/*
 * 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 <ber_tlv_length.h>
#include <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;

#include <ber_decoder.h>     /* Basic Encoding Rules decoder */
#include <der_encoder.h>     /* Distinguished Encoding Rules encoder */
#include <xer_decoder.h>     /* Decoder of XER (XML, text) */
#include <xer_encoder.h>     /* Encoder into XER (XML, text) */
#include <per_decoder.h>     /* Packet Encoding Rules decoder */
#include <per_encoder.h>     /* Packet Encoding Rules encoder */
#include <constraints.h>     /* Subtype constraints support */
#include <asn_random_fill.h> /* Random structures support */

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

/*
 * 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);

/*
 * 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 */
  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 */
  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 {
  const struct asn_oer_constraints_s* oer_constraints;
  const struct asn_per_constraints_s* per_constraints;
  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 occurence of the el_tag, relative */
  int toff_last;        /* Last occurence 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 */

#ifdef __cplusplus
}
#endif

#endif /* _CONSTR_TYPE_H_ */
