/*
 * Copyright (c) 2003-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
 * Redistribution and modifications are permitted subject to BSD license.
 */
/*
 * This file contains the declaration structure called "ASN.1 Type Definition",
 * which holds all information necessary for encoding and decoding routines.
 * This structure even contains pointer to these encoding and decoding routines
 * for each defined ASN.1 type.
 */
#ifndef	_CONSTR_TYPE_H_
#define	_CONSTR_TYPE_H_

#include <osmocom/tcap/ber_tlv_length.h>
#include <osmocom/tcap/ber_tlv_tag.h>

#ifdef __cplusplus
extern "C" {
#endif

struct asn_TYPE_descriptor_s;	/* Forward declaration */
struct asn_TYPE_member_s;	/* Forward declaration */

/*
 * This type provides the context information for various ASN.1 routines,
 * primarily ones doing decoding. A member _asn_ctx of this type must be
 * included into certain target language's structures, such as compound types.
 */
typedef struct asn_struct_ctx_s {
	short phase;		/* Decoding phase */
	short step;		/* Elementary step of a phase */
	int context;		/* Other context information */
	void *ptr;		/* Decoder-specific stuff (stack elements) */
	ber_tlv_len_t left;	/* Number of bytes left, -1 for indefinite */
} asn_struct_ctx_t;

#if !defined(ASN_DISABLE_BER_SUPPORT)
#include <osmocom/tcap/ber_decoder.h>  /* Basic Encoding Rules decoder */
#include <osmocom/tcap/der_encoder.h>  /* Distinguished Encoding Rules encoder */
#else
typedef void (ber_type_decoder_f)(void);
typedef void (der_type_encoder_f)(void);
#endif  /* !defined(ASN_DISABLE_BER_SUPPORT) */

#if !defined(ASN_DISABLE_XER_SUPPORT)
#include <xer_decoder.h>  /* Decoder of XER (XML, text) */
#include <xer_encoder.h>  /* Encoder into XER (XML, text) */
#else
typedef void (xer_type_decoder_f)(void);
typedef void (xer_type_encoder_f)(void);
#endif  /* !defined(ASN_DISABLE_XER_SUPPORT) */

#if !defined(ASN_DISABLE_JER_SUPPORT)
#include <jer_decoder.h>  /* Decoder of JER (JSON, text) */
#include <jer_encoder.h>  /* Encoder into JER (JSON, text) */
#else
typedef void (jer_type_decoder_f)(void);
typedef void (jer_type_encoder_f)(void);
#endif  /* !defined(ASN_DISABLE_JER_SUPPORT) */

#if !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT)
#include <per_decoder.h>  /* Packet Encoding Rules decoder */
#include <per_encoder.h>  /* Packet Encoding Rules encoder */
#else
typedef void (per_type_decoder_f)(void);
typedef void (per_type_encoder_f)(void);
#endif  /* !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT) */

#include <osmocom/tcap/constraints.h>  /* Subtype constraints support */

#if !defined(ASN_DISABLE_RFILL_SUPPORT)
#include <osmocom/tcap/asn_random_fill.h>  /* Random structures support */
#else
typedef void (asn_random_fill_f)(void);
#endif  /* !defined(ASN_DISABLE_RFILL_SUPPORT) */

#if !defined(ASN_DISABLE_OER_SUPPORT)
#include <oer_decoder.h>  /* Octet Encoding Rules encoder */
#include <oer_encoder.h>  /* Octet Encoding Rules encoder */
#else
typedef void (oer_type_decoder_f)(void);
typedef void (oer_type_encoder_f)(void);
#endif  /* !defined(ASN_DISABLE_OER_SUPPORT) */

/*
 * Free the structure according to its specification.
 * Use one of ASN_STRUCT_{FREE,RESET,CONTENTS_ONLY} macros instead.
 * Do not use directly.
 */
enum asn_struct_free_method {
    ASFM_FREE_EVERYTHING,   /* free(struct_ptr) and underlying members */
    ASFM_FREE_UNDERLYING,   /* free underlying members */
    ASFM_FREE_UNDERLYING_AND_RESET   /* FREE_UNDERLYING + memset(0) */
};
typedef void (asn_struct_free_f)(
		const struct asn_TYPE_descriptor_s *type_descriptor,
		void *struct_ptr, enum asn_struct_free_method);

/*
 * Free the structure including freeing the memory pointed to by ptr itself.
 */
#define ASN_STRUCT_FREE(asn_DEF, ptr) \
    (asn_DEF).op->free_struct(&(asn_DEF), (ptr), ASFM_FREE_EVERYTHING)

/*
 * Free the memory used by the members of the structure without freeing the
 * the structure pointer itself.
 * ZERO-OUT the structure to the safe clean state.
 * (Retaining the pointer may be useful in case the structure is allocated
 *  statically or arranged on the stack, yet its elements are dynamic.)
 */
#define ASN_STRUCT_RESET(asn_DEF, ptr) \
    (asn_DEF).op->free_struct(&(asn_DEF), (ptr), ASFM_FREE_UNDERLYING_AND_RESET)

/*
 * Free memory used by the members of the structure without freeing
 * the structure pointer itself.
 * (Retaining the pointer may be useful in case the structure is allocated
 *  statically or arranged on the stack, yet its elements are dynamic.)
 * AVOID using it in the application code;
 * Use a safer ASN_STRUCT_RESET() instead.
 */
#define ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF, ptr) \
    (asn_DEF).op->free_struct(&(asn_DEF), (ptr), ASFM_FREE_UNDERLYING)

/*
 * Print the structure according to its specification.
 */
typedef int(asn_struct_print_f)(
    const struct asn_TYPE_descriptor_s *type_descriptor,
    const void *struct_ptr,
    int level, /* Indentation level */
    asn_app_consume_bytes_f *callback, void *app_key);

/*
 * Compare two structs between each other.
 * Returns <0 if struct_A is "smaller" than struct_B, >0 if "greater",
 * and =0 if "equal to", for some type-specific, stable definition of
 * "smaller", "greater" and "equal to".
 */
typedef int (asn_struct_compare_f)(
		const struct asn_TYPE_descriptor_s *type_descriptor,
		const void *struct_A,
		const void *struct_B);

/*
 * Copies struct B into struct A.
 * Allocates memory for struct A, if necessary.
 */
typedef int (asn_struct_copy_f)(
		const struct asn_TYPE_descriptor_s *type_descriptor,
		void **struct_A,
		const void *struct_B
        );

/*
 * Return the outmost tag of the type.
 * If the type is untagged CHOICE, the dynamic operation is performed.
 * NOTE: This function pointer type is only useful internally.
 * Do not use it in your application.
 */
typedef ber_tlv_tag_t (asn_outmost_tag_f)(
		const struct asn_TYPE_descriptor_s *type_descriptor,
		const void *struct_ptr, int tag_mode, ber_tlv_tag_t tag);
/* The instance of the above function type; used internally. */
asn_outmost_tag_f asn_TYPE_outmost_tag;

/*
 * Fetch the desired type of the Open Type based on the
 * Information Object Set driven constraints.
 */
typedef struct asn_type_selector_result_s {
    const struct asn_TYPE_descriptor_s *type_descriptor; /* Type encoded. */
    unsigned presence_index; /* Associated choice variant. */
} asn_type_selector_result_t;
typedef asn_type_selector_result_t(asn_type_selector_f)(
    const struct asn_TYPE_descriptor_s *parent_type_descriptor,
    const void *parent_structure_ptr);

/*
 * Generalized functions for dealing with the speciic type.
 * May be directly invoked by applications.
 */
typedef struct asn_TYPE_operation_s {
    asn_struct_free_f *free_struct;     /* Free the structure */
    asn_struct_print_f *print_struct;   /* Human readable output */
    asn_struct_compare_f *compare_struct; /* Compare two structures */
    asn_struct_copy_f *copy_struct;       /* Copy method */
    ber_type_decoder_f *ber_decoder;      /* Generic BER decoder */
    der_type_encoder_f *der_encoder;      /* Canonical DER encoder */
    xer_type_decoder_f *xer_decoder;      /* Generic XER decoder */
    xer_type_encoder_f *xer_encoder;      /* [Canonical] XER encoder */
    jer_type_decoder_f *jer_decoder;      /* Generic JER encoder */
    jer_type_encoder_f *jer_encoder;      /* Generic JER encoder */
    oer_type_decoder_f *oer_decoder;      /* Generic OER decoder */
    oer_type_encoder_f *oer_encoder;      /* Canonical OER encoder */
    per_type_decoder_f *uper_decoder;     /* Unaligned PER decoder */
    per_type_encoder_f *uper_encoder;     /* Unaligned PER encoder */
    per_type_decoder_f *aper_decoder;     /* Aligned PER decoder */
    per_type_encoder_f *aper_encoder;     /* Aligned PER encoder */
    asn_random_fill_f *random_fill;       /* Initialize with a random value */
    asn_outmost_tag_f *outmost_tag;       /* <optional, internal> */
} asn_TYPE_operation_t;

/*
 * A constraints tuple specifying both the OER and PER constraints.
 */
typedef struct asn_encoding_constraints_s {
#if !defined(ASN_DISABLE_OER_SUPPORT)
    const struct asn_oer_constraints_s *oer_constraints;
#endif  /* !defined(ASN_DISABLE_OER_SUPPORT) */
#if !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT)
    const struct asn_per_constraints_s *per_constraints;
#endif  /* !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT) */
#if !defined(ASN_DISABLE_JER_SUPPORT)
    const struct asn_jer_constraints_s *jer_constraints;
#endif  /* !defined(ASN_DISABLE_JER_SUPPORT) */
    asn_constr_check_f *general_constraints;
} asn_encoding_constraints_t;

/*
 * The definitive description of the destination language's structure.
 */
typedef struct asn_TYPE_descriptor_s {
    const char *name;       /* A name of the ASN.1 type. "" in some cases. */
    const char *xml_tag;    /* Name used in XML tag */

    /*
     * Generalized functions for dealing with the specific type.
     * May be directly invoked by applications.
     */
    asn_TYPE_operation_t *op;

    /***********************************************************************
     * Internally useful members. Not to be used by applications directly. *
     **********************************************************************/

    /*
     * Tags that are expected to occur.
     */
    const ber_tlv_tag_t *tags;      /* Effective tags sequence for this type */
    unsigned tags_count;            /* Number of tags which are expected */
    const ber_tlv_tag_t *all_tags;  /* Every tag for BER/containment */
    unsigned all_tags_count;        /* Number of tags */

    /* OER, PER, and general constraints */
    asn_encoding_constraints_t encoding_constraints;

    /*
     * An ASN.1 production type members (members of SEQUENCE, SET, CHOICE).
     */
    struct asn_TYPE_member_s *elements;
    unsigned elements_count;

    /*
     * Additional information describing the type, used by appropriate
     * functions above.
     */
    const void *specifics;
} asn_TYPE_descriptor_t;

/*
 * This type describes an element of the constructed type,
 * i.e. SEQUENCE, SET, CHOICE, etc.
 */
  enum asn_TYPE_flags_e {
    ATF_NOFLAGS,
    ATF_POINTER = 0x01,   /* Represented by the pointer */
    ATF_OPEN_TYPE = 0x02, /* Open Type */
    ATF_ANY_TYPE = 0x04   /* ANY type (deprecated!) */
  };
typedef struct asn_TYPE_member_s {
    enum asn_TYPE_flags_e flags; /* Element's presentation flags */
    unsigned optional;      /* Following optional members, including current */
    unsigned memb_offset;   /* Offset of the element */
    ber_tlv_tag_t tag;      /* Outmost (most immediate) tag */
    int tag_mode;           /* IMPLICIT/no/EXPLICIT tag at current level */
    asn_TYPE_descriptor_t *type;            /* Member type descriptor */
    asn_type_selector_f *type_selector;     /* IoS runtime type selector */
    asn_encoding_constraints_t encoding_constraints;
    int (*default_value_cmp)(const void *sptr); /* Compare DEFAULT <value> */
    int (*default_value_set)(void **sptr);      /* Set DEFAULT <value> */
    const char *name; /* ASN.1 identifier of the element */
} asn_TYPE_member_t;

/*
 * BER tag to element number mapping.
 */
typedef struct asn_TYPE_tag2member_s {
    ber_tlv_tag_t el_tag;   /* Outmost tag of the member */
    unsigned el_no;         /* Index of the associated member, base 0 */
    int toff_first;         /* First occurrence of the el_tag, relative */
    int toff_last;          /* Last occurrence of the el_tag, relative */
} asn_TYPE_tag2member_t;

/*
 * This function prints out the contents of the target language's structure
 * (struct_ptr) into the file pointer (stream) in human readable form.
 * RETURN VALUES:
 * 	 0: The structure is printed.
 * 	-1: Problem dumping the structure.
 * (See also xer_fprint() in xer_encoder.h)
 */
int asn_fprint(FILE *stream, /* Destination stream descriptor */
               const asn_TYPE_descriptor_t *td, /* ASN.1 type descriptor */
               const void *struct_ptr);         /* Structure to be printed */

/*
 * Copies a source structure (struct_src) into destination structure 
 * (struct_dst). Allocates memory for the destination structure, if necessary.
 * RETURN VALUES:
 *   0: Copy OK.
 * 	-1: Problem copying the structure.
 */
int asn_copy(const asn_TYPE_descriptor_t *td, /* ASN.1 type descriptor */
             void **struct_dst,               /* Structure to be populated */
             const void *struct_src);         /* Structure to be copied */

#ifdef __cplusplus
}
#endif

#endif	/* _CONSTR_TYPE_H_ */
