/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application - mod_mono
 * Copyright (C) 2008, Michael Giagnocavo <mgg@packetrino.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application - mod_mono
 *
 * The Initial Developer of the Original Code is
 * Michael Giagnocavo <mgg@packetrino.com>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Michael Giagnocavo <mgg@packetrino.com>
 * 
 * mod_mono.cpp -- FreeSWITCH mod_mono main class
 *
 * Most of mod_mono is implmented in the mod_mono_managed Loader class. 
 * The native code just handles getting the Mono runtime up and down
 * and passing pointers into managed code.
 */

#include <switch.h>


SWITCH_BEGIN_EXTERN_C

#include "freeswitch_mono.h"
#include <glib.h>
#include <mono/jit/jit.h>
#include <mono/metadata/assembly.h>
#include <mono/metadata/environment.h>
#include <mono/metadata/threads.h>
#include <mono/metadata/debug-helpers.h>

#ifdef WIN32
#include <shlobj.h>
#define EXPORT __declspec(dllexport)
#elif
#define EXPORT 
#endif

#define MOD_MONO_MANAGED_DLL "mod_mono_managed.dll"

mod_mono_globals globals = { 0 };

SWITCH_MODULE_LOAD_FUNCTION(mod_mono_load);
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_mono_shutdown);
SWITCH_MODULE_DEFINITION(mod_mono, mod_mono_load, mod_mono_shutdown, NULL);

SWITCH_STANDARD_API(monorun_api_function); /* ExecuteBackground */
SWITCH_STANDARD_API(mono_api_function); /* Execute */
SWITCH_STANDARD_APP(mono_app_function); /* Run */


// Sets up delegates (and anything else needed) on the MonoSession object
// Called via internalcall
SWITCH_MOD_DECLARE(void) InitMonoSession(MonoSession *session, MonoObject *dtmfDelegate, MonoObject *hangupDelegate)
{
	switch_assert(session);
	if (!session) return;
	session->setDTMFCallback(NULL, "");
	session->setHangupHook(NULL);
	session->dtmfDelegateHandle = mono_gchandle_new(dtmfDelegate, FALSE);
	session->hangupDelegateHandle = mono_gchandle_new(hangupDelegate, FALSE);
}

switch_status_t setMonoDirs() 
{
#ifdef WIN32	
	/* Win32 Mono installs can't figure out their own path
	// Guys in #mono say we should just deploy all the libs we need
	// I think it's much nicer to let the user deal with installing Mono
	// and we'll just look for it in program files. */
	HANDLE hFind;
	WIN32_FIND_DATA findData;
	char progFilesPath[MAX_PATH];
	char findPath[MAX_PATH];
	SHGetFolderPath(NULL, CSIDL_PROGRAM_FILES, NULL, SHGFP_TYPE_CURRENT, progFilesPath);
	switch_snprintf(findPath, MAX_PATH, "%s\\Mono-*", progFilesPath);
	hFind = FindFirstFile(findPath, &findData);
	if (hFind == INVALID_HANDLE_VALUE) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error looking for Mono in Program Files.\n");
		return SWITCH_STATUS_FALSE;
	}
	while((findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != FILE_ATTRIBUTE_DIRECTORY) {
		if (FindNextFile(hFind, &findData) == 0) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not find Mono directory in Program Files.\n");
			FindClose(hFind);
			return SWITCH_STATUS_FALSE;
		}
	}
	/* Got it */
	{
		char libPath[MAX_PATH];
		char etcPath[MAX_PATH];
		switch_snprintf(libPath, MAX_PATH, "%s\\%s\\lib", progFilesPath, findData.cFileName);
		switch_snprintf(etcPath, MAX_PATH, "%s\\%s\\etc", progFilesPath, findData.cFileName);
		FindClose(hFind);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Using Mono paths '%s' and '%s'.\n", libPath, etcPath);
		mono_set_dirs(libPath, etcPath);
		return SWITCH_STATUS_SUCCESS;
	}
#elif
	// On other platforms, it should just work if it hasn't been relocated
	mono_set_dirs(NULL, NULL);
	return SWITCH_STATUS_SUCCESS;
#endif
}

switch_status_t loadModMonoManaged() 
{ 
	/* Find and load mod_mono_managed.exe */
	char filename[256];
	switch_snprintf(filename, 256, "%s%s%s", SWITCH_GLOBAL_dirs.mod_dir, SWITCH_PATH_SEPARATOR, MOD_MONO_MANAGED_DLL);
	globals.domain = mono_jit_init(filename);

	if (!globals.domain) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "mono_jit_init failed.\n");
		return SWITCH_STATUS_FALSE;
	}

	/* Open the assembly */
	globals.mod_mono_asm = mono_domain_assembly_open(globals.domain, filename);
	if (!globals.mod_mono_asm) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "mono_domain_assembly_open failed.\n");
		return SWITCH_STATUS_FALSE;
	}
	return SWITCH_STATUS_SUCCESS;
}

MonoMethod *getMethod(const char *name, MonoClass *klass) 
{
	MonoMethodDesc *desc;
	MonoMethod *method;
	desc = mono_method_desc_new(name, TRUE);
	method = mono_method_desc_search_in_class(desc, klass);
	if (!method) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not find %s method.\n", name);
		return NULL;
	}
	return method;
}

switch_status_t findLoader() 
{
	/* Find loader class and methods*/
	MonoImage* img;
	MonoClass* loaderClass;
	img = mono_assembly_get_image(globals.mod_mono_asm);
	loaderClass = mono_class_from_name(img, "FreeSWITCH", "Loader");
	if (!loaderClass) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Could not find FreeSWITCH.Loader class.\n");
		return SWITCH_STATUS_FALSE;
	}

	globals.loadMethod = getMethod("FreeSWITCH.Loader:Load()", loaderClass);
	if (!globals.loadMethod) return SWITCH_STATUS_FALSE;

	globals.unloadMethod = getMethod("FreeSWITCH.Loader:Unload()", loaderClass);
	if (!globals.unloadMethod) return SWITCH_STATUS_FALSE;

	globals.runMethod = getMethod("FreeSWITCH.Loader:Run(string,intptr)", loaderClass);
	if (!globals.runMethod) return SWITCH_STATUS_FALSE;

	globals.executeMethod = getMethod("FreeSWITCH.Loader:Execute(string,intptr,intptr)", loaderClass);
	if (!globals.executeMethod) return SWITCH_STATUS_FALSE;
	
	globals.executeBackgroundMethod = getMethod("FreeSWITCH.Loader:ExecuteBackground(string)", loaderClass);
	if (!globals.executeBackgroundMethod) return SWITCH_STATUS_FALSE;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Found all loader functions.\n");
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_LOAD_FUNCTION(mod_mono_load) 
{
	/* connect my internal structure to the blank pointer passed to me */
	*module_interface = switch_loadable_module_create_module_interface(pool, modname);
	globals.pool = pool;

	if (setMonoDirs() != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;
	}
	if (loadModMonoManaged() != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;
	}
	if (findLoader() != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_FALSE;
	}
		
	/* Not sure if this is necesary on the loading thread */
	mono_thread_attach(globals.domain);
	mono_add_internal_call("FreeSWITCH.Native.MonoSession::InitMonoSession", InitMonoSession);

	/* Run loader */
	MonoObject *objResult;
	MonoObject *exception = NULL;
	objResult = mono_runtime_invoke(globals.loadMethod, NULL, NULL, &exception);
	if (exception) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Load threw an exception.\n");
		mono_print_unhandled_exception(exception);
		return SWITCH_STATUS_FALSE;
	}
	if (*(int*)mono_object_unbox(objResult)) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Load completed successfully.\n");
	} else {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Load did not return true.\n");
		return SWITCH_STATUS_FALSE;
	}


	/* We're good to register */
	switch_api_interface_t *api_interface;
	switch_application_interface_t *app_interface;

	SWITCH_ADD_API(api_interface, "monorun", "Run a module (ExecuteBackground)", monorun_api_function, "<module> [<args>]");
	SWITCH_ADD_API(api_interface, "mono", "Run a module as an API function (Execute)", mono_api_function, "<module> [<args>]");
	SWITCH_ADD_APP(app_interface, "mono", "Run Mono IVR", "Run a Mono IVR on a channel", mono_app_function, "<modulename> [<args>]", SAF_NONE);
	
	return SWITCH_STATUS_SUCCESS;	
}

SWITCH_STANDARD_API(monorun_api_function) 
{
	// TODO: Should we be detaching after all this?
	mono_thread_attach(globals.domain);
	if (switch_strlen_zero(cmd)) {
		stream->write_function(stream, "-ERR no args specified!\n");
		return SWITCH_STATUS_SUCCESS;
	}

	// ExecuteBackground(string command)
	void *args[1];
	args[0] = mono_string_new(globals.domain, cmd);
	MonoObject *exception = NULL;
	MonoObject *objResult = mono_runtime_invoke(globals.executeBackgroundMethod, NULL, args, &exception);
	if (exception) {
		stream->write_function(stream, "-ERR FreeSWITCH.Loader.ExecuteBackground threw an exception.\n");
		mono_print_unhandled_exception(exception);
		return SWITCH_STATUS_SUCCESS;
	}
	if (*(int*)mono_object_unbox(objResult)) {
		stream->write_function(stream, "+OK\n");
	} else {
		stream->write_function(stream, "-ERR ExecuteBackground returned false (unknown module?).\n");
	}
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_STANDARD_API(mono_api_function)
{
	mono_thread_attach(globals.domain);
	if (switch_strlen_zero(cmd)) {
		stream->write_function(stream, "-ERR no args specified!\n");
		return SWITCH_STATUS_SUCCESS;
	}
	
	// Method is: Execute(string command, IntPtr streamPtr, IntPtr eventPtr)
	void *args[3];
	args[0] = mono_string_new(globals.domain, cmd);
	args[1] = &stream; // Address of the arguments
	args[2] = &(stream->param_event);
	
	MonoObject *exception = NULL;
	MonoObject *objResult = mono_runtime_invoke(globals.executeMethod, NULL, args, &exception);
	if (exception) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Exception trying to execute mono %s.\n", cmd);
		mono_print_unhandled_exception(exception);
	}
	if (!(*(int*)mono_object_unbox(objResult))) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Execute failed for %s (unknown module?).\n", cmd);
	}
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_STANDARD_APP(mono_app_function)
{
	mono_thread_attach(globals.domain);
	if (switch_strlen_zero(data)) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No args specified!\n");
	}

	// bool Run(string command, IntPtr sessionHandle)
	void *args[2];
	args[0] = mono_string_new(globals.domain, data);
	args[1] = &session;

	MonoObject *exception = NULL;
	MonoObject *objResult = mono_runtime_invoke(globals.runMethod, NULL, args, &exception);
	if (exception) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Exception trying to execute application mono %s.\n", data);
		mono_print_unhandled_exception(exception);
	}
	if (!(*(int*)mono_object_unbox(objResult))) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Application run failed for %s (unknown module?).\n", data);
	}
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_mono_shutdown)
{
	mono_thread_attach(globals.domain);
	MonoObject *ex;
	mono_runtime_invoke(globals.unloadMethod, NULL, NULL, &ex);
	if (ex) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Exception occurred in Loader::Unload.\n");
		mono_print_unhandled_exception(ex);
	}
	mono_runtime_set_shutting_down();
	mono_runtime_cleanup(globals.domain);
	mono_runtime_quit();
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_END_EXTERN_C