/* 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 <http://www.gnu.org/licenses/>.
 */
#include "crypto/random/Random.h"
#include "crypto/CryptoAuth.h"
#include "io/FileWriter.h"
#include "benc/String.h"
#include "memory/MallocAllocator.h"
#include "util/events/EventBase.h"
#include "util/Assert.h"
#include "util/Bits.h"
#include "util/Hex.h"
#include "util/Endian.h"
#include "util/log/WriterLog.h"
#include "wire/Error.h"

#include <stdio.h>

static uint8_t* privateKey = (uint8_t*)
    "\x20\xca\x45\xd9\x5b\xbf\xca\xe7\x35\x3c\xd2\xdf\xfa\x12\x84\x4b"
    "\x4e\xff\xbe\x7d\x39\xd8\x4d\x8e\x14\x2b\x9d\x21\x89\x5b\x38\x09";

static uint8_t* publicKey = (uint8_t*)
    "\x51\xaf\x8d\xd9\x35\xe8\x61\x86\x3e\x94\x2b\x1b\x6d\x21\x22\xe0"
    "\x2f\xb2\xd0\x88\x20\xbb\xf3\xf0\x6f\xcd\xe5\x85\x30\xe0\x08\x34";

static struct CryptoAuth* ca1;
static struct Interface* if1;
static struct Interface* cif1;

static struct CryptoAuth* ca2;
static struct Interface* if2;
static struct Interface* cif2;

static struct Message msg;

#define BUFFER_SIZE 400
static uint8_t* textBuff;
#define ALIGNED_LEN(x) (CString_strlen(x) + 4 - (CString_strlen(x) % 4))
#define MK_MSG(x) \
    Bits_memset(textBuff, 0, BUFFER_SIZE);                                      \
    Bits_memcpy(&textBuff[BUFFER_SIZE - ALIGNED_LEN(x)], x, CString_strlen(x));         \
    msg.length = CString_strlen(x);                                                     \
    msg.bytes = textBuff + BUFFER_SIZE - ALIGNED_LEN(x);                        \
    msg.padding = BUFFER_SIZE - ALIGNED_LEN(x)

static uint8_t* if1Msg;
static uint8_t* if2Msg;

static char* userObj = "This represents a user";

static bool suppressMessages = false;
static int if1Messages = 0;
static int if2Messages = 0;


static uint8_t sendMessageToIf2(struct Message* message, struct Interface* iface)
{
    uint32_t nonce = Endian_bigEndianToHost32(((uint32_t*)message->bytes)[0]);
    printf("sent message -->  nonce=%d%s\n", nonce, suppressMessages ? " SUPPRESSED" : "");
    if (!suppressMessages) {
        Assert_true(message->length + message->padding <= BUFFER_SIZE);
        if2->receiveMessage(message, if2);
    }
    return Error_NONE;
}

static uint8_t sendMessageToIf1(struct Message* message, struct Interface* iface)
{
    uint32_t nonce = Endian_bigEndianToHost32(((uint32_t*)message->bytes)[0]);
    printf("sent message <--  nonce=%d%s\n", nonce, suppressMessages ? " SUPPRESSED" : "");
    if (!suppressMessages) {
        Assert_true(message->length + message->padding <= BUFFER_SIZE);
        if1->receiveMessage(message, if1);
    }
    return Error_NONE;
}

static uint8_t recvMessageOnIf1(struct Message* message, struct Interface* iface)
{
    if1Messages++;
    fputs("if1 got message! ", stdout);
    fwrite(message->bytes, 1, message->length, stdout);
    puts("");
    if1Msg = Message_clone(message, iface->allocator)->bytes;
    return Error_NONE;
}

static uint8_t recvMessageOnIf2(struct Message* message, struct Interface* iface)
{
    if2Messages++;
    fputs("if2 got message! ", stdout);
    fwrite(message->bytes, 1, message->length, stdout);
    puts("");
    if2Msg = Message_clone(message, iface->allocator)->bytes;
    return Error_NONE;
}

static int init(const uint8_t* privateKey,
                uint8_t* publicKey,
                const uint8_t* password)
{
    printf("\nSetting up:\n");
    struct Allocator* allocator = MallocAllocator_new(1048576);
    textBuff = Allocator_malloc(allocator, BUFFER_SIZE);
    struct Writer* logwriter = FileWriter_new(stdout, allocator);
    struct Log* logger = WriterLog_new(logwriter, allocator);
    struct Random* rand = Random_new(allocator, logger, NULL);

    struct EventBase* base = EventBase_new(allocator);

    ca1 = CryptoAuth_new(allocator, NULL, base, logger, rand);
    if1 = Allocator_clone(allocator, (&(struct Interface) {
        .sendMessage = sendMessageToIf2,
        .receiveMessage = recvMessageOnIf2,
        .allocator = allocator
    }));
    cif1 = CryptoAuth_wrapInterface(if1, publicKey, NULL, false, "cif1", ca1);
    cif1->receiveMessage = recvMessageOnIf1;


    ca2 = CryptoAuth_new(allocator, privateKey, base, logger, rand);
    if (password) {
        String passStr = {.bytes=(char*)password,.len=CString_strlen((char*)password)};
        CryptoAuth_setAuth(&passStr, 1, cif1);
        CryptoAuth_addUser(&passStr, 1, String_new(userObj, allocator), ca2);
    }
    if2 = Allocator_clone(allocator, (&(struct Interface) {
        .sendMessage = sendMessageToIf1,
        .allocator = allocator
    }));
    cif2 = CryptoAuth_wrapInterface(if2, NULL, NULL, false, "cif2", ca2);
    cif2->receiveMessage = recvMessageOnIf2;

    return 0;
}

static int simpleInit()
{
    return init(NULL, NULL, NULL);
}

static int sendToIf1(const char* x)
{
    if1Msg = NULL;
    MK_MSG(x);
    cif2->sendMessage(&msg, cif2);
    if (!suppressMessages) {
        Assert_true(if1Msg);
        if (CString_strncmp((char*)if1Msg, x, CString_strlen(x)) != 0) {
            printf("expected %s, got %s\n", x, (char*)if1Msg);
            Assert_true(0);
        }
    } else {
        Assert_true(!if1Msg);
    }
    return 0;
}

static int sendToIf2(const char* x)
{
    if2Msg = NULL;
    MK_MSG(x);
    cif1->sendMessage(&msg, cif1);
    if (!suppressMessages) {
        Assert_true(if2Msg);
        if (CString_strncmp((char*)if2Msg, x, CString_strlen(x)) != 0) {
            printf("expected %s, got %s\n", x, (char*)if2Msg);
            Assert_true(0);
        }
    } else {
        Assert_true(!if2Msg);
    }
    return 0;
}

static int normal()
{
    simpleInit();
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int repeatKey()
{
    simpleInit();
    return
        sendToIf2("hello world")
      | sendToIf2("r u thar?")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int repeatHello()
{
    init(privateKey, publicKey, NULL);
    return
        sendToIf2("hello world")
      | sendToIf2("r u thar?")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int chatter()
{
    simpleInit();
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int auth()
{
    init(privateKey, publicKey, (uint8_t*)"password");
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int authWithoutKey()
{
    init(NULL, NULL, (uint8_t*)"password");
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int poly1305()
{
    init(privateKey, publicKey, NULL);
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int poly1305UnknownKey()
{
    init(NULL, NULL, NULL);
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int poly1305AndPassword()
{
    init(privateKey, publicKey, (uint8_t*)"aPassword");
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static int poly1305UnknownKeyAndPassword()
{
    init(NULL, NULL, (uint8_t*)"anotherPassword");
    return
        sendToIf2("hello world")
      | sendToIf1("hello cjdns")
      | sendToIf2("hai")
      | sendToIf1("goodbye");
}

static void connectToMe()
{
    simpleInit();
    sendToIf1("hello world");
    sendToIf1("hello cjdns");
    sendToIf2("hai");
    sendToIf1("goodbye");
}

static void connectToMeDropMsg()
{
    simpleInit();
    // send a message which is lost in the network.
    suppressMessages = true;
    sendToIf1("hello world");
    suppressMessages = false;

    // Now we learn their key some other way...
    uint8_t* pk = CryptoAuth_getHerPublicKey(cif2);
    Bits_memcpyConst(pk, ca1->publicKey, 32);

    sendToIf1("hello again world");
    sendToIf2("hai");
    sendToIf1("goodbye");
}

int main()
{
    normal();
    repeatKey();
    repeatHello();
    chatter();
    auth();
    authWithoutKey();
    poly1305();
    poly1305UnknownKey();
    poly1305AndPassword();
    poly1305UnknownKeyAndPassword();
    connectToMe();
    connectToMeDropMsg();
    return 0;
}