Initial commit.

config.go

@@ -0,0 +1,85 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+// Config holds all tunable parameters for the ingest engine.
+type Config struct {
+	// WebSocket endpoint for Bybit V5 public linear trades.
+	WebSocketURL string `json:"websocket_url"`
+
+	// Symbol to subscribe to.
+	Symbol string `json:"symbol"`
+
+	// DataDir is the base directory for all database files.
+	DataDir string `json:"data_dir"`
+
+	// HotRetentionHours is how many hours of raw ticks to keep in the hot DB.
+	HotRetentionHours int `json:"hot_retention_hours"`
+
+	// FeatureRetentionDays is how many days of 5s features to keep.
+	FeatureRetentionDays int `json:"feature_retention_days"`
+
+	// WriterFlushIntervalMs is how often (ms) the batch writer flushes to disk.
+	WriterFlushIntervalMs int `json:"writer_flush_interval_ms"`
+
+	// WriterBatchSize is the max number of ticks before a forced flush.
+	WriterBatchSize int `json:"writer_batch_size"`
+
+	// TickChannelBuffer is the capacity of the tick channel between WS reader and DB writer.
+	TickChannelBuffer int `json:"tick_channel_buffer"`
+
+	// MaintenanceIntervalMinutes controls how often the hourly maintenance runs.
+	MaintenanceIntervalMinutes int `json:"maintenance_interval_minutes"`
+}
+
+// DefaultConfig returns a Config populated with sensible defaults.
+func DefaultConfig() Config {
+	return Config{
+		WebSocketURL:               "wss://stream.bybit.com/v5/public/linear",
+		Symbol:                     "BTCUSDT",
+		DataDir:                    "data",
+		HotRetentionHours:          12,
+		FeatureRetentionDays:       30,
+		WriterFlushIntervalMs:      500,
+		WriterBatchSize:            100,
+		TickChannelBuffer:          10000,
+		MaintenanceIntervalMinutes: 60,
+	}
+}
+
+// LoadConfig reads a JSON config file and merges with defaults.
+// If the file does not exist, defaults are returned and a config file is written.
+func LoadConfig(path string) (Config, error) {
+	cfg := DefaultConfig()
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Write default config for user reference
+			if writeErr := writeDefaultConfig(path, cfg); writeErr != nil {
+				return cfg, fmt.Errorf("failed to write default config: %w", writeErr)
+			}
+			fmt.Printf("No config found, wrote defaults to %s\n", path)
+			return cfg, nil
+		}
+		return cfg, fmt.Errorf("failed to read config: %w", err)
+	}
+
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return cfg, fmt.Errorf("failed to parse config: %w", err)
+	}
+
+	return cfg, nil
+}
+
+func writeDefaultConfig(path string, cfg Config) error {
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, data, 0644)
+}