package config

import "os"

// Config holds runtime configuration for the TTS gRPC gateway.
type Config struct {
	GRPCPort     string // GRPC_PORT, default "50053"
	TLSDir       string // TLS_DIR, empty disables mTLS for local dev
	OTELEndpoint string // OTEL_ENDPOINT, e.g. "otel-collector.monitoring.svc:4317"
	LogLevel     string // LOG_LEVEL, default "info"
	LogFormat    string // LOG_FORMAT, default "json"

	OpenJTalkBin     string // OPEN_JTALK_BIN, default "open_jtalk"
	OpenJTalkDictDir string // OPEN_JTALK_DICT_DIR, empty auto-discovers under /usr and /var
	OpenJTalkVoice   string // OPEN_JTALK_VOICE, empty auto-discovers the first *.htsvoice found

	InferenceSidecarAddr string // INFERENCE_SIDECAR_ADDR, e.g. "localhost:50054"
}

// Load reads configuration from environment variables and applies defaults.
func Load() (*Config, error) {
	return &Config{
		GRPCPort:     getenvDefault("GRPC_PORT", "50053"),
		TLSDir:       os.Getenv("TLS_DIR"),
		OTELEndpoint: os.Getenv("OTEL_ENDPOINT"),
		LogLevel:     getenvDefault("LOG_LEVEL", "info"),
		LogFormat:    getenvDefault("LOG_FORMAT", "json"),

		OpenJTalkBin:     getenvDefault("OPEN_JTALK_BIN", "open_jtalk"),
		OpenJTalkDictDir: os.Getenv("OPEN_JTALK_DICT_DIR"),
		OpenJTalkVoice:   os.Getenv("OPEN_JTALK_VOICE"),

		InferenceSidecarAddr: getenvDefault("INFERENCE_SIDECAR_ADDR", "localhost:50054"),
	}, nil
}

// getenvDefault keeps config loading concise for optional variables with defaults.
func getenvDefault(key, fallback string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return fallback
}