From 93ca8cfa047ed5e97ed1300a6816b92845f4c1f0 Mon Sep 17 00:00:00 2001
From: Winston Chang <winston@posit.co>
Date: Fri, 5 Apr 2024 23:22:04 -0500
Subject: [PATCH] Add functions for lzstring compressing to URI components

---
 NAMESPACE         |  1 +
 R/cpp11.R         |  9 +++++++++
 R/utils.R         |  2 ++
 src/code.cpp      | 27 ++++++++++++++++++++++++++-
 src/cpp11.cpp     | 35 +++++++++++++++++++++++++++++++++++
 src/lz-string.hpp | 22 ++++++++++++++++++++++
 6 files changed, 95 insertions(+), 1 deletion(-)
 create mode 100644 R/cpp11.R
 create mode 100644 src/cpp11.cpp

diff --git a/NAMESPACE b/NAMESPACE
index 6a56160..cd3285f 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -10,3 +10,4 @@ export(assets_remove)
 export(assets_version)
 export(export)
 importFrom(rlang,is_interactive)
+useDynLib(shinylive, .registration = TRUE)
diff --git a/R/cpp11.R b/R/cpp11.R
new file mode 100644
index 0000000..47a4f0c
--- /dev/null
+++ b/R/cpp11.R
@@ -0,0 +1,9 @@
+# Generated by cpp11: do not edit by hand
+
+compressToEncodedURIComponent <- function(uncompressed8) {
+  .Call(`_shinylive_compressToEncodedURIComponent`, uncompressed8)
+}
+
+decompressFromEncodedURIComponent <- function(compressed8) {
+  .Call(`_shinylive_decompressFromEncodedURIComponent`, compressed8)
+}
diff --git a/R/utils.R b/R/utils.R
index 6eb6f79..f7d0e46 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -1,3 +1,5 @@
+#' @useDynLib shinylive, .registration = TRUE
+
 assert_nzchar_string <- function(x) {
   stopifnot(is.character(x) && nchar(x) > 0)
   invisible(TRUE)
diff --git a/src/code.cpp b/src/code.cpp
index 04ab900..0472a4b 100644
--- a/src/code.cpp
+++ b/src/code.cpp
@@ -1,6 +1,31 @@
 #include <cpp11.hpp>
+#include <codecvt>
 #include "lz-string.hpp"
 using namespace cpp11;
 
 [[cpp11::register]]
-void fun() {}
+std::string compressToEncodedURIComponent(std::string uncompressed8) {
+  std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> converter_8_to_16;
+  std::u16string uncompressed16 = converter_8_to_16.from_bytes(uncompressed8);
+
+  auto compressed16 = lzstring::compressToEncodedURIComponent(uncompressed16);
+
+  std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> converter_16_to_8;
+  std::string compressed8 = converter_16_to_8.to_bytes(compressed16);
+
+  return compressed8;
+}
+
+
+[[cpp11::register]]
+std::string decompressFromEncodedURIComponent(std::string compressed8) {
+  std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> converter_8_to_16;
+  std::u16string compressed16 = converter_8_to_16.from_bytes(compressed8);
+
+  auto uncompressed16 = lzstring::decompressFromEncodedURIComponent(compressed16);
+
+  std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t> converter_16_to_8;
+  std::string uncompressed8 = converter_16_to_8.to_bytes(uncompressed16);
+
+  return uncompressed8;
+}
diff --git a/src/cpp11.cpp b/src/cpp11.cpp
new file mode 100644
index 0000000..0b1b695
--- /dev/null
+++ b/src/cpp11.cpp
@@ -0,0 +1,35 @@
+// Generated by cpp11: do not edit by hand
+// clang-format off
+
+
+#include "cpp11/declarations.hpp"
+#include <R_ext/Visibility.h>
+
+// code.cpp
+std::string compressToEncodedURIComponent(std::string uncompressed8);
+extern "C" SEXP _shinylive_compressToEncodedURIComponent(SEXP uncompressed8) {
+  BEGIN_CPP11
+    return cpp11::as_sexp(compressToEncodedURIComponent(cpp11::as_cpp<cpp11::decay_t<std::string>>(uncompressed8)));
+  END_CPP11
+}
+// code.cpp
+std::string decompressFromEncodedURIComponent(std::string compressed8);
+extern "C" SEXP _shinylive_decompressFromEncodedURIComponent(SEXP compressed8) {
+  BEGIN_CPP11
+    return cpp11::as_sexp(decompressFromEncodedURIComponent(cpp11::as_cpp<cpp11::decay_t<std::string>>(compressed8)));
+  END_CPP11
+}
+
+extern "C" {
+static const R_CallMethodDef CallEntries[] = {
+    {"_shinylive_compressToEncodedURIComponent",     (DL_FUNC) &_shinylive_compressToEncodedURIComponent,     1},
+    {"_shinylive_decompressFromEncodedURIComponent", (DL_FUNC) &_shinylive_decompressFromEncodedURIComponent, 1},
+    {NULL, NULL, 0}
+};
+}
+
+extern "C" attribute_visible void R_init_shinylive(DllInfo* dll){
+  R_registerRoutines(dll, NULL, CallEntries, NULL, NULL);
+  R_useDynamicSymbols(dll, FALSE);
+  R_forceSymbols(dll, TRUE);
+}
diff --git a/src/lz-string.hpp b/src/lz-string.hpp
index 8268cdd..41f0b4b 100644
--- a/src/lz-string.hpp
+++ b/src/lz-string.hpp
@@ -33,6 +33,7 @@ using string = std::u16string;
 namespace __inner
 {
   const string keyStrBase64{_U("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=")};
+  const string keyStrUriSafe{_U("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-$")};
   const string::value_type equal{_U('=')};
 
   int charCodeAt(const string& str, int pos)
@@ -533,6 +534,27 @@ namespace __inner
 
 } // namespace __inner
 
+string compressToEncodedURIComponent(const string& input)
+{
+  if (input.empty()) return {};
+  using namespace __inner;
+  auto res = _compress(input, 6, [](int a) { return keyStrBase64.at(a); });
+  return res;
+}
+
+
+string decompressFromEncodedURIComponent(const string& input)
+{
+  if (input.empty()) return {};
+  using namespace __inner;
+  string input1 = input;
+  // std::replace(input1.begin(), input1.end(), ' ', '+');
+  std::unordered_map<string::value_type, int> baseReverseDic;
+  for (int i = 0; i < keyStrUriSafe.length(); ++i) baseReverseDic[keyStrUriSafe.at(i)] = i;
+  return _decompress(input1.length(), 32, [&](int index) { return baseReverseDic[input.at(index)]; });
+}
+
+
 // clang-format off
 string compressToBase64(const string& input)
 {