/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_V3_H_INCLUDED_
#define _NGX_HTTP_V3_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_http_v3_parse.h>


#define NGX_HTTP_V3_ALPN_ADVERTISE                 "\x02h3"
#define NGX_HTTP_V3_ALPN_DRAFT_FMT                 "\x05h3-%02uD"

#define NGX_HTTP_V3_VARLEN_INT_LEN                 4
#define NGX_HTTP_V3_PREFIX_INT_LEN                 11

#define NGX_HTTP_V3_STREAM_CONTROL                 0x00
#define NGX_HTTP_V3_STREAM_PUSH                    0x01
#define NGX_HTTP_V3_STREAM_ENCODER                 0x02
#define NGX_HTTP_V3_STREAM_DECODER                 0x03

#define NGX_HTTP_V3_FRAME_DATA                     0x00
#define NGX_HTTP_V3_FRAME_HEADERS                  0x01
#define NGX_HTTP_V3_FRAME_CANCEL_PUSH              0x03
#define NGX_HTTP_V3_FRAME_SETTINGS                 0x04
#define NGX_HTTP_V3_FRAME_PUSH_PROMISE             0x05
#define NGX_HTTP_V3_FRAME_GOAWAY                   0x07
#define NGX_HTTP_V3_FRAME_MAX_PUSH_ID              0x0d

#define NGX_HTTP_V3_PARAM_MAX_TABLE_CAPACITY       0x01
#define NGX_HTTP_V3_PARAM_MAX_HEADER_LIST_SIZE     0x06
#define NGX_HTTP_V3_PARAM_BLOCKED_STREAMS          0x07

#define NGX_HTTP_V3_STREAM_CLIENT_CONTROL          0
#define NGX_HTTP_V3_STREAM_SERVER_CONTROL          1
#define NGX_HTTP_V3_STREAM_CLIENT_ENCODER          2
#define NGX_HTTP_V3_STREAM_SERVER_ENCODER          3
#define NGX_HTTP_V3_STREAM_CLIENT_DECODER          4
#define NGX_HTTP_V3_STREAM_SERVER_DECODER          5
#define NGX_HTTP_V3_MAX_KNOWN_STREAM               6

#define NGX_HTTP_V3_DEFAULT_MAX_FIELD_SIZE         4096
#define NGX_HTTP_V3_DEFAULT_MAX_TABLE_CAPACITY     16384
#define NGX_HTTP_V3_DEFAULT_MAX_BLOCKED_STREAMS    16
#define NGX_HTTP_V3_DEFAULT_MAX_CONCURRENT_PUSHES  10

/* HTTP/3 errors */
#define NGX_HTTP_V3_ERR_NO_ERROR                   0x100
#define NGX_HTTP_V3_ERR_GENERAL_PROTOCOL_ERROR     0x101
#define NGX_HTTP_V3_ERR_INTERNAL_ERROR             0x102
#define NGX_HTTP_V3_ERR_STREAM_CREATION_ERROR      0x103
#define NGX_HTTP_V3_ERR_CLOSED_CRITICAL_STREAM     0x104
#define NGX_HTTP_V3_ERR_FRAME_UNEXPECTED           0x105
#define NGX_HTTP_V3_ERR_FRAME_ERROR                0x106
#define NGX_HTTP_V3_ERR_EXCESSIVE_LOAD             0x107
#define NGX_HTTP_V3_ERR_ID_ERROR                   0x108
#define NGX_HTTP_V3_ERR_SETTINGS_ERROR             0x109
#define NGX_HTTP_V3_ERR_MISSING_SETTINGS           0x10a
#define NGX_HTTP_V3_ERR_REQUEST_REJECTED           0x10b
#define NGX_HTTP_V3_ERR_REQUEST_CANCELLED          0x10c
#define NGX_HTTP_V3_ERR_REQUEST_INCOMPLETE         0x10d
#define NGX_HTTP_V3_ERR_CONNECT_ERROR              0x10f
#define NGX_HTTP_V3_ERR_VERSION_FALLBACK           0x110

/* QPACK errors */
#define NGX_HTTP_V3_ERR_DECOMPRESSION_FAILED       0x200
#define NGX_HTTP_V3_ERR_ENCODER_STREAM_ERROR       0x201
#define NGX_HTTP_V3_ERR_DECODER_STREAM_ERROR       0x202


#define ngx_http_v3_get_module_srv_conf(c, module)                            \
    ngx_http_get_module_srv_conf(                                             \
           ((ngx_http_v3_connection_t *) c->quic->parent->data)->hc.conf_ctx, \
           module)

#define ngx_http_v3_finalize_connection(c, code, reason)                      \
    ngx_quic_finalize_connection(c->quic->parent, code, reason)


typedef struct {
    ngx_quic_tp_t                 quic;
    size_t                        max_field_size;
    size_t                        max_table_capacity;
    ngx_uint_t                    max_blocked_streams;
    ngx_uint_t                    max_concurrent_pushes;
} ngx_http_v3_srv_conf_t;


typedef struct {
    ngx_flag_t                    push_preload;
    ngx_flag_t                    push;
    ngx_array_t                  *pushes;
} ngx_http_v3_loc_conf_t;


typedef struct {
    ngx_str_t                     name;
    ngx_str_t                     value;
} ngx_http_v3_header_t;


typedef struct {
    ngx_http_v3_header_t        **elts;
    ngx_uint_t                    nelts;
    ngx_uint_t                    base;
    size_t                        size;
    size_t                        capacity;
} ngx_http_v3_dynamic_table_t;


typedef struct {
    /* the http connection must be first */
    ngx_http_connection_t         hc;
    ngx_http_v3_dynamic_table_t   table;

    ngx_queue_t                   blocked;
    ngx_uint_t                    nblocked;

    ngx_queue_t                   pushing;
    ngx_uint_t                    npushing;
    uint64_t                      next_push_id;
    uint64_t                      max_push_id;

    ngx_connection_t             *known_streams[NGX_HTTP_V3_MAX_KNOWN_STREAM];
} ngx_http_v3_connection_t;


void ngx_http_v3_init(ngx_connection_t *c);
ngx_int_t ngx_http_v3_parse_request_body(ngx_http_request_t *r, ngx_buf_t *b,
    ngx_http_chunked_t *ctx);

uintptr_t ngx_http_v3_encode_varlen_int(u_char *p, uint64_t value);
uintptr_t ngx_http_v3_encode_prefix_int(u_char *p, uint64_t value,
    ngx_uint_t prefix);

uintptr_t ngx_http_v3_encode_header_block_prefix(u_char *p,
    ngx_uint_t insert_count, ngx_uint_t sign, ngx_uint_t delta_base);
uintptr_t ngx_http_v3_encode_header_ri(u_char *p, ngx_uint_t dynamic,
    ngx_uint_t index);
uintptr_t ngx_http_v3_encode_header_lri(u_char *p, ngx_uint_t dynamic,
    ngx_uint_t index, u_char *data, size_t len);
uintptr_t ngx_http_v3_encode_header_l(u_char *p, ngx_str_t *name,
    ngx_str_t *value);
uintptr_t ngx_http_v3_encode_header_pbi(u_char *p, ngx_uint_t index);
uintptr_t ngx_http_v3_encode_header_lpbi(u_char *p, ngx_uint_t index,
    u_char *data, size_t len);

ngx_int_t ngx_http_v3_init_session(ngx_connection_t *c);
void ngx_http_v3_init_uni_stream(ngx_connection_t *c);
ngx_connection_t *ngx_http_v3_create_push_stream(ngx_connection_t *c,
    uint64_t push_id);
ngx_int_t ngx_http_v3_ref_insert(ngx_connection_t *c, ngx_uint_t dynamic,
    ngx_uint_t index, ngx_str_t *value);
ngx_int_t ngx_http_v3_insert(ngx_connection_t *c, ngx_str_t *name,
    ngx_str_t *value);
ngx_int_t ngx_http_v3_set_capacity(ngx_connection_t *c, ngx_uint_t capacity);
ngx_int_t ngx_http_v3_duplicate(ngx_connection_t *c, ngx_uint_t index);
ngx_int_t ngx_http_v3_ack_header(ngx_connection_t *c, ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_cancel_stream(ngx_connection_t *c, ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_inc_insert_count(ngx_connection_t *c, ngx_uint_t inc);
ngx_int_t ngx_http_v3_lookup_static(ngx_connection_t *c, ngx_uint_t index,
    ngx_str_t *name, ngx_str_t *value);
ngx_int_t ngx_http_v3_lookup(ngx_connection_t *c, ngx_uint_t index,
    ngx_str_t *name, ngx_str_t *value);
ngx_int_t ngx_http_v3_decode_insert_count(ngx_connection_t *c,
    ngx_uint_t *insert_count);
ngx_int_t ngx_http_v3_check_insert_count(ngx_connection_t *c,
    ngx_uint_t insert_count);
ngx_int_t ngx_http_v3_set_param(ngx_connection_t *c, uint64_t id,
    uint64_t value);
ngx_int_t ngx_http_v3_set_max_push_id(ngx_connection_t *c,
    uint64_t max_push_id);
ngx_int_t ngx_http_v3_cancel_push(ngx_connection_t *c, uint64_t push_id);

ngx_int_t ngx_http_v3_client_ref_insert(ngx_connection_t *c, ngx_uint_t dynamic,
    ngx_uint_t index, ngx_str_t *value);
ngx_int_t ngx_http_v3_client_insert(ngx_connection_t *c, ngx_str_t *name,
    ngx_str_t *value);
ngx_int_t ngx_http_v3_client_set_capacity(ngx_connection_t *c,
    ngx_uint_t capacity);
ngx_int_t ngx_http_v3_client_duplicate(ngx_connection_t *c, ngx_uint_t index);
ngx_int_t ngx_http_v3_client_ack_header(ngx_connection_t *c,
    ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_client_cancel_stream(ngx_connection_t *c,
    ngx_uint_t stream_id);
ngx_int_t ngx_http_v3_client_inc_insert_count(ngx_connection_t *c,
    ngx_uint_t inc);


extern ngx_module_t  ngx_http_v3_module;


#endif /* _NGX_HTTP_V3_H_INCLUDED_ */