(Feat): Initial Commit, Termdoku

internal/savegame/persistence.go

@@ -0,0 +1,91 @@
+package savegame
+
+import (
+	"encoding/json"
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"time"
+
+	"termdoku/internal/game"
+)
+
+// SavedGame represents a saved game state
+type SavedGame struct {
+	Board        game.Grid          `json:"board"`
+	Solution     game.Grid          `json:"solution"`
+	Given        [9][9]bool         `json:"given"`
+	Difficulty   string             `json:"difficulty"`
+	Elapsed      int64              `json:"elapsed"` // seconds
+	StartTime    time.Time          `json:"startTime"`
+	HintsUsed    int                `json:"hintsUsed"`
+	Notes        map[string][]uint8 `json:"notes"` // JSON keys must be strings
+	SavedAt      time.Time          `json:"savedAt"`
+	AutoCheck    bool               `json:"autoCheck"`
+	TimerEnabled bool               `json:"timerEnabled"`
+}
+
+// path returns the save file path
+func path() (string, error) {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(h, ".termdoku", "savegame.json"), nil
+}
+
+// Save writes a game state to disk
+func Save(sg SavedGame) error {
+	p, err := path()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(sg, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(p, data, 0o644)
+}
+
+// Load reads a game state from disk
+func Load() (SavedGame, error) {
+	var sg SavedGame
+	p, err := path()
+	if err != nil {
+		return sg, err
+	}
+	b, err := os.ReadFile(p)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return sg, errors.New("no saved game found")
+		}
+		return sg, err
+	}
+	if err := json.Unmarshal(b, &sg); err != nil {
+		return sg, err
+	}
+	return sg, nil
+}
+
+// Exists checks if a saved game exists
+func Exists() bool {
+	p, err := path()
+	if err != nil {
+		return false
+	}
+	_, err = os.Stat(p)
+	return err == nil
+}
+
+// Delete removes the saved game
+func Delete() error {
+	p, err := path()
+	if err != nil {
+		return err
+	}
+	return os.Remove(p)
+}