/* diversity-osm.c - DiversityOsm
 *
 * Copyright 2008 OpenMoko, Inc.
 * Authored by Chia-I Wu <olv@openmoko.com>
 *
 * 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.
 *
 * 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 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <glib.h>
#include <diversity-equipment.h>
#include <diversity-atlas.h>
#include "diversity-osm.h"
#include "diversity-curl.h"
#include <math.h>
#include <string.h> /* for strcmp */

#define N_OSM_LEVELS	(18) /* must < 32 */
#define LON_LIMIT	(180.0)
#define LAT_LIMIT	(85.05)

#define COORD_VALID(lon, lat) ((lon) >= -LON_LIMIT && (lon) < LON_LIMIT && \
			       (lat) >= -LAT_LIMIT && (lat) < LAT_LIMIT)
#define TILE_VALID(priv, x, y) ((x) >= 0 && (x) < (1 << (priv)->cur_level) && \
				(y) >= 0 && (y) < (1 << (priv)->cur_level))

#define RADIANS(d) ((d) * M_PI / 180.0)
#define DEGREES(r) (180.0 * (r) / M_PI)

#define DIVERSITY_OSM_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE((o), DIVERSITY_TYPE_OSM, DiversityOsmPrivate))
typedef struct _DiversityOsmPrivate DiversityOsmPrivate;

struct _DiversityOsmPrivate {
	DiversityCurl *curl;

	const gchar **sources;
	const gchar **base_urls;

	guint levels[N_OSM_LEVELS];

	gint tile_width;
	gint tile_height;

	gchar *base;

	gint cur_source;
	gint cur_level;
};

static void diversity_osm_atlas_job_completed(DiversityCurl *curl, DiversityCurlJob *job, gpointer data);
static void diversity_osm_iface_init(gpointer g_iface, gpointer iface_data);

G_DEFINE_TYPE_EXTENDED(DiversityOsm, diversity_osm, DIVERSITY_TYPE_EQUIPMENT, 0,
		G_IMPLEMENT_INTERFACE(DIVERSITY_TYPE_ATLAS, diversity_osm_iface_init));

static const gchar *osm_sources[] = {
	"tah",
	"ojw",
	"osm",
	NULL
};

static const gchar *osm_base_urls[] = {
	"http://tah.openstreetmap.org/Tiles/tile",
	"http://dev.openstreetmap.org/~ojw/Tiles/tile.php",
	"http://tile.openstreetmap.org/mapnik",
	NULL
};

static void diversity_osm_dispose(GObject *obj)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(obj);

	if (priv->curl) {
		g_object_unref(priv->curl);
		priv->curl = NULL;
	}

	((GObjectClass *) diversity_osm_parent_class)->dispose(obj);
}

static void diversity_osm_finalize(GObject *obj)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(obj);

	g_free(priv->base);

	((GObjectClass *) diversity_osm_parent_class)->finalize(obj);
}

static gboolean diversity_osm_equip(DiversityEquipment *eqp)
{
	return TRUE;
}

static void diversity_osm_unequip(DiversityEquipment *eqp)
{
}

static gboolean diversity_osm_set_config(DiversityEquipment *eqp, const gchar *key, const GValue *val)
{
	return FALSE;
}

static gboolean diversity_osm_get_config(DiversityEquipment *eqp, const gchar *key, GValue *val)
{
	return FALSE;
}

static void diversity_osm_class_init(DiversityOsmClass *klass)
{
	GObjectClass *o_class = (GObjectClass *) klass;
	DiversityEquipmentClass *eqp_class = (DiversityEquipmentClass *) klass;

	o_class->dispose = diversity_osm_dispose;
	o_class->finalize = diversity_osm_finalize;

	eqp_class->equip = diversity_osm_equip;
	eqp_class->unequip = diversity_osm_unequip;

	eqp_class->set_config = diversity_osm_set_config;
	eqp_class->get_config = diversity_osm_get_config;

	g_type_class_add_private(klass, sizeof(DiversityOsmPrivate));
}

static void diversity_osm_init(DiversityOsm *osm)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(osm);
	gint i;

	priv->sources = osm_sources;
	priv->base_urls = osm_base_urls;

	for (i = 0; i < N_OSM_LEVELS; i++)
		priv->levels[i] = 1 << i;

	priv->tile_width = 256;
	priv->tile_height = 256;

	priv->cur_source = 0;
	priv->cur_level = 0;

	priv->base = g_strdup("/tmp/diversity-maps");
}

DiversityOsm *diversity_osm_new(gint pool_size, gint queue_size)
{
	DiversityOsm *osm;
	DiversityOsmPrivate *priv;

	osm = g_object_new(DIVERSITY_TYPE_OSM,
			    "name", "osm",
			    NULL);

	priv = DIVERSITY_OSM_GET_PRIVATE(osm);

	priv->curl = diversity_curl_new(pool_size, queue_size);
	if (!priv->curl) {
		g_object_unref(osm);

		return NULL;
	}

	g_signal_connect(priv->curl, "job-completed",
			G_CALLBACK(diversity_osm_atlas_job_completed),
			osm);

	return osm;
}

/* DiversityAtlas method implementations
 *
 * Inspired by pyroute and maemo-mapper.
 */

static void diversity_osm_atlas_job_completed(DiversityCurl *curl, DiversityCurlJob *job, gpointer data)
{
	DiversityAtlas *atlas = DIVERSITY_ATLAS(data);

	g_signal_emit_by_name(atlas, "tile-completed",
			GPOINTER_TO_UINT(job), job->status);
}

static const gchar **diversity_osm_atlas_list_sources(DiversityAtlas *atlas)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	return priv->sources;
}

static gboolean diversity_osm_atlas_set_source(DiversityAtlas *atlas, const gchar *src)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	const gchar **strv, *p;
	gint i = 0;

	strv = priv->sources;
	while (*strv) {
		p = *strv;

		if (*p == *src && strcmp(p, src) == 0)
			break;

		strv++;
		i++;
	}

	if (!*strv)
		return FALSE;

	priv->cur_source = i;

	return TRUE;
}

static const gchar *diversity_osm_atlas_get_source(DiversityAtlas *atlas)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	return priv->sources[priv->cur_source];
}

static const guint *diversity_osm_atlas_list_levels(DiversityAtlas *atlas, gint *size)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	if (size)
		*size = N_OSM_LEVELS;

	return priv->levels;
}

static gboolean diversity_osm_atlas_set_level(DiversityAtlas *atlas, gint level)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	if (level < 0 || level >= N_OSM_LEVELS)
		return FALSE;

	priv->cur_level = level;

	return TRUE;
}

static gint diversity_osm_atlas_get_level(DiversityAtlas *atlas)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	return priv->cur_level;
}

static void diversity_osm_atlas_get_tile_size(DiversityAtlas *atlas, gint *width, gint *height)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	if (width)
		*width = priv->tile_width;
	if (height)
		*height = priv->tile_height;
}

static gboolean diversity_osm_atlas_get_atlas_coord(DiversityAtlas *atlas, gdouble lon, gdouble lat, gdouble *x, gdouble *y)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	gdouble tmp;

	if (!COORD_VALID(lon, lat))
		return FALSE;

	*x = ((lon + 180.0) / 360.0) * (1 << priv->cur_level);

	lat = RADIANS(lat);
	tmp = log(tan(lat) + 1.0 / cos(lat));
	*y = (1.0 - tmp / M_PI) / 2.0 * (1 << priv->cur_level);

	return TRUE;
}

static gboolean diversity_osm_atlas_get_world_coord(DiversityAtlas *atlas, gdouble x, gdouble y, gdouble *lon, gdouble *lat)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	x /= (1 << priv->cur_level);
	y /= (1 << priv->cur_level);

	if (x < 0.0 || x >= 1.0 || y < 0.0 || y >= 1.0)
		return FALSE;

	*lon = -180.0 + x * 360.0;
	*lat = DEGREES(atan(sinh((1.0 - y * 2.0) * M_PI)));

	return TRUE;
}

#if 0
const gchar *quadstr(DiversityAtlas *atlas, gint x, gint y)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	static gchar buf[64];
	gchar *qrts = "qrts";
	gchar *p;
	gint i;

	p = buf;
	*p++ = 't';

	for (i = priv->cur_level; i > 0; i--) {
		gint quadx, quady;

		quadx = (x >> (i - 1)) & 1;
		quady = (y >> (i - 1)) & 1;

		*p++ = qrts[quadx + 2 * quady];
	}

	*p = '\0';

	g_print("(%d, %d, %d) -> %s\n", priv->cur_level, x, y, buf);

	return buf;
}
#endif

inline static gchar *osm_get_url(DiversityAtlas *atlas, gint x, gint y)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	const gchar *src;
	gchar *url;
	
	src = priv->base_urls[priv->cur_source];
	url = g_strdup_printf("%s/%d/%d/%d.png",
			src, priv->cur_level, x, y);

	return url;
}

static gchar *diversity_osm_atlas_get_uri(DiversityAtlas *atlas, gint x, gint y)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	gchar *uri;
	
	if (!TILE_VALID(priv, x, y))
		return NULL;

	uri = osm_get_url(atlas, x, y);

	return uri;
}

static guint diversity_osm_atlas_submit_tile(DiversityAtlas *atlas, gint x, gint y, gboolean force)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	DiversityCurlJob *job;
	gchar *uri;
	gchar buf[PATH_MAX];
	
	if (!TILE_VALID(priv, x, y))
		return 0;

	g_snprintf(buf, sizeof(buf), "%s/%s/%d/%d/%d.png",
			priv->base,
			priv->sources[priv->cur_source],
			priv->cur_level, x, y);

	if (g_file_test(buf, G_FILE_TEST_IS_REGULAR) && !force)
		return 0;

	uri = osm_get_url(atlas, x, y);
	if (!uri)
		return 0;

	job = diversity_curl_job_get(priv->curl);
	if (!job)
		return 0;

	job->uri = uri;
	job->path = g_strdup(buf);

	diversity_curl_job_submit(priv->curl, job);

	return GPOINTER_TO_UINT(job);
}

static gboolean diversity_osm_atlas_cancel_tile(DiversityAtlas *atlas, guint tile_id)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);
	DiversityCurlJob *job = GINT_TO_POINTER(tile_id);

	diversity_curl_job_cancel(priv->curl, job);

	return TRUE;
}

static const gchar *diversity_osm_atlas_get_path(DiversityAtlas *atlas)
{
	DiversityOsmPrivate *priv = DIVERSITY_OSM_GET_PRIVATE(atlas);

	return priv->base;
}

static void diversity_osm_iface_init(gpointer g_iface, gpointer iface_data)
{
	DiversityAtlasIface *iface = (DiversityAtlasIface *) g_iface;

	iface->list_sources = diversity_osm_atlas_list_sources;
	iface->set_source = diversity_osm_atlas_set_source;
	iface->get_source = diversity_osm_atlas_get_source;

	iface->list_levels = diversity_osm_atlas_list_levels;
	iface->set_level = diversity_osm_atlas_set_level;
	iface->get_level = diversity_osm_atlas_get_level;

	iface->get_tile_size = diversity_osm_atlas_get_tile_size;
	iface->get_atlas_coord = diversity_osm_atlas_get_atlas_coord;
	iface->get_world_coord = diversity_osm_atlas_get_world_coord;
	iface->get_uri = diversity_osm_atlas_get_uri;

	iface->submit_tile = diversity_osm_atlas_submit_tile;
	iface->cancel_tile = diversity_osm_atlas_cancel_tile;

	iface->get_path = diversity_osm_atlas_get_path;
}