feat(m1): backend scaffold - entries CRUD, start/stop, auth, migrations

internal/store/db.go

@@ -0,0 +1,91 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	_ "embed"
+	"fmt"
+	"strings"
+
+	_ "modernc.org/sqlite"
+)
+
+//go:embed 001_initial.sql
+var schema string
+
+// Open opens (or creates) the SQLite database at path and runs migrations.
+func Open(path string) (*sql.DB, error) {
+	dsn := fmt.Sprintf(
+		"file:%s?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)&_pragma=foreign_keys(ON)&_pragma=synchronous(NORMAL)",
+		path,
+	)
+	db, err := sql.Open("sqlite", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("open sqlite: %w", err)
+	}
+	db.SetMaxOpenConns(1) // SQLite WAL: single writer
+	if err := migrate(db); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("migrate: %w", err)
+	}
+	return db, nil
+}
+
+// migrate runs embedded SQL migrations. Simple single-file approach: we track
+// a user_version pragma and apply the schema once if version == 0.
+func migrate(db *sql.DB) error {
+	var version int
+	if err := db.QueryRow("PRAGMA user_version").Scan(&version); err != nil {
+		return err
+	}
+	if version >= 1 {
+		return nil
+	}
+
+	ctx := context.Background()
+
+	// Strip migration comments and split into individual statements
+	stmts := splitStatements(schema)
+	for _, stmt := range stmts {
+		stmt = strings.TrimSpace(stmt)
+		if stmt == "" {
+			continue
+		}
+		if _, err := db.ExecContext(ctx, stmt); err != nil {
+			return fmt.Errorf("exec %q: %w", stmt[:min(len(stmt), 60)], err)
+		}
+	}
+
+	// PRAGMA user_version cannot be set inside a regular transaction in all SQLite versions;
+	// execute it as a standalone statement.
+	if _, err := db.ExecContext(ctx, "PRAGMA user_version = 1"); err != nil {
+		return err
+	}
+	return nil
+}
+
+func splitStatements(sql string) []string {
+	// Only process statements up to the "-- +migrate Down" marker.
+	var lines []string
+	for _, line := range strings.Split(sql, "\n") {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "-- +migrate Down" {
+			break
+		}
+		if strings.HasPrefix(trimmed, "-- +migrate") {
+			continue
+		}
+		lines = append(lines, line)
+	}
+	joined := strings.Join(lines, "\n")
+	// Split on semicolons
+	parts := strings.Split(joined, ";")
+	return parts
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}