feat(inspect): add inspect package

internal/inspect/inspect.go

@@ -0,0 +1,162 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package inspect
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+
+	"github.com/cartesi/rollups-node/internal/node/advancer/machines"
+	. "github.com/cartesi/rollups-node/internal/node/model"
+	"github.com/cartesi/rollups-node/internal/nodemachine"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+)
+
+var (
+	ErrInvalidMachines = errors.New("machines must not be nil")
+	ErrNoApp           = errors.New("no machine for application")
+)
+
+type Inspector struct {
+	machines Machines
+}
+
+type InspectResponse struct {
+	Status     string   `json:"status"`
+	Exception  string   `json:"exception"`
+	Reports    []string `json:"reports"`
+	InputIndex uint64   `json:"processed_input_count"`
+}
+
+// New instantiates a new Inspector.
+func New(machines Machines) (*Inspector, error) {
+	if machines == nil {
+		return nil, ErrInvalidMachines
+	}
+
+	return &Inspector{machines: machines}, nil
+}
+
+func (inspect *Inspector) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	var (
+		dapp         Address
+		payload      []byte
+		err          error
+		reports      []string
+		status       string
+		errorMessage string
+	)
+
+	if r.PathValue("dapp") == "" {
+		slog.Info("Bad request",
+			"service", "inspect",
+			"err", "Missing application address")
+		http.Error(w, "Missing application address", http.StatusBadRequest)
+		return
+	}
+
+	dapp = common.HexToAddress(r.PathValue("dapp"))
+	if r.Method == "POST" {
+		payload, err = io.ReadAll(r.Body)
+		if err != nil {
+			slog.Info("Bad request",
+				"service", "inspect",
+				"err", err)
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+	} else {
+		if r.PathValue("payload") == "" {
+			slog.Info("Bad request",
+				"service", "inspect",
+				"err", "Missing payload")
+			http.Error(w, "Missing payload", http.StatusBadRequest)
+			return
+		}
+		payload, err = hexutil.Decode(r.PathValue("payload"))
+		if err != nil {
+			slog.Info("Internal server error",
+				"service", "inspect",
+				"err", err)
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+	}
+
+	result, err := inspect.process(r.Context(), dapp, payload)
+	if err != nil {
+		slog.Info("Internal server error",
+			"service", "inspect",
+			"err", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	for _, report := range result.Reports {
+		reports = append(reports, hexutil.Encode(report))
+	}
+
+	if result.Accepted {
+		status = "Accepted"
+	} else {
+		status = "Rejected"
+	}
+
+	if result.Error != nil {
+		status = "Exception"
+		errorMessage = fmt.Sprintf("Error on the machine while inspecting: %s", result.Error)
+	}
+
+	response := InspectResponse{
+		Status:     status,
+		Exception:  errorMessage,
+		Reports:    reports,
+		InputIndex: *result.InputIndex,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		slog.Info("Internal server error",
+			"service", "inspect",
+			"err", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+}
+
+// process sends an inspect request to the machine
+func (inspect *Inspector) process(
+	ctx context.Context,
+	app Address,
+	query []byte) (*nodemachine.InspectResult, error) {
+	// Asserts that the app has an associated machine.
+	machine := inspect.machines.GetInspectMachine(app)
+	if machine == nil {
+		return nil, fmt.Errorf("%w %s", ErrNoApp, app.String())
+	}
+
+	res, err := machine.Inspect(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+
+	return res, nil
+}
+
+// ------------------------------------------------------------------------------------------------
+
+type Machines interface {
+	GetInspectMachine(app Address) machines.InspectMachine
+}
+
+type Machine interface {
+	Inspect(_ context.Context, query []byte) (*nodemachine.InspectResult, error)
+}