/*

 * Copyright (c) 2021 Fastly, Inc.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

 * IN THE SOFTWARE.

 */

#include <assert.h>

#include "khash.h"

#include "quicly.h"

#include "quicly/sendstate.h"

#include "quicly/recvstate.h"

#include "quicly_mock.h"

KHASH_MAP_INIT_INT64(quicly_stream_t, quicly_stream_t *)

mquicly_context_t mquicly_context;

struct st_quicly_conn_t {

    struct _st_quicly_conn_public_t super;

    khash_t(quicly_stream_t) * streams;

    struct {

        quicly_address_t local, remote;

    } address;

};

struct st_quicly_send_context_t {

};

static quicly_conn_t *create_connection(quicly_context_t *ctx, int is_client, struct sockaddr *remote_addr,

                                        struct sockaddr *local_addr)

{

    quicly_conn_t *conn = calloc(1, sizeof(*conn));

    assert(conn != NULL);

    conn->super.ctx = ctx;

    if (is_client) {

        conn->super.local.bidi.next_stream_id = 0;

        conn->super.local.uni.next_stream_id = 2;

        conn->super.remote.bidi.next_stream_id = 1;

        conn->super.remote.uni.next_stream_id = 3;

    } else {

        conn->super.local.bidi.next_stream_id = 1;

        conn->super.local.uni.next_stream_id = 3;

        conn->super.remote.bidi.next_stream_id = 0;

        conn->super.remote.uni.next_stream_id = 2;

    }

    conn->streams = kh_init(quicly_stream_t);

    conn->address.local.sa = *local_addr;

    conn->address.remote.sa = *remote_addr;

    return conn;

}

quicly_error_t quicly_accept(quicly_conn_t **conn, quicly_context_t *ctx, struct sockaddr *dest_addr, struct sockaddr *src_addr,

                             quicly_decoded_packet_t *packet, quicly_address_token_plaintext_t *address_token,

                             const quicly_cid_plaintext_t *new_cid, ptls_handshake_properties_t *handshake_properties,

                             void *appdata)

{

    *conn = create_connection(ctx, 0, src_addr, dest_addr);

    (*conn)->super.state = QUICLY_STATE_CONNECTED;

    return 0;

}

int quicly_stream_sync_sendbuf(quicly_stream_t *stream, int activate)

{

    int ret;

    if (activate) {

        if ((ret = quicly_sendstate_activate(&stream->sendstate)) != 0)

            return ret;

    }

    quicly_stream_scheduler_t *scheduler = stream->conn->super.ctx->stream_scheduler;

    scheduler->update_state(scheduler, stream);

    return 0;

}

void quicly_stream_sync_recvbuf(quicly_stream_t *stream, size_t shift_amount)

{

    stream->recvstate.data_off += shift_amount;

}

int quicly_stream_can_send(quicly_stream_t *stream, int at_stream_level)

{

    /* return if there is nothing to be sent */

    if (stream->sendstate.pending.num_ranges == 0)

        return 0;

    return 1;

}

ptls_t *quicly_get_tls(quicly_conn_t *conn)

{

    /* TODO: is this okay */

    return NULL;

}

int quicly_is_blocked(quicly_conn_t *conn)

{

    return 0;

}

struct sockaddr *quicly_get_sockname(quicly_conn_t *conn)

{

    return &conn->address.local.sa;

}

struct sockaddr *quicly_get_peername(quicly_conn_t *conn)

{

    return &conn->address.remote.sa;

}

void quicly_request_stop(quicly_stream_t *stream, quicly_error_t err)

{

    stream->_send_aux.stop_sending.sender_state = QUICLY_SENDER_STATE_SEND;

}

void quicly_reset_stream(quicly_stream_t *stream, quicly_error_t err)

{

    /* dispose sendbuf state */

    quicly_sendstate_reset(&stream->sendstate);

    stream->_send_aux.reset_stream.sender_state = QUICLY_SENDER_STATE_SEND;

    /* inline expansion of resched_stream_data() */

    /* TODO: consider streams_blocked? */

    quicly_stream_scheduler_t *scheduler = stream->conn->super.ctx->stream_scheduler;

    scheduler->update_state(scheduler, stream);

}

socklen_t quicly_get_socklen(struct sockaddr *sa)

{

    switch (sa->sa_family) {

    case AF_INET:

        return sizeof(struct sockaddr_in);

    case AF_INET6:

        return sizeof(struct sockaddr_in6);

    default:

        assert(!"unexpected socket type");

        return 0;

    }

}

size_t quicly_decode_packet(quicly_context_t *ctx, quicly_decoded_packet_t *packet, const uint8_t *datagram, size_t datagram_size,

                            size_t *off)

{

    assert(0 && "unimplemented");

    return 0;

}

quicly_error_t quicly_send_stream(quicly_stream_t *stream, quicly_send_context_t *s)

{

    /* quicly_send -> scheduler->do_send -> quicly_send_stream -> on_send_emit */

    uint8_t buff[1024];

    uint64_t off = stream->sendstate.pending.ranges[0].start, end_off;

    size_t capacity = sizeof(buff);

    int wrote_all = 0, is_fin;

    quicly_error_t ret;

    if (!quicly_sendstate_is_open(&stream->sendstate) && off == stream->sendstate.final_size) {

        /* special case for emitting FIN only */

        end_off = off;

        wrote_all = 1;

        is_fin = 1;

        goto UpdateState;

    }

    { /* cap the capacity to the current range */

        uint64_t range_capacity = stream->sendstate.pending.ranges[0].end - off;

        if (!quicly_sendstate_is_open(&stream->sendstate) && off + range_capacity > stream->sendstate.final_size) {

            assert(range_capacity > 1); /* see the special case above */

            range_capacity -= 1;

        }

        if (capacity > range_capacity)

            capacity = range_capacity;

    }

    size_t len = capacity;

    size_t emit_off = (size_t)(off - stream->sendstate.acked.ranges[0].end);

    stream->callbacks->on_send_emit(stream, emit_off, buff, &len, &wrote_all);

    end_off = off + len;

    /* determine if the frame incorporates FIN */

    if (!quicly_sendstate_is_open(&stream->sendstate) && end_off == stream->sendstate.final_size) {

        is_fin = 1;

    } else {

        is_fin = 0;

    }

UpdateState:

    /* notify the fuzzing driver of stream send event */

    if (mquicly_context.on_stream_send != NULL) {

        mquicly_context.on_stream_send->cb(mquicly_context.on_stream_send, stream->conn, stream, buff, off, len, is_fin);

    }

    if (stream->sendstate.size_inflight < end_off) {

        stream->sendstate.size_inflight = end_off;

    }

    if ((ret = quicly_ranges_subtract(&stream->sendstate.pending, off, end_off + is_fin)) != 0)

        return ret;

    if (wrote_all) {

        if ((ret = quicly_ranges_subtract(&stream->sendstate.pending, stream->sendstate.size_inflight, UINT64_MAX)) != 0)

            return ret;

    }

    return 0;

}

static quicly_stream_t *open_stream(quicly_conn_t *conn, quicly_stream_id_t stream_id)

{

    quicly_stream_t *stream;

    if ((stream = calloc(1, sizeof(*stream))) == NULL)

        return NULL;

    stream->conn = conn;

    stream->stream_id = stream_id;

    stream->callbacks = NULL;

    stream->data = NULL;

    int r;

    khiter_t iter = kh_put(quicly_stream_t, conn->streams, stream_id, &r);

    assert(iter != kh_end(conn->streams));

    kh_val(conn->streams, iter) = stream;

    int is_client = quicly_is_client(stream->conn);

    if (quicly_stream_has_send_side(is_client, stream->stream_id)) {

        quicly_sendstate_init(&stream->sendstate);

    } else {

        quicly_sendstate_init_closed(&stream->sendstate);

    }

    if (quicly_stream_has_receive_side(is_client, stream->stream_id)) {

        quicly_recvstate_init(&stream->recvstate);

    } else {

        quicly_recvstate_init_closed(&stream->recvstate);

    }

    return stream;

}

static struct st_quicly_conn_streamgroup_state_t *get_streamgroup_state(quicly_conn_t *conn, quicly_stream_id_t stream_id)

{

    if (quicly_is_client(conn) == quicly_stream_is_client_initiated(stream_id)) {

        return quicly_stream_is_unidirectional(stream_id) ? &conn->super.local.uni : &conn->super.local.bidi;

    } else {

        return quicly_stream_is_unidirectional(stream_id) ? &conn->super.remote.uni : &conn->super.remote.bidi;

    }

}

int mquicly_open_stream(quicly_conn_t *conn, quicly_stream_t **stream, int is_remote_initiated, int unidirectional)

{

    struct st_quicly_conn_streamgroup_state_t *group;

    if (is_remote_initiated) {

        group = unidirectional ? &conn->super.remote.uni : &conn->super.remote.bidi;

    } else {

        group = unidirectional ? &conn->super.local.uni : &conn->super.local.bidi;

    }

    *stream = open_stream(conn, group->next_stream_id);

    group->next_stream_id += 4;

    group->num_streams++;

    conn->super.ctx->stream_open->cb(conn->super.ctx->stream_open, *stream);

    return 0;

}

static void destroy_stream(quicly_stream_t *stream, int err)

{

    quicly_conn_t *conn = stream->conn;

    if (stream->callbacks != NULL)

        stream->callbacks->on_destroy(stream, err);

    khiter_t iter = kh_get(quicly_stream_t, conn->streams, stream->stream_id);

    assert(iter != kh_end(conn->streams));

    kh_del(quicly_stream_t, conn->streams, iter);

    struct st_quicly_conn_streamgroup_state_t *group = get_streamgroup_state(conn, stream->stream_id);

    --group->num_streams;

    quicly_sendstate_dispose(&stream->sendstate);

    quicly_recvstate_dispose(&stream->recvstate);

    free(stream);

}

static void destroy_all_streams(quicly_conn_t *conn, int err)

{

    quicly_stream_t *stream;

    kh_foreach_value(conn->streams, stream, { destroy_stream(stream, err); });

    assert(quicly_num_streams(conn) == 0);

}

int mquicly_closed_by_remote(quicly_conn_t *conn, int err, uint64_t frame_type, ptls_iovec_t reason_phrase)

{

    /* TODO: invoke conn->super.ctx->closed_by_remote->cb() but h2o does not use it so far */

    assert(conn->super.ctx->closed_by_remote == NULL);

    conn->super.state = QUICLY_STATE_DRAINING;

    destroy_all_streams(conn, err);

    return 0;

}

quicly_error_t quicly_open_stream(quicly_conn_t *conn, quicly_stream_t **stream, int unidirectional)

{

    return mquicly_open_stream(conn, stream, 0, unidirectional);

}

quicly_error_t quicly_get_or_open_stream(quicly_conn_t *conn, uint64_t stream_id, quicly_stream_t **stream)

{

    /* conn->super.ctx->stream_open->cb */

    assert(0 && "unimplemented");

    return 0;

}

int quicly_is_destination(quicly_conn_t *conn, struct sockaddr *dest_addr, struct sockaddr *src_addr,

                          quicly_decoded_packet_t *decoded)

{

    assert(0 && "unimplemented");

    return 0;

}

uint32_t quicly_num_streams_by_group(quicly_conn_t *conn, int uni, int locally_initiated)

{

    int server_initiated = quicly_is_client(conn) != locally_initiated;

    struct st_quicly_conn_streamgroup_state_t *state = get_streamgroup_state(conn, uni * 2 + server_initiated);

    return state->num_streams;

}

quicly_error_t quicly_get_delivery_rate(quicly_conn_t *conn, quicly_rate_t *delivery_rate)

{

    /* Do nothing */

    *delivery_rate = (quicly_rate_t){};

    return 0;

}

quicly_error_t quicly_get_stats(quicly_conn_t *conn, quicly_stats_t *stats)

{

    /* Do nothing */

    memset(stats, 0, sizeof(*stats));

    return 0;

}

void quicly_stream_noop_on_destroy(quicly_stream_t *stream, quicly_error_t err)

{

}

void quicly_stream_noop_on_send_shift(quicly_stream_t *stream, size_t delta)

{

}

void quicly_stream_noop_on_send_emit(quicly_stream_t *stream, size_t off, void *dst, size_t *len, int *wrote_all)

{

}

void quicly_stream_noop_on_send_stop(quicly_stream_t *stream, quicly_error_t err)

{

}

void quicly_stream_noop_on_receive(quicly_stream_t *stream, size_t off, const void *src, size_t len)

{

}

void quicly_stream_noop_on_receive_reset(quicly_stream_t *stream, quicly_error_t err)

{

}

const quicly_stream_callbacks_t quicly_stream_noop_callbacks = {

    quicly_stream_noop_on_destroy,   quicly_stream_noop_on_send_shift, quicly_stream_noop_on_send_emit,

    quicly_stream_noop_on_send_stop, quicly_stream_noop_on_receive,    quicly_stream_noop_on_receive_reset};

size_t quicly_send_version_negotiation(quicly_context_t *ctx, ptls_iovec_t dest_cid, ptls_iovec_t src_cid, const uint32_t *versions,

                                       void *payload)

{

    assert(0 && "unimplemented");

    return 0;

}

size_t quicly_send_stateless_reset(quicly_context_t *ctx, const void *src_cid, void *payload)

{

    assert(0 && "unimplemented");

    return 0;

}

int quicly_can_send_data(quicly_conn_t *conn, quicly_send_context_t *s)

{

    return 1;

}

quicly_error_t quicly_connect(quicly_conn_t **conn, quicly_context_t *ctx, const char *server_name, struct sockaddr *dest_addr,

                              struct sockaddr *src_addr, const quicly_cid_plaintext_t *new_cid, ptls_iovec_t address_token,

                              ptls_handshake_properties_t *handshake_properties,

                              const quicly_transport_parameters_t *resumed_transport_params, void *appdata)

{

    assert(0 && "unimplemented");

    return 0;

}

int quicly_connection_is_ready(quicly_conn_t *conn)

{

    assert(0 && "unimplemented");

    return 0;

}

void quicly_amend_ptls_context(ptls_context_t *ptls)

{

    assert(0 && "unimplemented");

}

quicly_error_t quicly_receive(quicly_conn_t *conn, struct sockaddr *dest_addr, struct sockaddr *src_addr,

                              quicly_decoded_packet_t *packet)

{

    assert(0 && "unimplemented");

    return 0;

}

quicly_error_t quicly_close(quicly_conn_t *conn, quicly_error_t err, const char *reason_phrase)

{

    if (conn->super.state >= QUICLY_STATE_CLOSING)

        return 0;

    conn->super.state = QUICLY_STATE_CLOSING;

    return 0;

}

int64_t quicly_get_first_timeout(quicly_conn_t *conn)

{

    /* TODO: simulate delay */

    return conn->super.ctx->now->cb(conn->super.ctx->now) + 1;

}

void quicly_free(quicly_conn_t *conn)

{

    destroy_all_streams(conn, 0);

    kh_destroy(quicly_stream_t, conn->streams);

    free(conn);

}

quicly_error_t quicly_send(quicly_conn_t *conn, quicly_address_t *dest, quicly_address_t *src, struct iovec *datagrams,

                           size_t *num_datagrams, void *buf, size_t bufsize)

{

    quicly_send_context_t s = {};

    quicly_error_t ret;

    if (conn->super.state >= QUICLY_STATE_CLOSING) {

        ret = QUICLY_ERROR_FREE_CONNECTION;

        goto Exit;

    }

    ret = conn->super.ctx->stream_scheduler->do_send(conn->super.ctx->stream_scheduler, conn, &s);

Exit:

    *num_datagrams = 0;

    return ret;

}

int64_t quicly_foreach_stream(quicly_conn_t *conn, void *thunk, int64_t (*cb)(void *thunk, quicly_stream_t *stream))

{

    assert(0 && "unimplemented");

    return 0;

}

quicly_stream_t *quicly_get_stream(quicly_conn_t *conn, quicly_stream_id_t stream_id)

{

    assert(0 && "unimplemented");

    return NULL;

}

void quicly_send_datagram_frames(quicly_conn_t *conn, ptls_iovec_t *datagrams, size_t num_datagrams)

{

    assert(0 && "unimplemented");

}

void quicly_get_max_data(quicly_conn_t *conn, uint64_t *send_permitted, uint64_t *sent, uint64_t *consumed)

{

    if (send_permitted != NULL)

        *send_permitted = 0xdeadbeef;

    if (sent != NULL)

        *sent = 0xdeadbeef;

    if (consumed != NULL)

        *consumed = 0xdeadbeef;

}

quicly_error_t quicly_send_resumption_token(quicly_conn_t *conn)

{

    return 0;

}

const uint32_t quicly_supported_versions[] = {QUICLY_PROTOCOL_VERSION_1, QUICLY_PROTOCOL_VERSION_DRAFT29,

                                              QUICLY_PROTOCOL_VERSION_DRAFT27, 0};