//
//  main.m
//  iOS-python-test
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#include <python2.7/Python.h>
#include "SDL/SDL_main.h"
#include <dlfcn.h>

void export_orientation();
void custom_builtin_importer();

int main(int argc, char *argv[]) {
    int ret = 0;
    
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // Change the executing path to YourApp
    chdir("YourApp");
    
    // Special environment to prefer .pyo, and don't write bytecode if .py are found
    // because the process will not have write attribute on the device.
    putenv("PYTHONOPTIMIZE=2");
    putenv("PYTHONDONTWRITEBYTECODE=1");
    putenv("PYTHONNOUSERSITE=1");
    putenv("PYTHONPATH=.");
    //putenv("PYTHONVERBOSE=1");
    
    // Kivy environment to prefer some implementation on ios platform
    putenv("KIVY_BUILD=ios");
    putenv("KIVY_NO_CONFIG=1");
    putenv("KIVY_NO_FILELOG=1");
    putenv("KIVY_NO_CONSOLELOG=1");
    putenv("KIVY_WINDOW=sdl");
    putenv("KIVY_IMAGE=imageio");
    putenv("KIVY_AUDIO=sdl");
    
	// Export orientation preferences for Kivy
	export_orientation();

    NSString * resourcePath = [[NSBundle mainBundle] resourcePath];
    NSLog(@"PythonHome is: %s", (char *)[resourcePath UTF8String]);
    Py_SetPythonHome((char *)[resourcePath UTF8String]);

    NSLog(@"Initializing python");
    Py_Initialize();    
    PySys_SetArgv(argc, argv);

    // If other modules are using thread, we need to initialize them before.
    PyEval_InitThreads();

	// Add an importer for builtin modules
	load_custom_builtin_importer();

    // Search and start main.py
    const char * prog = [
        [[NSBundle mainBundle] pathForResource:@"YourApp/main" ofType:@"pyo"] cStringUsingEncoding:
        NSUTF8StringEncoding];
    NSLog(@"Running main.pyo: %s", prog);
    FILE* fd = fopen(prog, "r");
    if ( fd == NULL ) {
        ret = 1;
        NSLog(@"Unable to open main.pyo, abort.");
    } else {
        ret = PyRun_SimpleFileEx(fd, prog, 1);
        if (ret != 0)
            NSLog(@"Application quit abnormally!");
    }
    
    Py_Finalize();
    NSLog(@"Leaving");
    
    [pool release];
    
    // Look like the app still runn even when we leaved here.
    exit(ret);
    return ret;
}

// This method read available orientations from the Info.plist, and share them
// in an environment variable. Kivy will automatically set the orientation
// according to this environment value, if exist.
void export_orientation() {
	NSDictionary *info = [[NSBundle mainBundle] infoDictionary];
	NSArray *orientations = [info objectForKey:@"UISupportedInterfaceOrientations"];
    NSString *result = [[NSString alloc] initWithString:@"KIVY_ORIENTATION="];
    for (int i = 0; i < [orientations count]; i++) {
        NSString *item = [orientations objectAtIndex:i];
        item = [item substringFromIndex:22];
        if (i > 0)
            result = [result stringByAppendingString:@" "];
        result = [result stringByAppendingString:item];
    }

    putenv([result UTF8String]);
    //NSLog(@"Available orientation: %@", result);
}

void load_custom_builtin_importer() {
	static const char *custom_builtin_importer = \
		"import sys, imp\n" \
		"from os.path import exists, join\n" \
		"class CustomBuiltinImporter(object):\n" \
		"	def find_module(self, fullname, mpath=None):\n" \
		"		if '.' not in fullname:\n" \
		"			return\n" \
		"		if mpath is None:\n" \
		"			return\n" \
		"		part = fullname.rsplit('.')[-1]\n" \
		"		fn = join(mpath[0], '{}.so'.format(part))\n" \
		"		if exists(fn):\n" \
		"			return self\n" \
		"		return\n" \
		"	def load_module(self, fullname):\n" \
		"		f = fullname.replace('.', '_')\n" \
		"		mod = sys.modules.get(f)\n" \
		"		if mod is None:\n" \
		"			mod = imp.load_dynamic(f, f)\n" \
		"			return mod\n" \
		"		return mod\n" \
		"sys.meta_path.append(CustomBuiltinImporter())";
	PyRun_SimpleString(custom_builtin_importer);
}