/*
 *   mooedit-fileops.cpp
 *
 *   Copyright (C) 2004-2016 by Yevgen Muntyan <emuntyan@users.sourceforge.net>
 *   Copyright (C) 2014 by Ulrich Eckhardt <ulrich.eckhardt@base-42.de>
 *
 *   This file is part of medit.  medit 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 2.1 of the License,
 *   or (at your option) any later version.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with medit.  If not, see <http://www.gnu.org/licenses/>.
 */

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

#include "mooedit/mooedit-private.h"
#include "mooedit/mooeditor-impl.h"
#include "mooedit/mooedit-fileops.h"
#include "mooedit/mooeditdialogs.h"
#include "mooedit/mootextbuffer.h"
#include "mooedit/mooeditprefs.h"
#include "mooutils/moofileicon.h"
#include "mooutils/moofilewatch.h"
#include "mooutils/mooencodings.h"
#include "mooutils/mooi18n.h"
#include "mooutils/mootype-macros.h"
#include "mooutils/mooutils.h"
#include "mooutils/mooutils-fs.h"
#include "mooutils/moocompat.h"
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdio.h>

#include <mooglib/moo-glib.h>

#include <list>
#include <moocpp/moocpp.h>
using namespace moo;

#define ENCODING_LOCALE "LOCALE"

MOO_DEFINE_QUARK (MooEditFileErrorQuark, _moo_edit_file_error_quark)

static GSList *UNTITLED = NULL;
static GHashTable *UNTITLED_NO = NULL;

static void     block_buffer_signals        (Edit           edit);
static void     unblock_buffer_signals      (Edit           edit);
static void     check_file_status           (Edit           edit);
static void     file_modified_on_disk       (Edit           edit);
static void     file_deleted                (Edit           edit);
static void     add_status                  (Edit           edit,
                                             MooEditStatus  s);

static void     moo_edit_load_text          (Edit               edit,
                                             g::File            file,
                                             const char*        encoding,
                                             const char*        text);
static bool     moo_edit_reload_local       (Edit               edit,
                                             const char*        encoding,
                                             gerrp&             error);
static bool     moo_edit_save_local         (Edit               edit,
                                             g::File            file,
                                             const char*        encoding,
                                             MooEditSaveFlags   flags,
                                             gerrp&             error);
static bool     moo_edit_save_copy_local    (Edit               edit,
                                             g::File            file,
                                             const char*        encoding,
                                             MooEditSaveFlags   flags,
                                             gerrp&             error);
static void     _moo_edit_start_file_watch  (Edit               edit);

static gstr     moo_convert_file_data_to_utf8   (const char     *data,
                                                 gsize           len,
                                                 const char     *encoding,
                                                 const char     *cached_encoding,
                                                 gstr& /*out*/   used_enc);
static bool     encoding_needs_bom_save         (const char     *enc,
                                                 const char    **enc_no_bom,
                                                 const char    **bom,
                                                 gsize          *bom_len);
static bool     encoding_is_utf8                (const char     *encoding);

static bool     check_regular                   (g::File         file,
                                                 gerrp&          error);


bool _moo_is_file_error_cancelled(const gerrp& error)
{
    return error && error->domain == MOO_EDIT_FILE_ERROR &&
           error->code == MOO_EDIT_FILE_ERROR_CANCELLED;
}


static const char *
normalize_encoding (const char *encoding,
                    bool        for_save)
{
    if (!encoding || !encoding[0] || !strcmp (encoding, MOO_ENCODING_AUTO))
        encoding = for_save ? MOO_ENCODING_UTF8 : NULL;
    return encoding;
}

static gstr
normalize_encoding (const gstr& encoding,
                    bool        for_save)
{
    if (encoding.empty() || encoding == MOO_ENCODING_AUTO)
        return for_save ? gstr::wrap_const(MOO_ENCODING_UTF8) : gstr();
    else
        return encoding;
}


bool _moo_edit_file_is_new(g::File file)
{
    gstr filename = file.get_path();
    g_return_val_if_fail(!filename.empty(), FALSE);
    return !g_file_test (filename, G_FILE_TEST_EXISTS);
}


static gboolean
load_file_contents (g::File file,
                    gstr&   data,
                    gsize&  data_len,
                    gerrp&  error)
{
    if (!check_regular (file, error))
        return FALSE;

    auto path = file.get_path();

    if (path.empty())
    {
        g_set_error (&error, MOO_EDIT_FILE_ERROR,
                     MOO_EDIT_FILE_ERROR_NOT_IMPLEMENTED,
                     "Loading remote files is not implemented");
        return FALSE;
    }

    return g::file_get_contents (path, data, data_len, error);
}

static gstr
convert_file_data_to_utf8_with_prompt (const char*    data,
                                       gsize          data_len,
                                       g::File        file,
                                       gstr           encoding,
                                       gstr           cached_encoding,
                                       /*out*/ gstr&  used_encoding)
{
    gstr text_utf8;

    used_encoding.reset();

    while (TRUE)
    {
        MooEditTryEncodingResponse response;

        text_utf8 = moo_convert_file_data_to_utf8 (data, data_len, encoding, cached_encoding, /*out*/ used_encoding);

        if (!text_utf8.is_null())
            break;

        used_encoding.reset();
        response = _moo_edit_try_encoding_dialog (file, encoding, /*out*/ used_encoding);

        switch (response)
        {
            case MOO_EDIT_TRY_ENCODING_RESPONSE_CANCEL:
                used_encoding.reset();
                break;

            case MOO_EDIT_TRY_ENCODING_RESPONSE_TRY_ANOTHER:
                g_assert(!used_encoding.empty());
                break;
        }

        if (used_encoding.empty())
            break;

        encoding = normalize_encoding (used_encoding, false);
        cached_encoding = NULL;
    }

    return text_utf8;
}

bool
_moo_edit_load_file (Edit        edit,
                     g::File     file,
                     const gstr& init_encoding,
                     const gstr& init_cached_encoding,
                     gerrp&      error)
{
    bool result = false;
    gstr used_encoding;
    gstr data_utf8;

    moo_return_error_if_fail(!edit._is_busy());

    gstr encoding = normalize_encoding(init_encoding, false);
    gstr cached_encoding;
    if (!init_cached_encoding.empty())
        cached_encoding = normalize_encoding(init_cached_encoding, false);

    gstr data;
    gsize data_len = 0;

    if (!load_file_contents(file, /*out*/ data, /*out*/ data_len, error))
        goto done;

    data_utf8 = convert_file_data_to_utf8_with_prompt (data, data_len, file, encoding, cached_encoding, /*out*/ used_encoding);

    if (data_utf8.is_null())
    {
        g_set_error (&error, MOO_EDIT_FILE_ERROR, MOO_EDIT_FILE_ERROR_CANCELLED, "Cancelled");
        goto done;
    }

    moo_edit_load_text(edit, file, used_encoding, data_utf8);
    result = TRUE;

done:
    if (!result)
        edit._stop_file_watch();

    return result;
}


bool
_moo_edit_reload_file(Edit        edit,
                      const char* encoding,
                      gerrp&      error)
{
    return moo_edit_reload_local(edit, encoding, error);
}


bool _moo_edit_save_file(Edit             edit,
                         g::File          file,
                         const char*      encoding,
                         MooEditSaveFlags flags,
                         gerrp&           error)
{
    gstr encoding_copy = gstr::wrap(normalize_encoding(encoding, true));
    return moo_edit_save_local(edit, file, encoding_copy, flags, error);
}


bool _moo_edit_save_file_copy(Edit             edit,
                              g::File          file,
                              const char*      encoding,
                              MooEditSaveFlags flags,
                              gerrp&           error)
{
    gstr encoding_copy = gstr::wrap(normalize_encoding(encoding, true));
    return moo_edit_save_copy_local(edit, file, encoding_copy, flags, error);
}


static void
set_encoding_error (gerrp& error)
{
    gerrp tmp_error;
    g_set_error (&tmp_error, MOO_EDIT_FILE_ERROR,
                 MOO_EDIT_FILE_ERROR_ENCODING,
                 "%s", error ? error->message : "ERROR");
    error = std::move(tmp_error);
}


/**
 * moo_edit_get_line_end_type:
 **/
MooLineEndType
moo_edit_get_line_end_type (MooEdit *edit)
{
    g_return_val_if_fail (MOO_IS_EDIT (edit), MOO_LE_NATIVE);
    if (edit->priv->line_end_type == MOO_LE_NONE)
        return MOO_LE_NATIVE;
    else
        return edit->priv->line_end_type;
}

static void
moo_edit_set_line_end_type_full (Edit           edit,
                                 MooLineEndType le,
                                 bool           quiet)
{
    g_return_if_fail (le > 0);

    if (edit.get_priv().line_end_type != le)
    {
        edit.get_priv().line_end_type = le;
        if (!quiet)
            edit.notify("line-end-type");
    }
}

/**
 * moo_edit_set_line_end_type:
 **/
void
moo_edit_set_line_end_type (MooEdit        *edit,
                            MooLineEndType  le)
{
    g_return_if_fail(MOO_IS_EDIT(edit));
    moo_edit_set_line_end_type_full(*edit, le, false);
}


/***************************************************************************/
/* File loading
 */

static void do_load_text(Edit        edit,
                         const char* text);

static std::list<gstr>
get_encodings (void)
{
    const char *encodings;
    char **raw, **p;

    encodings = moo_prefs_get_string (moo_edit_setting (MOO_EDIT_PREFS_ENCODINGS));

    if (!encodings || !encodings[0])
        encodings = _moo_get_default_encodings ();

    std::list<gstr> result;
    raw = g_strsplit (encodings, ",", 0);

    for (p = raw; p && *p; ++p)
    {
        const char *enc;

        if (!g_ascii_strcasecmp (*p, ENCODING_LOCALE))
        {
            if (g_get_charset (&enc))
                enc = "UTF-8";
        }
        else
        {
            enc = *p;
        }

        if (!any_of(result, [enc](const char* s) { return g_ascii_strcasecmp(s, enc) == 0; }))
            result.emplace_back(gstr::wrap(enc));
    }

    if (result.empty())
    {
        g_critical ("oops");
        result.emplace_back(gstr::wrap_const("UTF-8"));
    }

    g_strfreev (raw);
    return result;
}


static bool check_regular (g::File file, gerrp& error)
{
    if (!file.is_native())
        return true;

    gerrp ignored;
    g::FileInfoPtr info;
    if (!(info = file.query_info(G_FILE_ATTRIBUTE_STANDARD_TYPE, G_FILE_QUERY_INFO_NONE, nullptr, ignored)))
        return true;

    GFileType type = g_file_info_get_file_type (info.gobj());
    if (type != G_FILE_TYPE_REGULAR && type != G_FILE_TYPE_UNKNOWN)
    {
        g_set_error (&error, MOO_EDIT_FILE_ERROR,
                     MOO_EDIT_FILE_ERROR_FAILED,
                     "%s", D_("Not a regular file", "glib20"));
        return false;
    }

    return true;
}

static void
moo_edit_load_text (Edit        edit,
                    g::File     file,
                    const char* encoding,
                    const char* text)
{
    MooEditPrivate& priv = edit.get_priv();

    bool undo = !moo_edit_is_empty(&edit);

    GtkTextBuffer *buffer = moo_edit_get_buffer(&edit);

    block_buffer_signals(edit);

    if (undo)
        gtk_text_buffer_begin_user_action(buffer);
    else
        moo_text_buffer_begin_non_undoable_action(MOO_TEXT_BUFFER(buffer));

    moo_text_buffer_begin_non_interactive_action(MOO_TEXT_BUFFER(buffer));

    MooLineEndType saved_le = priv.line_end_type;

    gboolean enable_highlight;
    buffer = moo_edit_get_buffer(&edit);
    gtk_text_buffer_set_text(buffer, "", 0);
    g_object_get(buffer, "highlight-syntax", &enable_highlight, (char*) 0);
    g_object_set(buffer, "highlight-syntax", FALSE, (char*) 0);
    do_load_text(edit, text);
    g_object_set(buffer, "highlight-syntax", enable_highlight, (char*) 0);

    unblock_buffer_signals(edit);

    if (undo)
        gtk_text_buffer_end_user_action(buffer);
    else
        moo_text_buffer_end_non_undoable_action(MOO_TEXT_BUFFER(buffer));

    moo_text_buffer_end_non_interactive_action(MOO_TEXT_BUFFER(buffer));

    GtkTextIter start;
    gtk_text_buffer_get_start_iter(buffer, &start);
    gtk_text_buffer_place_cursor(buffer, &start);
    priv.status = (MooEditStatus) 0;
    moo_edit_set_modified(&edit, false);
    edit._set_file(&file, encoding);
    if (priv.line_end_type != saved_le)
        edit.notify("line-end-type");
    _moo_edit_start_file_watch(edit);
}


static void do_load_text(Edit  edit, const char* text)
{
    MooLineEndType le = MOO_LE_NONE;

    GString *strbuf = g_string_new(NULL);
    GtkTextBuffer *buffer = moo_edit_get_buffer(&edit);

    MooLineReader lr;
    moo_line_reader_init(&lr, text, -1);

    bool mixed_le = false;
    const char *line;
    gsize line_len;
    gsize line_term_len;
    while ((line = moo_line_reader_get_line(&lr, &line_len, &line_term_len)) != NULL)
    {
        gboolean insert_line_term = FALSE;
        MooLineEndType le_here = MOO_LE_NONE;
        gsize copy_len = line_len;

        if (line_term_len != 0)
        {
            const char *line_term = line + line_len;

            insert_line_term = TRUE;

            if (line_term_len == 1 && !strncmp(line_term, "\r", line_term_len))
            {
                le_here = MOO_LE_MAC;
            }
            else if (line_term_len == 1 && !strncmp(line_term, "\n", line_term_len))
            {
                le_here = MOO_LE_UNIX;
            }
            else if (line_term_len == 2 && !strncmp(line_term, "\r\n", line_term_len))
            {
                le_here = MOO_LE_WIN32;
            }
            else if (line_term_len == 3 && !strncmp("\xe2\x80\xa9", line_term, line_term_len))
            {
                insert_line_term = FALSE;
                copy_len += line_term_len;
            }
            else
            {
                g_critical("oops");
                copy_len += line_term_len;
            }

            if (le_here)
            {
                if (mixed_le || (le && le != le_here))
                    mixed_le = TRUE;
                else
                    le = le_here;
            }
        }

        g_string_append_len(strbuf, line, copy_len);

        if (insert_line_term)
            g_string_append_c(strbuf, '\n');
    }

    gtk_text_buffer_insert_at_cursor(buffer, strbuf->str, (int) strbuf->len);

    if (mixed_le)
        le = MOO_LE_NATIVE;

    if (le != MOO_LE_NONE)
        moo_edit_set_line_end_type_full(edit, le, TRUE);

    g_string_free(strbuf, TRUE);
}


/* XXX */
static bool moo_edit_reload_local(Edit        edit,
                                  const char* encoding,
                                  gerrp&      error)
{
    g::FilePtr file = wrap_new(moo_edit_get_file(&edit));
    moo_return_error_if_fail(file != nullptr);

    auto& priv = edit.get_priv();
    gboolean result = _moo_edit_load_file(edit, *file,
                                          encoding ? gstr::wrap(encoding) : priv.encoding,
                                          nullptr,
                                          error);

    if (result)
    {
        priv.status = (MooEditStatus) 0;
        moo_edit_set_modified(&edit, false);
        _moo_edit_start_file_watch(edit);
        g_clear_error (&error);
    }

    return result;
}


/***************************************************************************/
/* File saving
 */

static gstr
get_contents_with_fixed_line_end (GtkTextBuffer *buffer, const char *le, gsize le_len)
{
    GtkTextIter line_start;
    strbuilder contents;

    gtk_text_buffer_get_start_iter (buffer, &line_start);

    do
    {
        GtkTextIter line_end = line_start;

        if (!gtk_text_iter_ends_line (&line_start))
        {
            gtk_text_iter_forward_to_line_end (&line_end);
            gstrp line (gtk_text_buffer_get_text (buffer, &line_start, &line_end, TRUE));
            contents.append (line);
        }

        if (!gtk_text_iter_is_end (&line_end))
            contents.append(le, le_len);
    }
    while (gtk_text_iter_forward_line (&line_start));

    return contents.release();
}

static gstr get_contents(MooEdit  edit)
{
    const char *le = "\n";
    gsize le_len = 1;
    GtkTextBuffer *buffer;

    switch (moo_edit_get_line_end_type(&edit))
    {
    case MOO_LE_UNIX:
        le = "\n";
        le_len = 1;
        break;
    case MOO_LE_WIN32:
        le = "\r\n";
        le_len = 2;
        break;
    case MOO_LE_MAC:
        le = "\r";
        le_len = 1;
        break;
    default:
        moo_assert_not_reached();
    }

    buffer = moo_edit_get_buffer(&edit);
    return get_contents_with_fixed_line_end(buffer, le, le_len);
}

static bool do_write(g::File          file,
                     const char*      data1,
                     gsize            len1,
                     const char*      data2,
                     gsize            len2,
                     MooEditSaveFlags flags,
                     gerrp&           error)
{
    MooFileWriter *writer;
    MooFileWriterFlags writer_flags;
    gboolean success = FALSE;

    writer_flags = (flags & MOO_EDIT_SAVE_BACKUP) ? MOO_FILE_WRITER_SAVE_BACKUP : (MooFileWriterFlags) 0;

    if ((writer = moo_file_writer_new_for_file (file, writer_flags, error)))
    {
        success = TRUE;
        if (success && len1 > 0)
            success = moo_file_writer_write (writer, data1, len1);
        if (success && len2 > 0)
            success = moo_file_writer_write (writer, data2, len2);
        if (success)
            success = moo_file_writer_close (writer, error);
    }

    return success;
}

static bool
do_save_local(Edit             edit,
              g::File          file,
              const char*      encoding,
              MooEditSaveFlags flags,
              gerrp&           error)
{
    const char *to_save;
    gsize to_save_size;
    const char *enc_no_bom = NULL;
    const char *bom = NULL;
    gsize bom_len = 0;

    gstr utf8_contents = get_contents(edit);
    moo_release_assert(!utf8_contents.is_null());

    if (encoding_needs_bom_save(encoding, &enc_no_bom, &bom, &bom_len))
        encoding = enc_no_bom;

    if (encoding && encoding_is_utf8(encoding))
        encoding = NULL;

    if (encoding)
    {
        gsize bytes_read;
        gsize bytes_written;
        gerrp encoding_error;
        gstr encoded = g::convert(utf8_contents, -1, encoding, "UTF-8",
                                  /*out*/ bytes_read, /*out*/ bytes_written,
                                  encoding_error);

        if (!encoded.is_null())
        {
            to_save = encoded;
            to_save_size = bytes_written;
        }
        else
        {
            error = std::move (encoding_error);
            set_encoding_error (error);
            return false;
        }
    }
    else
    {
        to_save = utf8_contents;
        to_save_size = strlen(utf8_contents);
    }

    if (!do_write(file, bom, bom_len, to_save, to_save_size, flags, error))
        return false;

    return true;
}


static bool
moo_edit_save_local(Edit             edit,
                    g::File          file,
                    const char*      encoding,
                    MooEditSaveFlags flags,
                    gerrp&           error)
{
    if (!do_save_local(edit, file, encoding, flags, error))
        return FALSE;

    edit.get_priv().status = (MooEditStatus) 0;
    edit._set_file(&file, encoding);
    moo_edit_set_modified(&edit, false);
    _moo_edit_start_file_watch (edit);
    return TRUE;
}


static bool moo_edit_save_copy_local(Edit             edit,
                                     g::File          file,
                                     const char*      encoding,
                                     MooEditSaveFlags flags,
                                     gerrp&           error)
{
    return do_save_local(edit, file, encoding, flags, error);
}


/***************************************************************************/
/* Aux stuff
 */

static void
block_buffer_signals(Edit edit)
{
    g_signal_handler_block (moo_edit_get_buffer (&edit), edit.get_priv().modified_changed_handler_id);
}


static void
unblock_buffer_signals(Edit edit)
{
    g_signal_handler_unblock(moo_edit_get_buffer(&edit), edit.get_priv().modified_changed_handler_id);
}


static void
file_watch_callback(G_GNUC_UNUSED MooFileWatch& watch,
                    MooFileEvent*               event,
                    gpointer                    data)
{
    g_return_if_fail(MOO_IS_EDIT(data));

    Edit edit = *MOO_EDIT(data);
    auto& priv = edit.get_priv();

    g_return_if_fail(event->monitor_id == priv.file_monitor_id);
    g_return_if_fail(!priv.filename.empty());
    g_return_if_fail(!(priv.status & MOO_EDIT_STATUS_CHANGED_ON_DISK));

    switch (event->code)
    {
        case MOO_FILE_EVENT_CHANGED:
            priv.modified_on_disk = TRUE;
            break;

        case MOO_FILE_EVENT_DELETED:
            priv.deleted_from_disk = TRUE;
            priv.file_monitor_id = 0;
            break;

        case MOO_FILE_EVENT_ERROR:
            /* XXX and what to do now? */
            break;

        case MOO_FILE_EVENT_CREATED:
            g_critical ("oops");
            break;
    }

    check_file_status (edit);
}


static void _moo_edit_start_file_watch(Edit edit)
{
    auto& priv = edit.get_priv();

    MooFileWatch *watch = _moo_editor_get_file_watch(priv.editor);
    g_return_if_fail(watch != NULL);

    if (priv.file_monitor_id)
        watch->cancel_monitor(priv.file_monitor_id);
    priv.file_monitor_id = 0;

    g_return_if_fail((priv.status & MOO_EDIT_STATUS_CHANGED_ON_DISK) == 0);
    g_return_if_fail(!priv.filename.empty());

    GError *error = nullptr;
    priv.file_monitor_id =
        watch->create_monitor(priv.filename,
                              file_watch_callback,
                              &edit, NULL, &error);

    if (!priv.file_monitor_id)
    {
        g_warning("could not start watch for '%s': %s",
                  priv.filename, moo_error_message(error));
        g_error_free(error);
        return;
    }
}


void Edit::_stop_file_watch()
{
    auto& priv = get_priv();
    MooFileWatch *watch = _moo_editor_get_file_watch (priv.editor);
    g_return_if_fail (watch != NULL);

    if (priv.file_monitor_id)
        watch->cancel_monitor (priv.file_monitor_id);
    priv.file_monitor_id = 0;
}


static void check_file_status(Edit edit)
{
    auto& priv = edit.get_priv();

    g_return_if_fail(!priv.filename.empty());
    g_return_if_fail(!(priv.status & MOO_EDIT_STATUS_CHANGED_ON_DISK));

    if (priv.deleted_from_disk)
        file_deleted(edit);
    else if (priv.modified_on_disk)
        file_modified_on_disk(edit);
}


static void file_modified_on_disk(Edit edit)
{
    auto& priv = edit.get_priv();

    g_return_if_fail (!priv.filename.empty());

    if (moo_prefs_get_bool (moo_edit_setting (MOO_EDIT_PREFS_AUTO_SYNC)))
    {
        moo_edit_reload(&edit, NULL, NULL);
    }
    else
    {
        priv.modified_on_disk = FALSE;
        priv.deleted_from_disk = FALSE;
        edit._stop_file_watch ();
        add_status(edit, MOO_EDIT_STATUS_MODIFIED_ON_DISK);
    }
}


static void file_deleted (Edit edit)
{
    auto& priv = edit.get_priv();

    g_return_if_fail(!priv.filename.empty());

    if (moo_prefs_get_bool(moo_edit_setting(MOO_EDIT_PREFS_AUTO_SYNC)))
    {
        moo_edit_close(&edit);
    }
    else
    {
        priv.modified_on_disk = FALSE;
        priv.deleted_from_disk = FALSE;
        edit._stop_file_watch();
        add_status(edit, MOO_EDIT_STATUS_DELETED);
    }
}


static void add_status(Edit edit, MooEditStatus s)
{
    edit.get_priv().status |= s;
    edit.signal_emit_by_name("doc-status-changed", NULL);
}


void Edit::_remove_untitled(Edit doc)
{
    gpointer n = g_hash_table_lookup (UNTITLED_NO, &doc);

    if (n)
    {
        UNTITLED = g_slist_remove (UNTITLED, n);
        g_hash_table_remove (UNTITLED_NO, &doc);
    }
}


static int add_untitled(Edit edit)
{
    int n;

    if (!(n = GPOINTER_TO_INT(g_hash_table_lookup(UNTITLED_NO, &edit))))
    {
        for (n = 1; ; ++n)
        {
            if (!g_slist_find(UNTITLED, GINT_TO_POINTER(n)))
            {
                UNTITLED = g_slist_prepend(UNTITLED, GINT_TO_POINTER(n));
                break;
            }
        }

        g_hash_table_insert(UNTITLED_NO, &edit, GINT_TO_POINTER(n));
    }

    return n;
}


static gstr moo_file_get_display_basename(g::File file)
{
    const char *slash;

    gstr name = moo_file_get_display_name(file);
    g_return_val_if_fail(!name.empty(), NULL);

    slash = strrchr(name, '/');

#ifdef G_OS_WIN32
    {
        const char *backslash = strrchr(name, '\\');
        if (backslash && (!slash || backslash > slash))
            slash = backslash;
    }
#endif

    if (slash)
        memmove(name.get_mutable(), slash + 1, strlen(slash + 1) + 1);

    return name;
}

static gstr normalize_filename_for_comparison(const char *filename)
{
    g_return_val_if_fail(filename != NULL, gstr::null);

#ifdef __WIN32__
    /* XXX */
    gstr tmp = g::utf8_normalize (filename, G_NORMALIZE_ALL_COMPOSE);
    return g::utf8_strdown (tmp);
#else
    return gstr::wrap (filename);
#endif
}

gstr Edit::_get_normalized_name(g::File file)
{
    gstr tmp = file.get_path();

    if (!tmp.empty())
    {
        gstr tmp2 = _moo_normalize_file_path(tmp);
        return normalize_filename_for_comparison(tmp2);
    }
    else
    {
        tmp = file.get_uri();
        g_return_val_if_fail(!tmp.empty(), nullptr);
        return normalize_filename_for_comparison(tmp);
    }
}

void Edit::_set_file(g::FileRawPtr file,
                     const char*   encoding)
{
    if (!UNTITLED_NO)
        UNTITLED_NO = g_hash_table_new(g_direct_hash, g_direct_equal);

    auto& priv = get_priv();

    if (!file)
    {
        int n = add_untitled(*this);

        priv.file = nullptr;
        priv.filename = nullptr;
        priv.norm_name = nullptr;

        if (n == 1)
            priv.display_filename.set(_("Untitled"));
        else
            priv.display_filename.set_new(g_strdup_printf(_("Untitled %d"), n));

        priv.display_basename = priv.display_filename;
    }
    else
    {
        _remove_untitled(*this);
        priv.file = file->dup();
        priv.filename = file->get_path();
        priv.norm_name = _get_normalized_name(*file);
        priv.display_filename = moo_file_get_display_name(*file);
        priv.display_basename = moo_file_get_display_basename(*file);
    }

    if (!encoding)
        moo_edit_set_encoding(gobj(), _moo_edit_get_default_encoding());
    else
        moo_edit_set_encoding(gobj(), encoding);

    signal_emit_by_name("filename-changed", nullptr);
    _status_changed();
    _queue_recheck_config();
}


GdkPixbuf *
_moo_edit_get_icon (MooEdit     *doc,
                    GtkWidget   *widget,
                    GtkIconSize  size)
{
    if (!doc->priv->filename.empty())
        return moo_get_icon_for_path (doc->priv->filename, widget, size);
    else if (doc->priv->file)
        return moo_get_icon_for_path (doc->priv->display_basename, widget, size);
    else
        return moo_get_icon_for_path (NULL, widget, size);
}


/***************************************************************************
 *
 * Character encoding conversion
 *
 */

#define BOM_UTF8        "\xEF\xBB\xBF"
#define BOM_UTF8_LEN    3
#define BOM_UTF16_LE    "\xFF\xFE"
#define BOM_UTF16_BE    "\xFE\xFF"
#define BOM_UTF16_LEN   2
#define BOM_UTF32_LE    "\xFF\xFE\x00\x00"
#define BOM_UTF32_BE    "\x00\x00\xFE\xFF"
#define BOM_UTF32_LEN   4

#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define BOM_UTF16 BOM_UTF16_LE
#define BOM_UTF32 BOM_UTF32_LE
#else
#define BOM_UTF16 BOM_UTF16_BE
#define BOM_UTF32 BOM_UTF32_BE
#endif

static gstr
try_convert_to_utf8_from_utf8 (const char *data,
                               gsize       len)
{
    const char *invalid;
    gboolean valid_utf8;

//     g_print ("try_convert_to_utf8_from_utf8()\n");

    if (len >= BOM_UTF8_LEN && memcmp (data, BOM_UTF8, BOM_UTF8_LEN) == 0)
    {
        data += BOM_UTF8_LEN;
        len -= BOM_UTF8_LEN;
    }

    valid_utf8 = g_utf8_validate (data, len, &invalid);

    // allow trailing zero byte
    if (!valid_utf8 && invalid + 1 == data + len && *invalid == 0)
        valid_utf8 = TRUE;

    return valid_utf8 ? gstr::wrap_const (data) : gstr::null;
}

static gboolean
encoding_needs_bom_load (const char  *enc,
                         gboolean    *bom_optional,
                         const char **enc_no_bom,
                         const char **bom,
                         gsize       *bom_len)
{
    guint i;

    static const struct {
        const char *enc_bom;
        const char *enc_no_bom;
        const char *bom;
        gsize bom_len;
        gboolean optional;
    } encs[] = {
        { "UTF-8-BOM",    "UTF-8",    BOM_UTF8,     BOM_UTF8_LEN,  FALSE },
        { "UTF-16",       "UTF-16",   BOM_UTF16,    BOM_UTF16_LEN, TRUE },
        { "UTF-16-BOM",   "UTF-16",   BOM_UTF16,    BOM_UTF16_LEN, FALSE },
        { "UTF-16LE-BOM", "UTF-16LE", BOM_UTF16_LE, BOM_UTF16_LEN, FALSE },
        { "UTF-16BE-BOM", "UTF-16BE", BOM_UTF16_BE, BOM_UTF16_LEN, FALSE },
        { "UTF-32",       "UTF-32",   BOM_UTF32,    BOM_UTF32_LEN, TRUE },
        { "UTF-32-BOM",   "UTF-32",   BOM_UTF32,    BOM_UTF32_LEN, FALSE },
        { "UTF-32LE-BOM", "UTF-32LE", BOM_UTF32_LE, BOM_UTF32_LEN, FALSE },
        { "UTF-32BE-BOM", "UTF-32BE", BOM_UTF32_BE, BOM_UTF32_LEN, FALSE },
    };

    for (i = 0; i < G_N_ELEMENTS (encs); ++i)
    {
        if (!g_ascii_strcasecmp (enc, encs[i].enc_bom))
        {
            *enc_no_bom = encs[i].enc_no_bom;
            *bom = encs[i].bom;
            *bom_len = encs[i].bom_len;
            *bom_optional = encs[i].optional;
            return TRUE;
        }
    }

    return FALSE;
}

static bool
encoding_needs_bom_save (const char  *enc,
                         const char **enc_no_bom,
                         const char **bom,
                         gsize       *bom_len)
{
    guint i;

    static const struct {
        const char *enc_bom;
        const char *enc_no_bom;
        const char *bom;
        gsize bom_len;
    } encs[] = {
        { "UTF-8-BOM",    "UTF-8",    BOM_UTF8,     BOM_UTF8_LEN },
        { "UTF-16LE-BOM", "UTF-16LE", BOM_UTF16_LE, BOM_UTF16_LEN },
        { "UTF-16BE-BOM", "UTF-16BE", BOM_UTF16_BE, BOM_UTF16_LEN },
        { "UTF-32LE-BOM", "UTF-32LE", BOM_UTF32_LE, BOM_UTF32_LEN },
        { "UTF-32BE-BOM", "UTF-32BE", BOM_UTF32_BE, BOM_UTF32_LEN },
    };

    for (i = 0; i < G_N_ELEMENTS (encs); ++i)
    {
        if (!g_ascii_strcasecmp (enc, encs[i].enc_bom))
        {
            *enc_no_bom = encs[i].enc_no_bom;
            *bom = encs[i].bom;
            *bom_len = encs[i].bom_len;
            return TRUE;
        }
    }

    return FALSE;
}

static gstr
try_convert_to_utf8_from_non_utf8_encoding (const char *data,
                                            gsize       len,
                                            const char *enc)
{
    const char *enc_no_bom = NULL;
    const char *bom = NULL;
    gsize bom_len = 0;
    gsize bytes_read = 0;
    gsize bytes_written = 0;
    gsize result_len = 0;
    gboolean bom_optional = FALSE;

//     g_print ("try_convert_to_utf8_from_non_utf8_encoding(%s)\n",
//              enc ? enc : "<null>");

    if (encoding_needs_bom_load (enc, &bom_optional, &enc_no_bom, &bom, &bom_len))
    {
        if (len < bom_len || memcmp (bom, data, bom_len) != 0)
        {
            if (!bom_optional)
                return NULL;
        }
        else
        {
            data += bom_len;
            len -= bom_len;
            enc = enc_no_bom;
        }
    }

    if (encoding_is_utf8 (enc))
        return try_convert_to_utf8_from_utf8 (data, len);

    gstr result = gstr::wrap_new (g_convert (data, len, "UTF-8", enc, &bytes_read, &bytes_written, NULL));

    if (result.is_null ())
        return gstr::null;

    if (bytes_read < len)
        return gstr::null;

    result_len = strlen (result);

    // ignore trailing zero
    if (bytes_written == result_len + 1)
        bytes_written -= 1;

    if (result_len < bytes_written)
        return gstr::null;

    return result;
}

static gstr
try_convert_to_utf8_from_encoding (const char *data,
                                   gsize       len,
                                   const char *enc)
{
    if (encoding_is_utf8 (enc))
        return try_convert_to_utf8_from_utf8 (data, len);
    else
        return try_convert_to_utf8_from_non_utf8_encoding (data, len, enc);
}

static gboolean
data_has_bom (const char  *data,
              gsize        len,
              const char **bom_enc)
{
    guint i;

    static const struct {
        const char *enc;
        const char *bom;
        gsize bom_len;
    } encs[] = {
        { "UTF-8-BOM",      BOM_UTF8,     BOM_UTF8_LEN },
        { "UTF-16-BOM",     BOM_UTF16,    BOM_UTF16_LEN },
        { "UTF-32-BOM",     BOM_UTF32,    BOM_UTF32_LEN },
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
        { "UTF-16BE-BOM",   BOM_UTF16_BE, BOM_UTF16_LEN },
        { "UTF-32BE-BOM",   BOM_UTF32_BE, BOM_UTF32_LEN },
#else
        { "UTF-16LE-BOM",   BOM_UTF16_LE, BOM_UTF16_LEN },
        { "UTF-32LE-BOM",   BOM_UTF32_LE, BOM_UTF32_LEN },
#endif
    };

    for (i = 0; i < G_N_ELEMENTS (encs); ++i)
    {
        const char *bom = encs[i].bom;
        gsize bom_len = encs[i].bom_len;

        if (len >= bom_len && memcmp (data, bom, bom_len) == 0)
        {
            *bom_enc = encs[i].enc;
            return TRUE;
        }
    }

    return FALSE;
}

static gstr
moo_convert_file_data_to_utf8 (const char  *data,
                               gsize        len,
                               const char  *encoding,
                               const char  *cached_encoding,
                               gstr&        used_enc)
{
    gstr result;
    const char *bom_enc = NULL;

//     g_print ("moo_convert_file_data_to_utf8(%s, %s)\n",
//              encoding ? encoding : "<null>",
//              cached_encoding ? cached_encoding : "<null>");

    if (!encoding && data_has_bom (data, len, &bom_enc))
    {
        encoding = bom_enc;
        result = try_convert_to_utf8_from_encoding (data, len, encoding);
        used_enc.set(bom_enc);
    }
    else if (!encoding)
    {
        std::list<gstr> encodings = get_encodings ();

        if (cached_encoding)
            encodings.push_front(gstr::wrap(cached_encoding));

        for (auto& enc: encodings)
        {
            result = try_convert_to_utf8_from_encoding (data, len, enc);

            if (!result.is_null ())
            {
                used_enc = std::move(enc);
                break;
            }
        }
    }
    else
    {
        result = try_convert_to_utf8_from_encoding (data, len, encoding);
        used_enc.set(encoding);
    }

    return result;
}

static bool
encoding_is_utf8 (const char *encoding)
{
    return !g_ascii_strcasecmp (encoding, "UTF-8") ||
           !g_ascii_strcasecmp (encoding, "UTF8");
}