/* this file is part of evince, a gnome document viewer
 *
 *  Copyright (C) 2009 Carlos Garcia Campos
 *
 * Evince 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.
 *
 * Evince 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <config.h>

#include <glib.h>
#include "ev-jobs.h"
#include "ev-job-scheduler.h"
#include "ev-mapping-list.h"
#include "ev-selection.h"
#include "ev-document-links.h"
#include "ev-document-forms.h"
#include "ev-document-images.h"
#include "ev-document-annotations.h"
#include "ev-document-text.h"
#include "ev-page-cache.h"

enum {
  PAGE_CACHED,
  LAST_SIGNAL
};

static guint ev_page_cache_signals[LAST_SIGNAL] = {0};

typedef struct _EvPageCacheData {
	EvJob             *job;
	gboolean           done : 1;
	gboolean           dirty : 1;
	EvJobPageDataFlags flags;

	EvMappingList     *link_mapping;
	EvMappingList     *image_mapping;
	EvMappingList     *form_field_mapping;
	EvMappingList     *annot_mapping;
	cairo_region_t    *text_mapping;
	EvRectangle       *text_layout;
	guint              text_layout_length;
	gchar             *text;
	PangoAttrList     *text_attrs;
        PangoLogAttr      *text_log_attrs;
        gulong             text_log_attrs_length;
} EvPageCacheData;

struct _EvPageCache {
	GObject parent;

	EvDocument        *document;
	EvPageCacheData   *page_list;
	gint               n_pages;

	/* Current range */
	gint               start_page;
	gint               end_page;

	EvJobPageDataFlags flags;
};

struct _EvPageCacheClass {
	GObjectClass parent_class;
};

#define EV_PAGE_DATA_FLAGS_DEFAULT (        \
	EV_PAGE_DATA_INCLUDE_LINKS        | \
	EV_PAGE_DATA_INCLUDE_TEXT_MAPPING | \
	EV_PAGE_DATA_INCLUDE_IMAGES       | \
	EV_PAGE_DATA_INCLUDE_FORMS        | \
	EV_PAGE_DATA_INCLUDE_ANNOTS)

#define PRE_CACHE_SIZE 1

static void job_page_data_finished_cb (EvJob       *job,
				       EvPageCache *cache);
static void job_page_data_cancelled_cb (EvJob       *job,
					EvPageCacheData *data);

G_DEFINE_TYPE (EvPageCache, ev_page_cache, G_TYPE_OBJECT)

static void
ev_page_cache_data_free (EvPageCacheData *data)
{
	if (data->job) {
		g_object_unref (data->job);
		data->job = NULL;
	}

	if (data->link_mapping) {
		ev_mapping_list_unref (data->link_mapping);
		data->link_mapping = NULL;
	}

	if (data->image_mapping) {
		ev_mapping_list_unref (data->image_mapping);
		data->image_mapping = NULL;
	}

	if (data->form_field_mapping) {
		ev_mapping_list_unref (data->form_field_mapping);
		data->form_field_mapping = NULL;
	}

	if (data->annot_mapping) {
		ev_mapping_list_unref (data->annot_mapping);
		data->annot_mapping = NULL;
	}

	if (data->text_mapping) {
		cairo_region_destroy (data->text_mapping);
		data->text_mapping = NULL;
	}

	if (data->text_layout) {
		g_free (data->text_layout);
		data->text_layout = NULL;
		data->text_layout_length = 0;
	}

	if (data->text) {
		g_free (data->text);
		data->text = NULL;
	}

	if (data->text_attrs) {
		pango_attr_list_unref (data->text_attrs);
		data->text_attrs = NULL;
	}

        if (data->text_log_attrs) {
                g_free (data->text_log_attrs);
                data->text_log_attrs = NULL;
                data->text_log_attrs_length = 0;
        }
}

static void
ev_page_cache_finalize (GObject *object)
{
	EvPageCache *cache = EV_PAGE_CACHE (object);
	gint         i;

	if (cache->page_list) {
		for (i = 0; i < cache->n_pages; i++) {
			EvPageCacheData *data;

			data = &cache->page_list[i];

			if (data->job) {
				g_signal_handlers_disconnect_by_func (data->job,
								      G_CALLBACK (job_page_data_finished_cb),
								      cache);
				g_signal_handlers_disconnect_by_func (data->job,
								      G_CALLBACK (job_page_data_cancelled_cb),
								      data);
			}
			ev_page_cache_data_free (data);
		}

		g_free (cache->page_list);
		cache->page_list = NULL;
		cache->n_pages = 0;
	}

	if (cache->document) {
		g_object_unref (cache->document);
		cache->document = NULL;
	}

	G_OBJECT_CLASS (ev_page_cache_parent_class)->finalize (object);
}

static void
ev_page_cache_init (EvPageCache *cache)
{
}

static void
ev_page_cache_class_init (EvPageCacheClass *klass)
{
	GObjectClass *g_object_class = G_OBJECT_CLASS (klass);

	g_object_class->finalize = ev_page_cache_finalize;

        ev_page_cache_signals [PAGE_CACHED] =
                  g_signal_new ("page-cached",
                                EV_TYPE_PAGE_CACHE,
                                G_SIGNAL_RUN_LAST,
                                0,
                                NULL, NULL,
                                g_cclosure_marshal_VOID__INT,
                                G_TYPE_NONE, 1, G_TYPE_INT);
}

static EvJobPageDataFlags
ev_page_cache_get_flags_for_data (EvPageCache     *cache,
				  EvPageCacheData *data)
{
	EvJobPageDataFlags flags = EV_PAGE_DATA_INCLUDE_NONE;

	if (data->flags == cache->flags && !data->dirty)
		return cache->flags;

	/* Flags changed or data is dirty */
	if (cache->flags & EV_PAGE_DATA_INCLUDE_LINKS) {
		flags = (data->link_mapping) ?
			flags & ~EV_PAGE_DATA_INCLUDE_LINKS :
			flags | EV_PAGE_DATA_INCLUDE_LINKS;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_IMAGES) {
		flags = (data->image_mapping) ?
			flags & ~EV_PAGE_DATA_INCLUDE_IMAGES :
			flags | EV_PAGE_DATA_INCLUDE_IMAGES;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_FORMS) {
		flags = (data->form_field_mapping) ?
			flags & ~EV_PAGE_DATA_INCLUDE_FORMS :
			flags | EV_PAGE_DATA_INCLUDE_FORMS;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_ANNOTS) {
		flags = (data->annot_mapping) ?
			flags & ~EV_PAGE_DATA_INCLUDE_ANNOTS :
			flags | EV_PAGE_DATA_INCLUDE_ANNOTS;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_MAPPING) {
		flags = (data->text_mapping) ?
			flags & ~EV_PAGE_DATA_INCLUDE_TEXT_MAPPING :
			flags | EV_PAGE_DATA_INCLUDE_TEXT_MAPPING;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_TEXT) {
		flags = (data->text) ?
			flags & ~EV_PAGE_DATA_INCLUDE_TEXT :
			flags | EV_PAGE_DATA_INCLUDE_TEXT;
	}

	if (cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT) {
		flags = (data->text_layout_length > 0) ?
			flags & ~EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT :
			flags | EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT;
	}

        if (cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_ATTRS) {
                flags = (data->text_attrs) ?
                        flags & ~EV_PAGE_DATA_INCLUDE_TEXT_ATTRS :
                        flags | EV_PAGE_DATA_INCLUDE_TEXT_ATTRS;
        }

        if (cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS) {
                flags = (data->text_log_attrs) ?
                        flags & ~EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS :
                        flags | EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS;
        }

	return flags;
}

EvPageCache *
ev_page_cache_new (EvDocument *document)
{
	EvPageCache *cache;

	g_return_val_if_fail (EV_IS_DOCUMENT (document), NULL);

	cache = EV_PAGE_CACHE (g_object_new (EV_TYPE_PAGE_CACHE, NULL));
	cache->document = g_object_ref (document);
	cache->n_pages = ev_document_get_n_pages (document);
	cache->flags = EV_PAGE_DATA_FLAGS_DEFAULT;
	cache->page_list = g_new0 (EvPageCacheData, cache->n_pages);

	return cache;
}

static void
job_page_data_finished_cb (EvJob       *job,
			   EvPageCache *cache)
{
	EvJobPageData   *job_data = EV_JOB_PAGE_DATA (job);
	EvPageCacheData *data;

	data = &cache->page_list[job_data->page];

	if (job_data->flags & EV_PAGE_DATA_INCLUDE_LINKS)
		data->link_mapping = job_data->link_mapping;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_IMAGES)
		data->image_mapping = job_data->image_mapping;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_FORMS)
		data->form_field_mapping = job_data->form_field_mapping;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_ANNOTS)
		data->annot_mapping = job_data->annot_mapping;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_TEXT_MAPPING)
		data->text_mapping = job_data->text_mapping;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT) {
		data->text_layout = job_data->text_layout;
		data->text_layout_length = job_data->text_layout_length;
	}
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_TEXT)
		data->text = job_data->text;
	if (job_data->flags & EV_PAGE_DATA_INCLUDE_TEXT_ATTRS)
		data->text_attrs = job_data->text_attrs;
        if (job_data->flags & EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS) {
                data->text_log_attrs = job_data->text_log_attrs;
                data->text_log_attrs_length = job_data->text_log_attrs_length;
        }

	data->done = TRUE;
	data->dirty = FALSE;

	g_object_unref (data->job);
	data->job = NULL;

        g_signal_emit (cache, ev_page_cache_signals[PAGE_CACHED], 0, job_data->page);
}

static void
job_page_data_cancelled_cb (EvJob           *job,
			    EvPageCacheData *data)
{
	g_object_unref (data->job);
	data->job = NULL;
}

static void
ev_page_cache_schedule_job_if_needed (EvPageCache *cache,
				      gint page)
{
	EvPageCacheData   *data = &cache->page_list[page];
	EvJobPageDataFlags flags;

	if (data->flags == cache->flags && !data->dirty && (data->done || data->job))
		return;

	if (data->job)
		ev_job_cancel (data->job);

	flags = ev_page_cache_get_flags_for_data (cache, data);

	data->flags = cache->flags;
	data->job = ev_job_page_data_new (cache->document, page, flags);
	g_signal_connect (data->job, "finished",
			  G_CALLBACK (job_page_data_finished_cb),
			  cache);
	g_signal_connect (data->job, "cancelled",
			  G_CALLBACK (job_page_data_cancelled_cb),
			  data);
	ev_job_scheduler_push_job (data->job, EV_JOB_PRIORITY_NONE);

}

void
ev_page_cache_set_page_range (EvPageCache *cache,
			      gint         start,
			      gint         end)
{
	gint i;
        gint pages_to_pre_cache;

	if (cache->flags == EV_PAGE_DATA_INCLUDE_NONE)
		return;

	for (i = start; i <= end; i++)
		ev_page_cache_schedule_job_if_needed (cache, i);

	cache->start_page = start;
	cache->end_page = end;

        i = 1;
        pages_to_pre_cache = PRE_CACHE_SIZE * 2;
        while ((start - i > 0) || (end + i < cache->n_pages)) {
                if (end + i < cache->n_pages) {
                        ev_page_cache_schedule_job_if_needed (cache, end + i);
                        if (--pages_to_pre_cache == 0)
                                break;
                }

                if (start - i > 0) {
                        ev_page_cache_schedule_job_if_needed (cache, start - i);
                        if (--pages_to_pre_cache == 0)
                                break;
                }
                i++;
        }
}

EvJobPageDataFlags
ev_page_cache_get_flags (EvPageCache *cache)
{
	return cache->flags;
}

void
ev_page_cache_set_flags (EvPageCache       *cache,
			 EvJobPageDataFlags flags)
{
	if (cache->flags == flags)
		return;

	cache->flags = flags;

	/* Update the current range for new flags */
	ev_page_cache_set_page_range (cache, cache->start_page, cache->end_page);
}

void
ev_page_cache_mark_dirty (EvPageCache       *cache,
			  gint               page,
                          EvJobPageDataFlags flags)
{
	EvPageCacheData *data;

	g_return_if_fail (EV_IS_PAGE_CACHE (cache));

	data = &cache->page_list[page];
	data->dirty = TRUE;

        if (flags & EV_PAGE_DATA_INCLUDE_LINKS)
                g_clear_pointer (&data->link_mapping, ev_mapping_list_unref);

	if (flags & EV_PAGE_DATA_INCLUDE_IMAGES)
                g_clear_pointer (&data->image_mapping, ev_mapping_list_unref);

	if (flags & EV_PAGE_DATA_INCLUDE_FORMS)
                g_clear_pointer (&data->form_field_mapping, ev_mapping_list_unref);

	if (flags & EV_PAGE_DATA_INCLUDE_ANNOTS)
                g_clear_pointer (&data->annot_mapping, ev_mapping_list_unref);

	if (flags & EV_PAGE_DATA_INCLUDE_TEXT_MAPPING)
                g_clear_pointer (&data->text_mapping, cairo_region_destroy);

	if (flags & EV_PAGE_DATA_INCLUDE_TEXT)
                g_clear_pointer (&data->text, g_free);

	if (flags & EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT) {
                g_clear_pointer (&data->text_layout, g_free);
                data->text_layout_length = 0;
        }

        if (flags & EV_PAGE_DATA_INCLUDE_TEXT_ATTRS)
                g_clear_pointer (&data->text_attrs, pango_attr_list_unref);

        if (flags & EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS) {
                g_clear_pointer (&data->text_log_attrs, g_free);
                data->text_log_attrs_length = 0;
        }

	/* Update the current range */
	ev_page_cache_set_page_range (cache, cache->start_page, cache->end_page);
}

EvMappingList *
ev_page_cache_get_link_mapping (EvPageCache *cache,
				gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_LINKS))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->link_mapping;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->link_mapping;

	return data->link_mapping;
}

EvMappingList *
ev_page_cache_get_image_mapping (EvPageCache *cache,
				 gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_IMAGES))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->image_mapping;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->image_mapping;

	return data->image_mapping;
}

EvMappingList *
ev_page_cache_get_form_field_mapping (EvPageCache *cache,
				      gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_FORMS))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->form_field_mapping;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->form_field_mapping;

	return data->form_field_mapping;
}

EvMappingList *
ev_page_cache_get_annot_mapping (EvPageCache *cache,
				 gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_ANNOTS))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->annot_mapping;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->annot_mapping;

	return data->annot_mapping;
}

cairo_region_t *
ev_page_cache_get_text_mapping (EvPageCache *cache,
				gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_MAPPING))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->text_mapping;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->text_mapping;

	return data->text_mapping;
}

const gchar *
ev_page_cache_get_text (EvPageCache *cache,
			     gint         page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_TEXT))
		return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->text;

	if (data->job)
		return EV_JOB_PAGE_DATA (data->job)->text;

	return data->text;
}

gboolean
ev_page_cache_get_text_layout (EvPageCache  *cache,
			       gint          page,
			       EvRectangle **areas,
			       guint        *n_areas)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), FALSE);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, FALSE);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_LAYOUT))
		return FALSE;

	data = &cache->page_list[page];
	if (data->done)	{
		*areas = data->text_layout;
		*n_areas = data->text_layout_length;

		return TRUE;
	}

	if (data->job) {
		*areas = EV_JOB_PAGE_DATA (data->job)->text_layout;
		*n_areas = EV_JOB_PAGE_DATA (data->job)->text_layout_length;

		return TRUE;
	}

	return FALSE;
}

/**
 * ev_page_cache_get_text_attrs:
 * @cache: a #EvPageCache
 * @page:
 *
 * FIXME
 *
 * Since: 3.10
 */
PangoAttrList *
ev_page_cache_get_text_attrs (EvPageCache    *cache,
			      gint            page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), NULL);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, NULL);

	if (!(cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_ATTRS))
	    return NULL;

	data = &cache->page_list[page];
	if (data->done)
		return data->text_attrs;

	if (data->job)
		return EV_JOB_PAGE_DATA(data->job)->text_attrs;

	return data->text_attrs;
}

/**
 * ev_page_cache_get_text_log_attrs:
 * @cache: a #EvPageCache
 * @page:
 * @log_attrs: (out) (transfer full) (array length=n_attrs):
 * @n_attrs: (out):
 *
 * FIXME
 *
 * Returns: %TRUE on success with @log_attrs filled in, %FALSE otherwise
 *
 * Since: 3.10
 */
gboolean
ev_page_cache_get_text_log_attrs (EvPageCache   *cache,
                                  gint           page,
                                  PangoLogAttr **log_attrs,
                                  gulong        *n_attrs)
{
        EvPageCacheData *data;

        g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), FALSE);
        g_return_val_if_fail (page >= 0 && page < cache->n_pages, FALSE);

        if (!(cache->flags & EV_PAGE_DATA_INCLUDE_TEXT_LOG_ATTRS))
                return FALSE;

        data = &cache->page_list[page];
        if (data->done) {
                *log_attrs = data->text_log_attrs;
                *n_attrs = data->text_log_attrs_length;

                return TRUE;
        }

        if (data->job) {
                *log_attrs = EV_JOB_PAGE_DATA (data->job)->text_log_attrs;
                *n_attrs = EV_JOB_PAGE_DATA (data->job)->text_log_attrs_length;

                return TRUE;
        }

        return FALSE;
}

void
ev_page_cache_ensure_page (EvPageCache *cache,
                           gint         page)
{
        g_return_if_fail (EV_IS_PAGE_CACHE (cache));
        g_return_if_fail (page >= 0 && page < cache->n_pages);

        ev_page_cache_schedule_job_if_needed (cache, page);
}

gboolean
ev_page_cache_is_page_cached (EvPageCache   *cache,
			      gint           page)
{
	EvPageCacheData *data;

	g_return_val_if_fail (EV_IS_PAGE_CACHE (cache), FALSE);
	g_return_val_if_fail (page >= 0 && page < cache->n_pages, FALSE);

	data = &cache->page_list[page];

	return data->done;
}
