Initial commit

Signed-off-by: Thomas Klaehn <thomas.klaehn@perinet.io>

internal/state/state.go

@@ -0,0 +1,166 @@
+package state
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+// ActivityInfo holds information about a downloaded activity
+type ActivityInfo struct {
+	ID               int64     `json:"id"`
+	Name             string    `json:"name"`
+	Date             time.Time `json:"date"`
+	FilePath         string    `json:"file_path"`
+	DownloadedAt     time.Time `json:"downloaded_at"`
+	SportType        string    `json:"sport_type,omitempty"`
+}
+
+// State manages the persistent state of downloaded activities
+type State struct {
+	DownloadedActivities map[int64]ActivityInfo `json:"downloaded_activities"`
+	LastCheck            time.Time              `json:"last_check"`
+	TotalDownloaded      int                    `json:"total_downloaded"`
+
+	filePath string
+	mu       sync.RWMutex
+}
+
+// New creates a new State instance
+func New(filePath string) *State {
+	return &State{
+		DownloadedActivities: make(map[int64]ActivityInfo),
+		LastCheck:            time.Time{},
+		TotalDownloaded:      0,
+		filePath:             filePath,
+	}
+}
+
+// Load loads state from JSON file
+func (s *State) Load() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	// Check if file exists
+	if _, err := os.Stat(s.filePath); os.IsNotExist(err) {
+		// File doesn't exist, start with empty state
+		return nil
+	}
+
+	// Read file
+	data, err := os.ReadFile(s.filePath)
+	if err != nil {
+		return fmt.Errorf("failed to read state file: %w", err)
+	}
+
+	// Unmarshal JSON
+	if err := json.Unmarshal(data, s); err != nil {
+		// Try to backup corrupted file
+		backupPath := s.filePath + ".backup"
+		_ = os.WriteFile(backupPath, data, 0600)
+		return fmt.Errorf("failed to unmarshal state file (backed up to %s): %w", backupPath, err)
+	}
+
+	return nil
+}
+
+// Save saves state to JSON file
+func (s *State) Save() error {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	// Create directory if it doesn't exist
+	dir := filepath.Dir(s.filePath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return fmt.Errorf("failed to create state directory: %w", err)
+	}
+
+	// Marshal to JSON
+	data, err := json.MarshalIndent(s, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal state: %w", err)
+	}
+
+	// Write to temporary file first (atomic write)
+	tmpFile := s.filePath + ".tmp"
+	if err := os.WriteFile(tmpFile, data, 0600); err != nil {
+		return fmt.Errorf("failed to write temporary state file: %w", err)
+	}
+
+	// Rename temporary file to actual file (atomic operation)
+	if err := os.Rename(tmpFile, s.filePath); err != nil {
+		return fmt.Errorf("failed to rename temporary state file: %w", err)
+	}
+
+	return nil
+}
+
+// IsDownloaded checks if an activity has already been downloaded
+func (s *State) IsDownloaded(activityID int64) bool {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	_, exists := s.DownloadedActivities[activityID]
+	return exists
+}
+
+// MarkDownloaded marks an activity as downloaded
+func (s *State) MarkDownloaded(info ActivityInfo) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.DownloadedActivities[info.ID] = info
+	s.TotalDownloaded++
+	s.LastCheck = time.Now()
+
+	// Save state after marking downloaded
+	return s.save()
+}
+
+// UpdateLastCheck updates the last check timestamp
+func (s *State) UpdateLastCheck() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.LastCheck = time.Now()
+	return s.save()
+}
+
+// GetStats returns statistics about downloaded activities
+func (s *State) GetStats() (totalDownloaded int, lastCheck time.Time) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	return s.TotalDownloaded, s.LastCheck
+}
+
+// save is an internal method that saves without locking (assumes lock is held)
+func (s *State) save() error {
+	// Create directory if it doesn't exist
+	dir := filepath.Dir(s.filePath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return fmt.Errorf("failed to create state directory: %w", err)
+	}
+
+	// Marshal to JSON
+	data, err := json.MarshalIndent(s, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal state: %w", err)
+	}
+
+	// Write to temporary file first (atomic write)
+	tmpFile := s.filePath + ".tmp"
+	if err := os.WriteFile(tmpFile, data, 0600); err != nil {
+		return fmt.Errorf("failed to write temporary state file: %w", err)
+	}
+
+	// Rename temporary file to actual file (atomic operation)
+	if err := os.Rename(tmpFile, s.filePath); err != nil {
+		return fmt.Errorf("failed to rename temporary state file: %w", err)
+	}
+
+	return nil
+}