/* SLV2
 * Copyright (C) 2007-2011 David Robillard <http://drobilla.net>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _XOPEN_SOURCE 500

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

#include <dirent.h>
#include <wordexp.h>
#ifdef SLV2_DYN_MANIFEST
#include <dlfcn.h>
#endif

#include "slv2_internal.h"

static void
slv2_world_set_prefix(SLV2World world, const char* name, const char* uri)
{
	const SerdNode name_node = serd_node_from_string(SERD_LITERAL,
	                                                 (const uint8_t*)name);
	const SerdNode uri_node  = serd_node_from_string(SERD_URI,
	                                                 (const uint8_t*)uri);
	serd_env_add(world->namespaces, &name_node, &uri_node);
}

SLV2_API
SLV2World
slv2_world_new()
{
	SLV2World world = (SLV2World)malloc(sizeof(struct _SLV2World));

	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->plugin_classes = slv2_plugin_classes_new();
	world->plugins        = slv2_plugins_new();

#define NS_DYNMAN (const uint8_t*)"http://lv2plug.in/ns/ext/dynmanifest#"

#define NEW_URI(uri)     sord_new_uri(world->world, uri)
#define NEW_URI_VAL(uri) slv2_value_new_from_node( \
		world, sord_new_uri(world->world, uri));

	world->dyn_manifest_node       = NEW_URI(NS_DYNMAN    "DynManifest");
	world->lv2_specification_node  = NEW_URI(SLV2_NS_LV2  "Specification");
	world->lv2_plugin_node         = NEW_URI(SLV2_NS_LV2  "Plugin");
	world->lv2_binary_node         = NEW_URI(SLV2_NS_LV2  "binary");
	world->lv2_default_node        = NEW_URI(SLV2_NS_LV2  "default");
	world->lv2_minimum_node        = NEW_URI(SLV2_NS_LV2  "minimum");
	world->lv2_maximum_node        = NEW_URI(SLV2_NS_LV2  "maximum");
	world->lv2_port_node           = NEW_URI(SLV2_NS_LV2  "port");
	world->lv2_portproperty_node   = NEW_URI(SLV2_NS_LV2  "portProperty");
	world->lv2_reportslatency_node = NEW_URI(SLV2_NS_LV2  "reportsLatency");
	world->lv2_index_node          = NEW_URI(SLV2_NS_LV2  "index");
	world->lv2_symbol_node         = NEW_URI(SLV2_NS_LV2  "symbol");
	world->rdf_a_node              = NEW_URI(SLV2_NS_RDF  "type");
	world->rdf_value_node          = NEW_URI(SLV2_NS_RDF  "value");
	world->rdfs_class_node         = NEW_URI(SLV2_NS_RDFS "Class");
	world->rdfs_label_node         = NEW_URI(SLV2_NS_RDFS "label");
	world->rdfs_seealso_node       = NEW_URI(SLV2_NS_RDFS "seeAlso");
	world->rdfs_subclassof_node    = NEW_URI(SLV2_NS_RDFS "subClassOf");
	world->slv2_bundleuri_node     = NEW_URI(SLV2_NS_SLV2 "bundleURI");
	world->slv2_dmanifest_node     = NEW_URI(SLV2_NS_SLV2 "dynamic-manifest");
	world->xsd_boolean_node        = NEW_URI(SLV2_NS_XSD  "boolean");
	world->xsd_decimal_node        = NEW_URI(SLV2_NS_XSD  "decimal");
	world->xsd_integer_node        = NEW_URI(SLV2_NS_XSD  "integer");

	world->doap_name_val = NEW_URI_VAL(SLV2_NS_DOAP "name");
	world->lv2_name_val  = NEW_URI_VAL(SLV2_NS_LV2  "name");

	world->lv2_plugin_class = slv2_plugin_class_new(
		world, NULL, world->lv2_plugin_node, "Plugin");
	assert(world->lv2_plugin_class);

	world->namespaces = serd_env_new();
	slv2_world_set_prefix(world, "rdf",   "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
	slv2_world_set_prefix(world, "rdfs",  "http://www.w3.org/2000/01/rdf-schema#");
	slv2_world_set_prefix(world, "doap",  "http://usefulinc.com/ns/doap#");
	slv2_world_set_prefix(world, "foaf",  "http://xmlns.com/foaf/0.1/");
	slv2_world_set_prefix(world, "lv2",   "http://lv2plug.in/ns/lv2core#");
	slv2_world_set_prefix(world, "lv2ev", "http://lv2plug.in/ns/ext/event#");

	world->n_read_files    = 0;
	world->filter_language = true;

	return world;

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

SLV2_API
void
slv2_world_free(SLV2World world)
{
	slv2_plugin_class_free(world->lv2_plugin_class);
	world->lv2_plugin_class = NULL;

	slv2_node_free(world->dyn_manifest_node);
	slv2_node_free(world->lv2_specification_node);
	slv2_node_free(world->lv2_plugin_node);
	slv2_node_free(world->lv2_binary_node);
	slv2_node_free(world->lv2_default_node);
	slv2_node_free(world->lv2_minimum_node);
	slv2_node_free(world->lv2_maximum_node);
	slv2_node_free(world->lv2_port_node);
	slv2_node_free(world->lv2_portproperty_node);
	slv2_node_free(world->lv2_reportslatency_node);
	slv2_node_free(world->lv2_index_node);
	slv2_node_free(world->lv2_symbol_node);
	slv2_node_free(world->rdf_a_node);
	slv2_node_free(world->rdf_value_node);
	slv2_node_free(world->rdfs_label_node);
	slv2_node_free(world->rdfs_seealso_node);
	slv2_node_free(world->rdfs_subclassof_node);
	slv2_node_free(world->rdfs_class_node);
	slv2_node_free(world->slv2_bundleuri_node);
	slv2_node_free(world->slv2_dmanifest_node);
	slv2_node_free(world->xsd_boolean_node);
	slv2_node_free(world->xsd_decimal_node);
	slv2_node_free(world->xsd_integer_node);

	slv2_value_free(world->doap_name_val);
	slv2_value_free(world->lv2_name_val);

#define SLV2_FOREACH(iter, seq) \
	for (GSequenceIter* (iter) = g_sequence_get_begin_iter(seq); \
	     (iter) != g_sequence_get_end_iter(seq); \
	     (iter) = g_sequence_iter_next(iter))

	SLV2_FOREACH(i, world->plugins) {
		SLV2Plugin p = g_sequence_get(i);
		slv2_plugin_free(p);
	}
	g_sequence_free(world->plugins);
	world->plugins = NULL;

	g_sequence_free(world->plugin_classes);
	world->plugin_classes = NULL;

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

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

	serd_env_free(world->namespaces);

	free(world);
}

SLV2_API
void
slv2_world_set_option(SLV2World       world,
                      const char*     option,
                      const SLV2Value value)
{
	if (!strcmp(option, SLV2_OPTION_FILTER_LANG)) {
		if (slv2_value_is_bool(value)) {
			world->filter_language = slv2_value_as_bool(value);
			return;
		}
	} else {
		SLV2_WARNF("Unrecognized or invalid option `%s'\n", option);
	}
}

static SLV2Matches
slv2_world_find_statements(SLV2World world,
                           SordModel model,
                           SLV2Node  subject,
                           SLV2Node  predicate,
                           SLV2Node  object,
                           SLV2Node  graph)
{
	SordQuad pat = { subject, predicate, object, graph };
	return sord_find(model, pat);
}

static SerdNode
slv2_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*
slv2_world_blank_node_prefix(SLV2World 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
slv2_header_compare_by_uri(const void* a, const void* b, void* user_data)
{
	const struct _SLV2Header* const header_a = (const struct _SLV2Header*)a;
	const struct _SLV2Header* const header_b = (const struct _SLV2Header*)b;
	return strcmp(slv2_value_as_uri(header_a->uri),
	              slv2_value_as_uri(header_b->uri));
}

/** Get an element of a sequence of any object with an SLV2Header by URI. */
struct _SLV2Header*
slv2_sequence_get_by_uri(GSequence* seq,
                         SLV2Value  uri)
{
	struct _SLV2Header key = { NULL, uri }; 
	GSequenceIter*     i   = g_sequence_search(
		seq, &key, slv2_header_compare_by_uri, NULL);

	// i points to where plugin would be inserted (not necessarily a match)

	if (!g_sequence_iter_is_end(i)) {
		SLV2Plugin p = g_sequence_get(i);
		if (slv2_value_equals(slv2_plugin_get_uri(p), uri)) {
			return (struct _SLV2Header*)p;
		}
	}

	if (!g_sequence_iter_is_begin(i)) {
		// Check if i is just past a match
		i = g_sequence_iter_prev(i);
		SLV2Plugin p = g_sequence_get(i);
		if (slv2_value_equals(slv2_plugin_get_uri(p), uri)) {
			return (struct _SLV2Header*)p;
		}
	}

	return NULL;
}

static void
slv2_world_add_plugin(SLV2World world,
                      SLV2Node  plugin_node,
                      SerdNode* manifest_uri,
                      SLV2Node  dyn_manifest_lib,
                      SLV2Node  bundle_node)
{
	SLV2Value plugin_uri  = slv2_value_new_from_node(world, plugin_node);

	SLV2Plugin last = slv2_plugins_get_by_uri(world->plugins, plugin_uri);
	if (last) {
		SLV2_ERRORF("Duplicate plugin <%s>\n", slv2_value_as_uri(plugin_uri));
		SLV2_ERRORF("... found in %s\n", slv2_value_as_string(
			            slv2_plugin_get_bundle_uri(last)));
		SLV2_ERRORF("... and      %s\n", sord_node_get_string(bundle_node));
		slv2_value_free(plugin_uri);
		return;
	}

	// Create SLV2Plugin
	SLV2Value  bundle_uri = slv2_value_new_from_node(world, bundle_node);
	SLV2Plugin plugin     = slv2_plugin_new(world, plugin_uri, bundle_uri);

	// Add manifest as plugin data file (as if it were rdfs:seeAlso)
	slv2_array_append(plugin->data_uris,
	                  slv2_value_new_uri(world, (const char*)manifest_uri->buf));

	// Set dynamic manifest library URI, if applicable
	if (dyn_manifest_lib) {
		plugin->dynman_uri = slv2_value_new_from_node(world, dyn_manifest_lib);
	}
		
	// Add all plugin data files (rdfs:seeAlso)
	SLV2Matches files = slv2_world_find_statements(
		world, world->model,
		plugin_node,
		world->rdfs_seealso_node,
		NULL,
		NULL);
	FOREACH_MATCH(files) {
		SLV2Node file_node = slv2_match_object(files);
		slv2_array_append(plugin->data_uris,
		                  slv2_value_new_from_node(world, file_node));
	}

	// Add plugin to world plugin sequence
	slv2_sequence_insert(world->plugins, plugin);
}

SLV2_API
void
slv2_world_load_bundle(SLV2World world, SLV2Value bundle_uri)
{
	if (!slv2_value_is_uri(bundle_uri)) {
		SLV2_ERROR("Bundle 'URI' is not a URI\n");
		return;
	}

	const SordNode bundle_node = bundle_uri->val.uri_val;

	SerdNode manifest_uri = slv2_new_uri_relative_to_base(
		(const uint8_t*)"manifest.ttl",
		(const uint8_t*)sord_node_get_string(bundle_node));

	sord_read_file(world->model, manifest_uri.buf, bundle_node,
	               slv2_world_blank_node_prefix(world));

	// ?plugin a lv2:Plugin
	SLV2Matches plug_results = slv2_world_find_statements(
		world, world->model,
		NULL,
		world->rdf_a_node,
		world->lv2_plugin_node,
		bundle_node);
	FOREACH_MATCH(plug_results) {
		SLV2Node plugin_node = slv2_match_subject(plug_results);
		slv2_world_add_plugin(world, plugin_node,
		                      &manifest_uri, NULL, bundle_node);
	}
	slv2_match_end(plug_results);

#ifdef SLV2_DYN_MANIFEST
	typedef void* LV2_Dyn_Manifest_Handle;
	LV2_Dyn_Manifest_Handle handle = NULL;

	// ?dman a dynman:DynManifest
	SLV2Matches dmanifests = slv2_world_find_statements(
		world, world->model,
		NULL,
		world->rdf_a_node,
		world->dyn_manifest_node,
		bundle_node);
	FOREACH_MATCH(dmanifests) {
		SLV2Node dmanifest = slv2_match_subject(dmanifests);

		// ?dman lv2:binary ?binary
		SLV2Matches binaries  = slv2_world_find_statements(
			world, world->model,
			dmanifest,
			world->lv2_binary_node,
			NULL,
			bundle_node);
		if (slv2_matches_end(binaries)) {
			slv2_match_end(binaries);
			SLV2_ERRORF("Dynamic manifest in <%s> has no binaries, ignored\n",
			            slv2_value_as_uri(bundle_uri));
			continue;
		}

		// Get binary path
		SLV2Node       binary   = slv2_node_copy(slv2_match_object(binaries));
		const uint8_t* lib_uri  = sord_node_get_string(binary);
		const char*    lib_path = slv2_uri_to_path((const char*)lib_uri);
		if (!lib_path)
			continue;

		// Open library
		void* lib = dlopen(lib_path, RTLD_LAZY);
		if (!lib)
			continue;

		// Open dynamic manifest
		typedef int (*OpenFunc)(LV2_Dyn_Manifest_Handle*, const LV2_Feature *const *);
		OpenFunc open_func = (OpenFunc)slv2_dlfunc(lib, "lv2_dyn_manifest_open");
		if (open_func)
			open_func(&handle, &dman_features);

		// Get subjects (the data that would be in manifest.ttl)
		typedef int (*GetSubjectsFunc)(LV2_Dyn_Manifest_Handle, FILE*);
		GetSubjectsFunc get_subjects_func = (GetSubjectsFunc)slv2_dlfunc(lib,
				"lv2_dyn_manifest_get_subjects");
		if (!get_subjects_func)
			continue;

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

		// Parse generated data file
		sord_read_file_handle(world->model, fd, lib_uri, bundle_node,
		                      slv2_world_blank_node_prefix(world));

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

		// ?plugin a lv2:Plugin
		SLV2Matches plug_results = slv2_world_find_statements(
			world, world->model,
			NULL,
			world->rdf_a_node,
			world->lv2_plugin_node,
			bundle_node);
		FOREACH_MATCH(plug_results) {
			SLV2Node plugin_node = slv2_match_subject(plug_results);
			slv2_world_add_plugin(world, plugin_node,
			                      &manifest_uri, binary, bundle_node);
		}
		slv2_match_end(plug_results);
	}
	slv2_match_end(dmanifests);
#endif // SLV2_DYN_MANIFEST
	
	// ?specification a lv2:Specification
	SLV2Matches spec_results = slv2_world_find_statements(
		world, world->model,
		NULL,
		world->rdf_a_node,
		world->lv2_specification_node,
		bundle_node);
	FOREACH_MATCH(spec_results) {
		SLV2Node spec = slv2_match_subject(spec_results);

		// Add ?specification rdfs:seeAlso <manifest.ttl>
		SordQuad see_also_tup = {
			slv2_node_copy(spec),
			world->rdfs_seealso_node,
			sord_new_uri(world->world, manifest_uri.buf),
			NULL
		};
		sord_add(world->model, see_also_tup);

		// Add ?specification slv2:bundleURI <file://some/path>
		SordQuad bundle_uri_tup = {
			slv2_node_copy(spec),
			slv2_node_copy(world->slv2_bundleuri_node),
			slv2_node_copy(bundle_uri->val.uri_val),
			NULL
		};
		sord_add(world->model, bundle_uri_tup);
	}
	slv2_match_end(spec_results);

	serd_node_free(&manifest_uri);
}

// Expand POSIX things in path (particularly ~)
static char*
expand(const char* path)
{
	char*     ret = NULL;
	wordexp_t p;

	wordexp(path, &p, 0);
	if (p.we_wordc == 0) {
		// Literal directory path (e.g. no variables or ~)
		ret = strdup(path);
	} else if (p.we_wordc == 1) {
		// Directory path expands (e.g. contains ~ or $FOO)
		ret = strdup(p.we_wordv[0]);
	} else {
		// Multiple expansions in a single directory path?
		fprintf(stderr, "lv2config: malformed path `%s' ignored\n", path);
	}

	wordfree(&p);
	return ret;
}

/** Load all bundles in the directory at @a dir_path. */
static void
slv2_world_load_directory(SLV2World world, const char* dir_path)
{
	char* path = expand(dir_path);
	if (!path) {
		return;
	}

	DIR* pdir = opendir(path);
	if (!pdir) {
		free(path);
		return;
	}

	struct dirent* pfile;
	while ((pfile = readdir(pdir))) {
		if (!strcmp(pfile->d_name, ".") || !strcmp(pfile->d_name, ".."))
			continue;

		char* uri = slv2_strjoin("file://",
		                         path, SLV2_DIR_SEP,
		                         pfile->d_name, SLV2_DIR_SEP,
		                         NULL);

		DIR* const bundle_dir = opendir(uri + 7);
		if (bundle_dir) {
			closedir(bundle_dir);
			SLV2Value uri_val = slv2_value_new_uri(world, uri);
			slv2_world_load_bundle(world, uri_val);
			slv2_value_free(uri_val);
		}

		free(uri);
	}

	free(path);
	closedir(pdir);
}

/** 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
slv2_world_load_path(SLV2World   world,
                     const char* lv2_path)
{
	while (lv2_path[0] != '\0') {
		const char* const sep = strchr(lv2_path, SLV2_PATH_SEP[0]);
		if (sep) {
			const size_t dir_len = sep - lv2_path;
			char* const  dir     = malloc(dir_len + 1);
			memcpy(dir, lv2_path, dir_len);
			dir[dir_len] = '\0';
			slv2_world_load_directory(world, dir);
			free(dir);
			lv2_path += dir_len + 1;
		} else {
			slv2_world_load_directory(world, lv2_path);
			lv2_path = "\0";
		}
	}
}

static void
slv2_world_load_specifications(SLV2World world)
{
	SLV2Matches specs = slv2_world_find_statements(
		world, world->model,
		NULL,
		world->rdf_a_node,
		world->lv2_specification_node,
		NULL);
	FOREACH_MATCH(specs) {
		SLV2Node    spec_node = slv2_match_subject(specs);
		SLV2Matches files     = slv2_world_find_statements(
			world, world->model,
			spec_node,
			world->rdfs_seealso_node,
			NULL,
			NULL);
		FOREACH_MATCH(files) {
			SLV2Node file_node = slv2_match_object(files);
			sord_read_file(world->model,
			               (const uint8_t*)sord_node_get_string(file_node),
			               NULL,
			               slv2_world_blank_node_prefix(world));
		}
		slv2_match_end(files);
	}
	slv2_match_end(specs);
}

static void
slv2_world_load_plugin_classes(SLV2World world)
{
	/* FIXME: This loads all classes, not just lv2:Plugin subclasses.
	   However, if the host gets all the classes via slv2_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...
	*/

	SLV2Matches classes = slv2_world_find_statements(
		world, world->model,
		NULL,
		world->rdf_a_node,
		world->rdfs_class_node,
		NULL);
	FOREACH_MATCH(classes) {
		SLV2Node class_node = slv2_match_subject(classes);

		// Get parents (superclasses)
		SLV2Matches parents = slv2_world_find_statements(
			world, world->model,
			class_node,
			world->rdfs_subclassof_node,
			NULL,
			NULL);

		if (slv2_matches_end(parents)) {
			slv2_match_end(parents);
			continue;
		}

		SLV2Node parent_node = slv2_node_copy(slv2_match_object(parents));
		slv2_match_end(parents);

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

		// Get labels
		SLV2Matches labels = slv2_world_find_statements(
			world, world->model,
			class_node,
			world->rdfs_label_node,
			NULL,
			NULL);

		if (slv2_matches_end(labels)) {
			slv2_match_end(labels);
			continue;
		}

		SLV2Node       label_node = slv2_node_copy(slv2_match_object(labels));
		const uint8_t* label      = (const uint8_t*)sord_node_get_string(label_node);
		slv2_match_end(labels);

		SLV2PluginClasses classes = world->plugin_classes;
		SLV2PluginClass   pclass  = slv2_plugin_class_new(
			world, parent_node, class_node, (const char*)label);

		if (pclass) {
			slv2_sequence_insert(classes, pclass);
		}

		slv2_node_free(parent_node);
		slv2_node_free(label_node);
	}
	slv2_match_end(classes);
}

SLV2_API
void
slv2_world_load_all(SLV2World world)
{
	const char* lv2_path = getenv("LV2_PATH");
	if (!lv2_path)
		lv2_path = SLV2_DEFAULT_LV2_PATH;

	// Discover bundles and read all manifest files into model
	slv2_world_load_path(world, lv2_path);

	// Query out things to cache
	slv2_world_load_specifications(world);
	slv2_world_load_plugin_classes(world);
}

SLV2_API
SLV2PluginClass
slv2_world_get_plugin_class(SLV2World world)
{
	return world->lv2_plugin_class;
}

SLV2_API
SLV2PluginClasses
slv2_world_get_plugin_classes(SLV2World world)
{
	return world->plugin_classes;
}

SLV2_API
SLV2Plugins
slv2_world_get_all_plugins(SLV2World world)
{
	return world->plugins;
}

SLV2_API
SLV2Plugins
slv2_world_get_plugins_by_filter(SLV2World world, bool (*include)(SLV2Plugin))
{
	SLV2Plugins result = slv2_plugins_new();

	const unsigned n = slv2_plugins_size(world->plugins);
	for (unsigned i = 0; i < n; ++i) {
		SLV2Plugin p = slv2_plugins_get_at(world->plugins, i);
		if (include(p))
			slv2_sequence_insert(result, p);
	}

	return result;
}

SLV2_API
SLV2Plugin
slv2_world_get_plugin_by_uri_string(SLV2World   world,
                                    const char* uri)
{
	SLV2Value  uri_val = slv2_value_new_uri(world, uri);
	SLV2Plugin plugin  = slv2_plugins_get_by_uri(world->plugins, uri_val);
	slv2_value_free(uri_val);
	return plugin;
}