/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *      Michael Zucchi <notzed@novell.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gtk/gtk.h>
#include <glib/gi18n-lib.h>
#include <gconf/gconf-client.h>
#include <string.h>
#include <stdio.h>

#include <em-format/em-format.h>
#include <mail/em-config.h>
#include <mail/em-format-hook.h>

void org_gnome_prefer_plain_multipart_alternative(gpointer ep, EMFormatHookTarget *t);
void org_gnome_prefer_plain_text_html(gpointer ep, EMFormatHookTarget *t);
GtkWidget *org_gnome_prefer_plain_config_mode(struct _EPlugin *epl, struct _EConfigHookItemFactoryData *data);

enum {
    EPP_NORMAL,
    EPP_PREFER,
    EPP_TEXT
};

static GConfClient *epp_gconf = NULL;
static gint epp_mode = -1;
static gboolean epp_show_suppressed = TRUE;

static void
make_part_attachment (EMFormat *format, CamelStream *stream, CamelMimePart *part, gint i)
{
    gint partidlen = format->part_id->len;

    if (i != -1)
        g_string_append_printf (format->part_id, ".alternative-prefer-plain.%d", i);

    if (camel_content_type_is (camel_mime_part_get_content_type (part), "text", "html")) {
        /* always show HTML as attachments and not inline */
        camel_mime_part_set_disposition (part, "attachment");

        if (!camel_mime_part_get_filename (part)) {
            gchar *str = g_strdup_printf ("%s.html", _("attachment"));
            camel_mime_part_set_filename (part, str);
            g_free (str);
        }

        em_format_part_as (format, stream, part, "application/octet-stream");
    } else
        em_format_part (format, stream, part);

    g_string_truncate (format->part_id, partidlen);
}

void
org_gnome_prefer_plain_text_html (gpointer ep, EMFormatHookTarget *t)
{
    /* In text-only mode, all html output is suppressed for the first processing */
    if (epp_mode != EPP_TEXT
        || strstr (t->format->part_id->str, ".alternative-prefer-plain.") != NULL
        || em_format_is_inline (t->format, t->format->part_id->str, t->part, &(t->item->handler)))
        t->item->handler.old->handler (t->format, t->stream, t->part, t->item->handler.old, FALSE);
    else if (epp_show_suppressed)
        make_part_attachment (t->format, t->stream, t->part, -1);
}

static void
export_as_attachments (CamelMultipart *mp, EMFormat *format, CamelStream *stream, CamelMimePart *except)
{
    gint i, nparts;
    CamelMimePart *part;

    if (!mp || !CAMEL_IS_MULTIPART (mp))
        return;

    nparts = camel_multipart_get_number(mp);
    for (i = 0; i < nparts; i++) {
        part = camel_multipart_get_part (mp, i);

        if (part != except) {
            CamelMultipart *multipart = (CamelMultipart *)camel_medium_get_content ((CamelMedium *)part);

            if (CAMEL_IS_MULTIPART (multipart)) {
                export_as_attachments (multipart, format, stream, except);
            } else {
                make_part_attachment (format, stream, part, i);
            }
        }
    }
}

void
org_gnome_prefer_plain_multipart_alternative(gpointer ep, EMFormatHookTarget *t)
{
    CamelMultipart *mp = (CamelMultipart *)camel_medium_get_content ((CamelMedium *)t->part);
    CamelMimePart *part, *display_part = NULL;
    gint i, nparts, partidlen, displayid = 0;

    /* FIXME: this part-id stuff is poking private data, needs api */
    partidlen = t->format->part_id->len;

    if (epp_mode == EPP_NORMAL) {
        gboolean have_plain = FALSE;

        /* Try to find text/html part even when not as last and force to show it.
           Old handler will show the last part of multipart/alternate, but if we
           can offer HTML, then offer it, regardless of position in multipart.
           But do this when have only text/plain and text/html parts, not more.
        */
        nparts = camel_multipart_get_number (mp);
        for (i = 0; i < nparts; i++) {
            CamelContentType *content_type;

            part = camel_multipart_get_part (mp, i);

            if (!part)
                continue;

            content_type = camel_mime_part_get_content_type (part);

            if (camel_content_type_is (content_type, "text", "html")) {
                displayid = i;
                display_part = part;

                if (have_plain)
                    break;
            } else if (camel_content_type_is (content_type, "text", "plain")) {
                have_plain = TRUE;

                if (display_part)
                    break;
            }
        }

        if (display_part && have_plain && nparts == 2) {
            g_string_append_printf (t->format->part_id, ".alternative-prefer-plain.%d", displayid);
            em_format_part_as (t->format, t->stream, display_part, "text/html");
            g_string_truncate (t->format->part_id, partidlen);
        } else {
            t->item->handler.old->handler (t->format, t->stream, t->part, t->item->handler.old, FALSE);
        }
        return;
    } else if (!CAMEL_IS_MULTIPART(mp)) {
        em_format_format_source(t->format, t->stream, t->part);
        return;
    }

    nparts = camel_multipart_get_number(mp);
    for (i=0; i<nparts; i++) {
        part = camel_multipart_get_part(mp, i);
        if (part && camel_content_type_is(camel_mime_part_get_content_type(part), "text", "plain")) {
            displayid = i;
            display_part = part;
            break;
        }
    }

    /* if we found a text part, show it */
    if (display_part) {
        g_string_append_printf(t->format->part_id, ".alternative-prefer-plain.%d", displayid);
        em_format_part_as(t->format, t->stream, display_part, "text/plain");
        g_string_truncate(t->format->part_id, partidlen);
    }

    /* all other parts are attachments */
    if (epp_show_suppressed)
        export_as_attachments (mp, t->format, t->stream, display_part);

    g_string_truncate(t->format->part_id, partidlen);
}

static struct {
    const gchar *key;
    const gchar *label;
    const gchar *description;
} epp_options[] = {
    { "normal",       N_("Show HTML if present"),       N_("Let Evolution choose the best part to show.") },
    { "prefer_plain", N_("Show plain text if present"), N_("Show plain text part, if present, otherwise let Evolution choose the best part to show.") },
    { "only_plain",   N_("Only ever show plain text"),  N_("Always show plain text part and make attachments from other parts, if requested.") },
};

static void
update_info_label (GtkWidget *info_label, guint mode)
{
    gchar *str = g_strconcat ("<i>", _(epp_options[mode > 2 ? 0 : mode].description), "</i>", NULL);

    gtk_label_set_markup (GTK_LABEL (info_label), str);

    g_free (str);
}

static void
epp_mode_changed(GtkComboBox *dropdown, GtkWidget *info_label)
{
    epp_mode = gtk_combo_box_get_active(dropdown);
    if (epp_mode > 2)
        epp_mode = 0;

    gconf_client_set_string(epp_gconf, "/apps/evolution/eplugin/prefer_plain/mode", epp_options[epp_mode].key, NULL);
    update_info_label (info_label, epp_mode);
}

static void
epp_show_suppressed_toggled (GtkToggleButton *check, gpointer data)
{
    g_return_if_fail (check != NULL);

    epp_show_suppressed = gtk_toggle_button_get_active (check);
    gconf_client_set_bool (epp_gconf, "/apps/evolution/eplugin/prefer_plain/show_suppressed", epp_show_suppressed, NULL);
}

GtkWidget *
org_gnome_prefer_plain_config_mode(struct _EPlugin *epl, struct _EConfigHookItemFactoryData *data)
{
    /*EMConfigTargetPrefs *ep = (EMConfigTargetPrefs *)data->target;*/
    GtkComboBox *dropdown;
    GtkCellRenderer *cell;
    GtkListStore *store;
    GtkWidget *dropdown_label, *info, *check;
    gint i;
    GtkTreeIter iter;

    if (data->old)
        return data->old;

    check = gtk_check_button_new_with_mnemonic (_("Show s_uppressed HTML parts as attachments"));
    gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), epp_show_suppressed);
    gtk_widget_show (check);
    g_signal_connect (check, "toggled", G_CALLBACK (epp_show_suppressed_toggled), NULL);

    dropdown = (GtkComboBox *)gtk_combo_box_new();
    cell = gtk_cell_renderer_text_new();
    store = gtk_list_store_new(1, G_TYPE_STRING);
    for (i = 0; i < G_N_ELEMENTS (epp_options); i++) {
        gtk_list_store_append(store, &iter);
        gtk_list_store_set(store, &iter, 0, _(epp_options[i].label), -1);
    }

    gtk_cell_layout_pack_start((GtkCellLayout *)dropdown, cell, TRUE);
    gtk_cell_layout_set_attributes((GtkCellLayout *)dropdown, cell, "text", 0, NULL);
    gtk_combo_box_set_model(dropdown, (GtkTreeModel *)store);
    /*gtk_combo_box_set_active(dropdown, -1);*/
    gtk_combo_box_set_active(dropdown, epp_mode);
    gtk_widget_show((GtkWidget *)dropdown);

    dropdown_label = gtk_label_new_with_mnemonic (_("HTML _Mode"));
    gtk_widget_show (dropdown_label);
    gtk_label_set_mnemonic_widget (GTK_LABEL (dropdown_label), (GtkWidget *)dropdown);

    info = gtk_label_new (NULL);
    gtk_misc_set_alignment (GTK_MISC (info), 0.0, 0.5);
    gtk_label_set_line_wrap (GTK_LABEL (info), TRUE);

    gtk_widget_show (info);
    update_info_label (info, epp_mode);

    g_signal_connect (dropdown, "changed", G_CALLBACK(epp_mode_changed), info);

    i = ((GtkTable *)data->parent)->nrows;
    gtk_table_attach((GtkTable *)data->parent, check, 0, 2, i, i + 1, GTK_FILL | GTK_EXPAND, 0, 0, 0);
    gtk_table_attach((GtkTable *)data->parent, dropdown_label, 0, 1, i + 1, i + 2, 0, 0, 0, 0);
    gtk_table_attach((GtkTable *)data->parent, (GtkWidget *)dropdown, 1, 2, i + 1, i + 2, GTK_FILL | GTK_EXPAND, 0, 0, 0);
    gtk_table_attach((GtkTable *)data->parent, info, 1, 2, i + 2, i + 3, GTK_FILL | GTK_EXPAND, 0, 0, 0);

    /* since this isnt dynamic, we don't need to track each item */

    return (GtkWidget *)dropdown;
}

gint e_plugin_lib_enable(EPlugin *ep, gint enable);

gint
e_plugin_lib_enable(EPlugin *ep, gint enable)
{
    gchar *key;
    gint i;

    if (epp_gconf || epp_mode != -1)
        return 0;

    if (enable) {
        GConfValue *val;

        epp_gconf = gconf_client_get_default();
        key = gconf_client_get_string(epp_gconf, "/apps/evolution/eplugin/prefer_plain/mode", NULL);
        if (key) {
            for (i = 0; i < G_N_ELEMENTS (epp_options); i++) {
                if (!strcmp(epp_options[i].key, key)) {
                    epp_mode = i;
                    break;
                }
            }
            g_free (key);
        } else {
            epp_mode = 0;
        }

        val = gconf_client_get (epp_gconf, "/apps/evolution/eplugin/prefer_plain/show_suppressed", NULL);
        if (val) {
            epp_show_suppressed = gconf_value_get_bool (val);
            gconf_value_free (val);
        } else
            epp_show_suppressed = TRUE;
    } else {
        if (epp_gconf) {
            g_object_unref(epp_gconf);
            epp_gconf = NULL;
        }
    }

    return 0;
}