#include "skynet.h"

#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>

#include <string.h>
#include <stdlib.h>
#include <stdio.h>

lua_State *
snlua_create(void) {
	return luaL_newstate();
}

static int
_try_load(lua_State *L, const char * path, int pathlen, const char * name) {
	int namelen = strlen(name);
	char tmp[pathlen + namelen];
	int i;
	for (i=0;i<pathlen;i++) {
		if (path[i] == '?')
			break;
		tmp[i] = path[i];
	}
	if (path[i] == '?') {
		memcpy(tmp+i,name,namelen);
		memcpy(tmp+i+namelen,path+i+1,pathlen - i -1);
	} else {
		fprintf(stderr,"snlua : Invalid lua service path\n");
		exit(1);
	}
	tmp[namelen+pathlen-1] = '\0';
	FILE *f = fopen(tmp,"rb");
	if (f == NULL) {
		return -1;
	} else {
		fclose(f);
		int r = luaL_loadfile(L,tmp);
		if (r == LUA_OK) {
			lua_getglobal(L,"package");
			lua_getfield(L,-1,"path");
			luaL_Buffer b;
			luaL_buffinit(L, &b);
			luaL_addlstring(&b, path, pathlen);
			luaL_addchar(&b,';');
			luaL_addvalue(&b);
			luaL_pushresult(&b);
			lua_setfield(L,-2,"path");
			lua_pop(L,1);
			return 0;
		}
		return 1;
	}
}

static int
_load(lua_State *L, char ** filename) {
	const char * name = strsep(filename, " \r\n");
	const char * path = skynet_command(NULL, "GETENV", "luaservice");
	while (path[0]) {
		int pathlen;
		char * pathend = strchr(path,';');
		if (pathend) {
			pathlen = pathend - path;
		} else {
			pathlen = strlen(path);
		}
		int r = _try_load(L, path, pathlen, name);
		if (r >=0) {
			return r;
		}
		path+=pathlen;
		if (path[0]==';')
			++path;
	}
	return -1;
}

static int 
traceback (lua_State *L) {
	const char *msg = lua_tostring(L, 1);
	if (msg)
		luaL_traceback(L, L, msg, 1);
	else {
		lua_pushliteral(L, "(no error message)");
	}
	return 1;
}

int
snlua_init(lua_State *L, struct skynet_context *ctx, const char * args) {
	lua_gc(L, LUA_GCSTOP, 0);
	luaL_openlibs(L);
	lua_pushlightuserdata(L, ctx);
	lua_setfield(L, LUA_REGISTRYINDEX, "skynet_context");
	lua_gc(L, LUA_GCRESTART, 0);

	char tmp[strlen(args)+1];
	char *parm = tmp;
	strcpy(parm,args);

	lua_pushcfunction(L, traceback);
	int traceback_index = lua_gettop(L);

	const char * filename = parm;
	int r = _load(L, &parm);
	if (r != 0) {
		if (r<0) {
			skynet_error(ctx, "lua parser [%s] load error", filename);
		} else {
			skynet_error(ctx, "lua parser [%s] error : %s", filename, lua_tostring(L,-1));
		}
		return 1;
	}
	int n=0;
	while(parm) {
		const char * arg = strsep(&parm, " \r\n");
		if (arg && arg[0]!='\0') {
			lua_pushstring(L, arg);
			++n;
		}
	}
	r = lua_pcall(L,n,0,traceback_index);
	switch (r) {
	case LUA_OK:
		return 0;
	case LUA_ERRRUN:
		skynet_error(ctx, "lua do [%s] error : %s", filename, lua_tostring(L,-1));
		break;
	case LUA_ERRMEM:
		skynet_error(ctx, "lua memory error : %s",filename);
		break;
	case LUA_ERRERR:
		skynet_error(ctx, "lua message error : %s",filename);
		break;
	case LUA_ERRGCMM:
		skynet_error(ctx, "lua gc error : %s",filename);
		break;
	};

	lua_pop(L,1);

	return 1;
}

void
snlua_release(lua_State *L) {
	lua_close(L);
}