[PHASE-5] Move requests to separate file and implement decoding

internal/protocol/requests.go

@@ -0,0 +1,35 @@
+package protocol
+
+import (
+	"encoding/json"
+	"io"
+
+	"hash-of-wisdom/internal/pow/challenge"
+)
+
+// ChallengeRequest is empty (no payload for challenge requests)
+type ChallengeRequest struct{}
+
+// Decode reads a challenge request from the payload stream
+func (r *ChallengeRequest) Decode(stream io.Reader) error {
+	// Challenge requests have no payload to decode
+	return nil
+}
+
+// SolutionRequest contains the client's solution attempt
+type SolutionRequest struct {
+	Challenge challenge.Challenge `json:"challenge"`
+	Nonce     uint64              `json:"nonce"`
+}
+
+// Decode reads a solution request from the payload stream
+func (r *SolutionRequest) Decode(stream io.Reader) error {
+	if stream == nil {
+		// json.NewDecoder panics on nil reader
+		return io.EOF
+	}
+
+	// Parse JSON directly from stream
+	decoder := json.NewDecoder(stream)
+	return decoder.Decode(r)
+}