/* vim: set expandtab ts=4 sw=4: */
/*
 * You may redistribute this program and/or modify it under the terms of
 * the GNU General Public License as published by the Free Software Foundation,
 * either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "crypto/random/Random.h"
#include "crypto/Ca.h"
#ifndef SUBNODE
#include "dht/Pathfinder.h"
#endif
#include "io/Writer.h"
#include "io/FileWriter.h"
#include "util/log/Log.h"
#include "memory/Allocator.h"
#include "subnode/SubnodePathfinder.h"
#include "test/TestFramework.h"
#include "util/log/WriterLog.h"
#include "util/events/EventBase.h"
#include "net/InterfaceController.h"
#include "net/SessionManager.h"
#include "interface/Iface.h"
#include "tunnel/IpTunnel.h"
#include "net/EventEmitter.h"
#include "net/SessionManager.h"
#include "net/UpperDistributor.h"
#include "net/TUNAdapter.h"
#include "wire/Headers.h"

// Needed just to get the encoding scheme that we're using
#define NumberCompress_OLD_CODE
#include "switch/NumberCompress.h"

struct TestFramework_Link
{
    struct Iface clientIf;
    struct Iface serverIf;
    struct TestFramework* client;
    struct TestFramework* server;
    int serverIfNum;
    int clientIfNum;
    Identity
};

static Iface_DEFUN sendTo(Message_t* msg,
                          struct Iface* dest,
                          struct TestFramework* srcTf,
                          struct TestFramework* destTf)
{
    Assert_true(!((uintptr_t)Message_bytes(msg) % 4) || !"alignment fault");
    Assert_true(!(Message_getCapacity(msg) % 4) || !"length fault");
    Assert_true(((int)Message_getCapacity(msg) >= Message_getLength(msg)) || !"length fault0");

    Log_debug(srcTf->logger, "Transferring message to [%p] - message length [%d]\n",
              (void*)dest, Message_getLength(msg));

    // Store the original message and a copy of the original so they can be compared later.
    srcTf->lastMsgBackup = Message_clone(msg, srcTf->alloc);
    srcTf->lastMsg = msg;
    if (Message_getAlloc(msg)) {
        // If it's a message which was buffered inside of CryptoAuth then it will be freed
        // so by adopting the allocator we can hold it in memory.
        Allocator_adopt(srcTf->alloc, Message_getAlloc(msg));
    }

    // Copy the original and send that to the other end.
    // Can't use Iface_next() when not sending the original msg.
    Message_t* sendMsg = Message_clone(msg, destTf->alloc);
    return Iface_send(dest, sendMsg);
}

static Iface_DEFUN sendClient(Message_t* msg, struct Iface* clientIf)
{
    struct TestFramework_Link* link =
        Identity_containerOf(clientIf, struct TestFramework_Link, clientIf);
    return sendTo(msg, &link->serverIf, link->client, link->server);
}

static Iface_DEFUN sendServer(Message_t* msg, struct Iface* serverIf)
{
    struct TestFramework_Link* link =
        Identity_containerOf(serverIf, struct TestFramework_Link, serverIf);
    return sendTo(msg, &link->clientIf, link->server, link->client);
}

struct TestFramework* TestFramework_setUp(char* privateKey,
                                          struct Allocator* allocator,
                                          EventBase_t* base,
                                          struct Random* rand,
                                          struct Log* logger,
                                          bool enableNoise)
{
    if (!logger) {
        struct Writer* logwriter = FileWriter_new(stdout, allocator);
        logger = WriterLog_new(logwriter, allocator);
    }

    if (!rand) {
        Err_assert(Random_new(&rand, allocator, logger));
    }

    if (!base) {
        base = EventBase_new(allocator);
    }

    uint64_t pks[4];
    if (!privateKey) {
        Random_longs(rand, pks, 4);
        privateKey = (char*)pks;
    }

    struct EncodingScheme* scheme = NumberCompress_defineScheme(allocator);

    struct NetCore* nc =
        NetCore_new(privateKey, allocator, base, rand, logger, enableNoise);

    struct RouteGen* rg = RouteGen_new(allocator, logger);

    struct GlobalConfig* globalConf = GlobalConfig_new(allocator);
    struct IpTunnel* ipTunnel =
        IpTunnel_new(logger, base, allocator, rand, rg, globalConf);
    Iface_plumb(&nc->tunAdapt->ipTunnelIf, &ipTunnel->tunInterface);
    Iface_plumb(&nc->upper->ipTunnelIf, &ipTunnel->nodeInterface);

    struct SubnodePathfinder* spf = SubnodePathfinder_new(
        allocator, logger, base, rand, nc->myAddress, privateKey, scheme, nc->ca);
    EventEmitter_regPathfinderIface(nc->ee, &spf->eventIf);

    #ifndef SUBNODE
        struct Pathfinder* pf = Pathfinder_register(allocator, logger, base, rand, NULL);
        pf->fullVerify = true;
        EventEmitter_regPathfinderIface(nc->ee, &pf->eventIf);
    #endif

    SubnodePathfinder_start(spf);

    struct TestFramework* tf = Allocator_calloc(allocator, sizeof(struct TestFramework), 1);
    Identity_set(tf);
    tf->alloc = allocator;
    tf->rand = rand;
    tf->eventBase = base;
    tf->logger = logger;
    tf->nc = nc;
    tf->tunIf = &nc->tunAdapt->tunIf;
    tf->publicKey = nc->myAddress->key;
    tf->ip = nc->myAddress->ip6.bytes;
    #ifndef SUBNODE
        tf->pathfinder = pf;
    #endif
    tf->subnodePathfinder = spf;
    tf->scheme = scheme;

    return tf;
}

void TestFramework_assertLastMessageUnaltered(struct TestFramework* tf)
{
    if (!tf->lastMsg) {
        return;
    }
    Message_t* a = tf->lastMsg;
    Message_t* b = tf->lastMsgBackup;
    Assert_true(Message_getLength(a) == Message_getLength(b));
    Assert_true(Message_getPadding(a) == Message_getPadding(b));
    Assert_true(!Bits_memcmp(Message_bytes(a), Message_bytes(b), Message_getLength(a)));
}

void TestFramework_linkNodes(struct TestFramework* client,
                             struct TestFramework* server,
                             bool beacon)
{
    // ifaceA is the client, ifaceB is the server
    struct TestFramework_Link* link =
        Allocator_calloc(client->alloc, sizeof(struct TestFramework_Link), 1);
    Identity_set(link);
    link->clientIf.send = sendClient;
    link->serverIf.send = sendServer;
    link->client = client;
    link->server = server;

    struct InterfaceController_Iface* clientIci = InterfaceController_newIface(
        client->nc->ifController, String_CONST("client"), client->alloc);
    link->clientIfNum = clientIci->ifNum;
    Iface_plumb(&link->clientIf, &clientIci->addrIf);

    struct InterfaceController_Iface* serverIci = InterfaceController_newIface(
        server->nc->ifController, String_CONST("server"), server->alloc);
    link->serverIfNum = serverIci->ifNum;
    Iface_plumb(&link->serverIf, &serverIci->addrIf);

    if (beacon) {
        int ret = InterfaceController_beaconState(client->nc->ifController,
                                           link->clientIfNum,
                                           InterfaceController_beaconState_newState_ACCEPT);
        Assert_true(!ret);

        ret = InterfaceController_beaconState(server->nc->ifController,
                                       link->serverIfNum,
                                       InterfaceController_beaconState_newState_SEND);
        Assert_true(!ret);
    } else {
        // Except that it has an authorizedPassword added.
        Ca_addUser(String_CONST("abcdefg123"), String_CONST("TEST"), server->nc->ca);

        // Client has pubKey and passwd for the server.
        InterfaceController_bootstrapPeer(client->nc->ifController,
                                   link->clientIfNum,
                                   server->publicKey,
                                   Sockaddr_LOOPBACK,
                                   String_CONST("abcdefg123"),
                                   NULL,
                                   NULL,
                                   Version_CURRENT_PROTOCOL);
    }
}

void TestFramework_craftIPHeader(Message_t* msg, uint8_t srcAddr[16], uint8_t destAddr[16])
{
    Err_assert(Message_eshift(msg, Headers_IP6Header_SIZE));
    struct Headers_IP6Header* ip = (struct Headers_IP6Header*) Message_bytes(msg);

    ip->versionClassAndFlowLabel = 0;
    ip->flowLabelLow_be = 0;
    ip->payloadLength_be = Endian_hostToBigEndian16(Message_getLength(msg) - Headers_IP6Header_SIZE);
    ip->nextHeader = 123; // made up number
    ip->hopLimit = 255;
    Bits_memcpy(ip->sourceAddr, srcAddr, 16);
    Bits_memcpy(ip->destinationAddr, destAddr, 16);
    Headers_setIpVersion(ip);
}

int TestFramework_peerCount(struct TestFramework* node)
{
    struct Allocator* alloc = Allocator_child(node->alloc);
    struct InterfaceController_PeerStats* statsOut = NULL;
    int len = InterfaceController_getPeerStats(node->nc->ifController, alloc, &statsOut);
    int out = 0;
    for (int i = 0; i < len; i++) {
        out += (statsOut[i].state == InterfaceController_PeerState_ESTABLISHED);
    }
    Allocator_free(alloc);
    return out;
}

int TestFramework_sessionCount(struct TestFramework* node)
{
    struct Allocator* alloc = Allocator_child(node->alloc);
    struct SessionManager_HandleList* list = SessionManager_getHandleList(node->nc->sm, alloc);
    int count = 0;
    for (int i = 0; i < list->length; i++) {
        struct SessionManager_Session* sess =
            SessionManager_sessionForHandle(list->handles[i], node->nc->sm);
        count += (Ca_getState(sess->caSession) == Ca_State_ESTABLISHED);
    }
    Allocator_free(alloc);
    return count;
}