feat(tfstated): implement GET and POST methods, states are encrypted in a sqlite3 database

4 files changed, 206 insertions, 0 deletions

diff --git a/pkg/database/db.go b/pkg/database/db.go
new file mode 100644
index 0000000..2744570
--- /dev/null
+++ b/pkg/database/db.go
@@ -0,0 +1,103 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"runtime"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/scrypto"
+)
+
+func initDB(ctx context.Context, url string) (*sql.DB, error) {
+	db, err := sql.Open("sqlite3", url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = db.Close()
+		}
+	}()
+	if _, err = db.ExecContext(ctx, "PRAGMA busy_timeout = 5000"); err != nil {
+		return nil, err
+	}
+
+	return db, nil
+}
+
+type DB struct {
+	ctx               context.Context
+	dataEncryptionKey scrypto.AES256Key
+	readDB            *sql.DB
+	writeDB           *sql.DB
+}
+
+func NewDB(ctx context.Context, url string) (*DB, error) {
+	readDB, err := initDB(ctx, url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = readDB.Close()
+		}
+	}()
+	readDB.SetMaxOpenConns(max(4, runtime.NumCPU()))
+
+	writeDB, err := initDB(ctx, url)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = writeDB.Close()
+		}
+	}()
+	writeDB.SetMaxOpenConns(1)
+
+	db := DB{
+		ctx:     ctx,
+		readDB:  readDB,
+		writeDB: writeDB,
+	}
+	if _, err = db.Exec("PRAGMA foreign_keys = ON"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA cache_size = 10000000"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA journal_mode = WAL"); err != nil {
+		return nil, err
+	}
+	if _, err = db.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+		return nil, err
+	}
+	if err = db.migrate(); err != nil {
+		return nil, err
+	}
+
+	return &db, nil
+}
+
+func (db *DB) Begin() (*sql.Tx, error) {
+	return db.writeDB.Begin()
+}
+
+func (db *DB) Close() error {
+	if err := db.readDB.Close(); err != nil {
+		_ = db.writeDB.Close()
+	}
+	return db.writeDB.Close()
+}
+
+func (db *DB) Exec(query string, args ...any) (sql.Result, error) {
+	return db.writeDB.ExecContext(db.ctx, query, args...)
+}
+
+func (db *DB) QueryRow(query string, args ...any) *sql.Row {
+	return db.readDB.QueryRowContext(db.ctx, query, args...)
+}
+
+func (db *DB) SetDataEncryptionKey(s string) error {
+	return db.dataEncryptionKey.FromBase64(s)
+}
diff --git a/pkg/database/migrations.go b/pkg/database/migrations.go
new file mode 100644
index 0000000..b460884
--- /dev/null
+++ b/pkg/database/migrations.go
@@ -0,0 +1,63 @@
+package database
+
+import (
+	"embed"
+	"io/fs"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+//go:embed sql/*.sql
+var schemaFiles embed.FS
+
+func (db *DB) migrate() error {
+	statements := make([]string, 0)
+	err := fs.WalkDir(schemaFiles, ".", func(path string, d fs.DirEntry, err error) error {
+		if d.IsDir() || err != nil {
+			return err
+		}
+		var stmts []byte
+		if stmts, err = schemaFiles.ReadFile(path); err != nil {
+			return err
+		} else {
+			statements = append(statements, string(stmts))
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			_ = tx.Rollback()
+		}
+	}()
+
+	var version int
+	if err = tx.QueryRowContext(db.ctx, `SELECT version FROM schema_version;`).Scan(&version); err != nil {
+		if err.Error() == "no such table: schema_version" {
+			version = 0
+		} else {
+			return err
+		}
+	}
+
+	for version < len(statements) {
+		if _, err = tx.ExecContext(db.ctx, statements[version]); err != nil {
+			return err
+		}
+		version++
+	}
+	if _, err = tx.ExecContext(db.ctx, `DELETE FROM schema_version; INSERT INTO schema_version (version) VALUES (?);`, version); err != nil {
+		return err
+	}
+	if err = tx.Commit(); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/pkg/database/sql/000_init.sql b/pkg/database/sql/000_init.sql
new file mode 100644
index 0000000..0248896
--- /dev/null
+++ b/pkg/database/sql/000_init.sql
@@ -0,0 +1,10 @@
+CREATE TABLE schema_version (
+  version INTEGER NOT NULL
+) STRICT;
+
+CREATE TABLE states (
+  id INTEGER PRIMARY KEY,
+  name TEXT NOT NULL,
+  data BLOB NOT NULL
+) STRICT;
+CREATE UNIQUE INDEX states_name on states(name);
diff --git a/pkg/database/states.go b/pkg/database/states.go
new file mode 100644
index 0000000..ef2263b
--- /dev/null
+++ b/pkg/database/states.go
@@ -0,0 +1,30 @@
+package database
+
+import (
+	"database/sql"
+)
+
+func (db *DB) GetState(name string) ([]byte, error) {
+	var encryptedData []byte
+	err := db.QueryRow(`SELECT data FROM states WHERE name = ?;`, name).Scan(&encryptedData)
+	if err != nil {
+		return nil, err
+	}
+	return db.dataEncryptionKey.DecryptAES256(encryptedData)
+}
+
+func (db *DB) SetState(name string, data []byte) error {
+	encryptedData, err := db.dataEncryptionKey.EncryptAES256(data)
+	if err != nil {
+		return err
+	}
+	_, err = db.Exec(
+		`INSERT INTO states(name, data) VALUES (:name, :data) ON CONFLICT DO UPDATE SET data = :data WHERE name = :name;`,
+		sql.Named("data", encryptedData),
+		sql.Named("name", name),
+	)
+	if err != nil {
+		return err
+	}
+	return nil
+}