/* LICENSE BLOCK
Part of mde: a Modular D game-oriented Engine
Copyright © 2007-2008 Diggory Hardy

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, see <http://www.gnu.org/licenses/>. */

/** This module is responsible for calling all init functions.
*
* It is also responsible for setting up all scheduled functions for now.

* Idea: change import direction so this module adds all init functions. All init functions are
* wrapped in another function before being run in a thread (i.e. run indirectly). Functions fail
* either by throwing an exception or by returning a boolean. Functions may take parameters, e.g.
* "out cleanupFunc[]". */
module mde.scheduler.InitFunctions;

static import mde.gl;

import tango.util.log.Log : Log, Logger;
static this() {
    logger = Log.getLogger ("mde.scheduler.InitFunctions");
}

/** Should be called by an init function when a failure occurs. */
void setInitFailure () {
    initFailure = true;
}

package:

/** Represents all functions to be called for a particular init stage. */
struct InitStage
{
    alias void function() InitFunction; /// Alias
    
    /** Add a function to be called during this init stage.
    *
    * Called in order added when not threaded (reverse order for cleanup).
    *
    * Exceptions should never be thrown, since each function may run as a thread, and catching
    * thread exceptions is not guaranteed to work. Log a message, call setFailure() and return
    * instead. */
    void addFunc (InitFunction f) {
        funcs ~= f;
    }
    
    InitFunction[] funcs = [];
}

InitStage init;     // all functions called during init (all should be thread-safe)
InitStage cleanup;  // all functions called during cleanup (all should be thread-safe)

bool initFailure = false;   // set on failure (throwing through threads isn't a good idea)

private:
Logger logger;
const FAIL_MSG = "Init function failed: ";
// Template to call function, catching exceptions:
void initInput(alias Func) () {
    try {
        Func();
    } catch (Exception e) {
        logger.fatal (FAIL_MSG ~ e.msg);
        initFailure = true;
    }
}