#include <plugin.hpp>
#include <system.hpp>
#include <network.hpp>
#include <asset.hpp>
#include <string.hpp>
#include <app.hpp>
#include <app/common.hpp>
#include <plugin/callbacks.hpp>
#include <settings.hpp>

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/param.h> // for MAXPATHLEN
#include <fcntl.h>
#include <thread>
#include <map>
#include <stdexcept>

#define ZIP_STATIC
#include <zip.h>
#include <jansson.h>

#if defined ARCH_WIN
#include <windows.h>
#include <direct.h>
#define mkdir(_dir, _perms) _mkdir(_dir)
#else
#include <dlfcn.h>
#endif
#include <dirent.h>
#include <osdialog.h>


namespace rack {

namespace core {
void init(rack::plugin::Plugin *plugin);
} // namespace core

namespace plugin {


////////////////////
// private API
////////////////////

typedef void (*InitCallback)(Plugin*);

static InitCallback loadLibrary(Plugin *plugin) {
	// Load plugin library
	std::string libraryFilename;
#if defined ARCH_LIN
	libraryFilename = plugin->path + "/" + "plugin.so";
#elif defined ARCH_WIN
	libraryFilename = plugin->path + "/" + "plugin.dll";
#elif ARCH_MAC
	libraryFilename = plugin->path + "/" + "plugin.dylib";
#endif

	// Check file existence
	if (!system::isFile(libraryFilename)) {
		throw UserException(string::f("Library %s does not exist", libraryFilename.c_str()));
	}

	// Load dynamic/shared library
#if defined ARCH_WIN
	SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);
	HINSTANCE handle = LoadLibrary(libraryFilename.c_str());
	SetErrorMode(0);
	if (!handle) {
		int error = GetLastError();
		throw UserException(string::f("Failed to load library %s: code %d", libraryFilename.c_str(), error));
	}
#else
	void *handle = dlopen(libraryFilename.c_str(), RTLD_NOW);
	if (!handle) {
		throw UserException(string::f("Failed to load library %s: %s", libraryFilename.c_str(), dlerror()));
	}
#endif
	plugin->handle = handle;

	// Get plugin's init() function
	InitCallback initCallback;
#if defined ARCH_WIN
	initCallback = (InitCallback) GetProcAddress(handle, "init");
#else
	initCallback = (InitCallback) dlsym(handle, "init");
#endif
	if (!initCallback) {
		throw UserException(string::f("Failed to read init() symbol in %s", libraryFilename.c_str()));
	}

	return initCallback;
}


/** If path is blank, loads Core */
static Plugin *loadPlugin(std::string path) {
	Plugin *plugin = new Plugin;
	try {
		plugin->path = path;

		// Get modified timestamp
		if (path != "") {
			struct stat statbuf;
			if (!stat(path.c_str(), &statbuf)) {
#if defined ARCH_MAC
				plugin->modifiedTimestamp = (double) statbuf.st_mtimespec.tv_sec + statbuf.st_mtimespec.tv_nsec * 1e-9;
#elif defined ARCH_WIN
				plugin->modifiedTimestamp = (double) statbuf.st_mtime;
#elif defined ARCH_LIN
				plugin->modifiedTimestamp = (double) statbuf.st_mtim.tv_sec + statbuf.st_mtim.tv_nsec * 1e-9;
#endif
			}
		}
		// DEBUG("%lf", plugin->modifiedTimestamp);

		// Load plugin.json
		std::string metadataFilename = (path == "") ? asset::system("Core.json") : (path + "/plugin.json");
		FILE *file = fopen(metadataFilename.c_str(), "r");
		if (!file) {
			throw UserException(string::f("Metadata file %s does not exist", metadataFilename.c_str()));
		}
		DEFER({
			fclose(file);
		});

		json_error_t error;
		json_t *rootJ = json_loadf(file, 0, &error);
		if (!rootJ) {
			throw UserException(string::f("JSON parsing error at %s %d:%d %s", metadataFilename.c_str(), error.line, error.column, error.text));
		}
		DEFER({
			json_decref(rootJ);
		});

		// Call init callback
		InitCallback initCallback;
		if (path == "") {
			initCallback = core::init;
		}
		else {
			initCallback = loadLibrary(plugin);
		}
		initCallback(plugin);

		// Load manifest
		plugin->fromJson(rootJ);

		// Reject plugin if slug already exists
		Plugin *oldPlugin = getPlugin(plugin->slug);
		if (oldPlugin) {
			throw UserException(string::f("Plugin %s is already loaded, not attempting to load it again", plugin->slug.c_str()));
		}

		INFO("Loaded plugin %s v%s from %s", plugin->slug.c_str(), plugin->version.c_str(), path.c_str());
		plugins.push_back(plugin);
	}
	catch (UserException &e) {
		WARN("Could not load plugin %s: %s", path.c_str(), e.what());
		delete plugin;
		plugin = NULL;
	}
	return plugin;
}

static void loadPlugins(std::string path) {
	for (std::string pluginPath : system::getEntries(path)) {
		if (!system::isDirectory(pluginPath))
			continue;
		if (!loadPlugin(pluginPath)) {
			// Ignore bad plugins. They are reported in the log.
		}
	}
}

/** Returns 0 if successful */
static int extractZipHandle(zip_t *za, std::string dir) {
	int err;
	for (int i = 0; i < zip_get_num_entries(za, 0); i++) {
		zip_stat_t zs;
		err = zip_stat_index(za, i, 0, &zs);
		if (err) {
			WARN("zip_stat_index() failed: error %d", err);
			return err;
		}

		std::string path = dir + "/" + zs.name;

		if (path[path.size() - 1] == '/') {
			system::createDirectory(path);
			// HACK
			// Create and delete file to update the directory's mtime.
			std::string tmpPath = path + "/.tmp";
			FILE *tmpFile = fopen(tmpPath.c_str(), "w");
			fclose(tmpFile);
			std::remove(tmpPath.c_str());
		}
		else {
			zip_file_t *zf = zip_fopen_index(za, i, 0);
			if (!zf) {
				WARN("zip_fopen_index() failed");
				return -1;
			}

			FILE *outFile = fopen(path.c_str(), "wb");
			if (!outFile)
				continue;

			while (1) {
				char buffer[1 << 15];
				int len = zip_fread(zf, buffer, sizeof(buffer));
				if (len <= 0)
					break;
				fwrite(buffer, 1, len, outFile);
			}

			err = zip_fclose(zf);
			if (err) {
				WARN("zip_fclose() failed: error %d", err);
				return err;
			}
			fclose(outFile);
		}
	}
	return 0;
}

/** Returns 0 if successful */
static int extractZip(std::string filename, std::string path) {
	int err;
	zip_t *za = zip_open(filename.c_str(), 0, &err);
	if (!za) {
		WARN("Could not open zip %s: error %d", filename.c_str(), err);
		return err;
	}
	DEFER({
		zip_close(za);
	});

	err = extractZipHandle(za, path);
	return err;
}

static void extractPackages(std::string path) {
	std::string message;

	for (std::string packagePath : system::getEntries(path)) {
		if (string::filenameExtension(packagePath) != "zip")
			continue;
		INFO("Extracting package %s", packagePath.c_str());
		// Extract package
		if (extractZip(packagePath, path)) {
			WARN("Package %s failed to extract", packagePath.c_str());
			message += string::f("Could not extract package %s\n", packagePath.c_str());
			continue;
		}
		// Remove package
		if (remove(packagePath.c_str())) {
			WARN("Could not delete file %s: error %d", packagePath.c_str(), errno);
		}
	}
	if (!message.empty()) {
		osdialog_message(OSDIALOG_WARNING, OSDIALOG_OK, message.c_str());
	}
}

////////////////////
// public API
////////////////////

void init() {
	// Load Core
	loadPlugin("");

	// Get user plugins directory
	mkdir(asset::pluginsPath.c_str(), 0755);

	// Extract packages and load plugins
	extractPackages(asset::pluginsPath);
	loadPlugins(asset::pluginsPath);

	// If Fundamental wasn't loaded, copy the bundled Fundamental package and load it
	std::string fundamentalSrc = asset::system("Fundamental.zip");
	std::string fundamentalDir = asset::pluginsPath + "/Fundamental";
	if (!settings::devMode && !getPlugin("Fundamental") && system::isFile(fundamentalSrc)) {
		INFO("Extracting bundled Fundamental package");
		extractZip(fundamentalSrc.c_str(), asset::pluginsPath.c_str());
		loadPlugin(fundamentalDir);
	}

	// Sync in a detached thread
	if (!settings::devMode) {
		std::thread t([] {
			queryUpdates();
		});
		t.detach();
	}
}

void destroy() {
	for (Plugin *plugin : plugins) {
		// Free library handle
#if defined ARCH_WIN
		if (plugin->handle)
			FreeLibrary((HINSTANCE) plugin->handle);
#else
		if (plugin->handle)
			dlclose(plugin->handle);
#endif

		// For some reason this segfaults.
		// It might be best to let them leak anyway, because "crash on exit" issues would occur with badly-written plugins.
		// delete plugin;
	}
	plugins.clear();
}

void logIn(const std::string &email, const std::string &password) {
	loginStatus = "Logging in...";
	json_t *reqJ = json_object();
	json_object_set(reqJ, "email", json_string(email.c_str()));
	json_object_set(reqJ, "password", json_string(password.c_str()));
	std::string url = app::API_URL + "/token";
	json_t *resJ = network::requestJson(network::METHOD_POST, url, reqJ);
	json_decref(reqJ);

	if (!resJ) {
		loginStatus = "No response from server";
		return;
	}
	DEFER({
		json_decref(resJ);
	});

	json_t *errorJ = json_object_get(resJ, "error");
	if (errorJ) {
		const char *errorStr = json_string_value(errorJ);
		loginStatus = errorStr;
		return;
	}

	json_t *tokenJ = json_object_get(resJ, "token");
	if (!tokenJ) {
		loginStatus = "No token in response";
		return;
	}

	const char *tokenStr = json_string_value(tokenJ);
	settings::token = tokenStr;
	loginStatus = "";
	queryUpdates();
}

void logOut() {
	settings::token = "";
	updates.clear();
}

bool isLoggedIn() {
	return settings::token != "";
}

void queryUpdates() {
	if (settings::token.empty())
		return;

	updates.clear();
	updateStatus = "Querying for updates...";

	// Get user's plugins list
	std::string pluginsUrl = app::API_URL + "/plugins";
	json_t *pluginsReqJ = json_object();
	json_object_set(pluginsReqJ, "token", json_string(settings::token.c_str()));
	json_t *pluginsResJ = network::requestJson(network::METHOD_GET, pluginsUrl, pluginsReqJ);
	json_decref(pluginsReqJ);
	if (!pluginsResJ) {
		WARN("Request for user's plugins failed");
		updateStatus = "Could not query updates";
		return;
	}
	DEFER({
		json_decref(pluginsResJ);
	});

	json_t *errorJ = json_object_get(pluginsResJ, "error");
	if (errorJ) {
		WARN("Request for user's plugins returned an error: %s", json_string_value(errorJ));
		updateStatus = "Could not query updates";
		return;
	}

	// Get library manifests
	std::string manifestsUrl = app::API_URL + "/library/manifests";
	json_t *manifestsReq = json_object();
	json_object_set(manifestsReq, "version", json_string(app::API_VERSION.c_str()));
	json_t *manifestsResJ = network::requestJson(network::METHOD_GET, manifestsUrl, manifestsReq);
	json_decref(manifestsReq);
	if (!manifestsResJ) {
		WARN("Request for library manifests failed");
		updateStatus = "Could not query updates";
		return;
	}
	DEFER({
		json_decref(manifestsResJ);
	});

	json_t *manifestsJ = json_object_get(manifestsResJ, "manifests");
	json_t *pluginsJ = json_object_get(pluginsResJ, "plugins");

	size_t pluginIndex;
	json_t *pluginJ;
	json_array_foreach(pluginsJ, pluginIndex, pluginJ) {
		Update update;
		// Get plugin manifest
		update.pluginSlug = json_string_value(pluginJ);
		json_t *manifestJ = json_object_get(manifestsJ, update.pluginSlug.c_str());
		if (!manifestJ) {
			WARN("VCV account has plugin %s but no manifest was found", update.pluginSlug.c_str());
			continue;
		}

		// Get plugin name
		json_t *nameJ = json_object_get(manifestJ, "name");
		if (nameJ)
			update.pluginName = json_string_value(nameJ);

		// Get version
		json_t *versionJ = json_object_get(manifestJ, "version");
		if (!versionJ) {
			WARN("Plugin %s has no version in manifest", update.pluginSlug.c_str());
			continue;
		}
		update.version = json_string_value(versionJ);

		// Check if update is needed
		Plugin *p = getPlugin(update.pluginSlug);
		if (p && p->version == update.version)
			continue;

		// Check status
		json_t *statusJ = json_object_get(manifestJ, "status");
		if (!statusJ)
			continue;
		std::string status = json_string_value(statusJ);
		if (status != "available")
			continue;

		// Get changelog URL
		json_t *changelogUrlJ = json_object_get(manifestJ, "changelogUrl");
		if (changelogUrlJ) {
			update.changelogUrl = json_string_value(changelogUrlJ);
		}

		updates.push_back(update);
	}

	updateStatus = "";
}

bool hasUpdates() {
	for (Update &update : updates) {
		if (update.progress < 1.f)
			return true;
	}
	return false;
}

static bool isSyncingUpdate = false;
static bool isSyncingUpdates = false;

void syncUpdate(Update *update) {
	isSyncingUpdate = true;
	DEFER({
		isSyncingUpdate = false;
	});

	std::string downloadUrl = app::API_URL + "/download";
	downloadUrl += "?token=" + network::encodeUrl(settings::token);
	downloadUrl += "&slug=" + network::encodeUrl(update->pluginSlug);
	downloadUrl += "&version=" + network::encodeUrl(update->version);
	downloadUrl += "&arch=" + network::encodeUrl(app::APP_ARCH);

	INFO("Downloading plugin %s %s %s", update->pluginSlug.c_str(), update->version.c_str(), app::APP_ARCH.c_str());

	// Download zip
	std::string pluginDest = asset::pluginsPath + "/" + update->pluginSlug + ".zip";
	if (!network::requestDownload(downloadUrl, pluginDest, &update->progress)) {
		WARN("Plugin %s download was unsuccessful", update->pluginSlug.c_str());
		return;
	}
}

void syncUpdates() {
	isSyncingUpdates = true;
	DEFER({
		isSyncingUpdates = false;
	});

	if (settings::token.empty())
		return;

	for (Update &update : updates) {
		if (update.progress < 1.f)
			syncUpdate(&update);
	}
	restartRequested = true;
}

bool isSyncing() {
	return isSyncingUpdate || isSyncingUpdates;
}

Plugin *getPlugin(const std::string &pluginSlug) {
	std::string slug = normalizeSlug(pluginSlug);
	for (Plugin *plugin : plugins) {
		if (plugin->slug == slug) {
			return plugin;
		}
	}
	return NULL;
}

Model *getModel(const std::string &pluginSlug, const std::string &modelSlug) {
	Plugin *plugin = getPlugin(pluginSlug);
	if (!plugin)
		return NULL;
	Model *model = plugin->getModel(modelSlug);
	if (!model)
		return NULL;
	return model;
}


/** List of allowed tags in human display form, alphabetized.
All tags here should be in sentence caps for display consistency.
However, tags are case-insensitive in plugin metadata.
*/
const std::set<std::string> allowedTags = {
	"Arpeggiator",
	"Attenuator", // With a level knob and not much else.
	"Blank", // No parameters or ports. Serves no purpose except visual.
	"Chorus",
	"Clock generator",
	"Clock modulator", // Clock dividers, multipliers, etc.
	"Compressor", // With threshold, ratio, knee, etc parameters.
	"Controller", // Use only if the artist "performs" with this module. Simply having knobs is not enough. Examples: on-screen keyboard, XY pad.
	"Delay",
	"Digital",
	"Distortion",
	"Drum",
	"Dual", // The core functionality times two. If multiple channels are a requirement for the module to exist (ring modulator, mixer, etc), it is not a Dual module.
	"Dynamics",
	"Effect",
	"Envelope follower",
	"Envelope generator",
	"Equalizer",
	"Expander", // Expands the functionality of a "mother" module when placed next to it. Expanders should inherit the tags of its mother module.
	"External",
	"Flanger",
	"Function generator",
	"Granular",
	"LFO",
	"Limiter",
	"Logic",
	"Low pass gate",
	"MIDI",
	"Mixer",
	"Multiple",
	"Noise",
	"Panning",
	"Phaser",
	"Physical modeling",
	"Polyphonic",
	"Quad", // The core functionality times four. If multiple channels are a requirement for the module to exist (ring modulator, mixer, etc), it is not a Quad module.
	"Quantizer",
	"Random",
	"Recording",
	"Reverb",
	"Ring modulator",
	"Sample and hold",
	"Sampler",
	"Sequencer",
	"Slew limiter",
	"Switch",
	"Synth voice", // A synth voice must have, at the minimum, a built-in oscillator and envelope.
	"Tuner",
	"Utility", // Serves only extremely basic functions, like inverting, max, min, multiplying by 2, etc.
	"VCA",
	"VCF",
	"VCO",
	"Visual",
	"Vocoder",
	"Waveshaper",
};


/** List of common synonyms for allowed tags.
Aliases and tags must be lowercase.
*/
const std::map<std::string, std::string> tagAliases = {
	{"amplifier", "vca"},
	{"clock", "clock generator"},
	{"drums", "drum"},
	{"eq", "equalizer"},
	{"filter", "vcf"},
	{"low frequency oscillator", "lfo"},
	{"lowpass gate", "low pass gate"},
	{"oscillator", "vco"},
	{"percussion", "drum"},
	{"poly", "polyphonic"},
	{"s&h", "sample and hold"},
	{"voltage controlled amplifier", "vca"},
	{"voltage controlled filter", "vcf"},
	{"voltage controlled oscillator", "vco"},
};


std::string normalizeTag(const std::string &tag) {
	std::string lowercaseTag = string::lowercase(tag);
	// Transform aliases
	auto it = tagAliases.find(lowercaseTag);
	if (it != tagAliases.end())
		lowercaseTag = it->second;
	// Find allowed tag
	for (const std::string &allowedTag : allowedTags) {
		if (lowercaseTag == string::lowercase(allowedTag))
			return allowedTag;
	}
	return "";
}

bool isSlugValid(const std::string &slug) {
	for (char c : slug) {
		if (!(std::isalnum(c) || c == '-' || c == '_'))
			return false;
	}
	return true;
}

std::string normalizeSlug(const std::string &slug) {
	std::string s;
	for (char c : slug) {
		if (!(std::isalnum(c) || c == '-' || c == '_'))
			continue;
		s += c;
	}
	return s;
}


std::vector<Plugin*> plugins;

std::string loginStatus;
std::vector<Update> updates;
std::string updateStatus;
bool restartRequested = false;


} // namespace plugin
} // namespace rack