refactor: Rewrote in golang.

app/db.go

@@ -0,0 +1,376 @@
+package app
+
+import (
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"slices"
+
+	"filippo.io/age"
+	_ "modernc.org/sqlite"
+)
+
+// CloseMode determines whether or not the in-memory DB should be saved to disk
+// before closing the connection.
+type CloseMode int
+
+const (
+	ReadOnly CloseMode = iota
+	Write
+)
+
+type Db struct {
+	db       *sql.DB
+	cfg      Config
+	features *AvailableFeatures
+}
+
+func Open() (*Db, error) {
+	cfg, err := LoadConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := os.Stat("/home/spencer/.envr/data.age"); err != nil {
+		// Create a new DB
+		db, err := newDb()
+		return &Db{db, *cfg, nil}, err
+	} else {
+		// Open the existing DB
+		tmpFile, err := os.CreateTemp("", "envr-*.db")
+		if err != nil {
+			return nil, fmt.Errorf("failed to create temp file: %w", err)
+		}
+		defer tmpFile.Close()
+		defer os.Remove(tmpFile.Name())
+
+		err = decryptDb(tmpFile.Name(), (*cfg).Keys)
+		if err != nil {
+			return nil, fmt.Errorf("failed to decrypt database: %w", err)
+		}
+
+		memDb, err := newDb()
+		if err != nil {
+			return nil, fmt.Errorf("failed to open temp database: %w", err)
+		}
+
+		restoreDB(tmpFile.Name(), memDb)
+
+		return &Db{memDb, *cfg, nil}, nil
+	}
+}
+
+// Creates the database for the first time
+func newDb() (*sql.DB, error) {
+	db, err := sql.Open("sqlite", ":memory:")
+
+	if err != nil {
+		return nil, err
+	} else {
+		_, err := db.Exec(`create table envr_env_files (
+      path text primary key not null
+    , dir text not null
+    , remotes text -- JSON
+    , sha256 text not null
+    , contents text not null
+  );`)
+		if err != nil {
+			return nil, err
+		} else {
+			return db, err
+		}
+	}
+}
+
+// Decrypt the database from the age file into a temp sqlite file.
+func decryptDb(tmpFilePath string, keys []SshKeyPair) error {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("failed to get user home directory: %w", err)
+	}
+
+	tmpFile, err := os.OpenFile(tmpFilePath, os.O_WRONLY, 0)
+	if err != nil {
+		return fmt.Errorf("failed to open temp file: %w", err)
+	}
+	defer tmpFile.Close()
+
+	ageFilePath := filepath.Join(homeDir, ".envr", "data.age")
+	ageFile, err := os.Open(ageFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to open age file: %w", err)
+	}
+	defer ageFile.Close()
+
+	identities := make([]age.Identity, 0, len(keys))
+
+	for _, key := range keys {
+		id, err := key.Identity()
+
+		if err != nil {
+			return err
+		}
+
+		identities = append(identities, id)
+	}
+
+	reader, err := age.Decrypt(ageFile, identities[:]...)
+	if err != nil {
+		return fmt.Errorf("failed to decrypt age file: %w", err)
+	}
+
+	_, err = io.Copy(tmpFile, reader)
+	if err != nil {
+		return fmt.Errorf("failed to copy decrypted content: %w", err)
+	}
+
+	return nil
+}
+
+// Restore the database from a file into memory
+func restoreDB(path string, destDB *sql.DB) error {
+	// Attach the source database
+	_, err := destDB.Exec("ATTACH DATABASE ? AS source", path)
+	if err != nil {
+		return fmt.Errorf("failed to attach database: %w", err)
+	}
+	defer destDB.Exec("DETACH DATABASE source")
+
+	// Copy data from source to destination
+	_, err = destDB.Exec("INSERT INTO main.envr_env_files SELECT * FROM source.envr_env_files")
+	if err != nil {
+		return fmt.Errorf("failed to copy data: %w", err)
+	}
+
+	return nil
+}
+
+// Returns all the EnvFiles present in the database.
+func (db *Db) List() (results []EnvFile, err error) {
+	rows, err := db.db.Query("select * from envr_env_files")
+
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var envFile EnvFile
+		var remotesJSON string
+
+		err := rows.Scan(&envFile.Path, &envFile.Dir, &remotesJSON, &envFile.Sha256, &envFile.contents)
+		if err != nil {
+			return nil, err
+		}
+
+		// TODO: unmarshal remotesJSON into envFile.remotes
+
+		results = append(results, envFile)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return results, nil
+}
+
+func (db *Db) Close(mode CloseMode) error {
+	defer db.db.Close()
+
+	if mode == Write {
+		// Create tmp file
+		tmpFile, err := os.CreateTemp("", "envr-*.db")
+		if err != nil {
+			return fmt.Errorf("failed to create temp file: %w", err)
+		}
+		defer tmpFile.Close()
+		defer os.Remove(tmpFile.Name())
+
+		if err := backupDb(db.db, tmpFile.Name()); err != nil {
+			return err
+		}
+
+		if err := encryptDb(tmpFile.Name(), db.cfg.Keys); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Save the in-memory database to a tmp file.
+func backupDb(memDb *sql.DB, tmpFilePath string) error {
+	_, err := memDb.Exec("VACUUM INTO ?", tmpFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to vacuum database to file: %w", err)
+	}
+
+	return nil
+}
+
+// Encrypt the database from the temp sqlite file into an age file.
+func encryptDb(tmpFilePath string, keys []SshKeyPair) error {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("failed to get user home directory: %w", err)
+	}
+	ageFilePath := filepath.Join(homeDir, ".envr", "data.age")
+
+	// Ensure .envr directory exists
+	err = os.MkdirAll(filepath.Dir(ageFilePath), 0755)
+	if err != nil {
+		return fmt.Errorf("failed to create .envr directory: %w", err)
+	}
+
+	// Open temp file for reading
+	tmpFile, err := os.Open(tmpFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to open temp file: %w", err)
+	}
+	defer tmpFile.Close()
+
+	// Open/create age file for writing (this preserves hardlinks)
+	ageFile, err := os.OpenFile(ageFilePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return fmt.Errorf("failed to open age file: %w", err)
+	}
+	defer ageFile.Close()
+
+	recipients := make([]age.Recipient, 0, len(keys))
+	for _, key := range keys {
+		recipient, err := key.Recipient()
+
+		if err != nil {
+			return err
+		}
+
+		recipients = append(recipients, recipient)
+	}
+
+	writer, err := age.Encrypt(ageFile, recipients...)
+	if err != nil {
+		return fmt.Errorf("failed to create age writer: %w", err)
+	}
+
+	_, err = io.Copy(writer, tmpFile)
+	if err != nil {
+		return fmt.Errorf("failed to encrypt and write data: %w", err)
+	}
+
+	err = writer.Close()
+	if err != nil {
+		return fmt.Errorf("failed to close age writer: %w", err)
+	}
+
+	return nil
+}
+
+func (db *Db) Insert(file EnvFile) error {
+	// Marshal remotes to JSON
+	remotesJSON, err := json.Marshal(file.Remotes)
+	if err != nil {
+		return fmt.Errorf("failed to marshal remotes: %w", err)
+	}
+
+	// Insert into database
+	_, err = db.db.Exec(`
+		INSERT OR REPLACE INTO envr_env_files (path, dir, remotes, sha256, contents)
+		VALUES (?, ?, ?, ?, ?)
+	`, file.Path, file.Dir, string(remotesJSON), file.Sha256, file.contents)
+
+	if err != nil {
+		return fmt.Errorf("failed to insert env file: %w", err)
+	}
+
+	return nil
+}
+
+// Select a single EnvFile from the database.
+func (db *Db) Fetch(path string) (envFile EnvFile, err error) {
+	var remotesJSON string
+
+	row := db.db.QueryRow("SELECT path, dir, remotes, sha256, contents FROM envr_env_files WHERE path = ?", path)
+	err = row.Scan(&envFile.Path, &envFile.Dir, &remotesJSON, &envFile.Sha256, &envFile.contents)
+	if err != nil {
+		return EnvFile{}, fmt.Errorf("failed to fetch env file: %w", err)
+	}
+
+	if err = json.Unmarshal([]byte(remotesJSON), &envFile.Remotes); err != nil {
+		return EnvFile{}, fmt.Errorf("failed to unmarshal remotes: %w", err)
+	}
+
+	return envFile, nil
+}
+
+// Removes a file from the database, if present.
+func (db *Db) Delete(path string) error {
+	result, err := db.db.Exec("DELETE FROM envr_env_files WHERE path = ?", path)
+	if err != nil {
+		return fmt.Errorf("failed to delete env file: %w", err)
+	}
+
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("failed to get rows affected: %w", err)
+	}
+
+	if rowsAffected == 0 {
+		return fmt.Errorf("no file found with path: %s", path)
+	}
+
+	return nil
+}
+
+// Finds .env files in the filesystem that aren't present in the database.
+func (db *Db) Scan() ([]string, error) {
+	all_paths, err := db.cfg.scan()
+	if err != nil {
+		return []string{}, err
+	}
+
+	untracked_paths := make([]string, 0, len(all_paths)/2)
+	env_files, err := db.List()
+
+	if err != nil {
+		return untracked_paths, err
+	}
+
+	for _, path := range all_paths {
+		backed_up := slices.ContainsFunc(env_files, func(e EnvFile) bool {
+			return e.Path == path
+		})
+
+		if backed_up {
+			continue
+		} else {
+			untracked_paths = append(untracked_paths, path)
+		}
+	}
+
+	return untracked_paths, nil
+}
+
+// Determine the available features on the installed system.
+func (db *Db) Features() AvailableFeatures {
+	if db.features == nil {
+		feats := checkFeatures()
+		db.features = &feats
+	}
+
+	return *db.features
+}
+
+// Returns nil if [Db.Scan] is safe to use, null otherwise.
+func (db *Db) CanScan() error {
+	if db.Features()&Fd == 0 {
+		return fmt.Errorf(
+			"please install fd to use the scan function (https://github.com/sharkdp/fd)",
+		)
+	} else {
+		return nil
+	}
+}