nix-flake-c: Add basic flakeref parsing and locking

src/libflake-c/nix_api_flake.cc

@@ -1,7 +1,10 @@
 #include "nix_api_flake.h"
 #include "nix_api_flake_internal.hh"
+#include "nix_api_util.h"
 #include "nix_api_util_internal.h"
 #include "nix_api_expr_internal.h"
+#include "nix_api_fetchers_internal.hh"
+#include "nix_api_fetchers.h"
 
 #include "nix/flake/flake.hh"
 
@@ -27,3 +30,110 @@ nix_err nix_flake_settings_add_to_eval_state_builder(
     }
     NIXC_CATCH_ERRS
 }
+
+nix_flake_reference_parse_flags *
+nix_flake_reference_parse_flags_new(nix_c_context * context, nix_flake_settings * settings)
+{
+    nix_clear_err(context);
+    try {
+        return new nix_flake_reference_parse_flags{
+            .baseDirectory = std::nullopt,
+        };
+    }
+    NIXC_CATCH_ERRS_NULL
+}
+
+void nix_flake_reference_parse_flags_free(nix_flake_reference_parse_flags * flags)
+{
+    delete flags;
+}
+
+nix_err nix_flake_reference_parse_flags_set_base_directory(
+    nix_c_context * context,
+    nix_flake_reference_parse_flags * flags,
+    const char * baseDirectory,
+    size_t baseDirectoryLen)
+{
+    nix_clear_err(context);
+    try {
+        flags->baseDirectory.emplace(nix::Path{std::string(baseDirectory, baseDirectoryLen)});
+        return NIX_OK;
+    }
+    NIXC_CATCH_ERRS
+}
+
+nix_err nix_flake_reference_and_fragment_from_string(
+    nix_c_context * context,
+    nix_fetchers_settings * fetchSettings,
+    nix_flake_settings * flakeSettings,
+    nix_flake_reference_parse_flags * parseFlags,
+    const char * strData,
+    size_t strSize,
+    nix_flake_reference ** flakeReferenceOut,
+    nix_get_string_callback fragmentCallback,
+    void * fragmentCallbackUserData)
+{
+    nix_clear_err(context);
+    *flakeReferenceOut = nullptr;
+    try {
+        std::string str(strData, 0, strSize);
+
+        auto [flakeRef, fragment] =
+            nix::parseFlakeRefWithFragment(*fetchSettings->settings, str, parseFlags->baseDirectory, true);
+        *flakeReferenceOut = new nix_flake_reference{nix::make_ref<nix::FlakeRef>(flakeRef)};
+        return call_nix_get_string_callback(fragment, fragmentCallback, fragmentCallbackUserData);
+    }
+    NIXC_CATCH_ERRS
+}
+
+void nix_flake_reference_free(nix_flake_reference * flakeReference)
+{
+    delete flakeReference;
+}
+
+nix_flake_lock_flags * nix_flake_lock_flags_new(nix_c_context * context, nix_flake_settings * settings)
+{
+    nix_clear_err(context);
+    try {
+        auto lockSettings = nix::make_ref<nix::flake::LockFlags>();
+        return new nix_flake_lock_flags{lockSettings};
+    }
+    NIXC_CATCH_ERRS_NULL
+}
+
+void nix_flake_lock_flags_free(nix_flake_lock_flags * flags)
+{
+    delete flags;
+}
+
+nix_locked_flake * nix_flake_lock(
+    nix_c_context * context,
+    nix_flake_settings * settings,
+    EvalState * eval_state,
+    nix_flake_lock_flags * flags,
+    nix_flake_reference * flakeReference)
+{
+    try {
+        auto lockedFlake = nix::make_ref<nix::flake::LockedFlake>(nix::flake::lockFlake(
+            *settings->settings, eval_state->state, *flakeReference->flakeRef, *flags->lockFlags));
+        return new nix_locked_flake{lockedFlake};
+    }
+    NIXC_CATCH_ERRS_NULL
+}
+
+void nix_locked_flake_free(nix_locked_flake * lockedFlake)
+{
+    delete lockedFlake;
+}
+
+nix_value * nix_locked_flake_get_output_attrs(
+    nix_c_context * context, nix_flake_settings * settings, EvalState * evalState, nix_locked_flake * lockedFlake)
+{
+    nix_clear_err(context);
+    try {
+        auto v = nix_alloc_value(context, evalState);
+        nix::flake::callFlake(evalState->state, *lockedFlake->lockedFlake, v->value);
+        return v;
+    }
+    NIXC_CATCH_ERRS_NULL
+}