1 files changed, 139 insertions, 0 deletions
diff --git a/src/libcmd/installables.hh b/src/libcmd/installables.hh
new file mode 100644
index 000000000..b714f097b
--- /dev/null
+++ b/src/libcmd/installables.hh
@@ -0,0 +1,139 @@
+#pragma once
+
+#include "util.hh"
+#include "path.hh"
+#include "eval.hh"
+#include "flake/flake.hh"
+
+#include <optional>
+
+#include <nlohmann/json_fwd.hpp>
+
+namespace nix {
+
+struct DrvInfo;
+struct SourceExprCommand;
+
+namespace eval_cache { class EvalCache; class AttrCursor; }
+
+struct BuildableOpaque {
+    StorePath path;
+    nlohmann::json toJSON(ref<Store> store) const;
+};
+
+struct BuildableFromDrv {
+    StorePath drvPath;
+    std::map<std::string, std::optional<StorePath>> outputs;
+    nlohmann::json toJSON(ref<Store> store) const;
+};
+
+typedef std::variant<
+    BuildableOpaque,
+    BuildableFromDrv
+> Buildable;
+
+typedef std::vector<Buildable> Buildables;
+nlohmann::json buildablesToJSON(const Buildables & buildables, ref<Store> store);
+
+struct App
+{
+    std::vector<StorePathWithOutputs> context;
+    Path program;
+    // FIXME: add args, sandbox settings, metadata, ...
+};
+
+struct Installable
+{
+    virtual ~Installable() { }
+
+    virtual std::string what() = 0;
+
+    virtual Buildables toBuildables() = 0;
+
+    Buildable toBuildable();
+
+    App toApp(EvalState & state);
+
+    virtual std::pair<Value *, Pos> toValue(EvalState & state)
+    {
+        throw Error("argument '%s' cannot be evaluated", what());
+    }
+
+    /* Return a value only if this installable is a store path or a
+       symlink to it. */
+    virtual std::optional<StorePath> getStorePath()
+    {
+        return {};
+    }
+
+    virtual std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
+    getCursors(EvalState & state);
+
+    std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>
+    getCursor(EvalState & state);
+
+    virtual FlakeRef nixpkgsFlakeRef() const
+    {
+        return FlakeRef::fromAttrs({{"type","indirect"}, {"id", "nixpkgs"}});
+    }
+};
+
+struct InstallableValue : Installable
+{
+    ref<EvalState> state;
+
+    InstallableValue(ref<EvalState> state) : state(state) {}
+
+    struct DerivationInfo
+    {
+        StorePath drvPath;
+        std::optional<StorePath> outPath;
+        std::string outputName;
+    };
+
+    virtual std::vector<DerivationInfo> toDerivations() = 0;
+
+    Buildables toBuildables() override;
+};
+
+struct InstallableFlake : InstallableValue
+{
+    FlakeRef flakeRef;
+    Strings attrPaths;
+    Strings prefixes;
+    const flake::LockFlags & lockFlags;
+    mutable std::shared_ptr<flake::LockedFlake> _lockedFlake;
+
+    InstallableFlake(
+        SourceExprCommand * cmd,
+        ref<EvalState> state,
+        FlakeRef && flakeRef,
+        Strings && attrPaths,
+        Strings && prefixes,
+        const flake::LockFlags & lockFlags);
+
+    std::string what() override { return flakeRef.to_string() + "#" + *attrPaths.begin(); }
+
+    std::vector<std::string> getActualAttrPaths();
+
+    Value * getFlakeOutputs(EvalState & state, const flake::LockedFlake & lockedFlake);
+
+    std::tuple<std::string, FlakeRef, DerivationInfo> toDerivation();
+
+    std::vector<DerivationInfo> toDerivations() override;
+
+    std::pair<Value *, Pos> toValue(EvalState & state) override;
+
+    std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
+    getCursors(EvalState & state) override;
+
+    std::shared_ptr<flake::LockedFlake> getLockedFlake() const;
+
+    FlakeRef nixpkgsFlakeRef() const override;
+};
+
+ref<eval_cache::EvalCache> openEvalCache(
+    EvalState & state,
+    std::shared_ptr<flake::LockedFlake> lockedFlake);
+
+}