initial commit

backend/internal/store/storage.go

@@ -0,0 +1,190 @@
+package store
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/uuid"
+	"reichard.io/aethera/pkg/slices"
+)
+
+var _ Store = (*FileStore)(nil)
+
+// Settings represents the application settings
+type Settings struct {
+	APIEndpoint             string `json:"api_endpoint,omitempty"`
+	ImageEditSelector       string `json:"image_edit_selector,omitempty"`
+	ImageGenerationSelector string `json:"image_generation_selector,omitempty"`
+	TextGenerationSelector  string `json:"text_generation_selector,omitempty"`
+}
+
+// FileStore implements the Store interface using a file-based storage
+type FileStore struct {
+	filePath string
+	chatDir  string
+}
+
+// NewFileStore creates a new FileStore with the specified file path
+func NewFileStore(filePath string) (*FileStore, error) {
+	// Derive Chat Directory
+	chatDir := filepath.Join(filepath.Dir(filePath), "chats")
+
+	// Ensure Chat Directory Exists
+	if err := os.MkdirAll(chatDir, 0755); err != nil {
+		return nil, fmt.Errorf("failed to create directory: %w", err)
+	}
+
+	return &FileStore{
+		filePath: filePath,
+		chatDir:  chatDir,
+	}, nil
+}
+
+// GetSettings reads and returns the settings from the file
+func (fs *FileStore) GetSettings() (*Settings, error) {
+	data, err := os.ReadFile(fs.filePath)
+	if err != nil {
+		return &Settings{}, nil
+	}
+
+	var settings Settings
+	err = json.Unmarshal(data, &settings)
+	if err != nil {
+		return nil, err
+	}
+
+	return &settings, nil
+}
+
+// SaveSettings saves the settings to the file
+func (fs *FileStore) SaveSettings(settings *Settings) error {
+	data, err := json.MarshalIndent(settings, "", "  ")
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(fs.filePath, data, 0644)
+}
+
+// GetChat retrieves a chat from disk
+func (fs *FileStore) GetChat(chatID uuid.UUID) (*Chat, error) {
+	filePath := filepath.Join(fs.chatDir, chatID.String()+".json")
+
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrChatNotFound
+		}
+		return nil, fmt.Errorf("failed to read chat: %w", err)
+	}
+
+	var chat Chat
+	if err := json.Unmarshal(data, &chat); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal chat: %w", err)
+	}
+
+	return &chat, nil
+}
+
+// SaveChat creates or updates a chat and persists it to disk
+func (fs *FileStore) SaveChat(c *Chat) error {
+	c.ensureDefaults()
+	return fs.saveChatSession(c)
+}
+
+// DeleteChat removes a chat from disk
+func (fs *FileStore) DeleteChat(chatID uuid.UUID) error {
+	filePath := filepath.Join(fs.chatDir, chatID.String()+".json")
+
+	if _, err := os.Stat(filePath); os.IsNotExist(err) {
+		return ErrChatNotFound
+	}
+
+	if err := os.Remove(filePath); err != nil {
+		return fmt.Errorf("failed to delete chat: %w", err)
+	}
+
+	return nil
+}
+
+// ListChats returns all persisted chats
+func (fs *FileStore) ListChats() ([]*Chat, error) {
+	// Read Files
+	entries, err := os.ReadDir(fs.chatDir)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read chat directory: %w", err)
+	}
+
+	var chats []*Chat
+	for _, entry := range entries {
+		// Ensure JSON
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".json") {
+			continue
+		}
+
+		// Extract Chat ID
+		rawChatID := strings.TrimSuffix(entry.Name(), ".json")
+		chatID, err := uuid.Parse(rawChatID)
+		if err != nil {
+			return nil, fmt.Errorf("%w: invalid chat id %s", err, rawChatID)
+		}
+
+		// Read & Parse Chat
+		chat, err := fs.GetChat(chatID)
+		if err != nil {
+			return nil, fmt.Errorf("%w: failed to read chat id %s", err, rawChatID)
+		}
+
+		chats = append(chats, chat)
+	}
+
+	return chats, nil
+}
+
+// SaveChatMessage creates or updates a chat message to a chat and persists it to disk
+func (fs *FileStore) SaveChatMessage(m *Message) error {
+	if m.ChatID == uuid.Nil {
+		return ErrNilChatID
+	}
+	m.ensureDefaults()
+
+	// Get Chat
+	chat, err := fs.GetChat(m.ChatID)
+	if err != nil {
+		return err
+	}
+
+	// Find Existing
+	existingMsg, found := slices.FindFirst(chat.Messages, func(item *Message) bool {
+		return item.ID == m.ID
+	})
+
+	// Upsert
+	if found {
+		*existingMsg = *m
+	} else {
+		chat.Messages = append(chat.Messages, m)
+	}
+
+	// Save
+	return fs.saveChatSession(chat)
+}
+
+// saveChatSession is a helper method to save a chat to disk
+func (fs *FileStore) saveChatSession(session *Chat) error {
+	filePath := filepath.Join(fs.chatDir, session.ID.String()+".json")
+
+	data, err := json.MarshalIndent(session, "", "  ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal chat: %w", err)
+	}
+
+	if err := os.WriteFile(filePath, data, 0644); err != nil {
+		return fmt.Errorf("failed to write chat file: %w", err)
+	}
+
+	return nil
+}