/*
 * rofi
 *
 * MIT/X11 License
 * Copyright © 2013-2021 Qball Cow <qball@gmpclient.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

/** The log domain of this Helper. */
#define G_LOG_DOMAIN    "Helpers.IconFetcher"

#include <stdlib.h>
#include <config.h>

#include "rofi-icon-fetcher.h"
#include "rofi-types.h"
#include "helper.h"
#include "settings.h"

#include "xcb.h"
#include "keyb.h"
#include "view.h"

#include "nkutils-xdg-theme.h"
#include "nkutils-enum.h"

#include <stdint.h>

#include <gdk-pixbuf/gdk-pixbuf.h>

typedef struct
{
    // Context for icon-themes.
    NkXdgThemeContext *xdg_context;

    // On name.
    GHashTable        *icon_cache;
    // On uid.
    GHashTable        *icon_cache_uid;

    // list extensions
    GList             *supported_extensions;
    uint32_t          last_uid;
} IconFetcher;

typedef struct
{
    char  *name;
    GList *sizes;
} IconFetcherNameEntry;

typedef struct
{
    thread_state         state;

    GCond                *cond;
    GMutex               *mutex;
    unsigned int         *acount;

    uint32_t             uid;
    int                  wsize;
    int                  hsize;
    cairo_surface_t      *surface;

    IconFetcherNameEntry *entry;
} IconFetcherEntry;

/**
 * The icon fetcher internal state.
 */
IconFetcher *rofi_icon_fetcher_data = NULL;

static void rofi_icon_fetch_entry_free ( gpointer data )
{
    IconFetcherNameEntry *entry = (IconFetcherNameEntry *) data;

    // Free name/key.
    g_free ( entry->name );

    for ( GList *iter = g_list_first ( entry->sizes ); iter; iter = g_list_next ( iter ) ) {
        IconFetcherEntry *sentry = (IconFetcherEntry *) ( iter->data );

        cairo_surface_destroy ( sentry->surface );
        g_free ( sentry );
    }

    g_list_free ( entry->sizes );
    g_free ( entry );
}

void rofi_icon_fetcher_init ( void )
{
    g_assert ( rofi_icon_fetcher_data == NULL );

    static const gchar * const icon_fallback_themes[] = {
        "Adwaita",
        "gnome",
        NULL
    };
    const char                 *themes[2] = { config.icon_theme, NULL };

    rofi_icon_fetcher_data = g_malloc0 ( sizeof ( IconFetcher ) );

    rofi_icon_fetcher_data->xdg_context = nk_xdg_theme_context_new ( icon_fallback_themes, NULL );
    nk_xdg_theme_preload_themes_icon ( rofi_icon_fetcher_data->xdg_context, themes );

    rofi_icon_fetcher_data->icon_cache_uid = g_hash_table_new ( g_direct_hash, g_direct_equal );
    rofi_icon_fetcher_data->icon_cache     = g_hash_table_new_full ( g_str_hash, g_str_equal, NULL, rofi_icon_fetch_entry_free );

    GSList *l = gdk_pixbuf_get_formats ();
    for ( GSList *li = l; li != NULL; li = g_slist_next ( li ) ) {
        gchar **exts = gdk_pixbuf_format_get_extensions ( (GdkPixbufFormat *) li->data );

        for ( unsigned int i = 0; exts && exts[i]; i++ ) {
            rofi_icon_fetcher_data->supported_extensions = g_list_append ( rofi_icon_fetcher_data->supported_extensions, exts[i] );
            g_info ( "Add image extension: %s", exts[i] );
            exts[i] = NULL;
        }

        g_free ( exts );
    }
    g_slist_free ( l );
}

static void free_wrapper ( gpointer data, G_GNUC_UNUSED gpointer user_data )
{
    g_free ( data ) ;
}

void rofi_icon_fetcher_destroy ( void )
{
    if ( rofi_icon_fetcher_data == NULL ) {
        return;
    }

    nk_xdg_theme_context_free ( rofi_icon_fetcher_data->xdg_context );

    g_hash_table_unref ( rofi_icon_fetcher_data->icon_cache_uid );
    g_hash_table_unref ( rofi_icon_fetcher_data->icon_cache );

    g_list_foreach ( rofi_icon_fetcher_data->supported_extensions, free_wrapper, NULL );
    g_list_free ( rofi_icon_fetcher_data->supported_extensions );
    g_free ( rofi_icon_fetcher_data );
}

/*
 * _rofi_icon_fetcher_get_icon_surface and alpha_mult
 * are inspired by gdk_cairo_set_source_pixbuf
 * GDK is:
 *     Copyright (C) 2011-2018 Red Hat, Inc.
 */
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
/** Location of red byte */
#define RED_BYTE      2
/** Location of green byte */
#define GREEN_BYTE    1
/** Location of blue byte */
#define BLUE_BYTE     0
/** Location of alpha byte */
#define ALPHA_BYTE    3
#else
/** Location of red byte */
#define RED_BYTE      1
/** Location of green byte */
#define GREEN_BYTE    2
/** Location of blue byte */
#define BLUE_BYTE     3
/** Location of alpha byte */
#define ALPHA_BYTE    0
#endif

static inline guchar alpha_mult ( guchar c, guchar a )
{
    guint16 t;
    switch ( a )
    {
    case 0xff:
        return c;
    case 0x00:
        return 0x00;
    default:
        t = c * a + 0x7f;
        return ( ( t >> 8 ) + t ) >> 8;
    }
}

static cairo_surface_t * rofi_icon_fetcher_get_surface_from_pixbuf ( GdkPixbuf
                                                                     *pixbuf )
{
    gint         width, height;
    const guchar *pixels;
    gint         stride;
    gboolean     alpha;

    if ( pixbuf == NULL ) {
        return NULL;
    }

    width  = gdk_pixbuf_get_width ( pixbuf );
    height = gdk_pixbuf_get_height ( pixbuf );
    pixels = gdk_pixbuf_read_pixels ( pixbuf );
    stride = gdk_pixbuf_get_rowstride ( pixbuf );
    alpha  = gdk_pixbuf_get_has_alpha ( pixbuf );

    cairo_surface_t *surface = NULL;

    gint            cstride;
    guint           lo, o;
    guchar          a = 0xff;
    const guchar    *pixels_end, *line;
    guchar          *cpixels;

    pixels_end = pixels + height * stride;
    o          = alpha ? 4 : 3;
    lo         = o * width;

    surface = cairo_image_surface_create ( CAIRO_FORMAT_ARGB32, width, height );
    cpixels = cairo_image_surface_get_data ( surface );
    cstride = cairo_image_surface_get_stride ( surface );

    cairo_surface_flush ( surface );
    while ( pixels < pixels_end ) {
        line = pixels;
        const guchar *line_end = line + lo;
        guchar       *cline    = cpixels;

        while ( line < line_end ) {
            if ( alpha ) {
                a = line[3];
            }
            cline[RED_BYTE]   = alpha_mult ( line[0], a );
            cline[GREEN_BYTE] = alpha_mult ( line[1], a );
            cline[BLUE_BYTE]  = alpha_mult ( line[2], a );
            cline[ALPHA_BYTE] = a;

            line  += o;
            cline += 4;
        }

        pixels  += stride;
        cpixels += cstride;
    }
    cairo_surface_mark_dirty ( surface );
    cairo_surface_flush ( surface );

    return surface;
}

gboolean rofi_icon_fetcher_file_is_image ( const char * const path )
{
    if ( path == NULL ) {
        return FALSE;
    }
    const char *suf = strrchr ( path, '.' );
    if ( suf == NULL  ) {
        return FALSE;
    }
    suf++;

    for ( GList *iter = rofi_icon_fetcher_data->supported_extensions; iter != NULL; iter = g_list_next ( iter ) ) {
        if ( g_ascii_strcasecmp ( iter->data, suf ) == 0 ) {
            return TRUE;
        }
    }
    return FALSE;
}

static void rofi_icon_fetcher_worker ( thread_state *sdata, G_GNUC_UNUSED gpointer user_data )
{
    g_debug ( "starting up icon fetching thread." );
    // as long as dr->icon is updated atomicly.. (is a pointer write atomic?)
    // this should be fine running in another thread.
    IconFetcherEntry *sentry   = (IconFetcherEntry *) sdata;
    const gchar      *themes[] = {
        config.icon_theme,
        NULL
    };

    const gchar      *icon_path;
    gchar            *icon_path_ = NULL;

    if ( g_path_is_absolute ( sentry->entry->name ) ) {
        icon_path = sentry->entry->name;
    }
    else {
        icon_path = icon_path_ = nk_xdg_theme_get_icon ( rofi_icon_fetcher_data->xdg_context, themes, NULL, sentry->entry->name, MIN(sentry->wsize,sentry->hsize), 1, TRUE );
        if ( icon_path_ == NULL ) {
            g_debug ( "failed to get icon %s(%dx%d): n/a", sentry->entry->name, sentry->wsize, sentry->hsize  );
            return;
        }
        else{
            g_debug ( "found icon %s(%dx%d): %s", sentry->entry->name, sentry->wsize, sentry->hsize, icon_path  );
        }
    }
    cairo_surface_t *icon_surf = NULL;

    const char      *suf = strrchr ( icon_path, '.' );
    if ( suf == NULL  ) {
        return;
    }

    GError    *error = NULL;
    GdkPixbuf *pb    = gdk_pixbuf_new_from_file_at_scale ( icon_path, sentry->wsize, sentry->hsize, TRUE, &error );
    if ( error != NULL ) {
        g_warning ( "Failed to load image: %s", error->message );
        g_error_free ( error );
        if ( pb ) {
            g_object_unref ( pb );
        }
    }
    else {
        icon_surf = rofi_icon_fetcher_get_surface_from_pixbuf ( pb );
        g_object_unref ( pb );
    }

    sentry->surface = icon_surf;
    g_free ( icon_path_ );
    rofi_view_reload ();
}

uint32_t rofi_icon_fetcher_query_advanced ( const char *name, const int wsize, const int hsize )
{
    g_debug ( "Query: %s(%dx%d)", name, wsize, hsize );
    IconFetcherNameEntry *entry = g_hash_table_lookup ( rofi_icon_fetcher_data->icon_cache, name );
    if ( entry == NULL ) {
        entry       = g_new0 ( IconFetcherNameEntry, 1 );
        entry->name = g_strdup ( name );
        g_hash_table_insert ( rofi_icon_fetcher_data->icon_cache, entry->name, entry );
    }
    IconFetcherEntry *sentry;
    for ( GList *iter = g_list_first ( entry->sizes ); iter; iter = g_list_next ( iter ) ) {
        sentry = iter->data;
        if ( sentry->wsize == wsize && sentry->hsize == hsize ) {
            return sentry->uid;
        }
    }

    // Not found.
    sentry          = g_new0 ( IconFetcherEntry, 1 );
    sentry->uid     = ++( rofi_icon_fetcher_data->last_uid );
    sentry->wsize    = wsize;
    sentry->hsize    = hsize;
    sentry->entry   = entry;
    sentry->surface = NULL;

    entry->sizes = g_list_prepend ( entry->sizes, sentry );
    g_hash_table_insert ( rofi_icon_fetcher_data->icon_cache_uid, GINT_TO_POINTER ( sentry->uid ), sentry );

    // Push into fetching queue.
    sentry->state.callback = rofi_icon_fetcher_worker;
    g_thread_pool_push ( tpool, sentry, NULL );

    return sentry->uid;
}
uint32_t rofi_icon_fetcher_query ( const char *name, const int size )
{
    g_debug ( "Query: %s(%d)", name, size );
    IconFetcherNameEntry *entry = g_hash_table_lookup ( rofi_icon_fetcher_data->icon_cache, name );
    if ( entry == NULL ) {
        entry       = g_new0 ( IconFetcherNameEntry, 1 );
        entry->name = g_strdup ( name );
        g_hash_table_insert ( rofi_icon_fetcher_data->icon_cache, entry->name, entry );
    }
    IconFetcherEntry *sentry;
    for ( GList *iter = g_list_first ( entry->sizes ); iter; iter = g_list_next ( iter ) ) {
        sentry = iter->data;
        if ( sentry->wsize == size && sentry->hsize == size ) {
            return sentry->uid;
        }
    }

    // Not found.
    sentry          = g_new0 ( IconFetcherEntry, 1 );
    sentry->uid     = ++( rofi_icon_fetcher_data->last_uid );
    sentry->wsize    = size;
    sentry->hsize    = size;
    sentry->entry   = entry;
    sentry->surface = NULL;

    entry->sizes = g_list_prepend ( entry->sizes, sentry );
    g_hash_table_insert ( rofi_icon_fetcher_data->icon_cache_uid, GINT_TO_POINTER ( sentry->uid ), sentry );

    // Push into fetching queue.
    sentry->state.callback = rofi_icon_fetcher_worker;
    g_thread_pool_push ( tpool, sentry, NULL );

    return sentry->uid;
}

cairo_surface_t * rofi_icon_fetcher_get  ( const uint32_t uid )
{
    IconFetcherEntry *sentry = g_hash_table_lookup ( rofi_icon_fetcher_data->icon_cache_uid, GINT_TO_POINTER ( uid ) );
    if ( sentry ) {
        return sentry->surface;
    }
    return NULL;
}