/*
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Author: Michael Wallner <mike@php.net>                               |
   +----------------------------------------------------------------------+
*/

#ifndef PHP_OUTPUT_H
#define PHP_OUTPUT_H

#define PHP_OUTPUT_NEWAPI 1

/* handler ops */
#define PHP_OUTPUT_HANDLER_WRITE	0x00	/* standard passthru */
#define PHP_OUTPUT_HANDLER_START	0x01	/* start */
#define PHP_OUTPUT_HANDLER_CLEAN	0x02	/* restart */
#define PHP_OUTPUT_HANDLER_FLUSH	0x04	/* pass along as much as possible */
#define PHP_OUTPUT_HANDLER_FINAL	0x08	/* finalize */
#define PHP_OUTPUT_HANDLER_CONT		PHP_OUTPUT_HANDLER_WRITE
#define PHP_OUTPUT_HANDLER_END		PHP_OUTPUT_HANDLER_FINAL

/* handler types */
#define PHP_OUTPUT_HANDLER_INTERNAL		0x0000
#define PHP_OUTPUT_HANDLER_USER			0x0001

/* handler ability flags */
#define PHP_OUTPUT_HANDLER_CLEANABLE	0x0010
#define PHP_OUTPUT_HANDLER_FLUSHABLE	0x0020
#define PHP_OUTPUT_HANDLER_REMOVABLE	0x0040
#define PHP_OUTPUT_HANDLER_STDFLAGS		0x0070

/* handler status flags */
#define PHP_OUTPUT_HANDLER_STARTED		0x1000
#define PHP_OUTPUT_HANDLER_DISABLED		0x2000
#define PHP_OUTPUT_HANDLER_PROCESSED	0x4000
#define PHP_OUTPUT_HANDLER_PRODUCED_OUTPUT 0x8000

#define PHP_OUTPUT_HANDLER_ABILITY_FLAGS(bitmask) ((bitmask) & ~0xf00f)

/* handler op return values */
typedef enum _php_output_handler_status_t {
	PHP_OUTPUT_HANDLER_FAILURE,
	PHP_OUTPUT_HANDLER_SUCCESS,
	PHP_OUTPUT_HANDLER_NO_DATA
} php_output_handler_status_t;

/* php_output_stack_pop() flags */
#define PHP_OUTPUT_POP_TRY			0x000
#define PHP_OUTPUT_POP_FORCE		0x001
#define PHP_OUTPUT_POP_DISCARD		0x010
#define PHP_OUTPUT_POP_SILENT		0x100

/* real global flags */
#define PHP_OUTPUT_IMPLICITFLUSH		0x01
#define PHP_OUTPUT_DISABLED				0x02
#define PHP_OUTPUT_WRITTEN				0x04
#define PHP_OUTPUT_SENT					0x08
/* supplementary flags for php_output_get_status() */
#define PHP_OUTPUT_ACTIVE				0x10
#define PHP_OUTPUT_LOCKED				0x20
/* output layer is ready to use */
#define PHP_OUTPUT_ACTIVATED		0x100000

/* handler hooks */
typedef enum _php_output_handler_hook_t {
	PHP_OUTPUT_HANDLER_HOOK_GET_OPAQ,
	PHP_OUTPUT_HANDLER_HOOK_GET_FLAGS,
	PHP_OUTPUT_HANDLER_HOOK_GET_LEVEL,
	PHP_OUTPUT_HANDLER_HOOK_IMMUTABLE,
	PHP_OUTPUT_HANDLER_HOOK_DISABLE,
	/* unused */
	PHP_OUTPUT_HANDLER_HOOK_LAST
} php_output_handler_hook_t;

#define PHP_OUTPUT_HANDLER_INITBUF_SIZE(s) \
( ((s) > 0) ? \
	ZEND_MM_ALIGNED_SIZE_EX(s, PHP_OUTPUT_HANDLER_ALIGNTO_SIZE) : \
	PHP_OUTPUT_HANDLER_DEFAULT_SIZE \
)
#define PHP_OUTPUT_HANDLER_ALIGNTO_SIZE		0x1000
#define PHP_OUTPUT_HANDLER_DEFAULT_SIZE		0x4000

typedef struct _php_output_buffer {
	char *data;
	size_t size;
	size_t used;
	uint32_t free:1;
	uint32_t _reserved:31;
} php_output_buffer;

typedef struct _php_output_context {
	int op;
	php_output_buffer in;
	php_output_buffer out;
} php_output_context;

/* old-style, stateless callback */
typedef void (*php_output_handler_func_t)(char *output, size_t output_len, char **handled_output, size_t *handled_output_len, int mode);
/* new-style, opaque context callback */
typedef zend_result (*php_output_handler_context_func_t)(void **handler_context, php_output_context *output_context);
/* output handler context dtor */
typedef void (*php_output_handler_context_dtor_t)(void *opaq);
/* conflict check callback */
typedef zend_result (*php_output_handler_conflict_check_t)(const char *handler_name, size_t handler_name_len);
/* ctor for aliases */
typedef struct _php_output_handler *(*php_output_handler_alias_ctor_t)(const char *handler_name, size_t handler_name_len, size_t chunk_size, int flags);

typedef struct _php_output_handler {
	zend_string *name;
	int flags;
	int level;
	size_t size;
	php_output_buffer buffer;

	void *opaq;
	void (*dtor)(void *opaq);

	union {
		zend_fcall_info_cache *user_fcc;
		php_output_handler_context_func_t internal;
	} func;
} php_output_handler;

ZEND_BEGIN_MODULE_GLOBALS(output)
	zend_stack handlers;
	php_output_handler *active;
	php_output_handler *running;
	zend_string *output_start_filename;
	int output_start_lineno;
	int flags;
ZEND_END_MODULE_GLOBALS(output)

PHPAPI ZEND_EXTERN_MODULE_GLOBALS(output)

/* there should not be a need to use OG() from outside of output.c */
#ifdef ZTS
# define OG(v) ZEND_TSRMG(output_globals_id, zend_output_globals *, v)
#else
# define OG(v) (output_globals.v)
#endif

/* convenience macros */
#define PHPWRITE(str, str_len)		php_output_write((str), (str_len))
#define PHPWRITE_H(str, str_len)	php_output_write_unbuffered((str), (str_len))

#define PUTC(c)						php_output_write((const char *) &(c), 1)
#define PUTC_H(c)					php_output_write_unbuffered((const char *) &(c), 1)

#define PUTS(str)					do {				\
	const char *__str = (str);							\
	php_output_write(__str, strlen(__str));	\
} while (0)
#define PUTS_H(str)					do {							\
	const char *__str = (str);										\
	php_output_write_unbuffered(__str, strlen(__str));	\
} while (0)


BEGIN_EXTERN_C()

extern const char php_output_default_handler_name[sizeof("default output handler")];
extern const char php_output_devnull_handler_name[sizeof("null output handler")];

#define php_output_tearup() \
	php_output_startup(); \
	php_output_activate()
#define php_output_teardown() \
	php_output_end_all(); \
	php_output_deactivate(); \
	php_output_shutdown()

/* MINIT */
PHPAPI void php_output_startup(void);
/* MSHUTDOWN */
PHPAPI void php_output_shutdown(void);

/* RINIT */
PHPAPI int php_output_activate(void);
/* RSHUTDOWN */
PHPAPI void php_output_deactivate(void);

PHPAPI void php_output_set_status(int status);
PHPAPI int php_output_get_status(void);
PHPAPI void php_output_set_implicit_flush(int flush);
PHPAPI const char *php_output_get_start_filename(void);
PHPAPI int php_output_get_start_lineno(void);

PHPAPI size_t php_output_write_unbuffered(const char *str, size_t len);
PHPAPI size_t php_output_write(const char *str, size_t len);

PHPAPI zend_result php_output_flush(void);
PHPAPI void php_output_flush_all(void);
PHPAPI zend_result php_output_clean(void);
PHPAPI void php_output_clean_all(void);
PHPAPI zend_result php_output_end(void);
PHPAPI void php_output_end_all(void);
PHPAPI zend_result php_output_discard(void);
PHPAPI void php_output_discard_all(void);

PHPAPI zend_result php_output_get_contents(zval *p);
PHPAPI zend_result php_output_get_length(zval *p);
PHPAPI int php_output_get_level(void);
PHPAPI php_output_handler* php_output_get_active_handler(void);

PHPAPI zend_result php_output_start_default(void);
PHPAPI zend_result php_output_start_devnull(void);

PHPAPI zend_result php_output_start_user(zval *output_handler, size_t chunk_size, int flags);
PHPAPI zend_result php_output_start_internal(const char *name, size_t name_len, php_output_handler_func_t output_handler, size_t chunk_size, int flags);

PHPAPI php_output_handler *php_output_handler_create_user(zval *handler, size_t chunk_size, int flags);
PHPAPI php_output_handler *php_output_handler_create_internal(const char *name, size_t name_len, php_output_handler_context_func_t handler, size_t chunk_size, int flags);

PHPAPI void php_output_handler_set_context(php_output_handler *handler, void *opaq, void (*dtor)(void*));
PHPAPI zend_result php_output_handler_start(php_output_handler *handler);
PHPAPI bool php_output_handler_started(const char *name, size_t name_len);
PHPAPI zend_result php_output_handler_hook(php_output_handler_hook_t type, void *arg);
PHPAPI void php_output_handler_dtor(php_output_handler *handler);
PHPAPI void php_output_handler_free(php_output_handler **handler);

PHPAPI bool php_output_handler_conflict(const char *handler_new, size_t handler_new_len, const char *handler_set, size_t handler_set_len);
PHPAPI zend_result php_output_handler_conflict_register(const char *handler_name, size_t handler_name_len, php_output_handler_conflict_check_t check_func);
PHPAPI zend_result php_output_handler_reverse_conflict_register(const char *handler_name, size_t handler_name_len, php_output_handler_conflict_check_t check_func);

PHPAPI php_output_handler_alias_ctor_t php_output_handler_alias(const char *handler_name, size_t handler_name_len);
PHPAPI zend_result php_output_handler_alias_register(const char *handler_name, size_t handler_name_len, php_output_handler_alias_ctor_t func);

END_EXTERN_C()

#endif
