#include <glib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <libxml/parser.h>
#include <unistd.h>

#include "gm-options.h"
#include "gm-string.h"
#include "gm-debug.h"

extern int errno;

#define GM_OPTIONS_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE((object), \
		GM_TYPE_OPTIONS, GmOptionsPrivate))

struct _GmOptionsPrivate {
	GHashTable *options;
	gchar *filepath;
};

/* Signals */

enum {
	OPTION_CHANGED,
	NUM_SIGNALS
};

#define XML_ROOT_NAME "options"
#define XML_OPTION_NAME "option"

static guint options_signals[NUM_SIGNALS] = {0};

G_DEFINE_TYPE(GmOptions, gm_options, G_TYPE_OBJECT)

static void
gm_options_finalize(GObject *object) {
	GmOptions *options = GM_OPTIONS(object);
	
	g_hash_table_destroy(options->priv->options);
	g_free(options->priv->filepath);
	
	G_OBJECT_CLASS(gm_options_parent_class)->finalize(object);
}

static void
gm_options_class_init(GmOptionsClass *klass) {
	GObjectClass *object_class = G_OBJECT_CLASS(klass);
	
	object_class->finalize = gm_options_finalize;

	options_signals[OPTION_CHANGED] = 
		g_signal_new("option_changed",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmOptionsClass, option_changed),
			NULL, NULL,
			g_cclosure_marshal_VOID__STRING,
			G_TYPE_NONE,
			1,
			G_TYPE_STRING);
			
	g_type_class_add_private(object_class, sizeof(GmOptionsPrivate));
}

static void
gm_options_init(GmOptions *options) {
	options->priv = GM_OPTIONS_GET_PRIVATE(options);
	options->priv->options = g_hash_table_new_full(g_str_hash, g_str_equal,
			g_free, g_free);
	options->priv->filepath = NULL;
}

static void
gm_options_load_option(GmOptions *options, xmlDocPtr doc, xmlNodePtr ptr) {
	xmlChar *key, *value;

	key = xmlGetProp(ptr, (const xmlChar *)"key");
	value = xmlGetProp(ptr, (const xmlChar *)"value");
	
	if (key == NULL) {
		gm_debug_msg(DEBUG_DEFAULT, 
				"GmOptions.load_option: key not present in option");
	} else if (value == NULL) {
		gm_debug_msg(DEBUG_DEFAULT, 
				"GmOptions.load_option: value not present in option");
	} else {	
		gm_debug_msg(DEBUG_DEFAULT,
				"GmOptions.load_option: adding option %s: %s", key, value);
		gm_options_set(options, (gchar const *)key, (gchar const *)value);
	}
	
	xmlFree(key);
	xmlFree(value);
}

static void
gm_options_save_option(gchar *key, gchar *value, xmlNodePtr root) {
	xmlNodePtr option;

	gm_debug_msg(DEBUG_DEFAULT, "GmOptions.SaveValue: saving %s, %s", key, 
			value);
	
	option = xmlNewChild(root, NULL, (const xmlChar *)(XML_OPTION_NAME), NULL);
	xmlNewProp(option, (const xmlChar *)("key"), (const xmlChar *)(key));
	xmlNewProp(option, (const xmlChar *)("value"), (const xmlChar *)(value));
}

static void
gm_options_dup_option(gchar *key, gchar *value, GmOptions *copy) {
	gm_options_set(copy, key, value);
}

/* Public functions */

GmOptions *
gm_options_new(void) {
	GmOptions *options = GM_OPTIONS(g_object_new(GM_TYPE_OPTIONS, NULL));
	
	return options;
}

GmOptions *
gm_options_dup(GmOptions *source) {
	GmOptions *copy = gm_options_new();
	
	g_hash_table_foreach(source->priv->options, (GHFunc)gm_options_dup_option,
			copy);
	
	return copy;
}

// Adds an option to opt, even if key already exists
void
gm_options_set(GmOptions * options, gchar const *key, gchar const *value) {
	gchar *trimmed = gm_string_trim(key);
	gchar *lookup = g_hash_table_lookup(options->priv->options, trimmed);
	gboolean changed = lookup != NULL && lookup != value;
	
	if (lookup != value) {
		g_hash_table_insert(options->priv->options, g_strdup(trimmed), 
				g_strdup(value));
	}
	
	if (changed) {
		g_signal_emit(options, options_signals[OPTION_CHANGED], 0, trimmed);
	}
	
	g_free(trimmed);
}

gchar const *
gm_options_get(GmOptions *options, gchar const *key) {
	return g_hash_table_lookup(options->priv->options, key);
}

void
gm_options_set_int(GmOptions *options, gchar const *key, int value) {
	gchar val[15];

	g_snprintf((gchar *) &val, 15, "%d", value);
	gm_options_set(options, key, (gchar const *)val);
}

int
gm_options_get_int(GmOptions *options, gchar const *key) {
	gchar const *val = gm_options_get(options, key);
	int ret;

	if (val && gm_string_to_int(val, &ret)) {
		return ret;
	} else {
		return 0;
	}
}

void
gm_options_remove(GmOptions *options, gchar const *key) {
	g_hash_table_remove(options->priv->options, key);
}

void
gm_options_save(GmOptions *options) {
	xmlDocPtr doc;
	xmlNodePtr root;

	if (options->priv->filepath == NULL) {
		return;
	}

	gm_debug_msg(DEBUG_DEFAULT, "GmOptions.save: saving options (%s)!", 
			options->priv->filepath);

	doc = xmlNewDoc((const xmlChar *)("1.0"));
	root = xmlNewNode(NULL, (const xmlChar *)(XML_ROOT_NAME));
	xmlDocSetRootElement(doc, root);

	g_hash_table_foreach(options->priv->options, 
			(GHFunc)gm_options_save_option, root);

	xmlSaveFormatFileEnc(options->priv->filepath, doc, "UTF-8", 1);
	xmlFreeDoc(doc);

	// Make sure to make this only readable for the user and the group
	chmod(options->priv->filepath, 0660);
}

void
gm_options_save_as(GmOptions *options, gchar const *filename) {
	g_free(options->priv->filepath);
	options->priv->filepath = g_strdup(filename);
	
	gm_options_save(options);
}

gboolean
gm_options_load(GmOptions *options, gchar const *filename) {
	xmlDocPtr doc;
	xmlNodePtr root;
	
	gm_debug_msg(DEBUG_DEFAULT, "GmOptions.load: loading options (%s)!", 
			filename);

	g_free(options->priv->filepath);
	options->priv->filepath = g_strdup(filename);

	if (!g_file_test(filename, G_FILE_TEST_EXISTS)) {
		gm_debug_msg(DEBUG_DEFAULT, "GmOptions.load: file does not exist");
		return FALSE;
	}
	
	doc = xmlParseFile(filename);
	
	if (doc == NULL) {
		gm_debug_msg(DEBUG_DEFAULT, 
				"GmOptions.load: error on parsing options file");
		return FALSE;
	}
	
	root = xmlDocGetRootElement(doc);

	if (root == NULL) {
		xmlFreeDoc(doc);
		return FALSE;
	}
	
	if (xmlStrcmp(root->name, (const xmlChar *)(XML_ROOT_NAME))) {
		gm_debug_msg(DEBUG_DEFAULT, "GmOptions.load: invalid root node");
		xmlFreeDoc(doc);
		return FALSE;
	}

	for (root = root->xmlChildrenNode; root; root = root->next) {
		if (!xmlStrcmp(root->name, (const xmlChar *)(XML_OPTION_NAME))) {
			gm_options_load_option(options, doc, root);
		}
	}

	xmlFreeDoc(doc);
	return TRUE;
}

void 
_gm_options_check_old_options(gchar const *xmlname) {
	gchar *filename;
	xmlDocPtr doc;
	xmlNodePtr root;
	FILE *f;
	gchar **keyvalue, line[1024];
	gint i;

	filename = g_strdup(xmlname);
	filename[strlen(xmlname) - 4] = '\0';

	if (g_file_test(xmlname, G_FILE_TEST_EXISTS) || 
			!g_file_test(filename, G_FILE_TEST_EXISTS)) {
		g_free(filename);
		return;
	}

	doc = xmlNewDoc((const xmlChar *)("1.0"));
	root = xmlNewNode(NULL, (const xmlChar *)(XML_ROOT_NAME));
	xmlDocSetRootElement(doc, root);

	if ((f = fopen(filename, "r")) != NULL) {
		i = 0;
		while (fgets((char *) &line, 1024 - 1, f) != NULL) {
			line[strlen((char *) &line) - 1] = '\0';
			i++;
			
			if (strlen(line) != 0) {
				// Empty lines, we don't need to process those
				keyvalue = g_strsplit(line, "=", 2);
				// This will return at least 1 element, at most 2, we need 2
				if (strncmp(keyvalue[0], "#", 1) != 0) {
					// Commented lines, well ignore them too
					if (keyvalue[1] != NULL) {
						gm_debug_msg(DEBUG_DEFAULT, 
								"GmOptions.check_old_options: converting %s, %s", 
								keyvalue[0], keyvalue[1]);
						gm_options_save_option(keyvalue[0], keyvalue[1], root);
					} else {
						gm_debug_msg(DEBUG_DEFAULT, "GmOptions.load: wrong "
								"syntax of options line in %s line %d", 
								filename, i);
					}
				}
				
				g_strfreev(keyvalue);
			}
		}

		fclose(f);
	} else {
		gm_debug_msg(DEBUG_DEFAULT, "GmOptions.check_old_options: could not "
				"retrieve contents of file %s (%s)", filename, strerror(errno));
	}

	xmlSaveFormatFileEnc(xmlname, doc, "UTF-8", 1);
	xmlFreeDoc(doc);

	if (g_file_test(xmlname, G_FILE_TEST_EXISTS)) {
		// Make sure to make this only readable for the user and the group
		chmod(xmlname, 0660);
		unlink(filename);
	}
	
	g_free(filename);
}