#include "lua_objs.h"

#include <string.h>

#include <lua5.1/lua.h>
#include <lua5.1/lualib.h>
#include <lua5.1/lauxlib.h>

/**
 * Convenience function to register a new metatable for a type, this leaves the metatable on the stack
 */
static void lua_obj_create_type (lua_State *L, const char *name, const struct luaL_Reg methods[])
{
    luaL_newmetatable(L, name);

    // set the metatable __index to itself
    lua_pushvalue(L, -1);
    lua_setfield(L, -1, "__index");

    // register the methods to the metatable
    luaL_register(L, NULL, methods);
}

/**
 * Convenience function to create a new userdata with the given type metatable name, return the pointer, and keep it
 * on the stack
 */
static void* lua_obj_create_obj (lua_State *L, const char *name, size_t size)
{
    // create the new userdata on the stack
    void *ud = lua_newuserdata(L, size);

    // get the type and set it
    luaL_getmetatable(L, name);
    lua_setmetatable(L, -2);
    
    // ok
    return ud;
}

/**
 * Convenience function to get a userdata with the given type metatable name as the first argument for a function
 */
static void* lua_obj_get_obj (lua_State *L, const char *func, const char *name)
{
    void *ud;

    // validate the userdata arg
    if ((ud = luaL_checkudata(L, 1, name)) == NULL) {
        luaL_error(L, "bad type argument to %s: `%s` expected", func, name);

    } else {
        // ok
        return ud;

    }
}

/**
 * Our lua wrapper for irc_chan
 */
struct lua_chan {
    struct irc_chan *chan;
};

/**
 * Create a lua_chan userdata from the given irc_chan and leave it on the stack, returning 1
 */
static int lua_chan_create (lua_State *L, struct irc_chan *chan)
{
    // create the new obj
    struct lua_chan *lua_chan = lua_obj_create_obj(L, "evirc.chan", sizeof(*lua_chan));

    // initialize
    lua_chan->chan = chan;

    // ok
    return 1;
}

/**
 * Return the channel name as a lua string
 */
static int lua_chan_tostring (lua_State *L)
{
    struct lua_chan *lua_chan = lua_obj_get_obj(L, __func__, "evirc.chan");
    
    lua_pushfstring(L, "<irc_chan %s>", irc_chan_name(lua_chan->chan));

    return 1;
}

/**
 * Send a PRIVMSG to the channel
 */
static int lua_chan_say (lua_State *L)
{
    err_t err;

    struct lua_chan *lua_chan = lua_obj_get_obj(L, __func__, "evirc.chan");
    
    // the message
    const char *message = luaL_checkstring(L, 2);

    // send
    if ((err = irc_chan_PRIVMSG(lua_chan->chan, message)))
        return luaL_error(L, "irc_chan_PRIVMSG: '%s': %s", message, error_name(err));
    
    // ok
    return 0;
}

static const struct luaL_Reg lua_chan_methods[] = {
    {   "__tostring",       &lua_chan_tostring  },
    {   "say",              &lua_chan_say       },
    {   NULL,               NULL                },
};

/**
 * Initialize the lua_chan object type
 */
static void lua_chan_init (lua_State *L)
{
    lua_obj_create_type(L, "evirc.chan", lua_chan_methods);
}

/**
 * Our lua wrapper for irc_net
 */
struct lua_net {
    struct irc_net *net;
};

/**
 * Create a lua_net userdata from the given irc_net and push it onto the stack, returning 1.
 */
static int lua_net_create (lua_State *L, struct irc_net *net)
{
    // create the new obj
    struct lua_net *lua_net = lua_obj_create_obj(L, "evirc.net", sizeof(*lua_net));

    // initialize
    lua_net->net = net;

    // ok
    return 1;
}

/**
 * Return the network name as a lua string
 */
static int lua_net_tostring (lua_State *L)
{
    struct lua_net *lua_net = lua_obj_get_obj(L, __func__, "evirc.net");
    
    lua_pushfstring(L, "<irc_net %s>", irc_net_name(lua_net->net));

    return 1;
}

/**
 * Join a new channel, returning the lua_chan
 */
static int lua_net_join (lua_State *L)
{
    struct lua_net *lua_net = lua_obj_get_obj(L, __func__, "evirc.net");
    struct irc_chan_info chan_info;
    struct irc_chan *chan;
    struct error_info err;
    
    // the channel name
    chan_info.channel = luaL_checkstring(L, 2);
    
    // add it
    if (irc_net_add_chan(lua_net->net, &chan, &chan_info, &err))
        return luaL_error(L, "irc_net_add_chan: %s: %s", chan_info.channel, error_msg(&err));
    
    // return it
    return lua_chan_create(L, chan);    
}

/**
 * Look up a channel by name, returning the lua_chan
 */
static int lua_net_get_chan (lua_State *L)
{
    struct lua_net *lua_net = lua_obj_get_obj(L, __func__, "evirc.net");
    struct irc_chan *chan;
    
    // the channel name
    const char *channel = luaL_checkstring(L, 2);
    
    // lookup the irc_chan
    if ((chan = irc_net_get_chan(lua_net->net, channel)) == NULL)
        return luaL_error(L, "irc_net_get_chan: no such channel: %s", channel);

    // wrap it
    return lua_chan_create(L, chan);
}

static const struct luaL_Reg lua_net_methods[] = {
    {   "__tostring",   &lua_net_tostring   },
    {   "join",         &lua_net_join       },
    {   "channel",      &lua_net_get_chan   },
    {   NULL,           NULL                }
};

/**
 * Initialize the lua_net object type
 */
static void lua_net_init (lua_State *L)
{
    lua_obj_create_type(L, "evirc.net", lua_net_methods);
}

/**
 * Wrapper for irc_client
 */
struct lua_client {
    struct irc_client *client;
};

static int lua_client_connect (lua_State *L)
{
    struct lua_client *lua_client = lua_obj_get_obj(L, __func__, "evirc.client");
    struct irc_net_info net_info;
    struct irc_net *net;
    struct error_info err;

    // init net_info
    memset(&net_info, 0, sizeof(net_info));

    // the network name
    net_info.network = luaL_checkstring(L, 2);
    
    // the hostname
    net_info.hostname = luaL_checkstring(L, 3);

    // service remains default
    net_info.service = "6667";

    // create it
    if (irc_client_add_net(lua_client->client, &net, &net_info, &err))
        return luaL_error(L, "irc_client_add_net: %s/%s: %s", net_info.network, net_info.hostname, error_msg(&err));

    // wrap it
    return lua_net_create(L, net);
}

static int lua_client_get_network (lua_State *L)
{
    struct lua_client *lua_client = lua_obj_get_obj(L, __func__, "evirc.client");
    struct irc_net *net;
    
    // the network name
    const char *network = luaL_checkstring(L, 2);
    
    // lookup the irc_net
    if ((net = irc_client_get_net(lua_client->client, network)) == NULL)
        return luaL_error(L, "irc_client_get_net: no such network: %s", network);

    // wrap it
    return lua_net_create(L, net);
}

static int lua_client_quit (lua_State *L)
{
    struct lua_client *lua_client = lua_obj_get_obj(L, __func__, "evirc.client");
    err_t err;
   
    // the message
    const char *message = luaL_checkstring(L, 2);

    // execute
    if ((err = irc_client_quit(lua_client->client, message)))
        return luaL_error(L, "irc_client_quit: %s", error_name(err));

    // ok
    return 0;
}

static const struct luaL_Reg lua_client_methods[] = {
    {   "connect",      &lua_client_connect     },
    {   "network",      &lua_client_get_network },
    {   "quit",         &lua_client_quit        },
    {   NULL,           NULL                    }
};

/**
 * Initializes a lua_irc_client wrapper for the given client in the give lua state. This registers a set of globals for
 * 'client' and 'networks'.
 */
static void lua_client_init (lua_State *L, struct irc_client *client)
{
    // allocate the global "client" object
    struct lua_client *lua_client = lua_newuserdata(L, sizeof(*lua_client));
    
    // create the type metatable
    lua_obj_create_type(L, "evirc.client", lua_client_methods);

    // set the client userdata's metatable
    lua_setmetatable(L, -2);

    // initialize it
    lua_client->client = client;

    // store it as a global
    lua_setglobal(L, "client");
}

/**
 * Set up the lua state in protected mode
 */
static int _lua_objs_init (lua_State *L)
{
    struct nexus *nexus;
    
    // read the nexus off the stack
    if ((nexus = lua_touserdata(L, 1)) == NULL)
        luaL_error(L, "lua_touserdata: NULL");

    // init the various bits
    lua_client_init(L, nexus->client);
    lua_net_init(L);
    lua_chan_init(L);

    // nothing
    return 0;
}

err_t lua_objs_init (lua_State *L, struct nexus *nexus)
{
    // call in protected mode
    switch (lua_cpcall(L, &_lua_objs_init, nexus)) {
        case 0:             return SUCCESS;
        case LUA_ERRRUN:    return ERR_LUA_RUN;
        case LUA_ERRMEM:    return ERR_LUA_MEM;
        case LUA_ERRERR:    return ERR_LUA_ERR;
        default:            return ERR_UNKNOWN;
    }
}