From cfb6ab80cea7f0ed3f525e8120f2e569f963fa0e Mon Sep 17 00:00:00 2001
From: Nick Van den Broeck <nick.van.den.broeck666@gmail.com>
Date: Thu, 21 Feb 2019 06:53:01 +0100
Subject: [PATCH] Implemented "nix flake info"

---
 src/libexpr/primops/flake.cc | 13 -------------
 src/libexpr/primops/flake.hh | 14 ++++++++++++++
 src/nix/command.hh           | 11 +++++++++++
 src/nix/flake.cc             | 23 ++++++++++++++++++++++-
 4 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/src/libexpr/primops/flake.cc b/src/libexpr/primops/flake.cc
index 3998f9ef9..9f137a0b9 100644
--- a/src/libexpr/primops/flake.cc
+++ b/src/libexpr/primops/flake.cc
@@ -141,19 +141,6 @@ static FlakeSourceInfo fetchFlake(EvalState & state, const FlakeRef & flakeRef)
     else abort();
 }
 
-struct Flake
-{
-    FlakeId id;
-    std::string description;
-    Path path;
-    std::vector<FlakeRef> requires;
-    std::unique_ptr<FlakeRegistry> lockFile;
-    Value * vProvides; // FIXME: gc
-    // commit hash
-    // date
-    // content hash
-};
-
 static Flake getFlake(EvalState & state, const FlakeRef & flakeRef)
 {
     auto sourceInfo = fetchFlake(state, flakeRef);
diff --git a/src/libexpr/primops/flake.hh b/src/libexpr/primops/flake.hh
index e504dc196..af28bc5b0 100644
--- a/src/libexpr/primops/flake.hh
+++ b/src/libexpr/primops/flake.hh
@@ -21,4 +21,18 @@ Value * makeFlakeRegistryValue(EvalState & state);
 
 Value * makeFlakeValue(EvalState & state, std::string flakeUri, Value & v);
 
+struct Flake
+{
+    FlakeId id;
+    std::string description;
+    Path path;
+    std::vector<FlakeRef> requires;
+    std::unique_ptr<FlakeRegistry> lockFile;
+    Value * vProvides; // FIXME: gc
+    // commit hash
+    // date
+    // content hash
+};
+
+static Flake getFlake(EvalState & state, const FlakeRef & flakeRef);
 }
diff --git a/src/nix/command.hh b/src/nix/command.hh
index a08347945..b3248222e 100644
--- a/src/nix/command.hh
+++ b/src/nix/command.hh
@@ -34,6 +34,17 @@ struct Buildable
 
 typedef std::vector<Buildable> Buildables;
 
+struct FlakeCommand : virtual Args, StoreCommand, MixEvalArgs
+{
+  std::string flakeUri;
+
+public:
+  FlakeCommand()
+  {
+    expectArg("flake-uri", &flakeUri);
+  }
+};
+
 struct Installable
 {
     virtual std::string what() = 0;
diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 9b36c3cbd..099425688 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -33,10 +33,31 @@ struct CmdFlakeList : StoreCommand, MixEvalArgs
     }
 };
 
+struct CmdFlakeInfo : FlakeCommand
+{
+    std::string name() override
+    {
+        return "info";
+    }
+
+    std::string description() override
+    {
+        return "list info about a given flake";
+    }
+
+    void run(nix::ref<nix::Store> store) override
+    {
+        auto evalState = std::make_shared<EvalState>(searchPath, store);
+        nix::Flake flake = nix::getFlake(*evalState, FlakeRef(flakeUri));
+        std::cout << "Location:    " << flake.path << "\n";
+        std::cout << "Description: " << flake.description << "\n";
+    }
+};
+
 struct CmdFlake : virtual MultiCommand, virtual Command
 {
     CmdFlake()
-        : MultiCommand({make_ref<CmdFlakeList>()})
+        : MultiCommand({make_ref<CmdFlakeList>(), make_ref<CmdFlakeInfo>()})
     {
     }