const PTLS_MAX_DIGEST_SIZE* = 64
const PTLS_ALERT_BAD_CERTIFICATE* = 42
const PTLS_ALERT_UNKNOWN_CA* = 48

type
  List*[T] = object
    list*: ptr T
    count*: csize_t

  ptls_cipher_algorithm_t* {.importc, header: "picotls.h", bycopy.} = object
    name*: cstring
    key_size*: csize_t
    block_size*: csize_t
    iv_size*: csize_t
    context_size*: csize_t
    setup_crypto*: proc(ctx: ptr ptls_cipher_context_t, is_enc: cint,
                        key: pointer): cint {.cdecl.}

  ptls_aead_algorithm_t* {.importc, header: "picotls.h", bycopy.} = object
    name*: cstring
    confidentiality_limit*: uint64
    integrity_limit*: uint64
    ctr_cipher*: ptr ptls_cipher_algorithm_t
    ecb_cipher*: ptr ptls_cipher_algorithm_t
    key_size*: csize_t
    iv_size*: csize_t
    tag_size*: csize_t
    context_size*: csize_t
    setup_crypto*: proc(ctx: ptr ptls_aead_context_t, is_enc: cint,
                        key: pointer, iv: pointer): cint {.cdecl.}

  ptls_hash_final_mode_t* {.importc, header: "picotls.h", bycopy.} = enum
    PTLS_HASH_FINAL_MODE_FREE = 0,
    PTLS_HASH_FINAL_MODE_RESET = 1,
    PTLS_HASH_FINAL_MODE_SNAPSHOT = 2

  ptls_hash_context_t* {.importc, header: "picotls.h", bycopy.} = object
    update*: proc(ctx: ptr ptls_hash_context_t, src: pointer, len: csize_t)
                 {.cdecl.}
    final*: proc(ctx: ptr ptls_hash_context_t, md: pointer,
                 mode: ptls_hash_final_mode_t) {.cdecl.}
    clone*: proc(src: ptr ptls_hash_context_t): ptr ptls_hash_context_t
                {.cdecl.}

  ptls_hash_algorithm_t* {.importc, header: "picotls.h", bycopy.} = object
    block_size*: csize_t
    digest_size*: csize_t
    create*: proc(): ptr ptls_hash_context_t {.cdecl.}
    empty_digest*: array[PTLS_MAX_DIGEST_SIZE, uint8]

  ptls_cipher_suite_t* {.importc, header: "picotls.h", bycopy.} = object
    id*: uint16
    aead*: ptr ptls_aead_algorithm_t
    hash*: ptr ptls_hash_algorithm_t

  CipherSuiteListElem* = object
    cipher_suite*: ptr ptls_cipher_suite_t
    record_digest*: array[PTLS_MAX_DIGEST_SIZE, uint8]

  VerifySignCb* = proc(verify_ctx: pointer, data: ptls_iovec_t,
                       sign: ptls_iovec_t): cint {.cdecl.}

  ptls_t* {.importc, header: "picotls.h", incompleteStruct.} = object

  ptls_key_exchange_algorithm_t* {.importc, header: "picotls.h", bycopy.} = object
    id*: uint16
    create*: proc(algo: ptr ptls_key_exchange_algorithm_t,
                  ctx: ptr ptr ptls_key_exchange_context_t): cint {.cdecl.}
    exchange*: proc(algo: ptr ptls_key_exchange_algorithm_t,
                    pubkey: ptr ptls_iovec_t, secret: ptr ptls_iovec_t): cint
                   {.cdecl.}
    data*: pointer 

  ptls_key_exchange_context_t* {.importc, header: "picotls.h", bycopy.} = object
    algo*: ptr ptls_key_exchange_algorithm_t
    pubkey*: ptls_iovec_t
    on_exchange*: proc(keyex: ptr ptr ptls_key_exchange_context_t, release: cint,
                       secret: ptr ptls_iovec_t, peerkey: ptls_iovec_t): cint
                      {.cdecl.}

  ptls_esni_context_t* {.importc, header: "picotls.h", bycopy.} = object
    key_exchanges*: ptr ptr ptls_key_exchange_context_t
    cipher_suites*: ptr CipherSuiteListElem
    padded_length*: uint16
    not_before*: uint64
    not_after*: uint64
    version*: uint16

  ptls_iovec_t* {.importc, header: "picotls.h", bycopy.} = object
    base*: ptr uint8
    len*: csize_t

  ptls_on_client_hello_parameters_t* {.importc, header: "picotls.h", bycopy.} = object
    server_name*: ptls_iovec_t
    raw_message*: ptls_iovec_t
    negotiated_protocols*: List[ptls_iovec_t]
    signature_algorithms*: List[uint16]
    certificate_compression_algorithms*: List[uint16]
    cipher_suites*: List[uint16]
    esni* {.bitsize: 1.}: cuint
    incompatible_version* {.bitsize: 1.}: cuint

  ptls_traffic_protection_t* {.importc, header: "picotls.h", incompleteStruct.} = object

  ptls_message_emitter_t* {.importc, header: "picotls.h", bycopy.} = object
    buf*: ptr ptls_buffer_t
    enc*: ptr ptls_traffic_protection_t
    record_header_length*: csize_t
    begin_message*: proc (self: ptr ptls_message_emitter_t): cint {.cdecl.}
    commit_message*: proc (self: ptr ptls_message_emitter_t): cint {.cdecl.}

  ptls_key_schedule_t* {.importc, header: "picotls.h", bycopy.} = object

  ptls_buffer_t* {.importc, header: "picotls.h", bycopy.} = object
    base*: uint8
    capacity*: csize_t
    off*: csize_t
    is_allocated*: cint

  ptls_get_time_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_get_time_t): uint64 {.cdecl.}

  ptls_on_client_hello_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_on_client_hello_t, tls: ptr ptls_t,
              params: ptr ptls_on_client_hello_parameters_t): cint {.cdecl.}

  ptls_emit_certificate_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_emit_certificate_t, tls: ptr ptls_t,
              emitter: ptr ptls_message_emitter_t,
              key_sched: ptr ptls_key_schedule_t, context: ptls_iovec_t,
              push_status_request: cint, compress_algos: uint16,
              num_compress_algos: csize_t): cint {.cdecl.}

  ptls_sign_certificate_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_sign_certificate_t, tls: ptr ptls_t,
              selected_algorithm: uint16, output: ptr ptls_buffer_t,
              input: ptls_iovec_t, algorithms: uint16,
              num_algorithms: csize_t): cint {.cdecl.}

  ptls_verify_certificate_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_verify_certificate_t, tls: ptr ptls_t,
              verify_sign: ptr VerifySignCb, verify_data: ptr pointer,
              certs: ptr ptls_iovec_t, numCerts: csize_t): cint {.cdecl.}

  ptls_encrypt_ticket_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_encrypt_ticket_t, tls: ptr ptls_t, is_encrypt: cint,
              dst: ptr ptls_buffer_t, src: ptls_iovec_t): cint {.cdecl.}

  ptls_save_ticket_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_save_ticket_t, tls: ptr ptls_t,
              input: ptls_iovec_t): cint {.cdecl.}

  ptls_log_event_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_log_event_t, tls: ptr ptls_t, `type`: cstring,
              fmt: cstring) {.cdecl, varargs.}

  ptls_update_open_count_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_update_open_count_t, delta: BiggestInt) {.cdecl.}

  ptls_update_traffic_key_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_update_traffic_key_t, tls: ptr ptls_t, is_enc: cint,
              epoch: csize_t, secret: pointer): cint {.cdecl.}

  ptls_decompress_certificate_t* {.importc, header: "picotls.h", bycopy.} = object
    supported_algorithms*: uint16
    cb*: proc(self: ptr ptls_decompress_certificate_t, tls: ptr ptls_t,
              algorithm: uint16, output: ptls_iovec_t, input: ptls_iovec_t): cint
             {.cdecl.}

  ptls_update_esni_key_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_update_esni_key_t, tls: ptr ptls_t, secret: ptls_iovec_t,
              hash: ptls_hash_algorithm_t, hashed_esni_contents: pointer): cint
             {.cdecl.}

  ptls_on_extension_t* {.importc, header: "picotls.h", bycopy.} = object
    cb*: proc(self: ptr ptls_on_extension_t, tls: ptr ptls_t, hstype: uint8,
              exttype: uint16, extdata: ptls_iovec_t): cint {.cdecl.}

  ptls_context_t* {.importc, header: "picotls.h", bycopy.} = object
    random_bytes*: proc (buf: pointer, len: csize_t) {.cdecl.}
    get_time*: ptr ptls_get_time_t
    key_exchanges*: ptr ptr ptls_key_exchange_algorithm_t
    cipher_suites*: ptr ptr ptls_cipher_suite_t
    certificates*: List[ptls_iovec_t]
    esni*: ptr ptr ptls_esni_context_t
    on_client_hello*: ptr ptls_on_client_hello_t
    emit_certificate*: ptr ptls_emit_certificate_t
    sign_certificate*: ptr ptls_sign_certificate_t
    verify_certificate*: ptr ptls_verify_certificate_t
    ticket_lifetime*: uint32
    max_early_data_size*: uint32
    max_buffer_size*: csize_t
    hkdf_label_prefix_obsolete: cstring
    require_dhe_on_psk* {.bitsize: 1.}: cuint
    use_exporter* {.bitsize: 1.}: cuint
    send_change_cipher_spec* {.bitsize: 1.}: cuint
    require_client_authentication* {.bitsize: 1.}: cuint
    omit_end_of_early_data* {.bitsize: 1.}: cuint
    encrypt_ticket*: ptr ptls_encrypt_ticket_t
    save_ticket*: ptr ptls_save_ticket_t
    log_event*: ptr ptls_log_event_t
    update_open_count*: ptr ptls_update_open_count_t
    update_traffic_key*: ptr ptls_update_traffic_key_t
    decompress_certificate*: ptr ptls_decompress_certificate_t
    update_esni_key*: ptr ptls_update_esni_key_t
    on_extension*: ptr ptls_on_extension_t

  ptls_cipher_context_t* {.importc, header: "picotls.h", bycopy.} = object
    algo*: ptr ptls_cipher_algorithm_t
    do_dispose*: proc(ctx: ptr ptls_cipher_context_t) {.cdecl.}
    do_init*: proc(ctx: ptr ptls_cipher_context_t, iv: pointer) {.cdecl.}
    do_transform*: proc(ctx: ptr ptls_cipher_context_t, output: pointer,
                        input: pointer, len: csize_t) {.cdecl.}

  ptls_aead_supplementary_encryption_t* {.importc, header: "picotls.h", bycopy.} = object
    ctx*: ptr ptls_cipher_context_t
    input*: pointer
    output*: array[16, uint8]

  ptls_aead_context_t* {.importc, header: "picotls.h", bycopy.} = object
    algo*: ptr ptls_aead_algorithm_t
    dispose_crypto*: proc(ctx: ptr ptls_aead_context_t) {.cdecl.}
    do_encrypt_init*: proc(ctx: ptr ptls_aead_context_t, seq: uint64,
                           aad: pointer, aadlen: csize_t) {.cdecl.}
    do_encrypt_update*: proc(ctx: ptr ptls_aead_context_t, output: pointer,
                             input: pointer, inlen: csize_t): csize_t {.cdecl.}
    do_encrypt_final*: proc(ctx: ptr ptls_aead_context_t, output: pointer):
                           csize_t {.cdecl.}
    do_encrypt*: proc(ctx: ptr ptls_aead_context_t, output: pointer,
                      input: pointer, inlen: csize_t, seq: uint64, aad: pointer,
                      aadlen: csize_t,
                      supp: ptr ptls_aead_supplementary_encryption_t) {.cdecl.}

  ClientProperties* {.importc, header: "picotls.h", bycopy.} = object
    negotiated_protocols*: List[ptls_iovec_t]
    session_ticket*: ptls_iovec_t
    max_early_data_size*: ptr csize_t
    early_data_acceptance*: ptls_early_data_acceptance_t
    negotiate_before_key_exchange* {.bitsize: 1.}: cuint
    esni_keys*: ptls_iovec_t

  PskBinder* {.importc, header: "picotls.h", bycopy.} = object
    base*: array[64, uint8]
    len*: csize_t

  Cookie* {.importc, header: "picotls.h", bycopy.} = object
    key*: pointer
    additional_data*: ptls_iovec_t

  ServerProperties* {.importc, header: "picotls.h", bycopy.} = object
    selected_psk_binder*: PskBinder
    cookie*: Cookie
    enforce_retry* {.bitsize: 1.}: cuint
    retry_uses_cookie* {.bitsize: 1.}: cuint

  ClientOrServer* {.union, bycopy.} = object
    client*: ClientProperties
    server*: ServerProperties

  ptls_raw_extension_t* {.importc, header: "picotls.h", bycopy.} = object
    `type`*: uint16
    data*: ptls_iovec_t

  ptls_early_data_acceptance_t* {.importc, header: "picotls.h", bycopy.} = enum
    PTLS_EARLY_DATA_ACCEPTANCE_UNKNOWN = 0,
    PTLS_EARLY_DATA_REJECTED,
    PTLS_EARLY_DATA_ACCEPTED
  
  ptls_handshake_properties_t* {.importc, header: "picotls.h", bycopy.} = object
    properties*: ClientOrServer
    additional_extensions*: ptr ptls_raw_extension_t
    collect_extension*: proc (tls: ptr ptls_t;
                            properties: ptr ptls_handshake_properties_t;
                            `type`: uint16): cint {.cdecl.}
    collected_extensions*: proc (tls: ptr ptls_t;
                               properties: ptr ptls_handshake_properties_t;
                               extensions: ptr ptls_raw_extension_t): cint {.cdecl.}

var ptls_get_time* {.importc, header: "picotls.h".}: ptls_get_time_t

proc ptls_iovec_init*(p: pointer, len: csize_t): ptls_iovec_t {.importc, header: "picotls.h", cdecl.}

proc ptls_load_certificates*(ctx: ptr ptls_context_t, cert_pem_file: cstring):
                            cint {.importc, header: "picotls.h", cdecl.}

proc ptls_get_data_ptr*(tls: ptr ptls_t): ptr pointer
                       {.importc, header: "picotls.h", cdecl.}

proc ptls_set_server_name*(tls: ptr ptls_t, server_name: cstring,
                           server_name_len: csize_t): cint
                          {.importc, header: "picotls.h", cdecl.}