/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla IPC.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Darin Fisher <darin@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include <string.h>
#include <stdlib.h>

#include "prlink.h"
#include "prio.h"
#include "plstr.h"

#include "ipcConfig.h"
#include "ipcLog.h"
#include "ipcModuleReg.h"
#include "ipcModule.h"
#include "ipcCommandModule.h"
#include "ipcd.h"

struct ipcModuleRegEntry
{
    nsID       id;
    ipcModule *module;
    PRLibrary *lib;
};

#define IPC_MAX_MODULE_COUNT 64

static ipcModuleRegEntry ipcModules[IPC_MAX_MODULE_COUNT];
static int ipcModuleCount;

static PRStatus
AddModule(const nsID &id, ipcModule *module, PRLibrary *lib)
{
    if (ipcModuleCount == IPC_MAX_MODULE_COUNT) {
        LOG(("too many modules!\n"));
        return PR_FAILURE;
    }

    ipcModules[ipcModuleCount].id = id;
    ipcModules[ipcModuleCount].module = module;
    ipcModules[ipcModuleCount].lib = lib;

    ++ipcModuleCount;
    return PR_SUCCESS;
}

static void
InitModuleFromLib(const char *modulesDir, const char *fileName)
{
    LOG(("InitModuleFromLib [%s]\n", fileName));

    int dLen = strlen(modulesDir);
    int fLen = strlen(fileName);

    char *buf = (char *) malloc(dLen + 1 + fLen + 1);
    memcpy(buf, modulesDir, dLen);
    buf[dLen] = IPC_PATH_SEP_CHAR;
    memcpy(buf + dLen + 1, fileName, fLen);
    buf[dLen + 1 + fLen] = '\0';

    PRLibrary *lib = PR_LoadLibrary(buf);
    if (lib) {
        ipcGetModuleListFunc func =
            (ipcGetModuleListFunc) PR_FindFunctionSymbol(lib, "IPC_GetModuleList");
        if (func) {
            ipcModule **modules = func();
            if (modules) {
                while (*modules) {
                    AddModule((*modules)->ID(), *modules, PR_LoadLibrary(buf));
                    ++modules;
                }
            }
        }
        PR_UnloadLibrary(lib);
    }

    free(buf);
}

//-----------------------------------------------------------------------------
// ipcModuleReg API
//-----------------------------------------------------------------------------

//
// search for a module registered under the specified id
//
ipcModule *
IPC_GetModuleByID(const nsID &id)
{
    for (int i=0; i<ipcModuleCount; ++i) {
        ipcModuleRegEntry &entry = ipcModules[i];
        if (entry.id.Equals(id))
            return entry.module;
    }
    return NULL;
}

void
IPC_InitModuleReg(const char *exePath)
{
    //
    // register built-in modules
    //
    ipcModule *module = IPC_GetCommandModule();
    AddModule(module->ID(), module, NULL);

    //
    // register plug-in modules
    //
    if (exePath && *exePath) {
        static const char relModDir[] = "ipc/modules";

        char *p = PL_strrchr(exePath, IPC_PATH_SEP_CHAR);
        if (p == NULL) {
            LOG(("unexpected exe path\n"));
            return;
        }

        int baseLen = p - exePath;
        int finalLen = baseLen + 1 + sizeof(relModDir);

        // build full path to ipc modules
        char *modulesDir = (char*) malloc(finalLen);
        memcpy(modulesDir, exePath, baseLen);
        modulesDir[baseLen] = IPC_PATH_SEP_CHAR;
        memcpy(modulesDir + baseLen + 1, relModDir, sizeof(relModDir));

        LOG(("loading libraries in %s\n", modulesDir));
        // 
        // scan directory for IPC modules
        //
        PRDir *dir = PR_OpenDir(modulesDir);
        if (dir) {
            PRDirEntry *ent;
            while ((ent = PR_ReadDir(dir, PR_SKIP_BOTH)) != NULL) {
                // 
                // locate extension, and check if dynamic library
                //
                char *p = strrchr(ent->name, '.');
                if (p && PL_strcasecmp(p, MOZ_DLL_SUFFIX) == 0)
                    InitModuleFromLib(modulesDir, ent->name);
            }
            PR_CloseDir(dir);
        }
    }
}

void
IPC_ShutdownModuleReg()
{
    //
    // shutdown modules in reverse order    
    //
    for (int i = ipcModuleCount - 1; i >= 0; --i) {
        ipcModuleRegEntry &entry = ipcModules[i];
        if (entry.module)
            entry.module->Shutdown();
        if (entry.lib)
            PR_UnloadLibrary(entry.lib);
    }
    // memset(ipcModules, 0, sizeof(ipcModules));
    ipcModuleCount = 0;
}