scrobbler: add interface to the sqlite3 database

We want to persist the records in a database, so we can extract
statistics and an history.

The module for the database is straightforward: it opens the database if
it exists and return an handler to it. If the database does not exists,
we create it and we create the only table we need (records).

1 files changed, 54 insertions, 0 deletions

diff --git a/tools/mpd-stats/internal/scrobbler/db.go b/tools/mpd-stats/internal/scrobbler/db.go
new file mode 100644
index 0000000..a788b4c
--- /dev/null
+++ b/tools/mpd-stats/internal/scrobbler/db.go
@@ -0,0 +1,54 @@
+package scrobbler
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func initdb(dbpath string) error {
+	if _, err := os.Stat(dbpath); err == nil {
+		return fmt.Errorf("%s already exists", dbpath)
+	}
+
+	db, err := sql.Open("sqlite3", dbpath)
+	if err != nil {
+		return err
+	}
+	defer db.Close()
+
+	sqlStmt := `create table records (id text primary key,
+				title text,
+				artist text,
+                album text,
+                duration int,
+                time timestamp
+			);`
+
+	_, err = db.Exec(sqlStmt)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func opendatabase(dbpath string) (*sql.DB, error) {
+	var err error
+	_, err = os.Stat(dbpath)
+
+	if err != nil {
+		if err := initdb(dbpath); err != nil {
+			return nil, err
+		}
+	}
+
+	db, err := sql.Open("sqlite3", dbpath)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open database: %s", err)
+	}
+
+	return db, nil
+}