#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <vector>
#include <string>
#include <iostream>
#include "luastack.hpp"
#include "util.hpp"
#include "viewer.hpp"
#include "traceback.hpp"
#include "textgame.hpp"
#include "luaconsole.hpp"

// Add another error status.

static lua_State *globalL = NULL;


static void lstop(lua_State *L, lua_Debug *ar)
{
    (void)ar; /* unused arg. */
    lua_sethook(L, NULL, 0, 0);
    /* Avoid luaL_error -- a C hook doesn't add an extra frame. */
    luaL_where(L, 0);
    lua_pushfstring(L, "%sinterrupted!", lua_tostring(L, -1));
    lua_error(L);
}

static void laction(int i)
{
    signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
			 terminate process (default action) */
    lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
}

static void l_message(const char *msg)
{
    fputs(msg, stderr);
    fputc('\n', stderr);
    fflush(stderr);
}

static int report(lua_State *L, int status)
{
    if (status && !lua_isnil(L, -1))
    {
        const char *msg = lua_tostring(L, -1);
        if (msg == NULL)
            msg = "(error object is not a string)";
        l_message(msg);
        lua_pop(L, 1);
    }
    return status;
}

static void doexp(lua_State *L, const std::string &exp)
{
    int status = luaL_loadbuffer(L, exp.c_str(), exp.size(), "=stdin");
    assert(status == LUA_OK);
    globalL = L;
    signal(SIGINT, laction);
    status = traceback_pcall(L, 0, LUA_MULTRET);
    signal(SIGINT, SIG_DFL);
    if (status != LUA_OK) {
        report(L, status);
        lua_gc(L, LUA_GCCOLLECT, 0);
    }
    if (status == LUA_OK && lua_gettop(L) > 0) {
        lua_getglobal(L, "pprint");
        if (lua_isnil(L, -1)) {
            lua_pop(L, 1);
            lua_getglobal(L, "print");
        }
        lua_insert(L, 1);
        if (lua_pcall(L, lua_gettop(L) - 1, 0, 0) != 0) {
            l_message(
                lua_pushfstring(L, "error calling 'print' (%s)",
                                lua_tostring(L, -1)));
        }
    }
}

void TextGame::run()
{
    LuaConsole console;
    while (true) {
        console.add_stdin();
        switch (console.state()) {
        case LuaConsole::STATE_INCOMPLETE:
            break;
        case LuaConsole::STATE_COMPLETE:
            doexp(viewer_.get_lua_state(), console.expression());
            console.clear();
            break;
        case LuaConsole::STATE_SLASHCOMMAND:
            std::cerr << "Slash commands not supported yet." << std::endl;
            console.clear();
            break;
        case LuaConsole::STATE_SYNTAX:
            std::cerr << console.syntax() << std::endl;
            console.clear();
            break;
        }
    }
}