/* radare - LGPL - Copyright 2008-2013 - pancake */

#include "r_types.h"
#include "r_util.h"
#include "r_lib.h"
#include <stdio.h>
#include <dirent.h>

R_LIB_VERSION(r_lib);

/* TODO: support for nested plugins ?? here */

#if __UNIX__
#include <dlfcn.h>
  #define DLOPEN(x)  dlopen(x, RTLD_GLOBAL | RTLD_NOW)
  #define DLSYM(x,y) dlsym(x,y)
  #define DLCLOSE(x) dlclose(x)
#elif __WINDOWS__
#include <windows.h>
  #define DLOPEN(x)  LoadLibrary(x)
  #define DLSYM(x,y) GetProcAddress(x,y)
  #define DLCLOSE(x) 0//(x)
//CloseLibrary(x)
#else
  #define DLOPEN(x)  NULL
  #define DLSYM(x,y) NULL
  #define DLCLOSE(x) NULL
#endif

/* XXX : this must be registered in runtime */
static const char *r_lib_types[] = {
	"io", "dbg", "lang", "asm", "anal", "parse", "bin", //"bininfo", 
	"bp", "syscall", "fastcall", "crypto", "cmd", NULL
};

static int __has_debug = 0;

#define IFDBG if(__has_debug)

/* XXX: Rename this helper function */
R_API const char *r_lib_types_get(int idx) {
	if (idx<0||idx>R_LIB_TYPE_LAST)
		return "unk";
	return r_lib_types[idx];
}

R_API void *r_lib_dl_open(const char *libname) {
	void *ret;
	ret = DLOPEN (libname);
	if (__has_debug && ret == NULL)
#if __UNIX__
		eprintf ("dlerror(%s): %s\n", libname, dlerror ());
#else
		eprintf ("r_lib_dl_open: Cannot open '%s'\n", libname);
#endif
	return ret;
}

R_API void *r_lib_dl_sym(void *handler, const char *name) {
	return DLSYM (handler, name);
}

R_API int r_lib_dl_close(void *handler) {
	return DLCLOSE (handler);
}

/* ---- */

R_API char *r_lib_path(const char *libname) {
	char *next, *path0, libpath[1024];
#if __APPLE__
	char *env = r_sys_getenv ("DYLD_LIBRARY_PATH");
	const char *ext = ".dylib";
	env = r_str_concat (env, ":/lib:/usr/lib:/usr/local/lib");
#elif __UNIX__
	char *env = r_sys_getenv ("LD_LIBRARY_PATH");
	const char *ext = ".so";
	env = r_str_concat (env, ":/lib:/usr/lib:/usr/local/lib");
#else
	char *env = strdup (".:../../../../../../../windows/system32");
	const char *ext = ".dll";
#endif
	if (!env) env = strdup (".");
	path0 = env;
	do {
		next = strchr (path0, ':');
		if (next) *next = 0;
		snprintf (libpath, sizeof (libpath), "%s/%s%s", path0, libname, ext);
		//eprintf ("--> %s\n", libpath);
		if (r_file_exists (libpath)) {
			free (env);
			return strdup (libpath);
		}
		path0 = next+1;
	} while (next);
	free (env);
	return NULL;
}

R_API RLib *r_lib_new(const char *symname) {
	RLib *lib = R_NEW (RLib);
	if (lib) {
		__has_debug = r_sys_getenv ("R_DEBUG")?R_TRUE:R_FALSE;
		lib->handlers = r_list_new ();
		lib->plugins = r_list_new ();
		strncpy (lib->symname, symname, sizeof (lib->symname)-1);
	}
	return lib;
}

R_API RLib *r_lib_free(RLib *lib) {
	if (!lib) return NULL;
	/* TODO: iterate over libraries and free them all */
	/* TODO: iterate over handlers and free them all */
	r_lib_close (lib, NULL);
	free (lib);
	return NULL;
}

/* THIS IS WRONG */
R_API int r_lib_dl_check_filename(const char *file) {
	if (strstr (file, "."R_LIB_EXT))
		return R_TRUE;
	return R_FALSE;
}

/* high level api */

R_API int r_lib_run_handler(RLib *lib, RLibPlugin *plugin, RLibStruct *symbol) {
	RLibHandler *h = plugin->handler;
	if (h && h->constructor)
		return h->constructor (plugin, h->user, symbol->data);
	return R_FAIL;
}

R_API RLibHandler *r_lib_get_handler(RLib *lib, int type) {
	RLibHandler *h;
	RListIter *iter;
	r_list_foreach (lib->handlers, iter, h) {
		if (h->type == type)
			return h;
	}
	return NULL;
}

R_API R_API int r_lib_close(RLib *lib, const char *file) {
	RLibPlugin *p;
	RListIter *iter;
	/* No _safe loop necessary because we return immediately after the delete. */
	r_list_foreach (lib->plugins, iter, p) {
		if ((file==NULL || (!strcmp(file, p->file))) && p->handler->destructor != NULL) {
			int ret = p->handler->destructor (p, p->handler->user, p->data);
			free (p->file);
			r_list_delete (lib->plugins, iter);
			free (p);
			return ret;
		}
	}
	return -1;
}

// XXX ugly hack ?
static int samefile(const char *a, const char *b) {
	char *sa = strdup (a);
	char *sb = strdup (b);
	char *ptr;
	int len, ret = R_FALSE;

	if (sa != NULL && sb != NULL) {
		do {
			ptr = strstr(sa, "//");
			if (ptr) {
				len = strlen (ptr+1) + 1;
				memmove (ptr, ptr+1, len);
			}
		} while (ptr);
		do {
			ptr = strstr(sb, "//");
			if (ptr) {
				len = strlen (ptr+1) + 1;
				memmove (ptr, ptr+1, len);
			}
		} while (ptr);
		ret = strcmp (sa,sb)? R_FALSE: R_TRUE;
	}

	free (sa);
	free (sb);
	return ret;
}

R_API int r_lib_open(RLib *lib, const char *file) {
	RLibPlugin *p;
	RListIter *iter;
	RLibStruct *stru;
	void *handler;
	int ret = R_FALSE;

	/* ignored by filename */
	if (!r_lib_dl_check_filename (file)) {
		eprintf ("Invalid library extension: %s\n", file);
		return R_FAIL;
	}

	handler = r_lib_dl_open (file);
	if (handler == NULL) {
		IFDBG eprintf ("Cannot open library: '%s'\n", file);
		return R_FAIL;
	}
	
	stru = (RLibStruct *) r_lib_dl_sym (handler, lib->symname);
	if (stru == NULL) {
		IFDBG eprintf ("Cannot find symbol '%s' in library '%s'\n",
			lib->symname, file);
		return R_FAIL;
	}

	r_list_foreach (lib->plugins, iter, p) {
		if (samefile (file, p->file)) {
			r_lib_dl_close (handler);
			return R_FAIL;
		}
	}

	p = R_NEW (RLibPlugin);
	p->type = stru->type;
	p->data = stru->data;
	p->file = strdup (file);
	p->dl_handler = handler;
	p->handler = r_lib_get_handler (lib, p->type);
	
	ret = r_lib_run_handler (lib, p, stru);
	if (ret == R_FAIL) {
		IFDBG eprintf ("Library handler has failed for '%s'\n", file);
		free (p->file);
		free (p);
		r_lib_dl_close (handler);
	} else r_list_append (lib->plugins, p);

	return ret;
}

R_API int r_lib_opendir(RLib *lib, const char *path) {
	char file[1024];
	struct dirent *de;
	DIR *dh;

#ifdef LIBR_PLUGINS
	if (path == NULL)
		path = LIBR_PLUGINS;
#endif
	if (path == NULL)
		return R_FALSE;

	dh = opendir (path);
	if (dh == NULL) {
		IFDBG eprintf ("Cannot open directory '%s'\n", path);
		return R_FALSE;
	}
	while ((de = (struct dirent *)readdir (dh))) {
		snprintf (file, sizeof (file), "%s/%s", path, de->d_name);
		if (r_lib_dl_check_filename (file))
			r_lib_open (lib, file);
	}
	closedir (dh);
	return R_TRUE;
}

R_API int r_lib_add_handler(RLib *lib,
	int type, const char *desc,
	int (*cb)(RLibPlugin *, void *, void *),  /* constructor */
	int (*dt)(RLibPlugin *, void *, void *),  /* destructor */
	void *user)
{
	RLibHandler *h;
	RListIter *iter;
	RLibHandler *handler = NULL;

	r_list_foreach (lib->handlers, iter, h) {
		if (type == h->type) {
			IFDBG eprintf ("Redefining library handler constructor for %d\n", type);
			handler = h;
			break;
		}
	}
	if (handler == NULL) {
		handler = R_NEW (RLibHandler);
		if (handler == NULL)
			return R_FALSE;
		handler->type = type;
		r_list_append (lib->handlers, handler);
	}
	strncpy (handler->desc, desc, sizeof (handler->desc)-1);
	handler->user = user;
	handler->constructor = cb;
	handler->destructor = dt;

	return R_TRUE;
}

R_API int r_lib_del_handler(RLib *lib, int type) {
	RLibHandler *h;
	RListIter *iter;
	// TODO: remove all handlers for that type? or only one?
	/* No _safe loop necessary because we return immediately after the delete. */
	r_list_foreach (lib->handlers, iter, h) {
		if (type == h->type) {
			r_list_delete (lib->handlers, iter);
			return R_TRUE;
		}
	}
	return R_FALSE;
}

/* XXX _list methods must be deprecated before r2-1.0 */
R_API void r_lib_list(RLib *lib) {
	RListIter *iter;
	RLibPlugin *p;
#if 0
	printf("Plugin Plugins:\n");
	list_for_each_prev(pos, &lib->handlers) {
		RLibHandler *h = list_entry(pos, RLibHandler, list);
		printf(" - %d: %s\n", h->type, h->desc);
	}
#endif
	//printf("Loaded plugins:\n");
	r_list_foreach (lib->plugins, iter, p) {
		printf (" %5s %p %s \n", r_lib_types_get (p->type),
			p->handler->destructor, p->file);
	}
}