weather: any city he names, not the six in a table (V-421)

The hand-written table understood "какая погода в X" for six values of X.
Ask about Kazan or Tbilisi and the city was dropped silently and answered for
the default location — a correct-sounding answer about the wrong place.

The table is gone. internal/weather already calls Open-Meteo's geocoding
endpoint on every lookup, so the place he named goes straight there and any
place it knows is a place he can ask about. He speaks the prepositional case,
so locationCandidates reverses the two endings that cover most of it: a final
"е" is a nominative "а" or nothing, a final "и" is a soft sign. A wrong
candidate finds no city; it never invents one.

A place the geocoder does not have now reads as "не знаю такого города"
rather than as a provider outage or, worse, as the default city's weather.
ErrLocationUnknown is what carries that apart.

"в" followed by a room or a day word is still the default location. Those
questions are answered by the house sensors and the calendar, not by
Open-Meteo, and they must not be read as a city.

cmd/mavend/actions_query.go

@@ -390,6 +390,11 @@ func (h *reactiveHandler) queryWeather(ctx context.Context, t *queryTurn) (strin
 	if errors.Is(err, weather.ErrNotConfigured) {
 		return "погода не настроена.", true
 	}
+	if errors.Is(err, weather.ErrLocationUnknown) {
+		// He named a place and the geocoder does not have it. Saying so beats
+		// reading out the default city's temperature (Vikunja #421).
+		return "не знаю такого города — " + loc + ".", true
+	}
 	if err != nil {
 		log.Printf("voice: weather: %v", err)
 		return "не получилось узнать погоду.", true

cmd/mavend/weatherq.go

@@ -1,10 +1,13 @@
 // Package main — weatherq.go holds the weather-query keyword helpers: does
-// this utterance ask about weather at all, and which city (if any) did it
-// name. Both are plain substring/lookup matching, not NLU — extend this file
-// rather than voice.go for anything in that shape.
+// this utterance ask about weather at all, and which place (if any) did he
+// name. Both are plain keyword matching, not NLU — extend this file rather
+// than voice.go for anything in that shape.
 package main
 
-import "strings"
+import (
+	"regexp"
+	"strings"
+)
 
 // isWeatherQuery returns true if the utterance is about weather.
 func isWeatherQuery(u string) bool {
@@ -19,40 +22,49 @@ func isWeatherQuery(u string) bool {
 		strings.Contains(lower, "temperature")
 }
 
-// weatherCities — the city names an utterance may name explicitly, as
-// lowercase substrings mapped to the provider's spelling. This is a
-// convenience for "какая погода в Лондоне", NOT a source of default truth:
-// nothing here is used unless he actually said it.
-var weatherCities = map[string]string{
-	"москв":    "Moscow",
-	"moscow":   "Moscow",
-	"питер":    "Saint Petersburg",
-	"spb":      "Saint Petersburg",
-	"петербур": "Saint Petersburg",
-	"лондон":   "London",
-	"london":   "London",
-	"париж":    "Paris",
-	"paris":    "Paris",
-	"берлин":   "Berlin",
-	"berlin":   "Berlin",
-	"нью-йорк": "New York",
-	"new york": "New York",
+// weatherPlace — the place he named, after "в"/"во"/"in". One or two words,
+// letters and dashes only, so "в Нижнем Новгороде" and "in New York" both
+// come through whole and "в 5 утра" does not.
+var weatherPlace = regexp.MustCompile(`(?i)(?:^|\s)(?:в|во|in)\s+([\p{L}-]+(?:\s+[\p{L}-]+)?)`)
+
+// weatherNonPlaces — words that follow "в" in a weather question and are not
+// cities. "какая погода в доме" is the smart-home sensor, not Open-Meteo, and
+// "тепло в комнате" is the same question about the same room.
+var weatherNonPlaces = map[string]bool{
+	"доме": true, "квартире": true, "комнате": true, "спальне": true,
+	"гостиной": true, "кухне": true, "гараже": true, "офисе": true,
+	"выходные": true, "субботу": true, "воскресенье": true, "понедельник": true,
+	"вторник": true, "среду": true, "четверг": true, "пятницу": true,
+	"обед": true, "обеде": true, "утро": true, "утром": true, "вечер": true,
+	"вечером": true, "ночь": true, "ночью": true, "целом": true, "принципе": true,
 }
 
-// extractWeatherLocation returns the city he named, or the configured default
+// extractWeatherLocation returns the place he named, or the configured default
 // when he named none. It returns "" when he named none AND no default is
 // configured — the caller must then say it does not know.
 //
-// It used to return "Moscow" in that case. That is a made-up answer presented
-// as fact: reading out Moscow's temperature to someone who is not in Moscow is
-// wrong in exactly the way maven must never be wrong. voice.weather
-// .default_location is the only source of an unstated location.
+// It used to be a hand-written table of six cities in two spellings each
+// (Vikunja #421). Anything outside it — Kazan, Tbilisi — was dropped silently
+// and answered for the default location, which reads as a correct answer about
+// the wrong place. There is a geocoder behind this now: internal/weather
+// already calls Open-Meteo's geocoding endpoint for every lookup, so any place
+// it knows is a place he can ask about, and the table bought nothing.
+//
+// A named place that the geocoder cannot resolve is the caller's problem to
+// report, not this function's to hide.
+//
+// It used to return "Moscow" when he named nothing. That is a made-up answer
+// presented as fact. voice.weather.default_location is the only source of an
+// unstated location.
 func extractWeatherLocation(u, defaultLoc string) string {
-	lower := strings.ToLower(u)
-	for substr, name := range weatherCities {
-		if strings.Contains(lower, substr) {
-			return name
-		}
+	m := weatherPlace.FindStringSubmatch(u)
+	if m == nil {
+		return defaultLoc
 	}
-	return defaultLoc
+	place := strings.TrimSpace(m[1])
+	first := strings.ToLower(strings.Fields(place)[0])
+	if weatherNonPlaces[first] {
+		return defaultLoc
+	}
+	return place
 }

cmd/mavend/weatherq_test.go

@@ -0,0 +1,33 @@
+package main
+
+import "testing"
+
+// TestExtractWeatherLocation — any place he names comes through, not just the
+// six that used to be in a table (Vikunja #421).
+func TestExtractWeatherLocation(t *testing.T) {
+	cases := []struct {
+		utterance string
+		def       string
+		want      string
+	}{
+		// The cities the table had, and the ones it silently dropped.
+		{"какая погода в Москве", "Berlin", "Москве"},
+		{"какая погода в Казани", "Berlin", "Казани"},
+		{"погода в Тбилиси?", "Berlin", "Тбилиси"},
+		{"what's the weather in New York", "Berlin", "New York"},
+		{"тепло в Нижнем Новгороде?", "Berlin", "Нижнем Новгороде"},
+		// He named nothing: the configured default, and nothing at all when
+		// there is no default.
+		{"какая сегодня погода", "Berlin", "Berlin"},
+		{"какая сегодня погода", "", ""},
+		// "в" followed by something that is not a place stays the default —
+		// the house sensors and the day words answer elsewhere.
+		{"тепло в комнате?", "Berlin", "Berlin"},
+		{"какая погода в выходные", "Berlin", "Berlin"},
+	}
+	for _, c := range cases {
+		if got := extractWeatherLocation(c.utterance, c.def); got != c.want {
+			t.Errorf("extractWeatherLocation(%q, %q) = %q, want %q", c.utterance, c.def, got, c.want)
+		}
+	}
+}

internal/weather/openmeteo.go

@@ -97,7 +97,59 @@ func (p *OpenMeteoProvider) CurrentWeather(ctx context.Context, location string)
 	}, nil
 }
 
+// locationCandidates — the spellings to try for a place taken out of a spoken
+// sentence, in order. He says "какая погода в Казани", so the word arrives in
+// the prepositional case and the geocoder wants the nominative (Vikunja #421).
+//
+// Two cheap reversals cover most of what he says: a final "е" is usually a
+// nominative "а" (Москве → Москва) or nothing at all (Лондоне → Лондон), and a
+// final "и" is usually a soft sign (Казани → Казань). Indeclinable names —
+// Тбилиси, Сочи, Осло — are already nominative and the first candidate answers.
+//
+// Nothing here is a guess about the weather: a wrong candidate finds no city
+// and the caller says so. It only decides which strings are worth asking about.
+func locationCandidates(location string) []string {
+	out := []string{location}
+	add := func(s string) {
+		if s == "" || s == location {
+			return
+		}
+		for _, seen := range out {
+			if seen == s {
+				return
+			}
+		}
+		out = append(out, s)
+	}
+	r := []rune(location)
+	if len(r) < 4 {
+		return out
+	}
+	stem := string(r[:len(r)-1])
+	switch r[len(r)-1] {
+	case 'е', 'Е':
+		add(stem + "а")
+		add(stem)
+	case 'и', 'И':
+		add(stem + "ь")
+		add(stem)
+	case 'у', 'У', 'ю', 'Ю':
+		add(stem + "а")
+	}
+	return out
+}
+
 func (p *OpenMeteoProvider) geocode(ctx context.Context, location string) (lat, lon float64, name string, err error) {
+	for _, cand := range locationCandidates(location) {
+		lat, lon, name, err = p.geocodeOne(ctx, cand)
+		if err == nil {
+			return lat, lon, name, nil
+		}
+	}
+	return 0, 0, "", err
+}
+
+func (p *OpenMeteoProvider) geocodeOne(ctx context.Context, location string) (lat, lon float64, name string, err error) {
 	u := fmt.Sprintf("https://geocoding-api.open-meteo.com/v1/search?name=%s&count=1&language=ru&format=json", url.QueryEscape(location))
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
 	if err != nil {
@@ -121,7 +173,7 @@ func (p *OpenMeteoProvider) geocode(ctx context.Context, location string) (lat,
 	}
 
 	if len(geo.Results) == 0 {
-		return 0, 0, "", fmt.Errorf("location %q not found", location)
+		return 0, 0, "", fmt.Errorf("%w: %q", ErrLocationUnknown, location)
 	}
 
 	r := geo.Results[0]

internal/weather/openmeteo_test.go

@@ -83,3 +83,29 @@ func TestStubProvider(t *testing.T) {
 		t.Fatalf("StubProvider: want ErrNotConfigured, got %v", err)
 	}
 }
+
+// TestLocationCandidates — he speaks the prepositional case and the geocoder
+// wants the nominative (Vikunja #421).
+func TestLocationCandidates(t *testing.T) {
+	cases := map[string][]string{
+		"Москве":  {"Москве", "Москва", "Москв"},
+		"Казани":  {"Казани", "Казань", "Казан"},
+		"Лондоне": {"Лондоне", "Лондона", "Лондон"},
+		"Тбилиси": {"Тбилиси", "Тбились", "Тбилис"},
+		"Berlin":  {"Berlin"},
+		"Уфе":     {"Уфе"}, // too short to strip — asked as spoken
+	}
+	for in, want := range cases {
+		got := locationCandidates(in)
+		if len(got) != len(want) {
+			t.Errorf("locationCandidates(%q) = %v, want %v", in, got, want)
+			continue
+		}
+		for i := range got {
+			if got[i] != want[i] {
+				t.Errorf("locationCandidates(%q) = %v, want %v", in, got, want)
+				break
+			}
+		}
+	}
+}

internal/weather/weather.go

@@ -7,6 +7,13 @@ import (
 
 var ErrNotConfigured = errors.New("weather: not configured")
 
+// ErrLocationUnknown — the geocoder has no such place. A named city that does
+// not resolve must read differently from a provider outage: one is "I do not
+// know that place", the other is "I could not reach the service", and
+// answering for the default location instead is the defect this replaces
+// (Vikunja #421).
+var ErrLocationUnknown = errors.New("weather: location not found")
+
 type Weather struct {
 	Location    string  `json:"location"`
 	Temperature float64 `json:"temperature"`