/*
 * GDSII-Converter Python Plugin
 * Copyright (C) 2019  Mario Hüttel <mario.huettel@gmx.net>
 *
 * This file is part of GDSII-Converter.
 *
 * GDSII-Converter is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * GDSII-Converter 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 GDSII-Converter. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file python-renderer/plugin-main.c
 * @author Mario Hüttel <mario.huettel@gmx.net>
 */

/**
 * @defgroup python-plugin Python Plugin for External Renderer
 * @ingroup plugins
 * This is a plugin for calling an external python script as renderer
 * @addtogroup python-plugin
 * @{
 */

#include <stdio.h>
#include <libgen.h>
#include <glib.h>
#include <unistd.h>
#include <Python.h>

#include <gds-render/gds-utils/gds-types.h>
#include <gds-render/output-renderers/external-renderer-interfaces.h>

#include <python-renderer/gds-render-module.h>

/**
 * @brief Global variable for loaded module. This is not very nice.
 * @warning This has to be changed, if this api wants to be re-entrant.
 */
static PyObject *p_module = NULL;

int EXPORTED_FUNC_DECL(EXTERNAL_LIBRARY_RENDER_FUNCTION)(struct gds_cell *toplevel, GList *layer_info_list, const char *output_file_name, double scale)
{
	int ret = 0;
	PyObject *p_render_func;
	PyObject *p_return_value;

	if (!toplevel)
		return -1000;
	if (!p_module)
		return -2000;

	printf("Rendering %s\n", toplevel->name);

	p_render_func = PyObject_GetAttrString(p_module, "test_func");
	if (!p_render_func && !PyCallable_Check(p_render_func)) {
		if (PyErr_Occurred())
			PyErr_Print();
		else
			fprintf(stderr, "Function not found in python module\n");

		ret = -1;
		goto return_value;
	}

	p_return_value = PyObject_CallObject(p_render_func, NULL);
	if (p_return_value) {
		printf("Result of call: %ld\n", PyLong_AsLong(p_return_value));
		Py_DECREF(p_return_value);
	}

	Py_XDECREF(p_render_func);

return_value:
	return ret;
}

int EXPORTED_FUNC_DECL(EXTERNAL_LIBRARY_INIT_FUNCTION)(const char *params, const char *version)
{
	int ret = 0;
	PyObject *p_name;
	PyObject *p_sys_path;
	PyObject *p_mod_dir_string;
	PyObject *gds_render_module;
	char file_path[PATH_MAX];
	char *file_path_for_dir;
	char *file_path_for_base;
	char *dir_name;
	char *base_name;

	if (!params || !version)
		return -1000;

	printf("Init with params: %s\ngds-render version: %s\n", params, version);

	ret = PyImport_AppendInittab("gds_render", &init_gds_render_module);
	if (ret) {
		ret = -1;
		fprintf(stderr, "Registration of gds_render python module failed\n");
		goto return_value;
	}

	Py_Initialize();

	if (!realpath(params, file_path)) {
		ret = -2;
		fprintf(stderr, "Invalid file name.\n");
		goto return_value;
	}

	file_path_for_dir = strdup(file_path);
	if (!file_path_for_dir) {
		ret = -3;
		goto return_value;
	}

	file_path_for_base = strdup(file_path);
	if (!file_path_for_base) {
		ret = -3;
		free (file_path_for_dir);
		goto return_value;
	}

	dir_name = dirname(file_path_for_dir);
	base_name = basename(file_path_for_base);

	printf("Dir name : %s\n BAse name: %s\n", dir_name, base_name);

	p_sys_path = PySys_GetObject("path");
	p_mod_dir_string = PyUnicode_FromString(dir_name);
	PyList_Append(p_sys_path, p_mod_dir_string);
	Py_DECREF(p_mod_dir_string);

	p_name = PyUnicode_DecodeFSDefault(strtok(base_name, "."));
	p_module = PyImport_Import(p_name);
	Py_DECREF(p_name);

	if (!p_module) {
		PyErr_Print();
		fprintf(stderr, "Failed to load %s\n", params);
		ret = -1;
		goto return_value;
	}

	free(file_path_for_dir);
	free(file_path_for_base);

return_value:
	return ret;
}

int EXPORTED_FUNC_DECL(EXTERNAL_LIBRARY_FINALIZE_FUNCTION)(void)
{
	int ret;

	printf("Finalizing\n");

	if (p_module)
		Py_DECREF(p_module);

	ret = Py_FinalizeEx();
	return ret;
}

/** @} */