4 files changed, 93 insertions, 1 deletions

diff --git a/src/nix/build.cc b/src/nix/build.cc
index b329ac38a..5ab22e26c 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -1,3 +1,5 @@
+#include "primops/flake.hh"
+#include "eval.hh"
 #include "command.hh"
 #include "common-args.hh"
 #include "shared.hh"
@@ -9,6 +11,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand
 {
     Path outLink = "result";
 
+    std::optional<std::string> gitRepo = std::nullopt;
+
     CmdBuild()
     {
         mkFlag()
@@ -22,6 +26,11 @@ struct CmdBuild : MixDryRun, InstallablesCommand
             .longName("no-link")
             .description("do not create a symlink to the build result")
             .set(&outLink, Path(""));
+
+        mkFlag()
+            .longName("update-lock-file")
+            .description("update the lock file")
+            .dest(&gitRepo);
     }
 
     std::string name() override
@@ -52,6 +61,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand
     {
         auto buildables = build(store, dryRun ? DryRun : Build, installables);
 
+        auto evalState = std::make_shared<EvalState>(searchPath, store);
+
         if (dryRun) return;
 
         for (size_t i = 0; i < buildables.size(); ++i) {
@@ -66,6 +77,9 @@ struct CmdBuild : MixDryRun, InstallablesCommand
                         store2->addPermRoot(output.second, absPath(symlink), true);
                     }
         }
+
+        if(gitRepo)
+            updateLockFile(*evalState, *gitRepo);
     }
 };
 
diff --git a/src/nix/command.hh b/src/nix/command.hh
index a08347945..c58d5d56e 100644
--- a/src/nix/command.hh
+++ b/src/nix/command.hh
@@ -34,6 +34,26 @@ struct Buildable
 
 typedef std::vector<Buildable> Buildables;
 
+struct GitRepoCommand : virtual Args
+{
+    std::string gitPath = absPath(".");
+
+    GitRepoCommand ()
+    {
+        expectArg("git-path", &gitPath, true);
+    }
+};
+
+struct FlakeCommand : virtual Args, StoreCommand, MixEvalArgs
+{
+    std::string flakeUri;
+
+    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..a5a1d34db 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -4,6 +4,7 @@
 #include "shared.hh"
 #include "progress-bar.hh"
 #include "eval.hh"
+#include <nlohmann/json.hpp>
 
 using namespace nix;
 
@@ -33,10 +34,66 @@ struct CmdFlakeList : StoreCommand, MixEvalArgs
     }
 };
 
+struct CmdFlakeUpdate : StoreCommand, GitRepoCommand, MixEvalArgs
+{
+    std::string name() override
+    {
+        return "update";
+    }
+
+    std::string description() override
+    {
+        return "update flake lock file";
+    }
+
+    void run(nix::ref<nix::Store> store) override
+    {
+        auto evalState = std::make_shared<EvalState>(searchPath, store);
+
+        if (flakeUri == "") flakeUri = absPath("./flake.nix");
+        int result = updateLockFile(*evalState, flakeUri);
+        if (result == 1) {
+            std::cout << "You can only update local flakes, not flakes on GitHub.\n";
+        } else if (result == 2) {
+            std::cout << "You can only update local flakes, not flakes through their FlakeId.\n";
+        }
+    }
+};
+
+struct CmdFlakeInfo : FlakeCommand, MixJSON
+{
+    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));
+        if (json) {
+            nlohmann::json j;
+            j["location"] = flake.path;
+            j["description"] = flake.description;
+            std::cout << j.dump(4) << std::endl;
+        } else {
+            std::cout << "Description: " << flake.description << "\n";
+            std::cout << "Location:    " << flake.path << "\n";
+        }
+    }
+};
+
 struct CmdFlake : virtual MultiCommand, virtual Command
 {
     CmdFlake()
-        : MultiCommand({make_ref<CmdFlakeList>()})
+        : MultiCommand({make_ref<CmdFlakeList>()
+            , make_ref<CmdFlakeInfo>()
+            , make_ref<CmdFlakeUpdate>()})
     {
     }
 
diff --git a/src/nix/installables.cc b/src/nix/installables.cc
index 0453c72c2..21e9e73b8 100644
--- a/src/nix/installables.cc
+++ b/src/nix/installables.cc
@@ -234,6 +234,7 @@ Buildables build(ref<Store> store, RealiseMode mode,
     PathSet pathsToBuild;
 
     for (auto & i : installables) {
+        std::cout << i->what() << std::endl;
         for (auto & b : i->toBuildables()) {
             if (b.drvPath != "") {
                 StringSet outputNames;