/*
  Copyright 2007-2011 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "lv2/lv2plug.in/ns/ext/presets/presets.h"

#include "lilv_internal.h"

LILV_API
LilvWorld*
lilv_world_new(void)
{
	LilvWorld* world = (LilvWorld*)malloc(sizeof(LilvWorld));

	world->world = sord_world_new();
	if (!world->world)
		goto fail;

	world->model = sord_new(world->world, SORD_SPO|SORD_OPS, true);
	if (!world->model)
		goto fail;

	world->specs          = NULL;
	world->plugin_classes = lilv_plugin_classes_new();
	world->plugins        = lilv_plugins_new();
	world->loaded_files   = zix_tree_new(
		false, lilv_resource_node_cmp, NULL, (ZixDestroyFunc)lilv_node_free);

#ifdef LILV_NEW_LV2
	world->libs = zix_tree_new(
		false, lilv_header_compare_by_uri, NULL, NULL);
#endif

#define NS_DCTERMS "http://purl.org/dc/terms/"
#define NS_DYNMAN  "http://lv2plug.in/ns/ext/dynmanifest#"

#define NEW_URI(uri) sord_new_uri(world->world, (const uint8_t*)uri)

	world->uris.dc_replaces         = NEW_URI(NS_DCTERMS   "replaces");
	world->uris.dman_DynManifest    = NEW_URI(NS_DYNMAN    "DynManifest");
	world->uris.doap_name           = NEW_URI(LILV_NS_DOAP "name");
	world->uris.lv2_Plugin          = NEW_URI(LV2_CORE__Plugin);
	world->uris.lv2_Specification   = NEW_URI(LV2_CORE__Specification);
	world->uris.lv2_appliesTo       = NEW_URI(LV2_CORE__appliesTo);
	world->uris.lv2_binary          = NEW_URI(LV2_CORE__binary);
	world->uris.lv2_default         = NEW_URI(LV2_CORE__default);
	world->uris.lv2_designation     = NEW_URI(LV2_CORE__designation);
	world->uris.lv2_extensionData   = NEW_URI(LV2_CORE__extensionData);
	world->uris.lv2_index           = NEW_URI(LV2_CORE__index);
	world->uris.lv2_maximum         = NEW_URI(LV2_CORE__maximum);
	world->uris.lv2_minimum         = NEW_URI(LV2_CORE__minimum);
	world->uris.lv2_name            = NEW_URI(LV2_CORE__name);
	world->uris.lv2_optionalFeature = NEW_URI(LV2_CORE__optionalFeature);
	world->uris.lv2_port            = NEW_URI(LV2_CORE__port);
	world->uris.lv2_portProperty    = NEW_URI(LV2_CORE__portProperty);
	world->uris.lv2_reportsLatency  = NEW_URI(LV2_CORE__reportsLatency);
	world->uris.lv2_requiredFeature = NEW_URI(LV2_CORE__requiredFeature);
	world->uris.lv2_symbol          = NEW_URI(LV2_CORE__symbol);
	world->uris.pset_value          = NEW_URI(LV2_PRESETS__value);
	world->uris.rdf_a               = NEW_URI(LILV_NS_RDF  "type");
	world->uris.rdf_value           = NEW_URI(LILV_NS_RDF  "value");
	world->uris.rdfs_Class          = NEW_URI(LILV_NS_RDFS "Class");
	world->uris.rdfs_label          = NEW_URI(LILV_NS_RDFS "label");
	world->uris.rdfs_seeAlso        = NEW_URI(LILV_NS_RDFS "seeAlso");
	world->uris.rdfs_subClassOf     = NEW_URI(LILV_NS_RDFS "subClassOf");
	world->uris.xsd_base64Binary    = NEW_URI(LILV_NS_XSD  "base64Binary");
	world->uris.xsd_boolean         = NEW_URI(LILV_NS_XSD  "boolean");
	world->uris.xsd_decimal         = NEW_URI(LILV_NS_XSD  "decimal");
	world->uris.xsd_double          = NEW_URI(LILV_NS_XSD  "double");
	world->uris.xsd_integer         = NEW_URI(LILV_NS_XSD  "integer");
	world->uris.null_uri            = NULL;

	world->lv2_plugin_class = lilv_plugin_class_new(
		world, NULL, world->uris.lv2_Plugin, "Plugin");
	assert(world->lv2_plugin_class);

	world->n_read_files        = 0;
	world->opt.filter_language = true;
	world->opt.dyn_manifest    = true;

	return world;

fail:
	/* keep on rockin' in the */ free(world);
	return NULL;
}

LILV_API
void
lilv_world_free(LilvWorld* world)
{
	if (!world) {
		return;
	}

	lilv_plugin_class_free(world->lv2_plugin_class);
	world->lv2_plugin_class = NULL;

	for (SordNode** n = (SordNode**)&world->uris; *n; ++n) {
		sord_node_free(world->world, *n);
	}

	for (LilvSpec* spec = world->specs; spec;) {
		LilvSpec* next = spec->next;
		sord_node_free(world->world, spec->spec);
		sord_node_free(world->world, spec->bundle);
		lilv_nodes_free(spec->data_uris);
		free(spec);
		spec = next;
	}
	world->specs = NULL;

	LILV_FOREACH(plugins, i, world->plugins) {
		const LilvPlugin* p = lilv_plugins_get(world->plugins, i);
		lilv_plugin_free((LilvPlugin*)p);
	}
	zix_tree_free((ZixTree*)world->plugins);
	world->plugins = NULL;

	zix_tree_free((ZixTree*)world->loaded_files);
	world->loaded_files = NULL;

#ifdef LILV_NEW_LV2
	zix_tree_free((ZixTree*)world->libs);
	world->libs = NULL;
#endif

	zix_tree_free((ZixTree*)world->plugin_classes);
	world->plugin_classes = NULL;

	sord_free(world->model);
	world->model = NULL;

	sord_world_free(world->world);
	world->world = NULL;

	free(world);
}

LILV_API
void
lilv_world_set_option(LilvWorld*      world,
                      const char*     option,
                      const LilvNode* value)
{
	if (!strcmp(option, LILV_OPTION_DYN_MANIFEST)) {
		if (lilv_node_is_bool(value)) {
			world->opt.dyn_manifest = lilv_node_as_bool(value);
			return;
		}
	} else if (!strcmp(option, LILV_OPTION_FILTER_LANG)) {
		if (lilv_node_is_bool(value)) {
			world->opt.filter_language = lilv_node_as_bool(value);
			return;
		}
	}
	LILV_WARNF("Unrecognized or invalid option `%s'\n", option);
}

LILV_API
LilvNodes*
lilv_world_find_nodes(LilvWorld*      world,
                      const LilvNode* subject,
                      const LilvNode* predicate,
                      const LilvNode* object)
{
	if (subject && !lilv_node_is_uri(subject) && !lilv_node_is_blank(subject)) {
		LILV_ERRORF("Subject `%s' is not a resource\n",
		            sord_node_get_string(subject->node));
		return NULL;
	} else if (!lilv_node_is_uri(predicate)) {
		LILV_ERRORF("Predicate `%s' is not a URI\n",
		            sord_node_get_string(predicate->node));
		return NULL;
	} else if (!subject && !object) {
		LILV_ERROR("Both subject and object are NULL\n");
		return NULL;
	}
	
	return lilv_world_find_nodes_internal(
		world,
		subject ? subject->node : NULL,
		predicate->node,
		object ? object->node : NULL);
}

LILV_API
LilvNode*
lilv_world_get(LilvWorld*      world,
               const LilvNode* subject,
               const LilvNode* predicate,
               const LilvNode* object)
{
	SordNode* snode = sord_get(world->model,
	                           subject   ? subject->node   : NULL,
	                           predicate ? predicate->node : NULL,
	                           object    ? object->node    : NULL,
	                           NULL);
	LilvNode* lnode = lilv_node_new_from_node(world, snode);
	sord_node_free(world->world, snode);
	return lnode;
}

SordIter*
lilv_world_query_internal(LilvWorld*      world,
                          const SordNode* subject,
                          const SordNode* predicate,
                          const SordNode* object)
{
	return sord_search(world->model, subject, predicate, object, NULL);
}

bool
lilv_world_ask_internal(LilvWorld*      world,
                        const SordNode* subject,
                        const SordNode* predicate,
                        const SordNode* object)
{
	return sord_ask(world->model, subject, predicate, object, NULL);
}

LILV_API
bool
lilv_world_ask(LilvWorld*      world,
               const LilvNode* subject,
               const LilvNode* predicate,
               const LilvNode* object)
{
	return sord_ask(
		world->model, subject->node, predicate->node, object->node, NULL);
}

LilvNodes*
lilv_world_find_nodes_internal(LilvWorld*      world,
                               const SordNode* subject,
                               const SordNode* predicate,
                               const SordNode* object)
{
	return lilv_nodes_from_stream_objects(
		world,
		lilv_world_query_internal(world, subject, predicate, object),
		(object == NULL) ? SORD_OBJECT : SORD_SUBJECT);
}

static SerdNode
lilv_new_uri_relative_to_base(const uint8_t* uri_str,
                              const uint8_t* base_uri_str)
{
	SerdURI base_uri;
	if (serd_uri_parse(base_uri_str, &base_uri)) {
		return SERD_NODE_NULL;
	}

	SerdURI ignored;
	return serd_node_new_uri_from_string(uri_str, &base_uri, &ignored);
}

const uint8_t*
lilv_world_blank_node_prefix(LilvWorld* world)
{
	static char str[32];
	snprintf(str, sizeof(str), "%d", world->n_read_files++);
	return (const uint8_t*)str;
}

/** Comparator for sequences (e.g. world->plugins). */
int
lilv_header_compare_by_uri(const void* a, const void* b, void* user_data)
{
	const struct LilvHeader* const header_a = (const struct LilvHeader*)a;
	const struct LilvHeader* const header_b = (const struct LilvHeader*)b;
	return strcmp(lilv_node_as_uri(header_a->uri),
	              lilv_node_as_uri(header_b->uri));
}

/** Get an element of a collection of any object with an LilvHeader by URI. */
struct LilvHeader*
lilv_collection_get_by_uri(const ZixTree*  const_seq,
                           const LilvNode* uri)
{
	if (!lilv_node_is_uri(uri)) {
		return NULL;
	}

	ZixTree*          seq = (ZixTree*)const_seq;
	struct LilvHeader key = { NULL, (LilvNode*)uri };

	ZixTreeIter* i  = NULL;
	ZixStatus    st = zix_tree_find(seq, &key, &i);
	if (!st) {
		return (struct LilvHeader*)zix_tree_get(i);
	}

	return NULL;
}

static void
lilv_world_add_spec(LilvWorld*      world,
                    const SordNode* specification_node,
                    const SordNode* bundle_node)
{
	LilvSpec* spec = (LilvSpec*)malloc(sizeof(LilvSpec));
	spec->spec      = sord_node_copy(specification_node);
	spec->bundle    = sord_node_copy(bundle_node);
	spec->data_uris = lilv_nodes_new();

	// Add all plugin data files (rdfs:seeAlso)
	SordIter* files = sord_search(
		world->model,
		specification_node,
		world->uris.rdfs_seeAlso,
		NULL,
		NULL);
	FOREACH_MATCH(files) {
		const SordNode* file_node = sord_iter_get_node(files, SORD_OBJECT);
		zix_tree_insert((ZixTree*)spec->data_uris,
		                lilv_node_new_from_node(world, file_node),
		                NULL);
	}
	sord_iter_free(files);

	// Add specification to world specification list
	spec->next   = world->specs;
	world->specs = spec;
}

static void
lilv_world_add_plugin(LilvWorld*       world,
                      const SordNode*  plugin_node,
                      SerdNode*        manifest_uri,
                      void*            dynmanifest,
                      const SordNode*  bundle_node)
{
	LilvNode* plugin_uri = lilv_node_new_from_node(world, plugin_node);

	const LilvPlugin* last = lilv_plugins_get_by_uri(world->plugins,
	                                                 plugin_uri);
	if (last) {
		LILV_ERRORF("Duplicate plugin <%s>\n", lilv_node_as_uri(plugin_uri));
		LILV_ERRORF("... found in %s\n", lilv_node_as_string(
			            lilv_plugin_get_bundle_uri(last)));
		LILV_ERRORF("... and      %s\n", sord_node_get_string(bundle_node));
		lilv_node_free(plugin_uri);
		return;
	}

	// Create LilvPlugin
	LilvNode*   bundle_uri = lilv_node_new_from_node(world, bundle_node);
	LilvPlugin* plugin     = lilv_plugin_new(world, plugin_uri, bundle_uri);

	// Add manifest as plugin data file (as if it were rdfs:seeAlso)
	zix_tree_insert((ZixTree*)plugin->data_uris,
	                lilv_new_uri(world, (const char*)manifest_uri->buf),
	                NULL);

#ifdef LILV_DYN_MANIFEST
	// Set dynamic manifest library URI, if applicable
	if (dynmanifest) {
		plugin->dynmanifest = (LilvDynManifest*)dynmanifest;
		++((LilvDynManifest*)dynmanifest)->refs;
	}
#endif

	// Add all plugin data files (rdfs:seeAlso)
	SordIter* files = sord_search(
		world->model,
		plugin_node,
		world->uris.rdfs_seeAlso,
		NULL,
		NULL);
	FOREACH_MATCH(files) {
		const SordNode* file_node = sord_iter_get_node(files, SORD_OBJECT);
		zix_tree_insert((ZixTree*)plugin->data_uris,
		                lilv_node_new_from_node(world, file_node),
		                NULL);
	}
	sord_iter_free(files);

	// Add plugin to world plugin sequence
	zix_tree_insert((ZixTree*)world->plugins, plugin, NULL);
}

static void
lilv_world_load_dyn_manifest(LilvWorld* world,
                             SordNode*  bundle_node,
                             SerdNode   manifest_uri)
{
#ifdef LILV_DYN_MANIFEST
	if (!world->opt.dyn_manifest) {
		return;
	}

	typedef void* LV2_Dyn_Manifest_Handle;
	LV2_Dyn_Manifest_Handle handle = NULL;

	// ?dman a dynman:DynManifest
	SordIter* dmanifests = sord_search(
		world->model,
		NULL,
		world->uris.rdf_a,
		world->uris.dman_DynManifest,
		bundle_node);
	FOREACH_MATCH(dmanifests) {
		const SordNode* dmanifest = sord_iter_get_node(dmanifests, SORD_SUBJECT);

		// ?dman lv2:binary ?binary
		SordIter* binaries = sord_search(
			world->model,
			dmanifest,
			world->uris.lv2_binary,
			NULL,
			bundle_node);
		if (sord_iter_end(binaries)) {
			sord_iter_free(binaries);
			LILV_ERRORF("Dynamic manifest in <%s> has no binaries, ignored\n",
			            sord_node_get_string(bundle_node));
			continue;
		}

		// Get binary path
		const SordNode* binary   = sord_iter_get_node(binaries, SORD_OBJECT);
		const uint8_t*  lib_uri  = sord_node_get_string(binary);
		const char*     lib_path = lilv_uri_to_path((const char*)lib_uri);
		if (!lib_path) {
			LILV_ERROR("No dynamic manifest library path\n");
			sord_iter_free(binaries);
			continue;
		}

		// Open library
		void* lib = dlopen(lib_path, RTLD_LAZY);
		if (!lib) {
			LILV_ERRORF("Failed to open dynmanifest library `%s'\n", lib_path);
			sord_iter_free(binaries);
			continue;
		}

		// Open dynamic manifest
		typedef int (*OpenFunc)(LV2_Dyn_Manifest_Handle*,
		                        const LV2_Feature *const *);
		OpenFunc dmopen = (OpenFunc)lilv_dlfunc(lib, "lv2_dyn_manifest_open");
		if (!dmopen || dmopen(&handle, &dman_features)) {
			LILV_ERRORF("No `lv2_dyn_manifest_open' in `%s'\n", lib_path);
			sord_iter_free(binaries);
			dlclose(lib);
			continue;
		}

		// Get subjects (the data that would be in manifest.ttl)
		typedef int (*GetSubjectsFunc)(LV2_Dyn_Manifest_Handle, FILE*);
		GetSubjectsFunc get_subjects_func = (GetSubjectsFunc)lilv_dlfunc(
			lib, "lv2_dyn_manifest_get_subjects");
		if (!get_subjects_func) {
			LILV_ERRORF("No `lv2_dyn_manifest_get_subjects' in `%s'\n",
			            lib_path);
			sord_iter_free(binaries);
			dlclose(lib);
			continue;
		}

		LilvDynManifest* desc = malloc(sizeof(LilvDynManifest));
		desc->bundle = lilv_node_new_from_node(world, bundle_node);
		desc->lib    = lib;
		desc->handle = handle;
		desc->refs   = 0;

		// Generate data file
		FILE* fd = tmpfile();
		get_subjects_func(handle, fd);
		rewind(fd);

		// Parse generated data file
		const SerdNode* base   = sord_node_to_serd_node(dmanifest);
		SerdEnv*        env    = serd_env_new(base);
		SerdReader*     reader = sord_new_reader(
			world->model, env, SERD_TURTLE, sord_node_copy(dmanifest));
		serd_reader_add_blank_prefix(reader,
		                             lilv_world_blank_node_prefix(world));
		serd_reader_read_file_handle(reader, fd,
		                             (const uint8_t*)"(dyn-manifest)");
		serd_reader_free(reader);
		serd_env_free(env);

		// Close (and automatically delete) temporary data file
		fclose(fd);

		// ?plugin a lv2:Plugin
		SordIter* plug_results = sord_search(
			world->model,
			NULL,
			world->uris.rdf_a,
			world->uris.lv2_Plugin,
			dmanifest);
		FOREACH_MATCH(plug_results) {
			const SordNode* plugin_node = sord_iter_get_node(plug_results, SORD_SUBJECT);
			lilv_world_add_plugin(world, plugin_node,
			                      &manifest_uri, desc, bundle_node);
		}
		sord_iter_free(plug_results);

		sord_iter_free(binaries);
	}
	sord_iter_free(dmanifests);
#endif  // LILV_DYN_MANIFEST
}

LILV_API
void
lilv_world_load_bundle(LilvWorld* world, LilvNode* bundle_uri)
{
	if (!lilv_node_is_uri(bundle_uri)) {
		LILV_ERRORF("Bundle URI `%s' is not a URI\n",
		            sord_node_get_string(bundle_uri->node));
		return;
	}

	SordNode* bundle_node = bundle_uri->node;

	SerdNode manifest_uri = lilv_new_uri_relative_to_base(
		(const uint8_t*)"manifest.ttl",
		(const uint8_t*)sord_node_get_string(bundle_node));

	SerdEnv*    env    = serd_env_new(&manifest_uri);
	SerdReader* reader = sord_new_reader(world->model, env, SERD_TURTLE,
	                                     bundle_node);
	serd_reader_add_blank_prefix(reader, lilv_world_blank_node_prefix(world));

	SerdStatus st = serd_reader_read_file(reader, manifest_uri.buf);
	serd_reader_free(reader);
	serd_env_free(env);
	if (st) {
		LILV_ERRORF("Error reading %s\n", manifest_uri.buf);
		return;
	}

	// ?plugin a lv2:Plugin
	SordIter* plug_results = sord_search(
		world->model,
		NULL,
		world->uris.rdf_a,
		world->uris.lv2_Plugin,
		bundle_node);
	FOREACH_MATCH(plug_results) {
		const SordNode* plugin_node = sord_iter_get_node(plug_results, SORD_SUBJECT);
		lilv_world_add_plugin(world, plugin_node,
		                      &manifest_uri, NULL, bundle_node);
	}
	sord_iter_free(plug_results);

	lilv_world_load_dyn_manifest(world, bundle_node, manifest_uri);

	// ?specification a lv2:Specification
	SordIter* spec_results = sord_search(
		world->model,
		NULL,
		world->uris.rdf_a,
		world->uris.lv2_Specification,
		bundle_node);
	FOREACH_MATCH(spec_results) {
		const SordNode* spec = sord_iter_get_node(spec_results, SORD_SUBJECT);
		lilv_world_add_spec(world, spec, bundle_node);
	}
	sord_iter_free(spec_results);

	serd_node_free(&manifest_uri);
}

static void
load_dir_entry(const char* dir, const char* name, void* data)
{
	LilvWorld* world = (LilvWorld*)data;
	if (!strcmp(name, ".") || !strcmp(name, ".."))
		return;

	const char* scheme  = (dir[0] == '/') ? "file://" : "file:///";
	char*       uri     = lilv_strjoin(scheme, dir, "/", name, "/", NULL);
	LilvNode*   uri_val = lilv_new_uri(world, uri);

	lilv_world_load_bundle(world, uri_val);
	lilv_node_free(uri_val);
	free(uri);
}

/** Load all bundles in the directory at @a dir_path. */
static void
lilv_world_load_directory(LilvWorld* world, const char* dir_path)
{
	char* path = lilv_expand(dir_path);
	if (!path) {
		LILV_WARNF("Empty path `%s'\n", path);
		return;
	}

	lilv_dir_for_each(path, world, load_dir_entry);
	free(path);
}

static bool
is_path_sep(char c)
{
	return c == LILV_PATH_SEP[0];
}

static const char*
first_path_sep(const char* path)
{
	for (const char* p = path; *p != '\0'; ++p) {
		if (is_path_sep(*p)) {
			return p;
		}
	}
	return NULL;
}

/** Load all bundles found in @a lv2_path.
 * @param lv2_path A colon-delimited list of directories.  These directories
 * should contain LV2 bundle directories (ie the search path is a list of
 * parent directories of bundles, not a list of bundle directories).
 */
static void
lilv_world_load_path(LilvWorld*  world,
                     const char* lv2_path)
{
	while (lv2_path[0] != '\0') {
		const char* const sep = first_path_sep(lv2_path);
		if (sep) {
			const size_t dir_len = sep - lv2_path;
			char* const  dir     = (char*)malloc(dir_len + 1);
			memcpy(dir, lv2_path, dir_len);
			dir[dir_len] = '\0';
			lilv_world_load_directory(world, dir);
			free(dir);
			lv2_path += dir_len + 1;
		} else {
			lilv_world_load_directory(world, lv2_path);
			lv2_path = "\0";
		}
	}
}

static void
lilv_world_load_specifications(LilvWorld* world)
{
	for (LilvSpec* spec = world->specs; spec; spec = spec->next) {
		LILV_FOREACH(nodes, f, spec->data_uris) {
			LilvNode* file = (LilvNode*)lilv_collection_get(spec->data_uris, f);

			const SerdNode* node   = sord_node_to_serd_node(file->node);
			SerdEnv*        env    = serd_env_new(node);
			SerdReader*     reader = sord_new_reader(world->model, env,
			                                         SERD_TURTLE, NULL);
			serd_reader_add_blank_prefix(reader,
			                             lilv_world_blank_node_prefix(world));
			serd_reader_read_file(reader, node->buf);
			serd_reader_free(reader);
			serd_env_free(env);
		}
	}
}

static void
lilv_world_load_plugin_classes(LilvWorld* world)
{
	/* FIXME: This loads all classes, not just lv2:Plugin subclasses.
	   However, if the host gets all the classes via lilv_plugin_class_get_children
	   starting with lv2:Plugin as the root (which is e.g. how a host would build
	   a menu), they won't be seen anyway...
	*/

	SordIter* classes = sord_search(
		world->model,
		NULL,
		world->uris.rdf_a,
		world->uris.rdfs_Class,
		NULL);
	FOREACH_MATCH(classes) {
		const SordNode* class_node = sord_iter_get_node(classes, SORD_SUBJECT);

		// Get parents (superclasses)
		SordIter* parents = sord_search(
			world->model,
			class_node,
			world->uris.rdfs_subClassOf,
			NULL,
			NULL);

		if (sord_iter_end(parents)) {
			sord_iter_free(parents);
			continue;
		}

		const SordNode* parent_node = sord_iter_get_node(parents, SORD_OBJECT);
		sord_iter_free(parents);

		if (!sord_node_get_type(parent_node) == SORD_URI) {
			// Class parent is not a resource, ignore (e.g. owl restriction)
			continue;
		}

		// Get labels
		SordIter* labels = sord_search(
			world->model,
			class_node,
			world->uris.rdfs_label,
			NULL,
			NULL);

		if (sord_iter_end(labels)) {
			sord_iter_free(labels);
			continue;
		}

		const SordNode* label_node = sord_iter_get_node(labels, SORD_OBJECT);
		const uint8_t*  label      = sord_node_get_string(label_node);
		sord_iter_free(labels);

		LilvPluginClass* pclass = lilv_plugin_class_new(
			world, parent_node, class_node, (const char*)label);
		if (pclass) {
			zix_tree_insert((ZixTree*)world->plugin_classes, pclass, NULL);
		}
	}
	sord_iter_free(classes);
}

LILV_API
void
lilv_world_load_all(LilvWorld* world)
{
	const char* lv2_path = getenv("LV2_PATH");
	if (!lv2_path)
		lv2_path = LILV_DEFAULT_LV2_PATH;

	// Discover bundles and read all manifest files into model
	lilv_world_load_path(world, lv2_path);

	LILV_FOREACH(plugins, p, world->plugins) {
		const LilvPlugin* plugin = (const LilvPlugin*)lilv_collection_get(
			(ZixTree*)world->plugins, p);

		// ?new dc:replaces plugin
		SordIter* replacement = sord_search(
			world->model,
			NULL,
			world->uris.dc_replaces,
			lilv_node_as_node(lilv_plugin_get_uri(plugin)),
			NULL);
		if (!sord_iter_end(replacement)) {
			/* TODO: Check if replacement is actually a known plugin,
			   though this is expensive...
			*/
			((LilvPlugin*)plugin)->replaced = true;
		}
		sord_iter_free(replacement);
	}

	// Query out things to cache
	lilv_world_load_specifications(world);
	lilv_world_load_plugin_classes(world);
}

LILV_API
int
lilv_world_load_resource(LilvWorld*      world,
                         const LilvNode* resource)
{
	if (!lilv_node_is_uri(resource) && !lilv_node_is_blank(resource)) {
		LILV_ERRORF("Node `%s' is not a resource\n",
		            sord_node_get_string(resource->node));
		return -1;
	}

	int       n_read = 0;
	SordIter* files  = sord_search(world->model,
	                               resource->node,
	                               world->uris.rdfs_seeAlso,
	                               NULL, NULL);
	FOREACH_MATCH(files) {
		const SordNode* file      = sord_iter_get_node(files, SORD_OBJECT);
		const uint8_t*  str       = sord_node_get_string(file);
		LilvNode*       file_node = lilv_node_new_from_node(world, file);
		ZixTreeIter*    iter;
		if (zix_tree_find((ZixTree*)world->loaded_files, file_node, &iter)) {
			if (sord_node_get_type(file) == SORD_URI) {
				const SerdNode* base   = sord_node_to_serd_node(file);
				SerdEnv*        env    = serd_env_new(base);
				SerdReader*     reader = sord_new_reader(
					world->model, env, SERD_TURTLE, (SordNode*)file);
				serd_reader_add_blank_prefix(
					reader, lilv_world_blank_node_prefix(world));
				if (!serd_reader_read_file(reader, str)) {
					++n_read;
					zix_tree_insert(
						(ZixTree*)world->loaded_files, file_node, NULL);
					file_node = NULL;  // prevent deletion...
				} else {
					LILV_ERRORF("Error loading resource `%s'\n", str);
				}
				serd_reader_free(reader);
				serd_env_free(env);
			} else {
				LILV_ERRORF("rdfs:seeAlso node `%s' is not a URI\n", str);
			}
		}
		lilv_node_free(file_node);  // ...here
	}
	sord_iter_free(files);

	return n_read;
}

LILV_API
const LilvPluginClass*
lilv_world_get_plugin_class(const LilvWorld* world)
{
	return world->lv2_plugin_class;
}

LILV_API
const LilvPluginClasses*
lilv_world_get_plugin_classes(const LilvWorld* world)
{
	return world->plugin_classes;
}

LILV_API
const LilvPlugins*
lilv_world_get_all_plugins(const LilvWorld* world)
{
	return world->plugins;
}