#include <utility>

#include <utility>

/**
 * Necronda Web Server 3.0
 * client.cpp - Client and Connection handler
 * Lorenz Stechauner, 2018-05-16
 */


#include <string>
#include <iostream>
#include <zlib.h>
#include <cassert>
#include <fstream>
#include <openssl/md5.h>
#include <cstring>
#include <fcntl.h>
#include <sstream>
#include <netinet/in.h>
#include <netinet/tcp.h>

#include "network/Socket.h"
#include "network/http/HttpRequest.h"
#include "network/http/HttpConnection.h"
#include "necronda-server.h"
#include "network/http/HttpStatusCode.h"
#include "URI.h"
#include "procopen.h"
#include "network/Address.h"


typedef struct {
    string host;
    string cc;
    string country;
    string prov;
    string provname;
    string city;
    string timezone;
    string localdate;
} IpAddressInfo;


void log_to_file(const char *prefix, const string &str, string host) {
    //FILE *file = fopen((getWebRoot(std::move(host)) + ".access.log").c_str(), "a");
    //fprintf(file, "%s%s\r\n", prefix, str.c_str());
    //fflush(file);
    //fclose(file);
}

void log_error_to_file(const char *prefix, const string &str, string host) {
    log_to_file(prefix, "\x1B[1;31m" + str + "\x1B[0m", std::move(host));
}

/**
 * Writes log messages to the console
 * @param prefix The connection prefix
 * @param str The string to be written
 */
void log(const char *prefix, const string &str) {
    printf("%s%s\r\n", prefix, str.c_str());
    flush(cout);
}

void log_error(const char *prefix, const string &str) {
    log(prefix, "\x1B[1;31m" + str + "\x1B[0m");
}

void php_error_handler(const char *prefix, FILE *stderr) {
    string line;
    while (!(line = read_line(stderr)).empty()) {
        log_error(prefix, line);
    }
    fclose(stderr);
}

IpAddressInfo get_ip_address_info(Address* addr) {
    FILE *name = popen(("/opt/ipinfo/ipinfo.py " + addr->toString()).c_str(), "r");
    char hostbuffer[1024];
    memset(hostbuffer, 0, 1024);
    size_t size = fread(hostbuffer, 1, 1024, name);
    istringstream buffer(hostbuffer);
    string line;

    IpAddressInfo info;
    int num = 0;
    while (std::getline(buffer, line)) {
        switch (num) {
            case 0: info.host = line; break;
            case 1: info.cc = line; break;
            case 2: info.country = line; break;
            case 3: info.prov = line; break;
            case 4: info.provname = line; break;
            case 5: info.city = line; break;
            case 6: info.timezone = line; break;
            case 7: info.localdate = line; break;
        }
        num++;
    }
    return info;
}

string get_os_info(int fd) {
    struct tcp_info ti;
    socklen_t tisize = sizeof(ti);
    getsockopt(fd, IPPROTO_TCP, TCP_INFO, &ti, &tisize);

    int ttl;
    socklen_t ttlsize = sizeof(ttl);
    getsockopt(fd, IPPROTO_IP, IP_TTL, &ttl, &ttlsize);

    return "win_size=" + to_string(ti.tcpi_rcv_space) + ", ttl=" + to_string(ttl);
}

string getETag(string filename) {
    ifstream etags = ifstream("/var/necronda/ETags");

    ifstream a = ifstream();
    string line;
    int index = 0;
    int i = 0;
    string timestamp = getTimestamp(filename);
    long size = getFileSize(filename);
    while (getline(etags, line)) {
        i++;
        if (line == filename) {
            index = i;
            break;
        }
        long p1 = line.find(':');
        if (p1 == string::npos) continue;
        long p2 = line.find(':', (unsigned) p1 + 1);
        if (p2 == string::npos) continue;
        long p3 = line.find(':', (unsigned) p2 + 1);
        if (p3 == string::npos) continue;
        string FILENAME = line.substr(0, (unsigned) p1);
        string HASH = line.substr((unsigned) p1 + 1, (unsigned) (p2 - p1));
        string TIMESTAMP = line.substr((unsigned) p2 + 1, (unsigned) (p3 - p2));
        long SIZE = strtol(line.substr((unsigned) p3 + 1, line.length() - p3).c_str(), nullptr, 10);
        if (FILENAME == filename) {
            index = i;
            if (timestamp != TIMESTAMP || size != SIZE) {
                break;
            } else {
                etags.close();
                return HASH;
            }
        }
    }
    etags.close();

    MD5_CTX mdContext;
    MD5_Init(&mdContext);
    size_t bytes;
    char buffer[4096];
    FILE *file = fopen(filename.c_str(), "rb");
    if (file == nullptr) {
        throw (char *) "Invalid file";
    }
    while ((bytes = fread(buffer, 1, 4096, file)) != 0) {
        MD5_Update(&mdContext, buffer, bytes);
    }
    fclose(file);
    unsigned char md[16];
    MD5_Final(md, &mdContext);
    char md5buff[32];
    for (int i = 0; i < 16; i++) {
        sprintf(md5buff + i * 2, "%02x", md[i]);
    }
    string md5 = string(md5buff);

    if (index == 0) {
        char buff[256];
        sprintf(buff, "%s:%s:%s:%ld\n", filename.c_str(), md5.c_str(), timestamp.c_str(), size);
        FILE *f = fopen("/var/necronda/ETags", "a");
        if (f == nullptr) {
            throw (char *) strerror(errno);
        }
        fseek(f, 0, SEEK_END);
        fwrite(buff, 1, strlen(buff), f);
        fflush(f);
        fclose(f);
    } else {

    }

    return md5;
}

#include <iostream>
#include <wait.h>
#include <thread>


long getPosition(std::string str, char c, int occurence) {
    int tempOccur = 0;
    int num = 0;
    for (auto it : str) {
        num++;
        if (it == c) {
            if (++tempOccur == occurence) {
                return num;
            }
        }
    }

    return -1;
}

int websocket_handler(Socket *socket, stds *pipes) {
    fd_set readfd;
    int maxfd = (socket->getFd() > pipes->stdout->_fileno) ? socket->getFd() : pipes->stdout->_fileno;
    FD_ZERO(&readfd);
    FD_SET(socket->getFd(), &readfd);
    FD_SET(pipes->stdout->_fileno, &readfd);

    while (true) {
        int ret = ::select(maxfd + 1, &readfd, nullptr, nullptr, nullptr);
        if (ret < 0) {
            throw (char *) strerror(errno);
        }
    }
}

/**
 * Handles (keep-alive) HTTP connections
 * @param prefix The connection prefix
 * @param socket The socket
 * @param id The client ID
 * @param num The Connection Number in the client
 * @return Should the server wait for another header?
 */
bool connection_handler(const char *preprefix, const char *col1, const char *col2, Socket *socket, long id, long num, IpAddressInfo *info) {
    bool error = false;
    char buffer[1024];
    char *prefix = (char *) preprefix;

    HttpConnection req;
    try {
        req = HttpConnection(socket);
    } catch (char *msg) {
        try {
            if (msg == "Malformed header") {
                log(prefix, "Unable to parse header: Malformed header");
                socket->send("HTTP/1.1 400 Bad Request\r\nConnection: close\r\n\r\n");
                error = true;
            } else if (msg == "timeout") {
                log(prefix, "Timeout!");
                socket->send("HTTP/1.1 408 Request Timeout\r\nConnection: close\r\n\r\n");
                error = true;
            } else {
                log(prefix, (string) "Unable to receive from socket: " + msg);
                error = true;
            }
        } catch (char *msg2) {

        }
    }

    try {
        bool noRedirect, redir, invalidMethod, etag, compress, websocket;
        URI path;
        pid_t childpid;
        FILE *file;
        int statuscode;
        string hash, type, host;
        thread *t;
        long pos;
        stds pipes;

        if (req.isExistingField("Connection") && req.getField("Connection") == "keep-alive") {
            req.setField("Connection", "keep-alive");
            req.setField("Keep-Alive", "timeout=3600, max=100");
        } else {
            req.setField("Connection", "close");
            error = true;
        }

        host = "";

        if (!req.isExistingField("Host")) {
            req.respond(400);
            goto respond;
        }
        host = req.getField("Host");
        pos = host.find(':');
        if (pos != string::npos) {
            host.erase(pos, host.length() - pos);
        }

        /*
        FILE *name = popen(("dig @8.8.8.8 +time=1 -x " + socket->getPeerAddress()->toString() +
                            " | grep -oP \"^[^;].*\\t\\K([^ ]*)\\w\"").c_str(), "r");
        char hostbuffer[1024];
        memset(hostbuffer, 0, 1024);
        size_t size = fread(hostbuffer, 1, 1024, name);
        hostbuffer[size - 1] = 0; // remove \n
        if (size <= 1) {
            sprintf(hostbuffer, "%s", socket->getPeerAddress()->toString().c_str());
        }
        */

        sprintf(buffer, "[\x1B[1m%s\x1B[0m][%i]%s[%s][%i]%s ", host.c_str(), socket->getSocketPort(), col1,
                info->host.c_str(), socket->getPeerPort(), col2);
        prefix = buffer;

        log(prefix, "\x1B[1m" + req.getMethod() + " " + req.getPath() + "\x1B[0m");
        log_to_file(prefix, "\x1B[1m" + req.getMethod() + " " + req.getPath() + "\x1B[0m", host);

        noRedirect = req.getPath().find("/.well-known/") == 0 || (req.getPath().find("/files/") == 0);
        redir = true;
        if (!noRedirect) {
            if (getWebRoot(host).empty()) {
                req.redirect(303, "https://www.necronda.net" + req.getPath());
            } else if (socket->getSocketPort() != 443) {
                req.redirect(302, "https://" + host + req.getPath());
            } else {
                redir = false;
            }
        } else {
            redir = false;
        }

        path = URI(getWebRoot(host), req.getPath());
        childpid = 0;

        if (redir) {
            goto respond;
        } else if (!path.getNewPath().empty() && req.getMethod() != "POST") {
            req.redirect(303, path.getNewPath());
            goto respond;
        }

        file = path.openFile();
        if (file == nullptr) {
            req.setField("Cache-Control", "public, max-age=60");
            req.respond(404);
            goto respond;
        }
        type = path.getFileType();

        if (type.find("inode/") == 0 || (path.getRelativeFilePath().find("/.") != string::npos && !noRedirect)) {
            req.respond(403);
            goto respond;
        }

        req.setField("Content-Type", type);
        req.setField("Last-Modified", getHttpDate(path.getFilePath()));

        invalidMethod = false;
        etag = false;

        if (path.isStatic()) {
            hash = getETag(path.getFilePath());
            req.setField("ETag", hash);
            req.setField("Accept-Ranges", "bytes");
            if (type.find("text/") == 0) {
                req.setField("Cache-Control", "public, max-age=3600");
            } else {
                req.setField("Cache-Control", "public, max-age=86400");
            }
            req.setField("Allow", "GET");
            if (req.getMethod() != "GET") {
                invalidMethod = true;
            }
            if (req.isExistingField("If-None-Match") && req.getField("If-None-Match") == hash) {
                etag = true;
            }
        } else {
            req.setField("Accept-Ranges", "none");
            req.setField("Cache-Control", "private, no-cache");
            req.setField("Allow", "GET, POST, PUT");
            if (req.getMethod() != "GET" && req.getMethod() != "POST" && req.getMethod() != "PUT") {
                invalidMethod = true;
            }
        }

        if (invalidMethod) {
            req.respond(405);
            goto respond;
        } else if (etag) {
            req.respond(304);
            goto respond;
        }

        statuscode = 0;
        if (!path.isStatic()) {
            string cmd = (string) "env -i" +
                         " REDIRECT_STATUS=" + cli_encode("CGI") +
                         " DOCUMENT_ROOT=" + cli_encode(getWebRoot(host)) +
                         " " + req.cgiExport() +
                         (req.isExistingField("Content-Length") ? " CONTENT_LENGTH=" +
                                                                  cli_encode(req.getField(
                                                                          "Content-Length"))
                                                                : "") +
                         (req.isExistingField("Content-Type") ? " CONTENT_TYPE=" + cli_encode(
                                 req.getField("Content-Type")) : "") +
                         ((socket->isSecured()) ? " HTTPS=on" : "") +
                         " PATH_INFO=" + cli_encode(path.getFilePathInfo()) +
                         " PATH_TRANSLATED=" + cli_encode(path.getAbsolutePath()) +
                         " QUERY_STRING=" + cli_encode(path.getQuery()) +
                         " REMOTE_ADDR=" + cli_encode(socket->getPeerAddress()->toString()) +
                         " REMOTE_HOST=" + cli_encode(info->host) +
                         " REMOTE_PORT=" + cli_encode(to_string(socket->getPeerPort())) +
                         " REQUEST_METHOD=" + cli_encode(req.getMethod()) +
                         " REQUEST_URI=" + cli_encode(req.getPath()) +
                         " SCRIPT_FILENAME=" + cli_encode(path.getFilePath()) +
                         " SCRIPT_NAME=" + cli_encode(path.getRelativePath()) +
                         " SERVER_ADMIN=" + cli_encode("lorenz.stechauner@gmail.com") +
                         " SERVER_NAME=" + cli_encode(host) +
                         " SERVER_PORT=" + cli_encode(to_string(socket->getSocketPort())) +
                         " SERVER_SOFTWARE=" + cli_encode("Necronda 3.0") +
                         " SERVER_PROTOCOL=" + cli_encode("HTTP/1.1") +
                         " GATEWAY_INTERFACE=" + cli_encode("CGI/1.1") +
                         " /usr/bin/php-cgi";

            pipes = procopen(cmd.c_str());
            childpid = pipes.pid;

            long len = req.isExistingField("Content-Length")
                    ? strtol(req.getField("Content-Length").c_str(), nullptr, 10)
                    : ((req.getMethod() == "POST" || req.getMethod() == "PUT") ? -1 : 0);

            socket->receive(pipes.stdin, len);
            t = new thread(php_error_handler, prefix, pipes.stderr);

            string line;
            while (!(line = read_line(pipes.stdout)).empty()) {
                pos = line.find(':');
                string index = line.substr(0, pos);
                string data = line.substr(pos + 1, line.length() - pos);

                while (index[0] == ' ') index.erase(index.begin() + 0);
                while (index[index.length() - 1] == ' ') index.erase(index.end() - 1);
                while (data[0] == ' ') data.erase(data.begin() + 0);
                while (data[data.length() - 1] == ' ') data.erase(data.end() - 1);

                if (index == "Status") {
                    statuscode = (int) strtol(data.substr(0, 3).c_str(), nullptr, 10);
                } else {
                    if (index == "Location" && statuscode == 0) {
                        statuscode = 303;
                    } else if (index == "Content-Type") {
                        type = data;
                    }
                    req.setField(index, data);
                }
            }

            websocket = statuscode == 101 && req.isExistingResponseField("Connection") && req.getResponseField("Connection") == "upgrade";

            fclose(file);
            file = pipes.stdout;
            if (websocket) {
                req.respond(statuscode);
                goto respond;
            } else {
                fclose(pipes.stdin);
                int c = fgetc(pipes.stdout);
                if (c == -1) {
                    // No Data -> Error
                    req.respond((statuscode == 0) ? 500 : statuscode);
                    goto respond;
                } else {
                    ungetc(c, pipes.stdout);
                }
            }
        }

        statuscode = (statuscode == 0) ? 200 : statuscode;

        compress = (type.find("text/") == 0 ||
                            (type.find("application/") == 0 && type.find("+xml") != string::npos) ||
                            type == "application/json" ||
                            type == "application/javascript") &&
                        req.isExistingField("Accept-Encoding") &&
                        req.getField("Accept-Encoding").find("deflate") != string::npos;

        if (compress) {
            req.setField("Accept-Ranges", "none");
        }

        if (compress && req.isExistingField("Range")) {
            req.respond(416);
        } else if (req.isExistingField("Range")) {
            string range = req.getField("Range");
            if (range.find("bytes=") != 0 || !path.isStatic()) {
                req.respond(416);
            } else {
                fseek(file, 0L, SEEK_END);
                long len = ftell(file);
                fseek(file, 0L, SEEK_SET);
                long p = range.find('-');
                if (p == string::npos) {
                    req.respond(416);
                } else {
                    string part1 = range.substr(6, (unsigned long) (p - 6));
                    string part2 = range.substr((unsigned long) (p + 1),
                                                range.length() - p - 1);
                    long num1 = stol(part1, nullptr, 10);
                    long num2 = len - 1;
                    if (!part2.empty()) {
                        num2 = stol(part2, nullptr, 10);
                    }
                    if (num1 < 0 || num1 >= len || num2 < 0 || num2 >= len) {
                        req.respond(416);
                    } else {
                        req.setField("Content-Range",
                                     (string) "bytes " + to_string(num1) + "-" +
                                     to_string(num2) +
                                     "/" + to_string(len));
                        req.respond(206, file, compress, num1, num2);
                    }
                }
            }
        } else {
            req.respond(statuscode, file, compress);
        }

        fclose(file);
        if (childpid > 0) {
            waitpid(childpid, nullptr, 0);
        }

        respond:

        HttpStatusCode status = req.getStatusCode();
        int code = status.code;
        string color;
        string comment;
        if ((code >= 200 && code < 300) || code == 304 || code == 101) {
            color = "\x1B[1;32m"; // Success (Cached, Switching Protocols): Green
        } else if (code >= 100 && code < 200) {
            color = "\x1B[1;93m"; // Continue: Yellow
        } else if (code >= 300 && code < 400) {
            color = "\x1B[1;93m"; // Redirect: Yellow
            comment = " -> " +
                      (req.isExistingResponseField("Location") ? req.getResponseField("Location") : "<invalid>");
        } else if (code >= 400 && code < 500) {
            color = "\x1B[1;31m"; // Client Error: Red
            //comment = " -> " + req.getPath();
        } else if (code >= 500 & code < 600) {
            color = "\x1B[1;31m"; // Server Error: Red
            //comment = " -> " + req.getPath();
        }
        string msg = color + to_string(status.code) + " " + status.message + comment + " (" + formatTime(req.getDuration()) + ")\x1B[0m";
        log(prefix, msg);
        if (!host.empty()) {
            log_to_file(prefix, msg, host);
        }

        if (websocket) {
            websocket_handler(socket, &pipes);
        }
    } catch (char *msg) {
        HttpStatusCode status = req.getStatusCode();
        log(prefix, to_string(status.code) + " " + status.message + " (" + formatTime(req.getDuration()) + ")");
        try {
            if (strncmp(msg, "timeout", strlen(msg)) == 0) {
                log(prefix, "Timeout!");
                req.setField("Connection", "close");
                req.respond(408);
                error = true;
            } else if (strncmp(msg, "Invalid path", strlen(msg)) == 0) {
                log(prefix, "Timeout!");
                req.setField("Connection", "close");
                req.respond(400);
            } else {
                log(prefix, (string) "Unable to receive from socket: " + msg);
                error = true;
            }
        } catch (char *msg2) {

        }
    }
    return !error;
}

/**
 * Handles HTTP clients
 * @param socket The socket
 * @param id The client ID
 */
void client_handler(Socket *socket, long id, bool ssl) {
    const char *prefix;
    char const *col1;
    char const *col2 = "\x1B[0m";
    IpAddressInfo info = get_ip_address_info(socket->getPeerAddress());
    auto os = get_os_info(socket->getFd());
    {
        auto group = (int) (id % 6);
        if (group == 0) {
            col1 = "\x1B[0;31m"; // Red
        } else if (group == 1) {
            col1 = "\x1B[0;32m"; // Green
        } else if (group == 2) {
            col1 = "\x1B[0;34m"; // Blue
        } else if (group == 3) {
            col1 = "\x1B[0;33m"; // Yellow
        } else if (group == 4) {
            col1 = "\x1B[0;35m"; // Magenta
        } else {
            col1 = "\x1B[0;36m"; // Cyan
        }

        string *a = new string("[" + socket->getSocketAddress()->toString() + "][" +
                               to_string(socket->getSocketPort()) + "]" + col1 +
                               "[" + info.host + "][" + to_string(socket->getPeerPort()) +
                               "]" + col2 + " ");
        prefix = a->c_str();
    }

    log(prefix, "Connection established");
    log(prefix, string("Host: ") + info.host + " (" + socket->getPeerAddress()->toString() + ")");
    log(prefix, string("OS: ") + os);
    log(prefix, string("Location: ") + info.cc + "/" + info.country + ", " + info.prov + "/" + info.provname + ", " + info.city);
    log(prefix, string("Local Date: ") + info.localdate + " (" + info.timezone + ")");


    bool err = false;
    try {
        socket->setReceiveTimeout(3600000);
        socket->setSendTimeout(36000000);
    } catch (char *msg) {
        log(prefix, (string) "Unable to set timeout on socket: " + msg);
        err = true;
    }

    try {
        if (ssl) {
            //socket->sslHandshake("/home/lorenz/Documents/Projects/Necronda-Server/necronda-server-3.0/privkey.pem",
            //                     "/home/lorenz/Documents/Projects/Necronda-Server/necronda-server-3.0/fullchain.pem");
            socket->sslHandshake("/cert/necronda.net/privkey.pem",
                                 "/cert/necronda.net/fullchain.pem");
        }
    } catch (char *msg) {
        log(prefix, (string) "Unable to perform handshake: " + msg);
        err = true;
    }

    long reqnum = 0;
    if (!err) {
        while (connection_handler(prefix, col1, col2, socket, id, ++reqnum, &info));
        reqnum--;
    }

    log(prefix,
        "Connection terminated (#:" + to_string(reqnum) + ", R: " + formatSize(socket->getBytesReceived()) + ", S: " +
        formatSize(socket->getBytesSent()) + ", T: " + formatTime(socket->getDuration()) + ")");
    socket->close();
}