/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-

   session.c for the Openbox window manager
   Copyright (c) 2003-2007   Dana Jansens

   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.

   See the COPYING file for a copy of the GNU General Public License.
*/

/* This session code is largely inspired by metacity code. */

#include "session.h"

struct _ObClient;

GList *session_saved_state = NULL;
gint session_desktop = -1;

#ifndef USE_SM
void session_startup(gint argc, gchar **argv) {}
void session_shutdown(gboolean permanent) {}
GList* session_state_find(struct _ObClient *c) { return NULL; }
#else

#include "debug.h"
#include "openbox.h"
#include "client.h"
#include "prop.h"
#include "screen.h"
#include "gettext.h"
#include "parser/parse.h"

#include <time.h>
#include <errno.h>
#include <stdio.h>

#ifdef HAVE_UNISTD_H
#  include <sys/types.h>
#  include <unistd.h>
#endif

#include <X11/SM/SMlib.h>

#define SM_ERR_LEN 1024

static SmcConn  sm_conn;
static gint     sm_argc;
static gchar  **sm_argv;

static gboolean session_connect();

static void session_load_file(gchar *path);
static gboolean session_save_to_file();

static void session_setup_program();
static void session_setup_user();
static void session_setup_restart_style(gboolean restart);
static void session_setup_pid();
static void session_setup_priority();
static void session_setup_clone_command();
static void session_setup_restart_command();

static void sm_save_yourself(SmcConn conn, SmPointer data, gint save_type,
                             Bool shutdown, gint interact_style, Bool fast);
static void sm_die(SmcConn conn, SmPointer data);
static void sm_save_complete(SmcConn conn, SmPointer data);
static void sm_shutdown_cancelled(SmcConn conn, SmPointer data);

static gboolean session_state_cmp(ObSessionState *s, ObClient *c);
static void session_state_free(ObSessionState *state);

void session_startup(gint argc, gchar **argv)
{
    gchar *dir;

    if (!ob_sm_use) return;

    sm_argc = argc;
    sm_argv = argv;

    dir = g_build_filename(parse_xdg_data_home_path(),
                           "openbox", "sessions", NULL);
    if (!parse_mkdir_path(dir, 0700)) {
        g_message(_("Unable to make directory '%s': %s"),
                  dir, g_strerror(errno));
    }

    if (ob_sm_save_file != NULL) {
        ob_debug_type(OB_DEBUG_SM, "Loading from session file %s\n",
                      ob_sm_save_file);
        session_load_file(ob_sm_save_file);
    } else {
        gchar *filename;

        /* this algo is from metacity */
        filename = g_strdup_printf("%u-%u-%u.obs",
                                   (guint)time(NULL),
                                   (guint)getpid(),
                                   g_random_int());
        ob_sm_save_file = g_build_filename(dir, filename, NULL);
        g_free(filename);
    }

    if (session_connect()) {
        session_setup_program();
        session_setup_user();
        session_setup_restart_style(TRUE);
        session_setup_pid();
        session_setup_priority();
        session_setup_clone_command();
    }

    g_free(dir);
}

void session_shutdown(gboolean permanent)
{
    if (!ob_sm_use) return;

    if (sm_conn) {
        /* if permanent is true then we will change our session state so that
           the SM won't run us again */
        session_setup_restart_style(!permanent);

        SmcCloseConnection(sm_conn, 0, NULL);

        while (session_saved_state) {
            session_state_free(session_saved_state->data);
            session_saved_state = g_list_delete_link(session_saved_state,
                                                     session_saved_state);
        }
    }
}

/*! Connect to the session manager and set up our callback functions */
static gboolean session_connect()
{
    SmcCallbacks cb;
    gchar *oldid;
    gchar sm_err[SM_ERR_LEN];

    /* set up our callback functions */
    cb.save_yourself.callback = sm_save_yourself;
    cb.save_yourself.client_data = NULL;
    cb.die.callback = sm_die;
    cb.die.client_data = NULL;
    cb.save_complete.callback = sm_save_complete;
    cb.save_complete.client_data = NULL;
    cb.shutdown_cancelled.callback = sm_shutdown_cancelled;
    cb.shutdown_cancelled.client_data = NULL;

    /* connect to the server */
    oldid = ob_sm_id;
    ob_debug_type(OB_DEBUG_SM, "Connecting to SM with id: %s\n",
                  oldid ? oldid : "(null)");
    sm_conn = SmcOpenConnection(NULL, NULL, 1, 0,
                                SmcSaveYourselfProcMask |
                                SmcDieProcMask |
                                SmcSaveCompleteProcMask |
                                SmcShutdownCancelledProcMask,
                                &cb, oldid, &ob_sm_id,
                                SM_ERR_LEN, sm_err);
    g_free(oldid);
    if (sm_conn == NULL)
        ob_debug("Failed to connect to session manager: %s\n", sm_err);
    return sm_conn != NULL;
}

static void session_setup_program()
{
    SmPropValue vals = {
        .value = sm_argv[0],
        .length = strlen(sm_argv[0]) + 1
    };
    SmProp prop = {
        .name = g_strdup(SmProgram),
        .type = g_strdup(SmARRAY8),
        .num_vals = 1,
        .vals = &vals
    };
    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
}

static void session_setup_user()
{
    char *user = g_strdup(g_get_user_name());

    SmPropValue vals = {
        .value = user,
        .length = strlen(user) + 1
    };
    SmProp prop = {
        .name = g_strdup(SmUserID),
        .type = g_strdup(SmARRAY8),
        .num_vals = 1,
        .vals = &vals
    };
    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
    g_free(user);
}

static void session_setup_restart_style(gboolean restart)
{
    char restart_hint = restart ? SmRestartImmediately : SmRestartIfRunning;

    SmPropValue vals = {
        .value = &restart_hint,
        .length = 1
    };
    SmProp prop = {
        .name = g_strdup(SmRestartStyleHint),
        .type = g_strdup(SmCARD8),
        .num_vals = 1,
        .vals = &vals
    };
    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
}

static void session_setup_pid()
{
    gchar *pid = g_strdup_printf("%ld", (glong) getpid());

    SmPropValue vals = {
        .value = pid,
        .length = strlen(pid) + 1
    };
    SmProp prop = {
        .name = g_strdup(SmProcessID),
        .type = g_strdup(SmARRAY8),
        .num_vals = 1,
        .vals = &vals
    };
    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
    g_free(pid);
}

/*! This is a gnome-session-manager extension */
static void session_setup_priority()
{
    gchar priority = 20; /* 20 is a lower prioity to run before other apps */

    SmPropValue vals = {
        .value = &priority,
        .length = 1
    };
    SmProp prop = {
        .name = g_strdup("_GSM_Priority"),
        .type = g_strdup(SmCARD8),
        .num_vals = 1,
        .vals = &vals
    };
    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
}

static void session_setup_clone_command()
{
    gint i;

    SmPropValue *vals = g_new(SmPropValue, sm_argc);
    SmProp prop = {
        .name = g_strdup(SmCloneCommand),
        .type = g_strdup(SmLISTofARRAY8),
        .num_vals = sm_argc,
        .vals = vals
    };

    for (i = 0; i < sm_argc; ++i) {
        vals[i].value = sm_argv[i];
        vals[i].length = strlen(sm_argv[i]) + 1;
    }

    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
    g_free(vals);
}

static void session_setup_restart_command()
{
    gint i;

    SmPropValue *vals = g_new(SmPropValue, sm_argc + 4);
    SmProp prop = {
        .name = g_strdup(SmRestartCommand),
        .type = g_strdup(SmLISTofARRAY8),
        .num_vals = sm_argc + 4,
        .vals = vals
    };

    for (i = 0; i < sm_argc; ++i) {
        vals[i].value = sm_argv[i];
        vals[i].length = strlen(sm_argv[i]) + 1;
    }

    vals[i].value = g_strdup("--sm-save-file");
    vals[i].length = strlen("--sm-save-file") + 1;
    vals[i+1].value = ob_sm_save_file;
    vals[i+1].length = strlen(ob_sm_save_file) + 1;

    vals[i+2].value = g_strdup("--sm-client-id");
    vals[i+2].length = strlen("--sm-client-id") + 1;
    vals[i+3].value = ob_sm_id;
    vals[i+3].length = strlen(ob_sm_id) + 1;

    SmProp *list = &prop;
    SmcSetProperties(sm_conn, 1, &list);
    g_free(prop.name);
    g_free(prop.type);
    g_free(vals[i].value);
    g_free(vals[i+2].value);
    g_free(vals);
}

static void sm_save_yourself_2(SmcConn conn, SmPointer data)
{
    gboolean success;

    /* save the current state */
    ob_debug_type(OB_DEBUG_SM, "Session save phase 2 requested\n");
    ob_debug_type(OB_DEBUG_SM,
                  "  Saving session to file '%s'\n", ob_sm_save_file);
    success = session_save_to_file();

    /* tell the session manager how to restore this state */
    if (success) session_setup_restart_command();

    ob_debug_type(OB_DEBUG_SM, "Saving is done (success = %d)\n", success);
    SmcSaveYourselfDone(conn, success);
}


static void sm_save_yourself(SmcConn conn, SmPointer data, gint save_type,
                             Bool shutdown, gint interact_style, Bool fast)
{
    ob_debug_type(OB_DEBUG_SM, "Session save requested\n");
    if (!SmcRequestSaveYourselfPhase2(conn, sm_save_yourself_2, data)) {
        ob_debug_type(OB_DEBUG_SM, "Requst for phase 2 failed\n");
        SmcSaveYourselfDone(conn, FALSE);
    }
}

static void sm_die(SmcConn conn, SmPointer data)
{
    ob_debug_type(OB_DEBUG_SM, "Die requested\n");
    ob_exit(0);
}

static void sm_save_complete(SmcConn conn, SmPointer data)
{
    ob_debug_type(OB_DEBUG_SM, "Save complete\n");
}

static void sm_shutdown_cancelled(SmcConn conn, SmPointer data)
{
    ob_debug_type(OB_DEBUG_SM, "Shutdown cancelled\n");    
}

static gboolean session_save_to_file()
{
    FILE *f;
    GList *it;
    gboolean success = TRUE;

    f = fopen(ob_sm_save_file, "w");
    if (!f) {
        success = FALSE;
        g_message(_("Unable to save the session to '%s': %s"),
                  ob_sm_save_file, g_strerror(errno));
    } else {
        fprintf(f, "<?xml version=\"1.0\"?>\n\n");
        fprintf(f, "<openbox_session>\n\n");

        fprintf(f, "<desktop>%d</desktop>\n", screen_desktop);

        /* they are ordered top to bottom in stacking order */
        for (it = stacking_list; it; it = g_list_next(it)) {
            gint prex, prey, prew, preh;
            ObClient *c;
            gchar *t;

            if (WINDOW_IS_CLIENT(it->data))
                c = WINDOW_AS_CLIENT(it->data);
            else
                continue;

            if (!client_normal(c))
                continue;

            if (!c->sm_client_id) {
                ob_debug_type(OB_DEBUG_SM, "Client %s does not have a client "
                              "id set, so we can't save its state\n",
                              c->title);
                continue;
            }

            ob_debug_type(OB_DEBUG_SM, "Saving state for client %s\n",
                          c->title);

            prex = c->area.x;
            prey = c->area.y;
            prew = c->area.width;
            preh = c->area.height;
            if (c->fullscreen) {
                prex = c->pre_fullscreen_area.x;
                prey = c->pre_fullscreen_area.x;
                prew = c->pre_fullscreen_area.width;
                preh = c->pre_fullscreen_area.height;
            }
            if (c->max_horz) {
                prex = c->pre_max_area.x;
                prew = c->pre_max_area.width;
            }
            if (c->max_vert) {
                prey = c->pre_max_area.y;
                preh = c->pre_max_area.height;
            }

            fprintf(f, "<window id=\"%s\">\n", c->sm_client_id);

            t = g_markup_escape_text(c->name, -1);
            fprintf(f, "\t<name>%s</name>\n", t);
            g_free(t);

            t = g_markup_escape_text(c->class, -1);
            fprintf(f, "\t<class>%s</class>\n", t);
            g_free(t);

            t = g_markup_escape_text(c->role, -1);
            fprintf(f, "\t<role>%s</role>\n", t);
            g_free(t);

            fprintf(f, "\t<desktop>%d</desktop>\n", c->desktop);
            fprintf(f, "\t<x>%d</x>\n", prex);
            fprintf(f, "\t<y>%d</y>\n", prey);
            fprintf(f, "\t<width>%d</width>\n", prew);
            fprintf(f, "\t<height>%d</height>\n", preh);
            if (c->shaded)
                fprintf(f, "\t<shaded />\n");
            if (c->iconic)
                fprintf(f, "\t<iconic />\n");
            if (c->skip_pager)
                fprintf(f, "\t<skip_pager />\n");
            if (c->skip_taskbar)
                fprintf(f, "\t<skip_taskbar />\n");
            if (c->fullscreen)
                fprintf(f, "\t<fullscreen />\n");
            if (c->above)
                fprintf(f, "\t<above />\n");
            if (c->below)
                fprintf(f, "\t<below />\n");
            if (c->max_horz)
                fprintf(f, "\t<max_horz />\n");
            if (c->max_vert)
                fprintf(f, "\t<max_vert />\n");
            if (c->undecorated)
                fprintf(f, "\t<undecorated />\n");
            if (client_focused(c))
                fprintf(f, "\t<focused />\n");
            fprintf(f, "</window>\n\n");
        }

        fprintf(f, "</openbox_session>\n");

        if (fflush(f)) {
            success = FALSE;
            g_message(_("Error while saving the session to '%s': %s"),
                      ob_sm_save_file, g_strerror(errno));
        }
        fclose(f);
    }

    return success;
}

static void session_state_free(ObSessionState *state)
{
    if (state) {
        g_free(state->id);
        g_free(state->name);
        g_free(state->class);
        g_free(state->role);

        g_free(state);
    }
}

static gboolean session_state_cmp(ObSessionState *s, ObClient *c)
{
    ob_debug_type(OB_DEBUG_SM, "Comparing client against saved state: \n");
    ob_debug_type(OB_DEBUG_SM, "  client id: %s \n", c->sm_client_id);
    ob_debug_type(OB_DEBUG_SM, "  client name: %s \n", c->name);
    ob_debug_type(OB_DEBUG_SM, "  client class: %s \n", c->class);
    ob_debug_type(OB_DEBUG_SM, "  client role: %s \n", c->role);
    ob_debug_type(OB_DEBUG_SM, "  state id: %s \n", s->id);
    ob_debug_type(OB_DEBUG_SM, "  state name: %s \n", s->name);
    ob_debug_type(OB_DEBUG_SM, "  state class: %s \n", s->class);
    ob_debug_type(OB_DEBUG_SM, "  state role: %s \n", s->role);
    return (c->sm_client_id &&
            !strcmp(s->id, c->sm_client_id) &&
            !strcmp(s->name, c->name) &&
            !strcmp(s->class, c->class) &&
            !strcmp(s->role, c->role));
}

GList* session_state_find(ObClient *c)
{
    GList *it;

    for (it = session_saved_state; it; it = g_list_next(it)) {
        ObSessionState *s = it->data;
        if (!s->matched && session_state_cmp(s, c)) {
            s->matched = TRUE;
            break;
        }
    }
    return it;
}

static void session_load_file(gchar *path)
{
    xmlDocPtr doc;
    xmlNodePtr node, n;

    if (!parse_load(path, "openbox_session", &doc, &node))
        return;

    if ((n = parse_find_node("desktop", node->children)))
        session_desktop = parse_int(doc, n);

    for (node = parse_find_node("window", node->children); node != NULL;
         node = parse_find_node("window", node->next))
    {
        ObSessionState *state;

        state = g_new0(ObSessionState, 1);

        if (!parse_attr_string("id", node, &state->id))
            goto session_load_bail;
        if (!(n = parse_find_node("name", node->children)))
            goto session_load_bail;
        state->name = parse_string(doc, n);
        if (!(n = parse_find_node("class", node->children)))
            goto session_load_bail;
        state->class = parse_string(doc, n);
        if (!(n = parse_find_node("role", node->children)))
            goto session_load_bail;
        state->role = parse_string(doc, n);
        if (!(n = parse_find_node("desktop", node->children)))
            goto session_load_bail;
        state->desktop = parse_int(doc, n);
        if (!(n = parse_find_node("x", node->children)))
            goto session_load_bail;
        state->x = parse_int(doc, n);
        if (!(n = parse_find_node("y", node->children)))
            goto session_load_bail;
        state->y = parse_int(doc, n);
        if (!(n = parse_find_node("width", node->children)))
            goto session_load_bail;
        state->w = parse_int(doc, n);
        if (!(n = parse_find_node("height", node->children)))
            goto session_load_bail;
        state->h = parse_int(doc, n);

        state->shaded =
            parse_find_node("shaded", node->children) != NULL;
        state->iconic =
            parse_find_node("iconic", node->children) != NULL;
        state->skip_pager =
            parse_find_node("skip_pager", node->children) != NULL;
        state->skip_taskbar =
            parse_find_node("skip_taskbar", node->children) != NULL;
        state->fullscreen =
            parse_find_node("fullscreen", node->children) != NULL;
        state->above =
            parse_find_node("above", node->children) != NULL;
        state->below =
            parse_find_node("below", node->children) != NULL;
        state->max_horz =
            parse_find_node("max_horz", node->children) != NULL;
        state->max_vert =
            parse_find_node("max_vert", node->children) != NULL;
        state->undecorated =
            parse_find_node("undecorated", node->children) != NULL;
        state->focused =
            parse_find_node("focused", node->children) != NULL;
        
        /* save this. they are in the file in stacking order, so preserve
           that order here */
        session_saved_state = g_list_append(session_saved_state, state);
        continue;

    session_load_bail:
        session_state_free(state);
    }

    xmlFreeDoc(doc);
}

#endif