package config

import (
	"os"
	"testing"
)

// Config is read once at startup, so a mistyped env key fails silently: the
// service boots on a default and points at the wrong host, or ships with a
// security switch left off. Cheap to pin.

func setEnv(t *testing.T, key, value string) {
	t.Helper()
	previous, had := os.LookupEnv(key)
	if value == "" {
		_ = os.Unsetenv(key)
	} else {
		_ = os.Setenv(key, value)
	}
	t.Cleanup(func() {
		if had {
			_ = os.Setenv(key, previous)
		} else {
			_ = os.Unsetenv(key)
		}
	})
}

// The geocoder settings added for the customer app. GEOCODER_URL is what the
// place search proxies through — the app is never handed a map key, after the
// legacy rider app's key had to be revoked.
func TestGeocoderDefaultsAndOverrides(t *testing.T) {
	setEnv(t, "GEOCODER_URL", "")
	setEnv(t, "GEOCODER_EMAIL", "")

	cfg := Load()
	if cfg.GeocoderURL != "https://nominatim.openstreetmap.org" {
		t.Errorf("GeocoderURL default = %q, want the Nominatim host", cfg.GeocoderURL)
	}
	if cfg.GeocoderEmail != "" {
		t.Errorf("GeocoderEmail default = %q, want empty", cfg.GeocoderEmail)
	}

	setEnv(t, "GEOCODER_URL", "https://nominatim.internal")
	setEnv(t, "GEOCODER_EMAIL", "ops@doormile.com")

	cfg = Load()
	if cfg.GeocoderURL != "https://nominatim.internal" {
		t.Errorf("GEOCODER_URL was not read: got %q", cfg.GeocoderURL)
	}
	if cfg.GeocoderEmail != "ops@doormile.com" {
		t.Errorf("GEOCODER_EMAIL was not read: got %q", cfg.GeocoderEmail)
	}
}

// Every env key the service reads must actually take effect. A typo in the key
// name means the override is ignored and the default is used — which is how a
// deploy silently points at the wrong database.
func TestEnvironmentOverridesAreRead(t *testing.T) {
	cases := []struct {
		key   string
		value string
		read  func(*Config) string
	}{
		{"ENV", "production", func(c *Config) string { return c.Env }},
		{"APP_PORT", "9999", func(c *Config) string { return c.Port }},
		{"DB_HOST", "db.internal", func(c *Config) string { return c.DBHost }},
		{"DB_NAME", "logistics_staging", func(c *Config) string { return c.DBName }},
		{"DB_PORT", "6543", func(c *Config) string { return c.DBPort }},
		{"REDIS_HOST", "redis.internal", func(c *Config) string { return c.RedisHost }},
		{"JWT_SECRET_KEY", "a-different-secret", func(c *Config) string { return c.JWTSecret }},
		{"TRUSTED_PROXIES", "10.0.0.0/8", func(c *Config) string { return c.TrustedProxies }},
		{"AI_LAYER_BASE_URL", "http://ai.internal", func(c *Config) string { return c.AILayerBaseURL }},
		{"ROUTE_OPTIMIZER_URL", "http://routes.internal", func(c *Config) string { return c.RouteOptimizerURL }},
	}

	for _, tc := range cases {
		setEnv(t, tc.key, tc.value)
		if got := tc.read(Load()); got != tc.value {
			t.Errorf("%s set to %q but Load() read %q", tc.key, tc.value, got)
		}
	}
}

// Production must not boot on a secret whose fallback is committed to the repo.
func TestMissingProductionSecrets(t *testing.T) {
	setEnv(t, "ENV", "production")
	setEnv(t, "JWT_SECRET_KEY", "")
	setEnv(t, "DB_PASSWORD", "set")
	setEnv(t, "NATS_PASSWORD", "")

	got := Load().MissingProductionSecrets()
	if len(got) != 2 || got[0] != "JWT_SECRET_KEY" || got[1] != "NATS_PASSWORD" {
		t.Fatalf("missing = %v, want [JWT_SECRET_KEY NATS_PASSWORD]", got)
	}

	setEnv(t, "JWT_SECRET_KEY", "set")
	setEnv(t, "NATS_PASSWORD", "set")
	if got := Load().MissingProductionSecrets(); len(got) != 0 {
		t.Errorf("all secrets set, still reported missing: %v", got)
	}
}

// Outside production the fallbacks are allowed, so local development runs
// with no .env at all.
func TestMissingProductionSecretsIgnoredOutsideProduction(t *testing.T) {
	setEnv(t, "JWT_SECRET_KEY", "")
	setEnv(t, "DB_PASSWORD", "")
	setEnv(t, "NATS_PASSWORD", "")
	for _, env := range []string{"", "development", "staging"} {
		setEnv(t, "ENV", env)
		if got := Load().MissingProductionSecrets(); len(got) != 0 {
			t.Errorf("ENV=%q reported missing secrets %v; only production should", env, got)
		}
	}
}

// An empty env var must fall through to the default rather than blanking the
// setting — an empty DB host is a service that cannot start with no clue why.
func TestEmptyEnvFallsBackToTheDefault(t *testing.T) {
	setEnv(t, "DB_NAME", "")
	if got := Load().DBName; got == "" {
		t.Error("DBName is empty when DB_NAME is unset; a default is required")
	}
}