Initial commit

db.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"git.agecem.com/bottin/presences/queries"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type DBClient struct {
+	Pool *pgxpool.Pool
+}
+
+func nilDBErrorf(failedAction string) error {
+	return fmt.Errorf("db: cannot %s using nil connection pool", failedAction)
+}
+
+func (d DBClient) Init(ctx context.Context) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		if d.Pool == nil {
+			return nilDBErrorf("init")
+		}
+
+		if _, err := d.Pool.Exec(ctx, queries.SQLSchema()); err != nil {
+			return err
+		}
+
+		return nil
+	}
+}
+
+func (d DBClient) CreatePresence(ctx context.Context, membreID string) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		if d.Pool == nil {
+			return nilDBErrorf("check health")
+		}
+
+		// CreatePresence
+		commandTag, err := d.Pool.Exec(ctx, `
+INSERT INTO "presences" (id)
+VALUES ($1);
+`, membreID)
+		if err != nil {
+			if err.Error() == `ERROR: duplicate key value violates unique constraint "presences_pkey" (SQLSTATE 23505)` {
+				return fmt.Errorf("Membre '%s' a déjà été enregistré·e", membreID)
+			}
+			return err
+		}
+
+		if commandTag.RowsAffected() == 0 {
+			return fmt.Errorf("No rows inserted")
+		}
+
+		return nil
+	}
+}
+
+func (d DBClient) CountPresences(ctx context.Context) (presencesAmount int, err error) {
+	select {
+	case <-ctx.Done():
+		err = ctx.Err()
+		return
+	default:
+		if d.Pool == nil {
+			return 0, nilDBErrorf("count presences")
+		}
+
+		if err := d.Pool.QueryRow(ctx, `
+SELECT COUNT(presences.id) FROM presences;
+`).Scan(&presencesAmount); err != nil {
+			return 0, err
+		}
+
+		return
+	}
+}