/*
 * Copyright (c) 2005-2007 Tilman Sauerbeck (tilman at code-monkey de)
 *
 * 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.
 */

#include <Eet.h>
#include <ruby.h>
#include <st.h>
#include <locale.h>

#define CHECK_KEY(key) \
	if (rb_funcall (key, id_include, 1, INT2FIX (0)) == Qtrue) \
		rb_raise (rb_eArgError, "key must not contain binary zeroes");

#define CHECK_CLOSED(ef) \
	if (!*(ef)) \
		rb_raise (rb_eIOError, "closed stream");

#define CHECK_READABLE(ef) \
	switch (eet_mode_get (*ef)) { \
		case EET_FILE_MODE_READ: \
		case EET_FILE_MODE_READ_WRITE: \
			break; \
		default: \
			rb_raise (rb_eIOError, "permission denied"); \
	}

#ifdef WORDS_BIGENDIAN
# define BSWAP32(x) \
	((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
	(((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
#else /* !WORDS_BIGENDIAN */
# define BSWAP32(x) (x)
#endif /* WORDS_BIGENDIAN */

static VALUE c_close (VALUE self);

static VALUE cStream, cChunk,
             eEetError, eNameError, ePropError,
             sym_lossy, sym_level, sym_quality, sym_char, sym_short,
             sym_long_long, sym_double;
static ID id_include, id_to_s, id_keys, id_pack,
          id_to_eet_chunks, id_to_eet_name, id_to_eet_properties,
          id_tag, id_data;

static void
c_free (Eet_File **ef)
{
	if (*ef) {
		eet_close (*ef);
		*ef = NULL;

		eet_shutdown ();
	}

	free (ef);
}

static VALUE
c_alloc (VALUE klass)
{
	Eet_File **ef = NULL;

	return Data_Make_Struct (klass, Eet_File *, NULL, c_free, ef);
}

/*
 * call-seq:
 *  Eet::File.open(file [, mode] )                -> ef or nil
 *  Eet::File.open(file [, mode] ) { |ef| block } -> nil
 *
 * If a block isn't specified, Eet::File.open is a synonym for
 * Eet::File.new.
 * If a block is given, it will be invoked with the
 * Eet::File object as a parameter, and the file will be
 * automatically closed when the block terminates. The call always
 * returns +nil+ in this case.
 */
static VALUE
c_open (int argc, VALUE *argv, VALUE klass)
{
	VALUE obj = rb_class_new_instance (argc, argv, klass);

	if (rb_block_given_p ())
		return rb_ensure (rb_yield, obj, c_close, obj);
	else
		return obj;
}

/*
 * call-seq:
 *  Eet::File.new(file [, mode] ) -> ef or nil
 *
 * Creates an Eet::File object for _file_.
 *
 * _file_ is opened with the specified mode (defaulting to "r").
 * Possible values for _mode_ are "r" for read-only access,
 * "w" for write-only access and "r+" for read/write access.
 */
static VALUE
c_init (int argc, VALUE *argv, VALUE self)
{
	VALUE file = Qnil, mode = Qnil;
	Eet_File **ef = NULL;
	Eet_File_Mode m = EET_FILE_MODE_READ;
	const char *tmp, *cfile;

	Data_Get_Struct (self, Eet_File *, ef);

	rb_scan_args (argc, argv, "11", &file, &mode);

	cfile = StringValuePtr (file);

	if (!NIL_P (mode)) {
		tmp = StringValuePtr (mode);
		if (!strcmp (tmp, "r+"))
			m = EET_FILE_MODE_READ_WRITE;
		else if (!strcmp (tmp, "w"))
			m = EET_FILE_MODE_WRITE;
		else if (strcmp (tmp, "r"))
			rb_raise (rb_eArgError, "illegal access mode %s", tmp);
	}

	eet_init ();

	*ef = eet_open (cfile, m);
	if (!*ef) {
		switch (m) {
			case EET_FILE_MODE_READ_WRITE:
			case EET_FILE_MODE_WRITE:
				tmp = "Permission denied - %s";
				break;
			default:
				tmp = "File not found - %s";
				break;
		}

		rb_raise (rb_eRuntimeError, tmp, cfile);
	}

	return self;
}

/*
 * call-seq:
 *  ef.close -> ef
 *
 * Closes _ef_ and flushes any pending writes.
 * _ef_ is unavailable for any further data operations;
 * an +IOError+ is raised if such an attempt is made.
 *
 * Eet::File objects are automatically closed when they
 * are claimed by the garbage collector.
 */
static VALUE
c_close (VALUE self)
{
	Eet_File **ef = NULL;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	eet_close (*ef);
	*ef = NULL;

	eet_shutdown ();

	return self;
}

static VALUE
get_keys (Eet_File *ef, const char *glob)
{
	VALUE ret;
	char **keys;
	int i, count = 0;

	keys = eet_list (ef, glob, &count);
	ret = rb_ary_new2 (count);

	for (i = 0; i < count; i++)
		rb_ary_store (ret, i, rb_str_new2 (keys[i]));

	free (keys);

	return ret;
}

/*
 * call-seq:
 *  ef.entries -> array
 *
 * Returns an Array with the keys of the entries in _ef_.
 * If the keys cannot be retrieved, an +IOError+ is raised.
 */
static VALUE
c_entries (VALUE self)
{
	Eet_File **ef = NULL;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);
	CHECK_READABLE (ef);

	return get_keys (*ef, "*");
}

/*
 * call-seq:
 *  ef[glob] -> array
 *
 * Returns an Array with the keys of entries in _ef_ that match the
 * shell glob _glob_.
 * If the keys cannot be retrieved, an +IOError+ is raised.
 */
static VALUE
c_glob (VALUE self, VALUE glob)
{
	Eet_File **ef = NULL;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);
	CHECK_READABLE (ef);

	return get_keys (*ef, StringValuePtr (glob));
}

/*
 * call-seq:
 *  ef.delete(key) -> ef
 *
 * Deletes the entry from _ef_ that is stored as _key_.
 * If the entry cannot be deleted, an +IOError+ is raised,
 * otherwise _ef_ is returned.
 */
static VALUE
c_delete (VALUE self, VALUE key)
{
	Eet_File **ef = NULL;
	char *ckey;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	ckey = StringValuePtr (key);
	CHECK_KEY (key);

	if (!eet_delete (*ef, ckey))
		rb_raise (rb_eIOError, "cannot delete entry - %s", ckey);

	return self;
}

/*
 * call-seq:
 *  ef.read(key) -> string
 *
 * Reads an entry from _ef_ that is stored as _key_.
 * If the data cannot be read, an +IOError+ is raised,
 * otherwise a String is returned that contains the data.
 */
static VALUE
c_read (VALUE self, VALUE key)
{
	VALUE ret;
	Eet_File **ef = NULL;
	void *data;
	char *ckey;
	int size = 0;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	ckey = StringValuePtr (key);
	CHECK_KEY (key);

	data = eet_read (*ef, ckey, &size);
	if (!data)
		rb_raise (rb_eIOError, "cannot read entry - %s", ckey);

	ret = rb_str_new (data, size);

	free (data);

	return ret;
}

/*
 * call-seq:
 *  ef.write(key, data [, compress] ) -> integer
 *
 * Stores _data_ in _ef_ as _key_.
 * If _compress_ is true (which is the default), the data will be
 * compressed.
 * If the data cannot be written, an +IOError+ is raised,
 * otherwise a the number of bytes written is returned.
 */
static VALUE
c_write (int argc, VALUE *argv, VALUE self)
{
	VALUE key = Qnil, buf = Qnil, comp = Qnil;
	Eet_File **ef = NULL;
	char *ckey, *cbuf;
	int n;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	rb_scan_args (argc, argv, "21", &key, &buf, &comp);

	if (NIL_P (comp))
		comp = Qtrue;

	ckey = StringValuePtr (key);
	CHECK_KEY (key);
	cbuf = StringValuePtr (buf);

	n = eet_write (*ef, ckey,
	               cbuf, RSTRING (buf)->len,
	               comp == Qtrue);
	if (!n)
		rb_raise (rb_eIOError, "couldn't write to file");
	else
		return INT2FIX (n);
}

/*
 * call-seq:
 *  ef.read_image(key) -> array
 *
 * Reads an image entry from _ef_ that is stored as _key_.
 * If the data cannot be read, an +IOError+ is raised,
 * otherwise an Array is returned that contains the image data,
 * the image width, the image height, a boolean that indicates
 * whether the image has an alpha channel or not and a hash
 * that contains the compression options that were used to store
 * the image (see Eet::File#write_image).
 */
static VALUE
c_read_image (VALUE self, VALUE key)
{
	VALUE ret, comp;
	Eet_File **ef = NULL;
	void *data;
	char *ckey;
	unsigned int w = 0, h = 0;
	int has_alpha = 0, level = 0, quality = 0, lossy = 0;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	ckey = StringValuePtr (key);
	CHECK_KEY (key);

	data = eet_data_image_read (*ef, ckey, &w, &h,
	                            &has_alpha, &level, &quality,
	                            &lossy);
	if (!data)
		rb_raise (rb_eIOError, "cannot read entry - %s", ckey);

	comp = rb_hash_new ();
	rb_hash_aset (comp, sym_lossy, INT2FIX (lossy));
	rb_hash_aset (comp, sym_level, INT2FIX (level));
	rb_hash_aset (comp, sym_quality, INT2FIX (quality));

	ret = rb_ary_new3 (5, rb_str_new (data, w * h * 4),
		               INT2FIX (w), INT2FIX (h),
		               has_alpha ? Qtrue : Qfalse, comp);
	free (data);

	return ret;
}

/*
 * call-seq:
 *  ef.write_image(key, image_data, w, h [, alpha] [, comp] ) -> integer
 *
 * Stores _image_data_ with width _w_ and height _h_ in _ef_ as _key_.
 * Pass true for _alpha_ if the image contains an alpha channel.
 * You can control how the image is compressed by passing _comp_, which
 * is a hash whose :lossy entry is true if the image should be
 * compressed lossily. If :lossy is true, the :quality entry
 * (0-100, default 100) sets the compression quality.
 * If :lossy is false, the :level entry (0-9, default 9) sets the
 * compression level. If _comp_ isn't passed, then the
 * image is stored losslessly.
 * If the data cannot be written, an +IOError+ is raised,
 * otherwise a the number of bytes written is returned.
 */
static VALUE
c_write_image (int argc, VALUE *argv, VALUE self)
{
	VALUE key = Qnil, buf = Qnil, w = Qnil, h = Qnil, has_alpha = Qnil;
	VALUE comp = Qnil, tmp;
	Eet_File **ef = NULL;
	char *ckey, *cbuf;
	int n, lossy = 0, level = 9, quality = 100;

	Data_Get_Struct (self, Eet_File *, ef);
	CHECK_CLOSED (ef);

	rb_scan_args (argc, argv, "42", &key, &buf, &w, &h, &has_alpha,
	              &comp);

	if (NIL_P (has_alpha))
		has_alpha = Qfalse;

	ckey = StringValuePtr (key);
	CHECK_KEY (key);
	cbuf = StringValuePtr (buf);
	Check_Type (w, T_FIXNUM);
	Check_Type (h, T_FIXNUM);

	if (!NIL_P (comp)) {
		Check_Type (comp, T_HASH);

		tmp = rb_hash_aref (comp, sym_lossy);
		if (!NIL_P (tmp))
			lossy = FIX2INT (tmp);

		tmp = rb_hash_aref (comp, sym_level);
		if (!NIL_P (tmp))
			level = FIX2INT (tmp);

		tmp = rb_hash_aref (comp, sym_quality);
		if (!NIL_P (tmp))
			quality = FIX2INT (tmp);
	}

	if (!RSTRING (buf)->len)
		return INT2FIX (0);

	n = eet_data_image_write (*ef, ckey, cbuf,
	                          FIX2INT (w), FIX2INT (h),
	                          has_alpha == Qtrue,
	                          level, quality, lossy);
	if (!n)
		rb_raise (rb_eIOError, "couldn't write to file");
	else
		return INT2FIX (n);
}

static VALUE
chunk_init (VALUE self, VALUE tag, VALUE data)
{
	long tag_len, data_len, tmp;

	StringValue (tag);
	StringValue (data);

	if (rb_funcall (tag, id_include, 1, INT2FIX (0)) == Qtrue)
		rb_raise (rb_eArgError, "tag must not contain binary zeroes");

	/* libeet uses a signed 32bit integer to store the
	 * chunk size, so make sure we don't overflow it
	 */
	tag_len = RSTRING (tag)->len;
	data_len = RSTRING (data)->len;
	tmp = tag_len + 1 + data_len;

	if (tmp < tag_len || tmp < data_len || tmp < 1 || tmp >= 2147483647L)
		rb_raise (rb_eArgError, "tag or data too long");

	rb_ivar_set (self, id_tag, rb_str_dup_frozen (tag));
	rb_ivar_set (self, id_data, rb_str_dup_frozen (data));

	return self;
}

static VALUE
chunk_to_s (VALUE self)
{
	VALUE tmp, ret;
	unsigned int size, buf_len;
	unsigned char *buf;
	struct RString *tag, *data;

	tmp = rb_ivar_get (self, id_tag);
	tag = RSTRING (tmp);

	tmp = rb_ivar_get (self, id_data);
	data = RSTRING (tmp);

	buf_len = 9 + tag->len + data->len;
	ret = rb_str_buf_new (buf_len);

	buf = (unsigned char *) RSTRING (ret)->ptr;
	RSTRING (ret)->len = buf_len;

	memcpy (buf, "CHnK", 4);
	buf += 4;

	size = tag->len + data->len + 1;
	size = BSWAP32 (size);
	memcpy (buf, &size, 4);
	buf += 4;

	memcpy (buf, tag->ptr, tag->len);
	buf += tag->len;

	*buf++ = 0;

	memcpy (buf, data->ptr, data->len);

	return ret;
}

static int
for_each_prop (VALUE tag, VALUE arg, VALUE stream)
{
	VALUE value, type, tmp;

	if (rb_obj_is_kind_of (arg, rb_cArray) == Qfalse)
		rb_raise (ePropError, "hash value is not an array");

	value = rb_ary_entry (arg, 0);
	if (NIL_P (value))
		return ST_CONTINUE;

	type = rb_ary_entry (arg, 1);
	tmp = rb_funcall (value, id_to_eet_chunks, 2, tag, type);

	rb_ary_concat (stream, tmp);

	return ST_CONTINUE;
}

/*
 * call-seq:
 *  object.to_eet -> string
 *
 * Serializes the receiver to EET format.
 */
static VALUE
c_to_eet (VALUE self)
{
	VALUE props, name, stream, chunk, args[2];
#ifndef HAVE_RB_HASH_FOREACH
	struct RArray *keys;
	long i;
#endif

	props = rb_funcall (self, id_to_eet_properties, 0);

	if (rb_obj_is_kind_of (props, rb_cHash) == Qfalse ||
	    !RHASH (props)->tbl->num_entries)
		rb_raise (ePropError, "invalid EET properties");

	name = rb_funcall (self, id_to_eet_name, 0);
	StringValue (name);

	if (!RSTRING (name)->len ||
	    rb_funcall (name, id_include, 1, INT2FIX (0)))
		rb_raise (eNameError, "invalid EET name");

	stream = rb_class_new_instance (0, NULL, cStream);

#ifdef HAVE_RB_HASH_FOREACH
	rb_hash_foreach (props, for_each_prop, stream);
#else
	keys = RARRAY (rb_funcall (props, id_keys, 0));

	for (i = 0; i < keys->len; i++)
		for_each_prop (keys->ptr[i],
		               rb_hash_aref (props, keys->ptr[i]),
		               stream);
#endif

	args[0] = name;
	args[1] = rb_ary_to_s (stream);

	rb_ary_clear (stream); /* give the GC a hand... */

	chunk = rb_class_new_instance (2, args, cChunk);

	return rb_funcall (chunk, id_to_s, 0);
}

static VALUE
int_to_eet_chunks (int argc, VALUE *argv, VALUE self)
{
	VALUE tag, type = Qnil, ary, args[2], chunk;
	const char *cfmt = "V";

	rb_scan_args (argc, argv, "11", &tag, &type);

	ary = rb_ary_new3 (1, self);

	if (type == sym_char)
		cfmt = "c";
	else if (type == sym_short)
		cfmt = "v";
	else if (type == sym_long_long)
		cfmt = "q";

	args[0] = tag;
	args[1] = rb_funcall (ary, id_pack, 1, rb_str_new2 (cfmt));
	chunk = rb_class_new_instance (2, args, cChunk);

	return rb_ary_new3 (1, chunk);
}

static VALUE
float_to_eet_chunks (int argc, VALUE *argv, VALUE self)
{
	VALUE tag, type = Qnil, args[2], chunk;
	char buf[65], *loc;
	double d;
	int len;

	rb_scan_args (argc, argv, "11", &tag, &type);

	d = NUM2DBL (self);

	/* switch locale to make sure we get proper snprintf output */
	loc = setlocale (LC_NUMERIC, "C");

	len = snprintf (buf, sizeof (buf) - 1, "%a",
	                type == sym_double ? d : (float) d);

	if (loc)
		setlocale (LC_NUMERIC, loc);

	buf[++len] = '\0';

	args[0] = tag;
	args[1] = rb_str_new (buf, len);
	chunk = rb_class_new_instance (2, args, cChunk);

	return rb_ary_new3 (1, chunk);
}

void
Init_eet_ext ()
{
	VALUE m, c;

	m = rb_define_module ("Eet");

	c = rb_define_class_under (m, "File", rb_cObject);
	rb_define_alloc_func (c, c_alloc);
	rb_define_singleton_method (c, "open", c_open, -1);
	rb_define_method (c, "initialize", c_init, -1);
	rb_define_method (c, "close", c_close, 0);
	rb_define_method (c, "entries", c_entries, 0);
	rb_define_method (c, "[]", c_glob, 1);
	rb_define_method (c, "delete", c_delete, 1);
	rb_define_method (c, "read", c_read, 1);
	rb_define_method (c, "write", c_write, -1);
	rb_define_method (c, "read_image", c_read_image, 1);
	rb_define_method (c, "write_image", c_write_image, -1);

	cStream = rb_define_class_under (m, "Stream", rb_cArray);

	cChunk = rb_define_class_under (m, "Chunk", rb_cObject);
	rb_define_method (cChunk, "initialize", chunk_init, 2);
	rb_define_method (cChunk, "to_s", chunk_to_s, 0);

	rb_define_attr (cChunk, "tag", 1, 0);
	rb_define_attr (cChunk, "data", 1, 0);

	rb_define_method (rb_cObject, "to_eet", c_to_eet, 0);

	rb_define_method (rb_cInteger, "to_eet_chunks", int_to_eet_chunks, -1);
	rb_define_method (rb_cFloat, "to_eet_chunks", float_to_eet_chunks, -1);

	eEetError = rb_define_class_under (m, "EetError", rb_eStandardError);
	eNameError = rb_define_class_under (m, "NameError", eEetError);
	ePropError = rb_define_class_under (m, "PropertyError", eEetError);

	id_include = rb_intern ("include?");
	id_to_s = rb_intern ("to_s");
	id_keys = rb_intern ("keys");
	id_pack = rb_intern ("pack");
	id_to_eet_chunks = rb_intern ("to_eet_chunks");
	id_to_eet_name = rb_intern ("to_eet_name");
	id_to_eet_properties = rb_intern ("to_eet_properties");
	id_tag = rb_intern ("@tag");
	id_data = rb_intern ("@data");
	sym_lossy = ID2SYM (rb_intern ("lossy"));
	sym_level = ID2SYM (rb_intern ("level"));
	sym_quality =  ID2SYM (rb_intern ("quality"));
	sym_char = ID2SYM (rb_intern ("char"));
	sym_short = ID2SYM (rb_intern ("short"));
	sym_long_long = ID2SYM (rb_intern ("long_long"));
	sym_double = ID2SYM (rb_intern ("double"));
}