 @@ type config struct {
 	importAfter            time.Time
 	artistSeparators       []*regexp.Regexp
 	loginGate              bool
+	forceTZ                *time.Location
 }
 
 var (
@@ -213,6 +215,13 @@ func loadConfig(getenv func(string) string, version string) (*config, error) {
 		cfg.loginGate = true
 	}
 
+	if getenv(FORCE_TZ) != "" {
+		cfg.forceTZ, err = time.LoadLocation(getenv(FORCE_TZ))
+		if err != nil {
+			return nil, fmt.Errorf("forced timezone '%s' is not a valid timezone", getenv(FORCE_TZ))
+		}
+	}
+
 	switch strings.ToLower(getenv(LOG_LEVEL_ENV)) {
 	case "debug":
 		cfg.logLevel = 0
@@ -430,3 +439,9 @@ func LoginGate() bool {
 	defer lock.RUnlock()
 	return globalConfig.loginGate
 }
+
+func ForceTZ() *time.Location {
+	lock.RLock()
+	defer lock.RUnlock()
+	return globalConfig.forceTZ
+}