Initial structure

internal/cli/client.go

@@ -0,0 +1,95 @@
+package cli
+
+import (
+	"context"
+	"encoding/binary"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"time"
+
+	"github.com/jasper/quptime/internal/config"
+	"github.com/jasper/quptime/internal/daemon"
+)
+
+// callDaemon sends one control-plane request and decodes the
+// response. Returns the raw body the daemon produced, ready for the
+// caller to unmarshal into the per-command result struct.
+func callDaemon(ctx context.Context, method string, body any) (json.RawMessage, error) {
+	var rawBody json.RawMessage
+	if body != nil {
+		b, err := json.Marshal(body)
+		if err != nil {
+			return nil, err
+		}
+		rawBody = b
+	}
+	req := daemon.CtrlRequest{Method: method, Body: rawBody}
+	reqBytes, err := json.Marshal(req)
+	if err != nil {
+		return nil, err
+	}
+
+	conn, err := dialControl(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	if dl, ok := ctx.Deadline(); ok {
+		_ = conn.SetDeadline(dl)
+	} else {
+		_ = conn.SetDeadline(time.Now().Add(30 * time.Second))
+	}
+
+	if err := writeFrame(conn, reqBytes); err != nil {
+		return nil, err
+	}
+	respBytes, err := readFrame(conn)
+	if err != nil {
+		return nil, err
+	}
+	var resp daemon.CtrlResponse
+	if err := json.Unmarshal(respBytes, &resp); err != nil {
+		return nil, err
+	}
+	if resp.Error != "" {
+		return nil, errors.New(resp.Error)
+	}
+	return resp.Body, nil
+}
+
+func dialControl(ctx context.Context) (net.Conn, error) {
+	sock := config.SocketPath()
+	d := net.Dialer{}
+	conn, err := d.DialContext(ctx, "unix", sock)
+	if err != nil {
+		return nil, fmt.Errorf("dial daemon socket %s: %w", sock, err)
+	}
+	return conn, nil
+}
+
+func writeFrame(w io.Writer, body []byte) error {
+	var hdr [4]byte
+	binary.BigEndian.PutUint32(hdr[:], uint32(len(body)))
+	if _, err := w.Write(hdr[:]); err != nil {
+		return err
+	}
+	_, err := w.Write(body)
+	return err
+}
+
+func readFrame(r io.Reader) ([]byte, error) {
+	var hdr [4]byte
+	if _, err := io.ReadFull(r, hdr[:]); err != nil {
+		return nil, err
+	}
+	n := binary.BigEndian.Uint32(hdr[:])
+	buf := make([]byte, n)
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}