Copy a garden (deep duplicate) from the gardens list (#46)

Co-authored-by: Steve Dudenhoeffer <[email protected]>

internal/api/gardens.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"errors"
+	"io"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
@@ -103,6 +104,34 @@ func (h *handlers) updateGarden(c *gin.Context) {
 	c.JSON(http.StatusOK, g)
 }
 
+// gardenCopyRequest is the (optional) body of POST /gardens/:id/copy. A blank or
+// absent name lets the service derive "<source> (copy)".
+type gardenCopyRequest struct {
+	Name string `json:"name"`
+}
+
+func (h *handlers) copyGarden(c *gin.Context) {
+	id, ok := parseIDParam(c, "id")
+	if !ok {
+		return
+	}
+	// The body is optional — POST with no body means "copy under the default
+	// name". An absent body surfaces as io.EOF from the decoder, which is the
+	// reliable signal: Content-Length is -1 (not 0) for a chunked request, so
+	// testing the length would misread an empty chunked body as malformed.
+	var req gardenCopyRequest
+	if err := c.ShouldBindJSON(&req); err != nil && !errors.Is(err, io.EOF) {
+		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "name must be a string")
+		return
+	}
+	g, err := h.svc.CopyGarden(c.Request.Context(), mustActor(c).ID, id, req.Name)
+	if err != nil {
+		writeServiceError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, g)
+}
+
 func (h *handlers) deleteGarden(c *gin.Context) {
 	id, ok := parseIDParam(c, "id")
 	if !ok {