#include <blue/core/stringstream.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define DEFAULT_CAPACITY 15

/*** PRIVATE DATA *************************************************************/

struct b_stringstream_p {
	char *ss_buf;
	size_t ss_len;
	size_t ss_max;
	unsigned char ss_alloc;
};

/*** PRIVATE FUNCTIONS ********************************************************/

static enum b_status __puts(
	struct b_stringstream_p *ss, const char *s, size_t len, size_t *nr_written)
{
	size_t available = ss->ss_max - ss->ss_len;
	size_t to_copy = len;

	if (to_copy > available && ss->ss_alloc == 1) {
		char *new_buf = realloc(ss->ss_buf, ss->ss_len + to_copy + 1);
		if (!new_buf) {
			return B_ERR_NO_MEMORY;
		}

		ss->ss_buf = new_buf;
		ss->ss_max = ss->ss_len + to_copy;
		available = ss->ss_max - ss->ss_len;
	}

	if (available < to_copy) {
		to_copy = available;
	}

	memcpy(ss->ss_buf + ss->ss_len, s, to_copy);

	/* increment the length by the full string length, even if only a
	 * portion was copied */
	ss->ss_len += len;

	if (nr_written) {
		*nr_written = to_copy;
	}

	return B_SUCCESS;
}

static enum b_status stringstream_reset(struct b_stringstream_p *ss)
{
	ss->ss_len = 0;

	if (ss->ss_buf) {
		*ss->ss_buf = 0;
	}

	return B_SUCCESS;
}

static enum b_status stringstream_reset_with_buffer(
	struct b_stringstream_p *ss, char *buf, size_t max)
{
	ss->ss_len = 0;

	if (ss->ss_buf && ss->ss_alloc) {
		free(ss->ss_buf);
	}

	ss->ss_buf = buf;
	ss->ss_max = max;
	ss->ss_alloc = 0;

	return B_SUCCESS;
}

static size_t stringstream_get_length(const struct b_stringstream_p *strv)
{
	return strv->ss_len;
}

static const char *stringstream_ptr(const struct b_stringstream_p *ss)
{
	return ss->ss_buf;
}

static char *stringstream_steal(struct b_stringstream_p *ss)
{
	char *out = ss->ss_buf;

	memset(ss, 0x0, sizeof *ss);

	ss->ss_alloc = 1;

	return out;
}

/*** PUBLIC FUNCTIONS *********************************************************/

b_stringstream *b_stringstream_create_with_buffer(char *buf, size_t max)
{
	b_stringstream *s = b_object_create(B_TYPE_STRINGSTREAM);
	if (!s) {
		return NULL;
	}

	b_stream_cfg *cfg = b_object_get_protected(s, B_TYPE_STREAM);
	struct b_stringstream_p *p = b_object_get_private(s, B_TYPE_STRINGSTREAM);

	cfg->s_mode = B_STREAM_WRITE | Z__B_STREAM_STATIC;

	p->ss_buf = buf;
	p->ss_max = max;
	p->ss_len = 0;
	p->ss_alloc = 0;

	return s;
}

b_stringstream *b_stringstream_create(void)
{
	b_stringstream *s = b_object_create(B_TYPE_STRINGSTREAM);
	if (!s) {
		return NULL;
	}

	b_stream_cfg *cfg = b_object_get_protected(s, B_TYPE_STREAM);
	struct b_stringstream_p *p = b_object_get_private(s, B_TYPE_STRINGSTREAM);

	cfg->s_mode = B_STREAM_WRITE | Z__B_STREAM_STATIC;

	p->ss_buf = malloc(DEFAULT_CAPACITY + 1);
	if (!p->ss_buf) {
		b_stringstream_unref(s);
		return NULL;
	}

	memset(p->ss_buf, 0x0, DEFAULT_CAPACITY + 1);
	p->ss_max = DEFAULT_CAPACITY;
	p->ss_len = 0;
	p->ss_alloc = 1;

	return s;
}

size_t b_stringstream_get_length(const b_stringstream *strv)
{
	B_CLASS_DISPATCH_STATIC_0(
		B_TYPE_STRINGSTREAM, stringstream_get_length, strv);
}

enum b_status b_stringstream_reset(b_stringstream *strv)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_STRINGSTREAM, stringstream_reset, strv);
}

enum b_status b_stringstream_reset_with_buffer(
	b_stringstream *strv, char *buf, size_t max)
{
	B_CLASS_DISPATCH_STATIC(
		B_TYPE_STRINGSTREAM, stringstream_reset_with_buffer, strv, buf,
		max);
}

const char *b_stringstream_ptr(const b_stringstream *ss)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_STRINGSTREAM, stringstream_ptr, ss);
}

char *b_stringstream_steal(b_stringstream *ss)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_STRINGSTREAM, stringstream_steal, ss);
}

/*** PUBLIC ALIAS FUNCTIONS ***************************************************/
/*** VIRTUAL FUNCTIONS ********************************************************/

static void stringstream_init(b_object *obj, void *priv)
{
	struct b_stringstream_p *stream = priv;
}

static void stringstream_fini(b_object *obj, void *priv)
{
	struct b_stringstream_p *stream = priv;

	if (stream->ss_alloc && stream->ss_buf) {
		free(stream->ss_buf);
	}
}

enum b_status stream_write(
	b_stream *stream, const void *buf, size_t count, size_t *nr_written)
{
	struct b_stringstream_p *s
		= b_object_get_private(stream, B_TYPE_STRINGSTREAM);

	enum b_status status = __puts(s, (const char *)buf, count, nr_written);

	return status;
}

/*** CLASS DEFINITION *********************************************************/

B_TYPE_CLASS_DEFINITION_BEGIN(b_stringstream)
	B_TYPE_CLASS_INTERFACE_BEGIN(b_object, B_TYPE_OBJECT)
		B_INTERFACE_ENTRY(to_string) = NULL;
	B_TYPE_CLASS_INTERFACE_END(b_object, B_TYPE_OBJECT)

	B_TYPE_CLASS_INTERFACE_BEGIN(b_stream, B_TYPE_STREAM)
		B_INTERFACE_ENTRY(s_close) = NULL;
		B_INTERFACE_ENTRY(s_seek) = NULL;
		B_INTERFACE_ENTRY(s_tell) = NULL;
		B_INTERFACE_ENTRY(s_getc) = NULL;
		B_INTERFACE_ENTRY(s_read) = NULL;
		B_INTERFACE_ENTRY(s_write) = stream_write;
		B_INTERFACE_ENTRY(s_reserve) = NULL;
	B_TYPE_CLASS_INTERFACE_END(b_stream, B_TYPE_STREAM)
B_TYPE_CLASS_DEFINITION_END(b_stringstream)

B_TYPE_DEFINITION_BEGIN(b_stringstream)
	B_TYPE_ID(0x508a609a, 0xfac5, 0x4d31, 0x843a, 0x44b68ad329f3);
	B_TYPE_EXTENDS(B_TYPE_STREAM);
	B_TYPE_CLASS(b_stringstream_class);
	B_TYPE_INSTANCE_PRIVATE(struct b_stringstream_p);
	B_TYPE_INSTANCE_INIT(stringstream_init);
	B_TYPE_INSTANCE_FINI(stringstream_fini);
B_TYPE_DEFINITION_END(b_stringstream)