Refactor project structure and enhance logging

internal/db/db.go

@@ -1,254 +1,320 @@
 package internal
 
 import (
+	"compress/gzip"
 	"context"
-	"errors"
+	"crypto/md5"
 	"fmt"
-	"log"
+	"io"
 	"net"
+	"net/http"
 	"os"
-	"os/exec"
+	"strings"
 	"sync"
 	"time"
 
+	"skidoodle/ipinfo/internal/logger"
+
 	"github.com/oschwald/maxminddb-golang"
+	"github.com/pkg/errors"
 )
 
-// Database paths
+// Constants for database names and paths
 const (
-	CityDBPath = "./GeoLite2-City.mmdb"
-	ASNDBPath  = "./GeoLite2-ASN.mmdb"
+	CityDBName  = "GeoLite2-City"
+	ASNDBName   = "GeoLite2-ASN"
+	DBExtension = ".mmdb"
+	CityDBPath  = CityDBName + DBExtension
+	ASNDBPath   = ASNDBName + DBExtension
 )
 
-// Common errors
+// Error messages
 var (
 	ErrDatabaseNotFound = errors.New("database file not found")
 	ErrDatabaseOpen     = errors.New("failed to open database")
 	ErrDownloadFailed   = errors.New("failed to download database")
 )
 
+// ASNRecord represents a record in the ASN database
 type ASNRecord struct {
 	AutonomousSystemNumber       uint   `maxminddb:"autonomous_system_number"`
 	AutonomousSystemOrganization string `maxminddb:"autonomous_system_organization"`
 }
 
-// Handles MaxMind GeoIP database operations
+// GeoIPManager manages the GeoIP databases
 type GeoIPManager struct {
 	cityDB       *maxminddb.Reader
 	asnDB        *maxminddb.Reader
 	asnPrefixMap map[uint][]*net.IPNet
+	httpClient   *http.Client
 	mu           sync.RWMutex
 }
 
-// Creates and initializes a new GeoIP database
+// NewGeoIPManager creates a new GeoIPManager
 func NewGeoIPManager() (*GeoIPManager, error) {
-	manager := &GeoIPManager{}
+	manager := &GeoIPManager{
+		httpClient: &http.Client{Timeout: 2 * time.Minute},
+	}
 	if err := manager.Initialize(); err != nil {
 		return nil, fmt.Errorf("initializing GeoIP manager: %w", err)
 	}
 	return manager, nil
 }
 
-// Initialize opens the GeoIP databases, downloading them if necessary
+// Initialize initializes the GeoIPManager by opening the database files
 func (g *GeoIPManager) Initialize() error {
 	g.mu.Lock()
 	defer g.mu.Unlock()
 
-	if err := g.openCityDB(); err != nil {
+	if err := g.openDB(CityDBPath); err != nil {
 		return err
 	}
-
-	if err := g.openASNDB(); err != nil {
+	if err := g.openDB(ASNDBPath); err != nil {
 		return err
 	}
 
 	g.buildASNPrefixMap()
-
 	return nil
 }
 
-// buildASNPrefixMap iterates the ASN database once and builds the lookup map.
+// openDB opens a MaxMind DB file
+func (g *GeoIPManager) openDB(path string) error {
+	db, err := maxminddb.Open(path)
+	if err == nil {
+		if path == CityDBPath {
+			g.cityDB = db
+		} else {
+			g.asnDB = db
+		}
+		return nil
+	}
+
+	if !os.IsNotExist(err) {
+		return errors.Wrapf(ErrDatabaseOpen, "failed to open %s: %v", path, err)
+	}
+
+	logger.Log.Info("Database not found, attempting initial download", "path", path)
+	if err := g.DownloadDatabases(context.Background()); err != nil {
+		return errors.Wrap(ErrDownloadFailed, err.Error())
+	}
+
+	db, err = maxminddb.Open(path)
+	if err != nil {
+		return errors.Wrapf(ErrDatabaseOpen, "failed to open %s after download: %v", path, err)
+	}
+
+	if path == CityDBPath {
+		g.cityDB = db
+	} else {
+		g.asnDB = db
+	}
+	return nil
+}
+
+// buildASNPrefixMap builds a map of ASN prefixes for fast lookups
 func (g *GeoIPManager) buildASNPrefixMap() {
-	log.Println("Building ASN prefix map for fast lookups...")
+	logger.Log.Info("Building ASN prefix map for fast lookups...")
 	startTime := time.Now()
-
 	g.asnPrefixMap = make(map[uint][]*net.IPNet)
+	if g.asnDB == nil {
+		logger.Log.Warn("ASN database is not available, skipping prefix map build")
+		return
+	}
 	networks := g.asnDB.Networks()
-
 	for networks.Next() {
 		var record ASNRecord
 		subnet, err := networks.Network(&record)
 		if err != nil {
-			continue // Skip records that fail to decode
+			continue
 		}
 		if record.AutonomousSystemNumber > 0 {
 			g.asnPrefixMap[record.AutonomousSystemNumber] = append(g.asnPrefixMap[record.AutonomousSystemNumber], subnet)
 		}
 	}
-	log.Printf("Finished building ASN prefix map in %v", time.Since(startTime))
+	logger.Log.Info("Finished building ASN prefix map", "duration", time.Since(startTime))
 }
 
-// Opens the city database, downloading it if necessary
-func (g *GeoIPManager) openCityDB() error {
-	var err error
-	g.cityDB, err = maxminddb.Open(CityDBPath)
-	if err != nil {
-		if os.IsNotExist(err) {
-			log.Println("City database not found, attempting to download...")
-			if err := g.downloadDatabases(); err != nil {
-				return fmt.Errorf("%w: %v", ErrDownloadFailed, err)
+// DownloadDatabases downloads the GeoIP databases
+func (g *GeoIPManager) DownloadDatabases(ctx context.Context) error {
+	accountID := os.Getenv("GEOIPUPDATE_ACCOUNT_ID")
+	licenseKey := os.Getenv("GEOIPUPDATE_LICENSE_KEY")
+	if accountID == "" || licenseKey == "" {
+		return errors.New("GEOIPUPDATE_ACCOUNT_ID and GEOIPUPDATE_LICENSE_KEY must be set")
+	}
+
+	editionIDs := os.Getenv("GEOIPUPDATE_EDITION_IDS")
+	if editionIDs == "" {
+		editionIDs = "GeoLite2-City GeoLite2-ASN"
+	}
+
+	var firstError error
+	for _, editionID := range strings.Fields(editionIDs) {
+		if err := g.downloadEdition(ctx, accountID, licenseKey, editionID); err != nil {
+			logger.Log.Error("Failed to download edition", "edition", editionID, "error", err)
+			if firstError == nil {
+				firstError = err
 			}
-			g.cityDB, err = maxminddb.Open(CityDBPath)
-			if err != nil {
-				return fmt.Errorf("%w (city): %v", ErrDatabaseOpen, err)
-			}
-			return nil
 		}
-		return fmt.Errorf("%w (city): %v", ErrDatabaseOpen, err)
 	}
-	return nil
+	return firstError
 }
 
-// Opens the ASN database, downloading it if necessary
-func (g *GeoIPManager) openASNDB() error {
-	var err error
-	g.asnDB, err = maxminddb.Open(ASNDBPath)
+// downloadEdition downloads a specific GeoIP database edition
+func (g *GeoIPManager) downloadEdition(ctx context.Context, accountID, licenseKey, editionID string) error {
+	dbPath := editionID + DBExtension
+	logger.Log.Info("Checking for updates", "database", dbPath)
+
+	hash, err := fileMD5(dbPath)
+	if err != nil && !os.IsNotExist(err) {
+		return errors.Wrapf(err, "could not calculate MD5 for %s", dbPath)
+	}
+
+	downloadURL := fmt.Sprintf("https://updates.maxmind.com/geoip/databases/%s/update?db_md5=%s", editionID, hash)
+	req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
 	if err != nil {
-		if os.IsNotExist(err) {
-			log.Println("ASN database not found, attempting to download...")
-			if err := g.downloadDatabases(); err != nil {
-				return fmt.Errorf("%w: %v", ErrDownloadFailed, err)
-			}
-			g.asnDB, err = maxminddb.Open(ASNDBPath)
-			if err != nil {
-				return fmt.Errorf("%w (ASN): %v", ErrDatabaseOpen, err)
-			}
-			return nil
-		}
-		return fmt.Errorf("%w (ASN): %v", ErrDatabaseOpen, err)
+		return errors.Wrap(err, "could not create request")
 	}
-	return nil
-}
+	req.SetBasicAuth(accountID, licenseKey)
 
-// Downloads both GeoIP databases using geoipupdate
-func (g *GeoIPManager) downloadDatabases() error {
-	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
-	defer cancel()
-
-	cmd := exec.CommandContext(ctx, "geoipupdate", "-d", "./")
-	output, err := cmd.CombinedOutput()
+	resp, err := g.httpClient.Do(req)
 	if err != nil {
-		return fmt.Errorf("failed to download databases: %v. Output: %s. Ensure geoipupdate is installed and configured", err, output)
+		return errors.Wrap(err, "http request failed")
 	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotModified {
+		logger.Log.Info("Database is already up to date", "database", dbPath)
+		return nil
+	}
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("received non-200 status code: %d - %s", resp.StatusCode, string(body))
+	}
+
+	logger.Log.Info("Downloading and decompressing new version", "database", dbPath)
+
+	gzr, err := gzip.NewReader(resp.Body)
+	if err != nil {
+		return errors.Wrap(err, "could not create gzip reader")
+	}
+	defer gzr.Close()
+
+	tmpPath := dbPath + ".tmp"
+	outFile, err := os.Create(tmpPath)
+	if err != nil {
+		return errors.Wrap(err, "could not create temporary file")
+	}
+	defer outFile.Close()
+
+	if _, err := io.Copy(outFile, gzr); err != nil {
+		os.Remove(tmpPath)
+		return errors.Wrap(err, "could not decompress and write db file")
+	}
+
+	if err := os.Rename(tmpPath, dbPath); err != nil {
+		return errors.Wrap(err, "could not replace database file")
+	}
+
+	logger.Log.Info("Successfully downloaded and updated", "database", dbPath)
 	return nil
 }
 
-// Close properly closes the database readers
-func (g *GeoIPManager) Close() error {
+// UpdateDatabases updates the GeoIP databases
+func (g *GeoIPManager) UpdateDatabases() error {
+	if err := g.DownloadDatabases(context.Background()); err != nil {
+		return err
+	}
+
 	g.mu.Lock()
 	defer g.mu.Unlock()
 
-	var errs []error
-
 	if g.cityDB != nil {
-		if err := g.cityDB.Close(); err != nil {
-			errs = append(errs, fmt.Errorf("closing city database: %w", err))
-		}
+		g.cityDB.Close()
 	}
-
 	if g.asnDB != nil {
-		if err := g.asnDB.Close(); err != nil {
-			errs = append(errs, fmt.Errorf("closing ASN database: %w", err))
-		}
+		g.asnDB.Close()
 	}
 
-	if len(errs) > 0 {
-		return fmt.Errorf("errors closing databases: %v", errs)
+	var openErr error
+	g.cityDB, openErr = maxminddb.Open(CityDBPath)
+	if openErr != nil {
+		return errors.Wrap(openErr, "reopening city database")
 	}
+
+	g.asnDB, openErr = maxminddb.Open(ASNDBPath)
+	if openErr != nil {
+		return errors.Wrap(openErr, "reopening ASN database")
+	}
+
+	g.buildASNPrefixMap()
+	logger.Log.Info("Successfully reloaded GeoIP databases")
 	return nil
 }
 
-// Safely provides read access to the City database
-func (g *GeoIPManager) GetCityDB() *maxminddb.Reader {
-	g.mu.RLock()
-	defer g.mu.RUnlock()
-	return g.cityDB
-}
-
-// Safely provides read access to the ASN database
-func (g *GeoIPManager) GetASNDB() *maxminddb.Reader {
-	g.mu.RLock()
-	defer g.mu.RUnlock()
-	return g.asnDB
-}
-
-// GetASNPrefixes returns the pre-computed list of prefixes for an ASN.
-func (g *GeoIPManager) GetASNPrefixes(asn uint) []*net.IPNet {
-	g.mu.RLock()
-	defer g.mu.RUnlock()
-	return g.asnPrefixMap[asn]
-}
-
-// Sets up automatic database updates
+// StartUpdater starts a background updater for the GeoIP databases
 func (g *GeoIPManager) StartUpdater(ctx context.Context, updateInterval time.Duration) {
-	log.Printf("Starting MaxMind GeoIP database updater with interval: %s", updateInterval)
-
+	logger.Log.Info("Starting MaxMind GeoIP database updater", "interval", updateInterval.String())
 	ticker := time.NewTicker(updateInterval)
 	go func() {
 		for {
 			select {
 			case <-ticker.C:
-				log.Println("Performing scheduled GeoIP database update")
+				logger.Log.Info("Performing scheduled GeoIP database update")
 				if err := g.UpdateDatabases(); err != nil {
-					log.Printf("Failed to update databases: %v", err)
+					logger.Log.Error("Failed to update databases", "error", err)
 				}
 			case <-ctx.Done():
 				ticker.Stop()
-				log.Println("GeoIP database updater stopped")
+				logger.Log.Info("GeoIP database updater stopped")
 				return
 			}
 		}
 	}()
 }
 
-// Downloads fresh copies of the databases and reloads them
-func (g *GeoIPManager) UpdateDatabases() error {
-	// Download new databases
-	if err := g.downloadDatabases(); err != nil {
-		return err
-	}
-
+// Close closes the GeoIP database readers
+func (g *GeoIPManager) Close() {
 	g.mu.Lock()
 	defer g.mu.Unlock()
-
-	// Close existing databases
 	if g.cityDB != nil {
-		if err := g.cityDB.Close(); err != nil {
-			log.Printf("Warning: error closing city database: %v", err)
-		}
+		g.cityDB.Close()
 	}
-
 	if g.asnDB != nil {
-		if err := g.asnDB.Close(); err != nil {
-			log.Printf("Warning: error closing ASN database: %v", err)
-		}
+		g.asnDB.Close()
 	}
-
-	// Reopen databases
-	var err error
-	g.cityDB, err = maxminddb.Open(CityDBPath)
-	if err != nil {
-		return fmt.Errorf("reopening city database: %w", err)
-	}
-
-	g.asnDB, err = maxminddb.Open(ASNDBPath)
-	if err != nil {
-		return fmt.Errorf("reopening ASN database: %w", err)
-	}
-
-	// Rebuild the prefix map with the new data.
-	g.buildASNPrefixMap()
-
-	log.Println("Successfully updated and reloaded GeoIP databases")
-	return nil
+}
+
+// GetCityDB retrieves the city database reader
+func (g *GeoIPManager) GetCityDB() *maxminddb.Reader {
+	g.mu.RLock()
+	defer g.mu.RUnlock()
+	return g.cityDB
+}
+
+// GetASNDB retrieves the ASN database reader
+func (g *GeoIPManager) GetASNDB() *maxminddb.Reader {
+	g.mu.RLock()
+	defer g.mu.RUnlock()
+	return g.asnDB
+}
+
+// GetASNPrefixes retrieves the list of IP prefixes for a given ASN
+func (g *GeoIPManager) GetASNPrefixes(asn uint) []*net.IPNet {
+	g.mu.RLock()
+	defer g.mu.RUnlock()
+	return g.asnPrefixMap[asn]
+}
+
+// fileMD5 calculates the MD5 hash of a file
+func fileMD5(path string) (string, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+	hash := md5.New()
+	if _, err := io.Copy(hash, file); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%x", hash.Sum(nil)), nil
 }