//
// Created by miti on 2019-12-28.
//

#include "MainLogic.h"
#include "crypto.h"
#include "stdio.h"
#include <errno.h>
#include <string.h>

// For socket programming
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define DECRYPTOR_PORT_DATA 3825
#define DECRYPTOR_PORT_HEADERS 3830

// Sets up a socket connected to the port passed as input - returns the socket FD on success and -1 on error.
// Also prints the errno on error.
int MainLogic::set_up_socket_connect(int port)
{
    int sock = 0;
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        printf("\n Error in socket call - errno is %d \n", errno); fflush(stdout);
        return -1;
    }

    struct sockaddr_in serv_addr;
    memset(&serv_addr, '0', sizeof(serv_addr));

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(port);

    // Convert IPv4 and IPv6 addresses from text to binary form
    if(inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr)<=0)
    {
        printf("\nError in inet_pton - errno is %d\n", errno); fflush(stdout);
        return -1;
    }

    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
    {
        printf("\nError in connect - errno is %d \n", errno); fflush(stdout);
        return -1;
    }

    return sock;
}

int MainLogic::conduct_la_get_initial_header(int data_fd, int headers_fd)
{
    uint8_t key[16];
    uint32_t ret_status;

    // Conduct LA.
    ret_status = laInitiator.conduct_la(data_fd);
    if (ret_status != 0) {
        printf("LA initiator returned an error: %d\n", ret_status);
        fflush(stdout);
        return ret_status;
    }
    printf("\nSuccessful LA with port %d.\n", data_fd);
    fflush(stdout);

    printf("Setting up fds for post LA messaging.\n");
    fflush(stdout);
    // Use the same channel for sending client data as the one used above for LA messages.
    postLaMessagingData.set_fd(data_fd);
    // Use a different channel for receiving headers asynchronously.
    postLaMessagingHeaders.set_fd(headers_fd);

    // Use the symmetric key from LA to send messages for the rest of the deployment stage.
    printf("Retrieving key from LA inititator.\n ");
    fflush(stdout);
    laInitiator.get_la_symmetric_key(key);
    printf("Setting key for post LA messaging for both data and headers channels.\n ");
    fflush(stdout);
    postLaMessagingData.set_la_symmetric_key(key);
    postLaMessagingHeaders.set_la_symmetric_key(key);

    //     Mitigator-Public-Key:
    return postLaMessagingHeaders.receive_secure_msg(last_header_value);
}

int MainLogic::decode_base64_fields_list(std::vector <std::string> &base64_fields_list, std::vector <std::string> &binary_fields_list)
{
    uint32_t binary_field_size, base64_field_size;
    const char* base64_field_ptr;
    unsigned char* binary_field_ptr = NULL;

    for (auto &base64_field : base64_fields_list)
    {
        base64_field_size = base64_field.size();
        base64_field_ptr = base64_field.c_str();
        // upper limit - the binary data will always be smaller than this (base64 length ~= 4/3 * binary length)
        binary_field_ptr = (unsigned char*) realloc(binary_field_ptr, base64_field_size);
        binary_field_size = base64_decoding_wrapper(base64_field_ptr, base64_field_size, binary_field_ptr);
        if(binary_field_size <= 0)
        {
            free(binary_field_ptr);
            return 0x1;
        }
        binary_fields_list.push_back(std::string(reinterpret_cast<const char*> (binary_field_ptr), binary_field_size));
    }
    return 0;
}

void MainLogic::deployment_stage() {
    setbuf(stdout,NULL);
    int data_fd = set_up_socket_connect(DECRYPTOR_PORT_DATA);
    if(data_fd <= 0)
    {
        // TODO: Proper error handling.
        printf("Could not set up a socket with port %d\n", DECRYPTOR_PORT_DATA);
        fflush(stdout);
        return;
    }

    int headers_fd = set_up_socket_connect(DECRYPTOR_PORT_HEADERS);
    if(headers_fd <= 0)
    {
        // TODO: Proper error handling.
        printf("Could not set up a socket with port %d\n", DECRYPTOR_PORT_HEADERS);
        fflush(stdout);
        return;
    }

    int ret_status = conduct_la_get_initial_header(data_fd, headers_fd);
    if(ret_status != 0) {
        printf("Error in deployment stage: %d.\n", ret_status);
        fflush(stdout);
        return;
    }

    // time_file_fd=open("target_time.txt", O_APPEND | O_WRONLY);
}

Php::Value MainLogic::php_decrypt_wrapper(Php::Parameters &params  ) {
    std::vector <std::string> base64_fields_list, binary_fields_list, plaintext_fields_list;
    uint32_t ret_status;
    Php::Object ret_object;
    ret_object["success"]="false";

    base64_fields_list = Php::array_values(params);
    ret_status = decode_base64_fields_list(base64_fields_list, binary_fields_list);
    if(ret_status != 0)
    {
        printf("Could not perform base64 decoding correctly."); fflush(stdout);
        ret_object["error"]="Could not perform base64 decoding correctly.";
        return ret_object;
    }

    ret_status = postLaMessagingData.send_secure_msgs(binary_fields_list);
    if(ret_status != 0)
    {
        printf("Cannot send messages to the decryptor.\n"); fflush(stdout);
        ret_object["error"]="Cannot send messages to the decryptor.\n";
        return ret_object;
    }

    ret_status = postLaMessagingData.receive_secure_msgs(plaintext_fields_list);
    if(ret_status != 0)
    {
        printf("Cannot receive messages from the decryptor.\n"); fflush(stdout);
        ret_object["error"]="Cannot receive messages from the decryptor.\n";
        return ret_object;
    }
    ret_object["success"]="true";
    ret_object["fields"]=Php::Array(plaintext_fields_list);

    return ret_object;
}

Php::Value MainLogic::get_mitigator_header() {
    std::string header_value;
    uint32_t ret_status;
    if(header_refresh_counter < 100)
    {
        header_value = last_header_value;
        header_refresh_counter++;
    }
    else
    {
        ret_status = postLaMessagingHeaders.receive_secure_msg(header_value);
        if(ret_status != 0)
        {
            printf(" Cannot obtain a header from the decryptor.\n"); fflush(stdout);
            header_value = "!! Cannot obtain a header from the decryptor.";
        }
        header_refresh_counter = 0;
    }
    return header_value;
}