/*-
 * Copyright (c) 2011 Wojciech A. Koszek <wkoszek@FreeBSD.org>
 * Copyright (c) 2014 Pedro Souza <pedrosouza@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stand.h>
#include "bootstrap.h"

#define lua_c

#include "lstd.h"

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

#include <lerrno.h>
#include <lfs.h>
#include <lutils.h>

struct interp_lua_softc {
        lua_State       *luap;
};

static struct interp_lua_softc lua_softc;

#ifdef LUA_DEBUG
#define LDBG(...)       do {                    \
        printf("%s(%d): ", __func__, __LINE__); \
        printf(__VA_ARGS__);                    \
        printf("\n");                           \
} while (0)
#else
#define LDBG(...)
#endif

#define LOADER_LUA      LUA_PATH "/loader.lua"

INTERP_DEFINE("lua");

static void *
interp_lua_realloc(void *ud __unused, void *ptr, size_t osize __unused, size_t nsize)
{

        if (nsize == 0) {
                free(ptr);
                return NULL;
        }
        return realloc(ptr, nsize);
}

/*
 * The libraries commented out below either lack the proper
 * support from libsa, or they are unlikely to be useful
 * in the bootloader, so have been commented out.
 */
static const luaL_Reg loadedlibs[] = {
  {"_G", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
//  {LUA_COLIBNAME, luaopen_coroutine},
//  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
//  {LUA_IOLIBNAME, luaopen_io},
//  {LUA_OSLIBNAME, luaopen_os},
//  {LUA_MATHLIBNAME, luaopen_math},
//  {LUA_UTF8LIBNAME, luaopen_utf8},
//  {LUA_DBLIBNAME, luaopen_debug},
  {"errno", luaopen_errno},
  {"io", luaopen_io},
  {"lfs", luaopen_lfs},
  {"loader", luaopen_loader},
  {"pager", luaopen_pager},
  {NULL, NULL}
};

static bool preinit_done = false;

void
interp_preinit(void)
{
        lua_State *luap;
        struct interp_lua_softc *softc = &lua_softc;
        const luaL_Reg *lib;
        lua_init_md_t **fnpp;

        TSENTER();

        if (preinit_done)
                return;

        setenv("script.lang", "lua", 1);
        LDBG("creating context");

        luap = lua_newstate(interp_lua_realloc, NULL);
        if (luap == NULL) {
                printf("problem initializing the Lua interpreter\n");
                abort();
        }
        softc->luap = luap;

        /* "require" functions from 'loadedlibs' and set results to global table */
        for (lib = loadedlibs; lib->func; lib++) {
                luaL_requiref(luap, lib->name, lib->func, 1);
                lua_pop(luap, 1);  /* remove lib */
        }

        LUA_FOREACH_SET(fnpp)
            (*fnpp)(luap);

        preinit_done = true;

        TSEXIT();
}

void
interp_init(void)
{
        lua_State *luap;
        struct interp_lua_softc *softc = &lua_softc;
        const char *filename;

        TSENTER();

        luap = softc->luap;
        filename = getenv("loader_lua");
        if (filename == NULL)
                filename = LOADER_LUA;
        if (interp_include(filename) != 0) {
                const char *errstr = lua_tostring(luap, -1);
                errstr = errstr == NULL ? "unknown" : errstr;
                printf("ERROR: %s.\n", errstr);
                lua_pop(luap, 1);
                setenv("autoboot_delay", "NO", 1);
        }

        TSEXIT();
}

int
interp_run(const char *line)
{
        int     argc, nargc;
        char    **argv;
        lua_State *luap;
        struct interp_lua_softc *softc = &lua_softc;
        int status, ret;

        TSENTER();
        luap = softc->luap;
        LDBG("executing line...");
        if ((status = luaL_dostring(luap, line)) != 0) {
                lua_pop(luap, 1);
                /*
                 * The line wasn't executable as lua; run it through parse to
                 * to get consistent parsing of command line arguments, then
                 * run it through cli_execute. If that fails, then we'll try it
                 * as a builtin.
                 */
                command_errmsg = NULL;
                if (parse(&argc, &argv, line) == 0) {
                        lua_getglobal(luap, "cli_execute");
                        for (nargc = 0; nargc < argc; ++nargc) {
                                lua_pushstring(luap, argv[nargc]);
                        }
                        status = lua_pcall(luap, argc, 1, 0);
                        ret = lua_tointeger(luap, 1);
                        lua_pop(luap, 1);
                        if (status != 0 || ret != 0) {
                                /*
                                 * Lua cli_execute will pass the function back
                                 * through loader.command, which is a proxy to
                                 * interp_builtin_cmd. If we failed to interpret
                                 * the command, though, then there's a chance
                                 * that didn't happen. Call interp_builtin_cmd
                                 * directly if our lua_pcall was not successful.
                                 */
                                status = interp_builtin_cmd(argc, argv);
                        }
                        if (status != 0) {
                                if (command_errmsg != NULL)
                                        printf("%s\n", command_errmsg);
                                else
                                        printf("Command failed\n");
                                status = CMD_ERROR;
                        }
                        free(argv);
                } else {
                        printf("Failed to parse \'%s\'\n", line);
                        status = CMD_ERROR;
                }
        }

        TSEXIT();
        return (status == 0 ? CMD_OK : CMD_ERROR);
}

int
interp_include(const char *filename)
{
        struct interp_lua_softc *softc = &lua_softc;

        LDBG("loading file %s", filename);

        return (luaL_dofile(softc->luap, filename));
}