/*
 *   mooencodings.c
 *
 *   Copyright (C) 2004-2006 by Yevgen Muntyan <muntyan@math.tamu.edu>
 *
 *   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.
 *
 *   See COPYING file that comes with this distribution.
 */

#include "mooutils/mooencodings.h"
#include "mooutils/mooi18n.h"
#include "mooutils/mooencodings-data.h"
#include <gtk/gtk.h>
#include <string.h>
#include <stdlib.h>

#define MAX_RECENT_ENCODINGS 5
#define ROW_RECENT(save_mode) ((save_mode) ? 1 : 3)
#define ROW_LOCALE(save_mode) ((save_mode) ? 0 : 2)
#define ROW_AUTO              0


typedef struct {
    const char *name;
    const char *short_display_name;
    char *display_name;
    char *subgroup_name;
} Encoding;

typedef struct {
    Encoding **encodings;
    guint n_encodings;
    char *name;
} EncodingGroup;

typedef struct {
    GSList *recent;
    EncodingGroup *groups;
    guint n_groups;
    Encoding *locale_encoding;
    GSList *user_defined;
    char *last_open;
    char *last_save;
    GHashTable *encodings;
} EncodingsManager;

enum {
    COLUMN_DISPLAY,
    COLUMN_ENCODING
};


static void     combo_changed   (GtkComboBox    *combo,
                                 gpointer        save_mode);


static Encoding *
lookup_encoding (EncodingsManager *mgr,
                 const char       *name)
{
    char *upper;
    Encoding *enc;

    g_return_val_if_fail (name != NULL, NULL);

    upper = g_ascii_strup (name, -1);
    enc = g_hash_table_lookup (mgr->encodings, upper);

    g_free (upper);
    return enc;
}

static Encoding *
get_encoding (EncodingsManager *mgr,
              const char       *name)
{
    Encoding *enc;

    g_return_val_if_fail (name != NULL, NULL);

    enc = lookup_encoding (mgr, name);

    if (!enc)
    {
        enc = g_new0 (Encoding, 1);
        enc->name = g_ascii_strup (name, -1);
        enc->short_display_name = enc->name;
        enc->display_name = g_strdup (name);
        mgr->user_defined = g_slist_prepend (mgr->user_defined, enc);
        g_hash_table_insert (mgr->encodings, (char*) enc->name, enc);
    }

    return enc;
}


static gboolean
validate_encoding_name (const char *name)
{
    return name && name[0];
}


static int
compare_encodings (Encoding **enc1,
                   Encoding **enc2)
{
    int result;

    result = g_utf8_collate ((*enc1)->subgroup_name, (*enc2)->subgroup_name);

    if (!result)
        result = g_utf8_collate ((*enc1)->short_display_name, (*enc2)->short_display_name);

    return result;
}

static void
fill_encoding_group (EncodingGroup *group,
                     GSList        *encodings)
{
    guint i;

    if (!encodings)
        return;

    group->n_encodings = g_slist_length (encodings);
    group->encodings = g_new0 (Encoding*, group->n_encodings);

    for (i = 0; encodings != NULL; encodings = encodings->next, ++i)
        group->encodings[i] = encodings->data;

    qsort (group->encodings, group->n_encodings, sizeof (Encoding*),
           (int(*)(const void *, const void *)) compare_encodings);
}

static void
sort_encoding_groups (EncodingsManager *mgr)
{
    const char *order = N_("012345");
    const char *new_order_s;
    int new_order[N_ENCODING_GROUPS] = {0, 0, 0, 0, 0, 0};
    guint i;
    EncodingGroup *new_array;

    g_return_if_fail (strlen (order) == N_ENCODING_GROUPS);
    g_return_if_fail (mgr->n_groups == N_ENCODING_GROUPS);

    new_order_s = _(order);

    if (!strcmp (order, new_order_s))
        return;

    for (i = 0; new_order_s[i]; ++i)
    {
        int n = new_order_s[i] - '0';

        if (n < 0 || n >= (int) mgr->n_groups)
        {
            g_critical ("invalid order string %s", new_order_s);
            return;
        }

        new_order[i] = n;
    }

    for (i = 0; i < mgr->n_groups; ++i)
    {
        if (!new_order[i])
        {
            g_critical ("invalid order string %s", new_order_s);
            return;
        }
    }

    new_array = g_new (EncodingGroup, mgr->n_groups);

    for (i = 0; i < mgr->n_groups; ++i)
        new_array[i] = mgr->groups[new_order[i]];

    g_free (mgr->groups);
    mgr->groups = new_array;
}

static EncodingsManager *
get_enc_mgr (void)
{
    static EncodingsManager *mgr;

    if (!mgr)
    {
        guint i;
        const char *locale_charset;
        GSList *enc_groups[N_ENCODING_GROUPS] = {NULL, NULL, NULL, NULL, NULL, NULL};

        mgr = g_new0 (EncodingsManager, 1);

        mgr->n_groups = N_ENCODING_GROUPS;
        mgr->groups = g_new0 (EncodingGroup, N_ENCODING_GROUPS);

        for (i = 0; i < mgr->n_groups; ++i)
            mgr->groups[i].name = g_strdup (_(moo_encoding_groups_names[i]));

        mgr->encodings = g_hash_table_new (g_str_hash, g_str_equal);

        for (i = 0; i < G_N_ELEMENTS (moo_encodings_data); ++i)
        {
            Encoding *enc;

            enc = g_new0 (Encoding, 1);
            enc->name = moo_encodings_data[i].name;
            enc->subgroup_name = g_strdup (_(moo_encodings_data[i].display_subgroup));
            enc->short_display_name = moo_encodings_data[i].short_display_name;
            enc->display_name = g_strdup_printf ("%s (%s)", enc->subgroup_name,
                                                 enc->short_display_name);

            enc_groups[moo_encodings_data[i].group] =
                g_slist_prepend (enc_groups[moo_encodings_data[i].group], enc);
            g_hash_table_insert (mgr->encodings, (char*) moo_encodings_data[i].name, enc);
        }

        for (i = 0; i < G_N_ELEMENTS (moo_encoding_aliases); ++i)
        {
            Encoding *enc;

            enc = g_hash_table_lookup (mgr->encodings, moo_encoding_aliases[i].name);

            if (!enc)
                g_critical ("%s: oops %s", G_STRLOC, moo_encoding_aliases[i].name);
            else
                g_hash_table_insert (mgr->encodings, (char*)
                                     moo_encoding_aliases[i].alias,
                                     enc);
        }

        for (i = 0; i < N_ENCODING_GROUPS; ++i)
        {
            fill_encoding_group (&mgr->groups[i], enc_groups[i]);
            g_slist_free (enc_groups[i]);
        }

        sort_encoding_groups (mgr);

        if (!g_get_charset (&locale_charset))
            locale_charset = MOO_ENCODING_UTF8;

        mgr->locale_encoding = get_encoding (mgr, locale_charset);
    }

    return mgr;
}


static void
enc_mgr_save (EncodingsManager *enc_mgr)
{
}


static const char *
current_locale_name (EncodingsManager *enc_mgr)
{
    static char *display_name;

    if (!display_name)
    {
        if (enc_mgr->locale_encoding)
            display_name = g_strdup_printf (_("Current locale (%s)"),
                                            enc_mgr->locale_encoding->short_display_name);
        else
            display_name = g_strdup (_("Current locale"));
    }

    return display_name;
}


typedef struct {
    const char *name;
    GtkTreeIter iter;
    gboolean found;
} FindEncodingData;

static gboolean
find_encoding_func (GtkTreeModel     *model,
                    G_GNUC_UNUSED GtkTreePath *path,
                    GtkTreeIter      *iter,
                    FindEncodingData *data)
{
    char *name;

    gtk_tree_model_get (model, iter, COLUMN_ENCODING, &name, -1);

    if (name && !strcmp (name, data->name))
    {
        data->iter = *iter;
        data->found = TRUE;
    }

    g_free (name);
    return data->found;
}

static gboolean
find_encoding_iter (GtkTreeModel *model,
                    GtkTreeIter  *iter,
                    const char   *name)
{
    FindEncodingData data;

    data.found = FALSE;
    data.name = name;

    gtk_tree_model_foreach (model, (GtkTreeModelForeachFunc) find_encoding_func, &data);

    if (data.found && iter)
        *iter = data.iter;

    return data.found;
}


static void
sync_recent_list (GtkTreeStore *store,
                  guint         n_old_items,
                  GSList       *list,
                  gboolean      save_mode)
{
    GtkTreeIter iter;
    guint i;

    for (i = 0; i < n_old_items; ++i)
    {
        gtk_tree_model_iter_nth_child (GTK_TREE_MODEL (store), &iter,
                                       NULL, ROW_RECENT (save_mode));
        gtk_tree_store_remove (store, &iter);
    }

    while (list)
    {
        Encoding *enc = list->data;
        gtk_tree_store_insert (store, &iter, NULL, ROW_RECENT (save_mode));
        gtk_tree_store_set (store, &iter,
                            COLUMN_DISPLAY, enc->display_name,
                            COLUMN_ENCODING, enc->name, -1);
        list = list->next;
    }
}

static void
set_last (EncodingsManager *mgr,
          const char       *name,
          gboolean          save_mode)
{
    char **ptr = save_mode ? &mgr->last_save : &mgr->last_open;
    char *tmp = *ptr;
    *ptr = g_strdup (name);
    g_free (tmp);
}

static void
encoding_combo_set_active (GtkComboBox *combo,
                           const char  *enc_name,
                           gboolean     save_mode)
{
    GtkTreeModel *model;
    GtkTreeIter iter;
    GSList *l, *recent_copy;
    EncodingsManager *mgr;
    gboolean found_recent;
    guint n_recent;
    Encoding *new_enc;

    mgr = get_enc_mgr ();

    if (!strcmp (enc_name, mgr->locale_encoding->name))
        enc_name = MOO_ENCODING_LOCALE;

    set_last (mgr, enc_name, save_mode);

    model = gtk_combo_box_get_model (combo);
    g_signal_handlers_block_by_func (combo, (gpointer) combo_changed,
                                     GINT_TO_POINTER (save_mode));

    if (!strcmp (enc_name, MOO_ENCODING_AUTO))
    {
        gtk_tree_model_iter_nth_child (model, &iter, NULL, ROW_AUTO);
        gtk_combo_box_set_active_iter (combo, &iter);
        goto out;
    }

    if (!strcmp (enc_name, MOO_ENCODING_LOCALE))
    {
        gtk_tree_model_iter_nth_child (model, &iter, NULL, ROW_LOCALE (save_mode));
        gtk_combo_box_set_active_iter (combo, &iter);
        goto out;
    }

    new_enc = get_encoding (mgr, enc_name);
    g_return_if_fail (new_enc != NULL);

    set_last (mgr, new_enc->name, save_mode);

    n_recent = g_slist_length (mgr->recent);

    for (l = mgr->recent, found_recent = FALSE; l != NULL; l = l->next)
    {
        Encoding *enc = l->data;

        if (!strcmp (new_enc->name, enc->name))
        {
            found_recent = TRUE;

            if (l != mgr->recent)
            {
                mgr->recent = g_slist_remove_link (mgr->recent, l);
                l->next = mgr->recent;
                mgr->recent = l;
            }
        }
    }

    if (!found_recent)
    {
        mgr->recent = g_slist_prepend (mgr->recent, new_enc);

        if (g_slist_length (mgr->recent) > MAX_RECENT_ENCODINGS)
            mgr->recent = g_slist_delete_link (mgr->recent, g_slist_last (mgr->recent));
    }

    recent_copy = g_slist_reverse (g_slist_copy (mgr->recent));
    sync_recent_list (GTK_TREE_STORE (model), n_recent, recent_copy, save_mode);
    g_slist_free (recent_copy);

    if (find_encoding_iter (model, &iter, new_enc->name))
        gtk_combo_box_set_active_iter (combo, &iter);

out:
    g_signal_handlers_unblock_by_func (combo, (gpointer) combo_changed,
                                       GINT_TO_POINTER (save_mode));
}

static void
combo_changed (GtkComboBox *combo,
               gpointer     save_mode)
{
    GtkTreeModel *model;
    GtkTreeIter iter;
    char *enc_name;

    if (!gtk_combo_box_get_active_iter (combo, &iter))
        return;

    model = gtk_combo_box_get_model (combo);

    if (gtk_tree_model_iter_has_child (model, &iter))
        return;

    gtk_tree_model_get (model, &iter, COLUMN_ENCODING, &enc_name, -1);

    if (!enc_name)
        return;

    encoding_combo_set_active (combo, enc_name, GPOINTER_TO_INT (save_mode));
    g_free (enc_name);
}


static gboolean
row_separator_func (GtkTreeModel *model,
                    GtkTreeIter  *iter)
{
    char *text;
    gboolean separator;

    gtk_tree_model_get (model, iter, COLUMN_DISPLAY, &text, -1);
    separator = text == NULL;

    g_free (text);
    return separator;
}

static void
cell_data_func (G_GNUC_UNUSED GtkCellLayout *layout,
		GtkCellRenderer *cell,
                GtkTreeModel    *model,
                GtkTreeIter     *iter)
{
    gboolean sensitive;
    sensitive = !gtk_tree_model_iter_has_child (model, iter);
    g_object_set (cell, "sensitive", sensitive, NULL);
}

static void
setup_combo (GtkComboBox      *combo,
             EncodingsManager *enc_mgr,
             gboolean          save_mode)
{
    GtkCellRenderer *cell;
    GtkTreeStore *store;
    GtkTreeIter iter;
    GSList *l;
    guint i;
    char *start;

    store = gtk_tree_store_new (2, G_TYPE_STRING, G_TYPE_STRING);

    if (!save_mode)
    {
        gtk_tree_store_append (store, &iter, NULL);
        gtk_tree_store_set (store, &iter,
                            COLUMN_DISPLAY, _("Auto Detected"),
                            COLUMN_ENCODING, MOO_ENCODING_AUTO,
                            -1);

        gtk_tree_store_append (store, &iter, NULL);
    }

    gtk_tree_store_append (store, &iter, NULL);
    gtk_tree_store_set (store, &iter,
                        COLUMN_DISPLAY, current_locale_name (enc_mgr),
                        COLUMN_ENCODING, MOO_ENCODING_LOCALE,
                        -1);

    for (l = enc_mgr->recent; l != NULL; l = l->next)
    {
        Encoding *enc = l->data;
        gtk_tree_store_append (store, &iter, NULL);
        gtk_tree_store_set (store, &iter,
                            COLUMN_DISPLAY, enc->display_name,
                            COLUMN_ENCODING, enc->name,
                            -1);
    }

    gtk_tree_store_append (store, &iter, NULL);
    gtk_tree_store_append (store, &iter, NULL);
    gtk_tree_store_set (store, &iter, COLUMN_DISPLAY, "Other", -1);

    for (i = 0; i < enc_mgr->n_groups; ++i)
    {
        guint j;
        GtkTreeIter child, group_iter;
        EncodingGroup *group;

        group = &enc_mgr->groups[i];
        gtk_tree_store_append (store, &group_iter, &iter);
        gtk_tree_store_set (store, &group_iter, COLUMN_DISPLAY, group->name, -1);

        for (j = 0; j < group->n_encodings; ++j)
        {
            gtk_tree_store_append (store, &child, &group_iter);
            gtk_tree_store_set (store, &child,
                                COLUMN_DISPLAY, group->encodings[j]->display_name,
                                COLUMN_ENCODING, group->encodings[j]->name,
                                -1);
        }
    }

    gtk_combo_box_set_model (combo, GTK_TREE_MODEL (store));
    gtk_combo_box_entry_set_text_column (GTK_COMBO_BOX_ENTRY (combo), COLUMN_DISPLAY);
    gtk_combo_box_set_row_separator_func (combo,
                                          (GtkTreeViewRowSeparatorFunc) row_separator_func,
                                          NULL, NULL);
    cell = gtk_cell_renderer_text_new ();
    gtk_cell_layout_clear (GTK_CELL_LAYOUT (combo));
    gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combo), cell, TRUE);
    gtk_cell_layout_set_attributes (GTK_CELL_LAYOUT (combo), cell,
                                    "text", COLUMN_DISPLAY, NULL);
    gtk_cell_layout_set_cell_data_func (GTK_CELL_LAYOUT (combo), cell,
                                        (GtkCellLayoutDataFunc) cell_data_func,
					NULL, NULL);

    if (save_mode)
    {
        if (enc_mgr->last_save)
            start = g_strdup (enc_mgr->last_save);
        else
            start = g_strdup (MOO_ENCODING_UTF8);
    }
    else
    {
        if (enc_mgr->last_open)
            start = g_strdup (enc_mgr->last_open);
        else
            start = g_strdup (MOO_ENCODING_AUTO);
    }

    g_signal_connect (combo, "changed", G_CALLBACK (combo_changed),
                      GINT_TO_POINTER (save_mode));
    encoding_combo_set_active (GTK_COMBO_BOX (combo), start, save_mode);

    g_free (start);
    g_object_unref (store);
}


void
_moo_encodings_attach_combo (GtkWidget  *dialog,
                             GtkWidget  *parent,
                             gboolean    save_mode,
                             const char *encoding)
{
    GtkWidget *hbox;
    GtkWidget *label;
    GtkWidget *combo;

    g_return_if_fail (GTK_IS_FILE_CHOOSER (dialog));

    hbox = gtk_hbox_new (FALSE, 0);
    gtk_widget_show (hbox);
    gtk_box_pack_start (GTK_BOX (parent), hbox, FALSE, FALSE, 0);

    label = gtk_label_new_with_mnemonic (_("Charact_er encoding:"));
    gtk_widget_show (label);
    gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);

    combo = gtk_combo_box_entry_new ();
    gtk_widget_show (combo);
    gtk_box_pack_start (GTK_BOX (hbox), combo, TRUE, TRUE, 0);

    setup_combo (GTK_COMBO_BOX (combo), get_enc_mgr (), save_mode);

    if (save_mode && encoding)
    {
        if (!validate_encoding_name (encoding))
            encoding = MOO_ENCODING_UTF8;
        encoding_combo_set_active (GTK_COMBO_BOX (combo), encoding, save_mode);
    }

    g_object_set_data (G_OBJECT (dialog), "moo-encodings-combo", combo);
}


void
_moo_encodings_sync_combo (GtkWidget *dialog,
                           gboolean   save_mode)
{
    GtkComboBox *combo;
    const char *enc_name;
    GtkTreeIter dummy;

    combo = g_object_get_data (G_OBJECT (dialog), "moo-encodings-combo");
    g_return_if_fail (combo != NULL);

    if (gtk_combo_box_get_active_iter (combo, &dummy))
        return;

    enc_name = gtk_entry_get_text (GTK_ENTRY (GTK_BIN (combo)->child));

    if (!validate_encoding_name (enc_name))
        enc_name = save_mode ? MOO_ENCODING_UTF8 : MOO_ENCODING_AUTO;

    encoding_combo_set_active (combo, enc_name, save_mode);
}


const char *
_moo_encodings_combo_get (GtkWidget *dialog,
                          gboolean   save_mode)
{
    const char *enc_name;
    EncodingsManager *mgr;

    _moo_encodings_sync_combo (dialog, save_mode);

    mgr = get_enc_mgr ();
    enc_mgr_save (mgr);

    if (save_mode)
    {
        if (mgr->last_save)
            enc_name = mgr->last_save;
        else
            enc_name = MOO_ENCODING_UTF8;
    }
    else
    {
        if (mgr->last_open)
            enc_name = mgr->last_open;
        else
            enc_name = MOO_ENCODING_AUTO;
    }

    if (!strcmp (enc_name, MOO_ENCODING_LOCALE))
        enc_name = mgr->locale_encoding->name;

    return enc_name;
}


const char *
_moo_encoding_locale (void)
{
    EncodingsManager *mgr;

    mgr = get_enc_mgr ();

    return mgr->locale_encoding->name;
}


gboolean
_moo_encodings_equal (const char *enc1_name,
                      const char *enc2_name)
{
    Encoding *enc1, *enc2;
    EncodingsManager *mgr;

    enc1_name = enc1_name && enc1_name[0] ? enc1_name : MOO_ENCODING_UTF8;
    enc2_name = enc2_name && enc2_name[0] ? enc2_name : MOO_ENCODING_UTF8;

    mgr = get_enc_mgr ();

    enc1 = lookup_encoding (mgr, enc1_name);
    enc2 = lookup_encoding (mgr, enc2_name);

    if (!enc1 || !enc2)
        return !strcmp (enc1_name, enc2_name);

    return enc1 == enc2;
}