feat: refactor

internal/downloader/config.go

@@ -0,0 +1,58 @@
+package downloader
+
+import (
+	"os"
+	"strconv"
+	"time"
+)
+
+// Config holds downloader configuration, loaded from environment variables.
+type Config struct {
+	// DataDir is the directory for storing dataset files and temporary GRIB data.
+	DataDir string
+
+	// Parallel is the maximum number of concurrent GRIB downloads.
+	Parallel int
+
+	// UpdateInterval is how often the scheduler checks for new forecast data.
+	UpdateInterval time.Duration
+
+	// DatasetTTL is how long a dataset is considered fresh before a new one is needed.
+	DatasetTTL time.Duration
+}
+
+// DefaultConfig returns the default configuration.
+func DefaultConfig() *Config {
+	return &Config{
+		DataDir:        "/tmp/predictor-data",
+		Parallel:       8,
+		UpdateInterval: 6 * time.Hour,
+		DatasetTTL:     48 * time.Hour,
+	}
+}
+
+// LoadConfig loads configuration from environment variables, falling back to defaults.
+func LoadConfig() *Config {
+	cfg := DefaultConfig()
+
+	if v := os.Getenv("PREDICTOR_DATA_DIR"); v != "" {
+		cfg.DataDir = v
+	}
+	if v := os.Getenv("PREDICTOR_DOWNLOAD_PARALLEL"); v != "" {
+		if n, err := strconv.Atoi(v); err == nil && n > 0 {
+			cfg.Parallel = n
+		}
+	}
+	if v := os.Getenv("PREDICTOR_UPDATE_INTERVAL"); v != "" {
+		if d, err := time.ParseDuration(v); err == nil {
+			cfg.UpdateInterval = d
+		}
+	}
+	if v := os.Getenv("PREDICTOR_DATASET_TTL"); v != "" {
+		if d, err := time.ParseDuration(v); err == nil {
+			cfg.DatasetTTL = d
+		}
+	}
+
+	return cfg
+}