/*
 * lua.c - Lua configuration management
 *
 * Copyright © 2008 Julien Danjou <julien@danjou.info>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <errno.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>

#include <ev.h>

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

#include <xcb/xcb.h>

#include "awesome-version-internal.h"
#include "ewmh.h"
#include "config.h"
#include "lua.h"
#include "tag.h"
#include "client.h"
#include "screen.h"
#include "event.h"
#include "layouts/tile.h"
#include "common/socket.h"

extern awesome_t globalconf;

extern const struct luaL_reg awesome_keygrabber_lib[];
extern const struct luaL_reg awesome_mouse_methods[];
extern const struct luaL_reg awesome_mouse_meta[];
extern const struct luaL_reg awesome_screen_methods[];
extern const struct luaL_reg awesome_screen_meta[];
extern const struct luaL_reg awesome_client_methods[];
extern const struct luaL_reg awesome_client_meta[];
extern const struct luaL_reg awesome_titlebar_methods[];
extern const struct luaL_reg awesome_titlebar_meta[];
extern const struct luaL_reg awesome_tag_methods[];
extern const struct luaL_reg awesome_tag_meta[];
extern const struct luaL_reg awesome_widget_methods[];
extern const struct luaL_reg awesome_widget_meta[];
extern const struct luaL_reg awesome_statusbar_methods[];
extern const struct luaL_reg awesome_statusbar_meta[];
extern const struct luaL_reg awesome_keybinding_methods[];
extern const struct luaL_reg awesome_keybinding_meta[];

static struct sockaddr_un *addr;
static ev_io csio = { .fd = -1 };

/** Add a global mouse binding. This binding will be available when you'll
 * click on root window.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A mouse button binding.
 */
static int
luaA_mouse_add(lua_State *L)
{
    button_t **button = luaA_checkudata(L, 1, "mouse");

    button_list_push(&globalconf.buttons.root, *button);
    button_ref(button);

    return 0;
}

/** Quit awesome.
 */
static int
luaA_quit(lua_State *L __attribute__ ((unused)))
{
    ev_unloop(globalconf.loop, 1);
    return 0;
}

/** Execute another application, probably a window manager, to replace
 * awesome.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam The command line to execute.
 */
static int
luaA_exec(lua_State *L)
{
    client_t *c;
    const char *cmd = luaL_checkstring(L, 1);

    for(c = globalconf.clients; c; c = c->next)
        client_unban(c);

    xcb_flush(globalconf.connection);
    xcb_disconnect(globalconf.connection);

    a_exec(cmd);
    return 0;
}

/** Restart awesome.
 */
static int
luaA_restart(lua_State *L __attribute__ ((unused)))
{
    ewmh_restart();
    return 0;
}

/** Set the function called each time a client gets focus. This function is
 * called with the client object as argument.
 * \param L The Lua VM state.
 * \return The number of elements pushed on stack.
 *
 * \luastack
 * \lparam A function to call each time a client gets focus.
 */
static int
luaA_hooks_focus(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.focus);
}

/** Set the function called each time a client loses focus. This function is
 * called with the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call each time a client loses focus.
 */
static int
luaA_hooks_unfocus(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.unfocus);
}

/** Set the function called each time a new client appears. This function is
 * called with the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call on each new client.
 */
static int
luaA_hooks_manage(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.manage);
}

/** Set the function called each time a client goes away. This function is
 * called with the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call when a client goes away.
 */
static int
luaA_hooks_unmanage(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.unmanage);
}

/** Set the function called each time the mouse enter a new window. This
 * function is called with the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call each time a client gets mouse over it.
 */
static int
luaA_hooks_mouseover(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.mouseover);
}

/** Set the function called on each screen arrange. This function is called
 * with the screen number as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call on each screen arrange.
 */
static int
luaA_hooks_arrange(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.arrange);
}

/** Set the function called on each title update. This function is called with
 * the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call on each title update of each client.
 */
static int
luaA_hooks_titleupdate(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.titleupdate);
}

/** Set the function called when a client get urgency flag. This function is called with
 * the client object as argument.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A function to call when a client get the urgent flag.
 */
static int
luaA_hooks_urgent(lua_State *L)
{
    return luaA_registerfct(L, &globalconf.hooks.urgent);
}

/** Set the function to be called every N seconds.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam The number of seconds to run function every. Set 0 to disable.
 * \lparam A function to call every N seconds (optional).
 */
static int
luaA_hooks_timer(lua_State *L)
{
    globalconf.timer.repeat = luaL_checknumber(L, 1);

    if(lua_gettop(L) == 2 && !lua_isnil(L, 2))
        luaA_registerfct(L, &globalconf.hooks.timer);

    ev_timer_again(globalconf.loop, &globalconf.timer);
    return 0;
}

/** Set default font.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A string with a font name in Pango format.
 */
static int
luaA_font_set(lua_State *L)
{
    const char *font = luaL_checkstring(L, 1);
    draw_font_delete(&globalconf.font);
    globalconf.font = draw_font_new(globalconf.connection,
                                    globalconf.default_screen, font);
    return 0;
}

/** Set default colors.
 * \param L The Lua VM state.
 *
 * \luastack
 * \lparam A table with `fg' and `bg' elements, containing colors.
 */
static int
luaA_colors_set(lua_State *L)
{
    const char *buf;
    size_t len;
    int8_t colors_nbr = -1, i;
    xcolor_init_request_t reqs[2];

    luaA_checktable(L, 1);

    if((buf = luaA_getopt_lstring(L, 1, "fg", NULL, &len)))
       reqs[++colors_nbr] = xcolor_init_unchecked(globalconf.connection,
                                                  &globalconf.colors.fg,
                                                  globalconf.default_screen,
                                                  buf, len);

    if((buf = luaA_getopt_lstring(L, 1, "bg", NULL, &len)))
       reqs[++colors_nbr] = xcolor_init_unchecked(globalconf.connection,
                                                  &globalconf.colors.bg,
                                                  globalconf.default_screen,
                                                  buf, len);

    for(i = 0; i <= colors_nbr; i++)
       xcolor_init_reply(globalconf.connection, reqs[i]);

    return 0;
}

/** Push a pointer onto the stack according to its type.
 * \param p The pointer.
 * \param type Its type.
 */
void
luaA_pushpointer(lua_State *L, void *p, awesome_type_t type)
{
    switch(type)
    {
      case AWESOME_TYPE_STATUSBAR:
        luaA_statusbar_userdata_new(L, p);
        break;
      case AWESOME_TYPE_TITLEBAR:
        luaA_titlebar_userdata_new(L, p);
        break;
    }
}

static void
luaA_openlib(lua_State *L, const char *name,
             const struct luaL_reg methods[],
             const struct luaL_reg meta[])
{
    luaL_newmetatable(L, name);                                        /* 1 */
    lua_pushvalue(L, -1);           /* dup metatable                      2 */
    lua_setfield(L, -2, "__index"); /* metatable.__index = metatable      1 */

    luaL_register(L, NULL, meta);                                      /* 1 */
    luaL_register(L, name, methods);                                   /* 2 */
    lua_pushvalue(L, -1);           /* dup self as metatable              3 */
    lua_setmetatable(L, -2);        /* set self as metatable              2 */
    lua_pop(L, 2);
}

static int
luaA_mbstrlen(lua_State *L)
{
    const char *cmd = luaL_checkstring(L, 1);
    lua_pushnumber(L, mbstowcs(NULL, NONULL(cmd), 0));
    return 1;
}

static int
luaA_next(lua_State *L)
{
    if(luaL_getmetafield(L, 1, "__next"))
    {
        lua_insert(L, 1);
        lua_call(L, lua_gettop(L) - 1, LUA_MULTRET);
        return lua_gettop(L);
    }

    luaL_checktype(L, 1, LUA_TTABLE);
    lua_settop(L, 2);
    if(lua_next(L, 1))
        return 2;
    lua_pushnil(L);
    return 1;
}

static int
luaA_pairs(lua_State *L)
{
    if(luaL_getmetafield(L, 1, "__pairs"))
    {
        lua_insert(L, 1);
        lua_call(L, lua_gettop(L) - 1, LUA_MULTRET);
        return lua_gettop(L);
    }

    luaL_checktype(L, 1, LUA_TTABLE);
    return luaA_generic_pairs(L);
}

static void
luaA_fixups(lua_State *L)
{
    lua_getglobal(L, "string");
    lua_pushcfunction(L, luaA_mbstrlen);
    lua_setfield(L, -2, "len");
    lua_pop(L, 1);
    lua_pushliteral(L, "next");
    lua_pushcfunction(L, luaA_next);
    lua_settable(L, LUA_GLOBALSINDEX);
    lua_pushliteral(L, "pairs");
    lua_pushcfunction(L, luaA_next);
    lua_pushcclosure(L, luaA_pairs, 1); /* pairs get next as upvalue */
    lua_settable(L, LUA_GLOBALSINDEX);
}

/** Object table.
 * This table can use safely object as key.
 * \param L The Lua VM state.
 * \return The number of elements pushed on stack.
 */
int
luaA_otable_index(lua_State *L)
{
    void **obj, **v;

    if((obj = lua_touserdata(L, 2)))
    {
        /* begins at nil */
        lua_pushnil(L);
        while(lua_next(L, 1))
        {
            /* check the key against the key if the key is a userdata,
             * otherwise check it again the value. */
            if((v = lua_touserdata(L, -2))
                && *v == *obj)
                /* return value */
                return 1;
            else if((v = lua_touserdata(L, -1))
                    && *v == *obj)
            {
                /* return key */
                lua_pop(L, 1);
                return 1;
            }
            /* removes 'value'; keeps 'key' for next iteration */
            lua_pop(L, 1);
        }
        return 0;
    }
    
    lua_rawget(L, 1);
    return 1;
}

/** Object table.
 * This table can use safely object as key.
 * \param L The Lua VM state.
 * \return The number of elements pushed on stack.
 */
static int
luaA_otable_newindex(lua_State *L)
{
    void **obj, **v;

    if((obj = lua_touserdata(L, 2)))
    {
        /* begins at nil */
        lua_pushnil(L);
        while(lua_next(L, 1))
        {
            if((v = lua_touserdata(L, -2))
               && *v == *obj)
            {
                /* remove value */
                lua_pop(L, 1);
                /* push new value on top */
                lua_pushvalue(L, 3);
                /* set in table key = value */
                lua_rawset(L, 1);
                return 0;
            }
            /* removes 'value'; keeps 'key' for next iteration */
            lua_pop(L, 1);
        }
    }
    
    lua_rawset(L, 1);

    return 0;
}

/** Spawn a program.
 * This function is multi-head (Zaphod) aware and will set display to
 * the right screen according to mouse position.
 * \param L The Lua VM state.
 * \return The number of elements pushed on stack
 * \luastack
 * \lparam The command to launch.
 * \lparam The optional screen number to spawn the command on.
 */
static int
luaA_spawn(lua_State *L)
{
    static const char *shell = NULL;
    char *host, newdisplay[128];
    const char *cmd;
    int screen = 0, screenp, displayp;

    if(!shell && !(shell = getenv("SHELL")))
        shell = "/bin/sh";

    if(lua_gettop(L) == 2)
    {
        screen = luaL_checknumber(L, 2) - 1;
        luaA_checkscreen(screen);
    }

    cmd = luaL_checkstring(L, 1);

    if(!globalconf.screens_info->xinerama_is_active)
    {
        xcb_parse_display(NULL, &host, &displayp, &screenp);
        snprintf(newdisplay, sizeof(newdisplay), "%s:%d.%d", host, displayp, screen);
        setenv("DISPLAY", newdisplay, 1);
        p_delete(&host);
    }

    /* The double-fork construct avoids zombie processes and keeps the code
     * clean from stupid signal handlers. */
    if(fork() == 0)
    {
        if(fork() == 0)
        {
            if(globalconf.connection)
                xcb_disconnect(globalconf.connection);
            setsid();
            execl(shell, shell, "-c", cmd, NULL);
            warn("execl '%s -c %s' failed: %s\n", shell, cmd, strerror(errno));
        }
        exit(EXIT_SUCCESS);
    }
    wait(0);

    return 0;
}

/** Initialize the Lua VM
 */
void
luaA_init(void)
{
    lua_State *L;

    static const struct luaL_reg otable_methods[] =
    {
        { "__call", luaA_otable_new },
        { NULL, NULL }
    };
    static const struct luaL_reg otable_meta[] =
    {
        { "__index", luaA_otable_index },
        { "__newindex", luaA_otable_newindex },
        { NULL, NULL }
    };
    static const struct luaL_reg awesome_lib[] =
    {
        { "quit", luaA_quit },
        { "exec", luaA_exec },
        { "spawn", luaA_spawn },
        { "restart", luaA_restart },
        { "mouse_add", luaA_mouse_add },
        { "font_set", luaA_font_set },
        { "colors_set", luaA_colors_set },
        { NULL, NULL }
    };
    static const struct luaL_reg awesome_hooks_lib[] =
    {
        { "focus", luaA_hooks_focus },
        { "unfocus", luaA_hooks_unfocus },
        { "manage", luaA_hooks_manage },
        { "unmanage", luaA_hooks_unmanage },
        { "mouseover", luaA_hooks_mouseover },
        { "arrange", luaA_hooks_arrange },
        { "titleupdate", luaA_hooks_titleupdate },
        { "urgent", luaA_hooks_urgent },
        { "timer", luaA_hooks_timer },
        { NULL, NULL }
    };

    L = globalconf.L = luaL_newstate();

    luaL_openlibs(L);

    luaA_fixups(L);

    /* Export awesome lib */
    luaL_register(L, "awesome", awesome_lib);

    /* Export hooks lib */
    luaL_register(L, "hooks", awesome_hooks_lib);

    /* Export keygrabber lib */
    luaL_register(L, "keygrabber", awesome_keygrabber_lib);

    /* Export otable lib */
    luaA_openlib(L, "otable", otable_methods, otable_meta);

    /* Export screen */
    luaA_openlib(L, "screen", awesome_screen_methods, awesome_screen_meta);

    /* Export mouse */
    luaA_openlib(L, "mouse", awesome_mouse_methods, awesome_mouse_meta);

    /* Export tag */
    luaA_openlib(L, "tag", awesome_tag_methods, awesome_tag_meta);

    /* Export statusbar */
    luaA_openlib(L, "statusbar", awesome_statusbar_methods, awesome_statusbar_meta);

    /* Export widget */
    luaA_openlib(L, "widget", awesome_widget_methods, awesome_widget_meta);

    /* Export client */
    luaA_openlib(L, "client", awesome_client_methods, awesome_client_meta);

    /* Export titlebar */
    luaA_openlib(L, "titlebar", awesome_titlebar_methods, awesome_titlebar_meta);

    /* Export keys */
    luaA_openlib(L, "keybinding", awesome_keybinding_methods, awesome_keybinding_meta);

    lua_pushliteral(L, "AWESOME_VERSION");
    lua_pushstring(L, AWESOME_VERSION);
    lua_settable(L, LUA_GLOBALSINDEX);

    luaA_dostring(L, "package.path = package.path .. \";" AWESOME_LUA_LIB_PATH  "/?.lua\"");
    luaA_dostring(L, "package.path = package.path .. \";" AWESOME_LUA_LIB_PATH  "/?/init.lua\"");

    /* init hooks */
    globalconf.hooks.manage = LUA_REFNIL;
    globalconf.hooks.unmanage = LUA_REFNIL;
    globalconf.hooks.focus = LUA_REFNIL;
    globalconf.hooks.unfocus = LUA_REFNIL;
    globalconf.hooks.mouseover = LUA_REFNIL;
    globalconf.hooks.arrange = LUA_REFNIL;
    globalconf.hooks.titleupdate = LUA_REFNIL;
    globalconf.hooks.urgent = LUA_REFNIL;
    globalconf.hooks.timer = LUA_REFNIL;
}

#define XDG_CONFIG_HOME_DEFAULT "/.config"

#define AWESOME_CONFIG_FILE "/awesome/rc.lua"

/** Load a configuration file.
 * \param rcfile The configuration file to load.
 */
void
luaA_parserc(const char *confpatharg)
{
    int screen;
    const char *confdir, *xdg_config_dirs;
    char *confpath = NULL, **xdg_files, **buf, path[1024];
    ssize_t len;

    if(confpatharg)
    {
        if(luaL_dofile(globalconf.L, confpatharg))
            fprintf(stderr, "%s\n", lua_tostring(globalconf.L, -1));
        else
            goto bailout;
    }

    confdir = getenv("XDG_CONFIG_HOME");

    if((len = a_strlen(confdir)))
    {
        len += sizeof(AWESOME_CONFIG_FILE);
        confpath = p_new(char, len);
        a_strcpy(confpath, len, confdir);
        /* update package.path */
        snprintf(path, sizeof(path), "package.path = package.path .. \";%s/awesome/?.lua\"", confdir);
        luaA_dostring(globalconf.L, path);
    }
    else
    {
        confdir = getenv("HOME");
        len = a_strlen(confdir) + sizeof(AWESOME_CONFIG_FILE)-1 + sizeof(XDG_CONFIG_HOME_DEFAULT);
        confpath = p_new(char, len);
        a_strcpy(confpath, len, confdir);
        a_strcat(confpath, len, XDG_CONFIG_HOME_DEFAULT);
        /* update package.path */
        snprintf(path, sizeof(path), "package.path = package.path .. \";%s" XDG_CONFIG_HOME_DEFAULT "/awesome/?.lua\"", confdir);
        luaA_dostring(globalconf.L, path);
    }
    a_strcat(confpath, len, AWESOME_CONFIG_FILE);

    if(luaL_dofile(globalconf.L, confpath))
        fprintf(stderr, "%s\n", lua_tostring(globalconf.L, -1));
    else
        goto bailout;

    xdg_config_dirs = getenv("XDG_CONFIG_DIRS");

    if(!(len = a_strlen(xdg_config_dirs)))
    {
        xdg_config_dirs = XDG_CONFIG_DIR;
        len = sizeof(XDG_CONFIG_DIR) - 1;
    }

    xdg_files = a_strsplit(xdg_config_dirs, len, ':');

    for(buf = xdg_files; *buf; buf++)
    {
        p_delete(&confpath);
        len = a_strlen(*buf) + sizeof("AWESOME_CONFIG_FILE");
        confpath = p_new(char, len);
        a_strcpy(confpath, len, *buf);
        a_strcat(confpath, len, AWESOME_CONFIG_FILE);
        snprintf(path, sizeof(path), "package.path = package.path .. \";%s/awesome/?.lua\"", *buf);
        luaA_dostring(globalconf.L, path);
        if(luaL_dofile(globalconf.L, confpath))
            fprintf(stderr, "%s\n", lua_tostring(globalconf.L, -1));
        else
            break;
    }

    for(buf = xdg_files; *buf; buf++)
        p_delete(buf);
    p_delete(&xdg_files);

  bailout:
    /* Assure there's at least one tag */
    for(screen = 0; screen < globalconf.screens_info->nscreen; screen++)
        if(!globalconf.screens[screen].tags.len)
            tag_append_to_screen(tag_new("default", sizeof("default")-1, layout_tile, 0.5, 1, 0),
                                 &globalconf.screens[screen]);

    p_delete(&confpath);
}

/** Parse a command.
 * \param cmd The buffer to parse.
 * \return true on succes, false on failure.
 */
static void
luaA_docmd(const char *cmd)
{
    char *p;

    while((p = strchr(cmd, '\n')))
    {
        *p = '\0';
        luaA_dostring(globalconf.L, cmd);
        cmd = p + 1;
    }
}

static void
luaA_cb(EV_P_ ev_io *w, int revents)
{
    char buf[1024];
    int r;

    switch(r = recv(w->fd, buf, sizeof(buf)-1, MSG_TRUNC))
    {
      case -1:
        warn("error reading UNIX domain socket: %s", strerror(errno));
        luaA_cs_cleanup();
        break;
      case 0:
        break;
      default:
        if(r >= ssizeof(buf))
            break;
        buf[r] = '\0';
        luaA_docmd(buf);
    }
    awesome_refresh(globalconf.connection);
}

void
luaA_cs_init(void)
{
    int csfd = socket_getclient();

    if (csfd < 0 || fcntl(csfd, F_SETFD, FD_CLOEXEC) == -1)
        return;

    addr = socket_getaddr(getenv("DISPLAY"));

    if(bind(csfd, (const struct sockaddr *) addr, SUN_LEN(addr)))
    {
        if(errno == EADDRINUSE)
        {
            if(unlink(addr->sun_path))
                warn("error unlinking existing file: %s", strerror(errno));
            if(bind(csfd, (const struct sockaddr *) addr, SUN_LEN(addr)))
                warn("error binding UNIX domain socket: %s", strerror(errno));
        }
        else
            warn("error binding UNIX domain socket: %s", strerror(errno));
    }
    ev_io_init(&csio, &luaA_cb, csfd, EV_READ);
    ev_io_start(EV_DEFAULT_UC_ &csio);
    ev_unref(EV_DEFAULT_UC);
}

void
luaA_cs_cleanup(void)
{
    if(csio.fd < 0)
        return;
    ev_ref(EV_DEFAULT_UC);
    ev_io_stop(EV_DEFAULT_UC_ &csio);
    if (close(csio.fd))
        warn("error closing UNIX domain socket: %s", strerror(errno));
    if(unlink(addr->sun_path))
        warn("error unlinking UNIX domain socket: %s", strerror(errno));
    p_delete(&addr);
    csio.fd = -1;
}

void
luaA_on_timer(EV_P_ ev_timer *w, int revents)
{
    luaA_dofunction(globalconf.L, globalconf.hooks.timer, 0, 0);
    awesome_refresh(globalconf.connection);
}

void
luaA_pushcolor(lua_State *L, const xcolor_t *c)
{
    uint8_t r = (unsigned)c->red   * 0xff / 0xffff;
    uint8_t g = (unsigned)c->green * 0xff / 0xffff;
    uint8_t b = (unsigned)c->blue  * 0xff / 0xffff;
    uint8_t a = (unsigned)c->alpha * 0xff / 0xffff;
    char s[10];
    snprintf(s, sizeof(s), "#%02x%02x%02x%02x", r, g, b, a);
    lua_pushlstring(L, s, sizeof(s));
}