From 0d7e12ce55d1ff4f303b37fb89fc01fad5dfb8cf Mon Sep 17 00:00:00 2001
From: Evgeny Zinoviev <me@ch1p.io>
Date: Mon, 29 Nov 2021 02:28:21 +0300
Subject: [PATCH] p18: fix variable field lengths in get-p-rated

---
 src/p18/response.cc | 25 +++++++++++++++++++++----
 src/p18/response.h  | 22 +++++++++++++++++++++-
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/p18/response.cc b/src/p18/response.cc
index f361dee..0239b2d 100644
--- a/src/p18/response.cc
+++ b/src/p18/response.cc
@@ -8,7 +8,6 @@
 
 #include "response.h"
 #include "exceptions.h"
-#include "../logging.h"
 
 #define RETURN_TABLE(...)                                        \
     return std::shared_ptr<formatter::Table<VariantHolder>>(     \
@@ -27,6 +26,19 @@ typedef formatter::TableItem<VariantHolder> LINE;
 
 using formatter::Unit;
 
+
+/**
+ * Helpers
+ */
+std::ostream& operator<<(std::ostream& os, FieldLength fl) {
+    if (fl.min_ == fl.max_)
+        os << fl.min_;
+    else
+        os << "[" << fl.min_ << ", " << fl.max_ << "]";
+    return os;
+}
+
+
 /**
  * Base responses
  */
@@ -58,7 +70,7 @@ size_t GetResponse::getDataSize() const {
     return rawSize_ - 5;
 }
 
-std::vector<std::string> GetResponse::getList(std::vector<size_t> itemLengths, int expectAtLeast) const {
+std::vector<std::string> GetResponse::getList(std::vector<FieldLength> itemLengths, int expectAtLeast) const {
     std::string buf(getData(), getDataSize());
     auto list = ::split(buf, ',');
 
@@ -77,7 +89,7 @@ std::vector<std::string> GetResponse::getList(std::vector<size_t> itemLengths, i
 
         // check each item's length
         for (int i = 0; i < list.size(); i++) {
-            if (list[i].size() != itemLengths[i]) {
+            if (!itemLengths[i].validate(list[i].size())) {
                 std::ostringstream error;
                 error << "while parsing " << demangle_type_name(typeid(*this).name());
                 error << ": item " << i << " is expected to be " << itemLengths[i] << " characters long, ";
@@ -635,7 +647,12 @@ void ParallelRatedInformation::unpack() {
         20, // CCCCCCCCCCCCCCCCCCCC
         1, // D
         3, // EEE
-        2, // FF
+
+        // FF
+        // note: protocol documentation says that the following field is 2 bytes long,
+        // but actual tests of the 6kw unit shows it can be 3 bytes long
+        FieldLength(2, 3),
+
         1 // G
     });
 
diff --git a/src/p18/response.h b/src/p18/response.h
index b14c9b0..42b84b8 100644
--- a/src/p18/response.h
+++ b/src/p18/response.h
@@ -124,6 +124,26 @@ public:
 };
 
 
+/**
+ * Some helpers
+ */
+class FieldLength {
+protected:
+    size_t min_;
+    size_t max_;
+
+public:
+    FieldLength(size_t n) : min_(n), max_(n) {}
+    FieldLength(size_t min, size_t max) : min_(min), max_(max) {}
+
+    [[nodiscard]] bool validate(size_t len) const {
+        return len >= min_ && len <= max_;
+    }
+
+    friend std::ostream& operator<<(std::ostream& os, FieldLength fl);
+};
+
+
 /**
  * Base responses
  */
@@ -145,7 +165,7 @@ class GetResponse : public BaseResponse {
 protected:
     const char* getData() const;
     size_t getDataSize() const;
-    std::vector<std::string> getList(std::vector<size_t> itemLengths, int expectAtLeast = -1) const;
+    std::vector<std::string> getList(std::vector<FieldLength> itemLengths, int expectAtLeast = -1) const;
 
 public:
     using BaseResponse::BaseResponse;