highlight dependencies on graph

src/main.cc

@@ -1,5 +1,6 @@
 #include "parser.h"
 #include "util.h"
+#include <algorithm>
 #include <filesystem>
 #include <functional>
 #include <span>
@@ -9,6 +10,7 @@
 
 std::unordered_map<std::string, Expr> packages;
 bool flag_raw = false;
+bool flag_graph = false;
 
 void load_packages() {
   for (const auto &e : std::filesystem::directory_iterator("./packages/")) {
@@ -87,7 +89,7 @@ void install_package(const std::string &name) {
     bool needs_download = true;
 
     // dont redownload if checksum matches
-    if (std::ifstream(archive_path)) {
+    if (std::filesystem::exists(archive_path)) {
       std::string current_hash = Util::hash_file(archive_path);
       if (current_hash == expected_hash) {
         needs_download = false;
@@ -183,14 +185,19 @@ void install_package(const std::string &name) {
   }
 }
 
-void generate_graph() {
+void generate_graph(const std::vector<std::string> &to_highlight) {
   std::ofstream out("/tmp/shrap/graph.dot");
 
   out << "digraph dependencies {\n";
   out << "    rankdir=LR;\n";
 
   for (const auto &[pkg_name, pkg] : packages) {
-    out << "    \"" << pkg_name << "\";\n";
+    if (std::find(to_highlight.begin(), to_highlight.end(), pkg_name) !=
+        to_highlight.end()) {
+      out << "    \"" << pkg_name << "\" [style=filled, fillcolor=yellow];\n";
+    } else {
+      out << "    \"" << pkg_name << "\";\n";
+    }
     try {
       for (const auto &dep : pkg.get("dependencies").children) {
         out << "    \"" << pkg_name << "\" -> \"" << dep.value << "\";\n";
@@ -217,22 +224,26 @@ int main(int argc, char **argv) {
     if (arg == "-r") {
       flag_raw = true;
     } else if (arg == "-g") {
-      generate_graph();
-      return 0;
+      flag_graph = true;
     } else {
       to_install.push_back(arg);
     }
   }
 
+  if (!flag_raw) {
+    to_install = resolve_dependencies(to_install);
+  }
+
+  if (flag_graph) {
+    generate_graph(to_install);
+    return 0;
+  }
+
   if (to_install.empty()) {
     std::cerr << "Usage: " << args[0] << " [-g] [-r] package1 [package2 ...]\n";
     return 1;
   }
 
-  if (!flag_raw) {
-    to_install = resolve_dependencies(to_install);
-  }
-
   if (geteuid() != 0) {
     std::cerr << "This program needs to be ran as root.\n";
     return 1;