import dataclasses
import os
import re
import socket
import select
import threading
import time
import logging
import sys
import signal
import pathlib

EXPORTER_LOG = "/exporter-log"

# set format for logs
if os.environ.get("DEBUG"):
    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=logging.DEBUG,
                        handlers=[
                            logging.FileHandler(EXPORTER_LOG), logging.StreamHandler(sys.stdout)
                        ])
else:
    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=logging.INFO,
                        handlers=[
                            logging.FileHandler(EXPORTER_LOG), logging.StreamHandler(sys.stdout)
                        ])


@dataclasses.dataclass
class Environment:
    FUZZ_REGEXP: str
    FUZZ_WORKDIR: str
    FUZZ_LOG_NAME: str
    HOST: str
    PORT: int
    CHECK_INTERVAL: float
    WAIT_LOG: bool
    TIMEOUT_WAIT_LOG: float
    EXPORTER_IGNORE_FILE: str

    def __init__(self):
        self.FUZZ_REGEXP = "([a-z_]*)\s*:\s*([-+]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][-+]?\d+)?)"
        self.FUZZ_WORKDIR = "/workdir"
        self.FUZZ_LOG_NAME = "fuzzer_stats"
        self.HOST = "0.0.0.0"
        self.PORT = 9550
        self.CHECK_INTERVAL = 1.0
        self.WAIT_LOG = False
        self.TIMEOUT_WAIT_LOG = 3.0
        self.EXPORTER_IGNORE_FILE = "/workdir/.expignore"

    def check_system_env(self):
        if os.environ.get("FUZZ_REGEXP"):
            self.FUZZ_REGEXP = os.environ.get("FUZZ_REGEXP")
            logging.debug("FUZZ_REGEXP set from system env.")

        if os.environ.get("FUZZ_WORKDIR"):
            self.FUZZ_WORKDIR = os.environ.get("FUZZ_WORKDIR")
            logging.debug("FUZZ_WORKDIR set from system env.")

        if os.environ.get("FUZZ_LOG_NAME"):
            self.FUZZ_LOG_NAME = os.environ.get("FUZZ_LOG_NAME")
            logging.debug("FUZZ_LOG_NAME set from system env.")

        if os.environ.get("WAIT_LOG"):
            self.WAIT_LOG = bool(os.environ.get("WAIT_LOG"))
            logging.debug("WAIT_LOG set from system env.")

        if os.environ.get("CHECK_INTERVAL"):
            try:
                self.CHECK_INTERVAL = float(os.environ.get("CHECK_INTERVAL"))
                logging.debug("CHECK_INTERVAL set from system env.")
            except Exception:
                logging.error("Failed to set CHECK_INTERVAL from system env.")


@dataclasses.dataclass
class Exporter:
    LISTEN_HOST: str
    LISTEN_PORT: int
    LIST_METRICS: list  # In formant - [["metric_name", "metric_value"], ...]
    # ---
    PREPARE_METRICS: str

    def __init__(self, env: Environment):
        self.LISTEN_HOST = env.HOST
        self.LISTEN_PORT = env.PORT
        self.LIST_METRICS = list()
        self.PREPARE_METRICS = str()

    def update_metric_list(self, metrics_list: list):
        # generating output data for Prometheus in the correct web format
        # without specifying the header, Prometheus cannot receive data
        s = 'HTTP/1.1 200 OK\n\n'
        for m in metrics_list:
            # specifying help info, "." for all metrics
            #            metric type
            #            metric_name metric_value
            s += f"# HELP {m[0]} .\n"
            s += f"# TYPE {m[0]} gauge\n"
            s += f"{m[0]} {m[1]}\n"

        self.PREPARE_METRICS = s
        logging.debug("Convert metrics to Prometheus format")

    def listen(self):
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:

            logging.debug("Socket created")

            try:
                sock.bind((self.LISTEN_HOST, self.LISTEN_PORT))
            except Exporter:
                logging.critical("Failed to bind socket")
                exit(1)

            logging.debug("Socket bound")
            if not self.LISTEN_PORT:
                logging.debug("Listen port - "+str(sock.getsockname()[1]))
            # Check env_net file. If exist write port value inside.
            if os.path.exists("/env_net"):
                with open("/env_net", "w") as env_net:
                    env_net.write("EXPORTER_PORT="+str(sock.getsockname()[1]))
                logging.debug("File env_net exist. Write port value inside")
            sock.listen(10)
            logging.debug('Socket listening')
            inputs = [sock]
            outputs = [sock]
            while True:
                logging.debug("Waiting for clients...")
                reads, writes, excepts = select.select(inputs, outputs, inputs)
                for conn in reads:
                    _conn, client_addr = conn.accept()
                    with _conn as client_conn:
                        ip_addr, client_port = client_addr
                        logging.debug(f'Client connected - {ip_addr}:{client_port}')
                        data = client_conn.recv(1024)
                        logging.debug("Send data")
                        client_conn.send(
                            bytes(self.PREPARE_METRICS, 'utf-8'))  # sending a response prepared for Prometheus


@dataclasses.dataclass
class Parser:
    PATH_TO_WORKDIR: str
    LOG_NAME: str
    REGEXP: str
    WAIT_LOG: bool
    TIMEOUT_WAIT_LOG = float
    IGNORE_LIST: list

    def __init__(self, env: Environment):
        self.PATH_TO_WORKDIR = env.FUZZ_WORKDIR
        self.LOG_NAME = env.FUZZ_LOG_NAME
        self.REGEXP = env.FUZZ_REGEXP
        self.WAIT_LOG = env.WAIT_LOG
        self.TIMEOUT_WAIT_LOG = env.TIMEOUT_WAIT_LOG
        self.IGNORE_LIST = list()

        if os.path.exists(self.PATH_TO_WORKDIR+"/"+'.expignore'):
            with open(self.PATH_TO_WORKDIR+"/"+'.expignore') as f:
                self.IGNORE_LIST = f.read().splitlines()
            logging.info(f"Ignored - {self.IGNORE_LIST}")

    def __check_exists(self, rootPath: str, searchFile: str) -> bool:
        for root, dirs, files in os.walk(rootPath):
            if os.path.exists(os.path.join(root, searchFile)):
                return True
        return False

    def __check_valid_dir(self):
        while True:
            if os.path.exists(self.PATH_TO_WORKDIR):
                if not self.__check_exists(rootPath=self.PATH_TO_WORKDIR, searchFile=self.LOG_NAME):
                    if self.WAIT_LOG:
                        logging.warning("Not found fuzzer_stats files. Waiting to be created")
                        time.sleep(self.TIMEOUT_WAIT_LOG)
                        continue
                    else:
                        logging.critical("Not AFL dir")
                        exit(1)
                else:
                    logging.debug("Check valid dir passed")
                    break
            else:
                if self.WAIT_LOG:
                    logging.warning("Dir not exists. Waiting for directory to be created")
                    time.sleep(self.TIMEOUT_WAIT_LOG)
                    continue
                else:
                    logging.critical("Dir not exists")
                    exit(1)

    def __check_ignore(self, currentPath: str) -> bool:
        for ignore in self.IGNORE_LIST:
            if pathlib.Path(ignore) == pathlib.Path(currentPath):
                return True
        return False

    def __search_fuzz_stats(self) -> list:
        fuzz_stats = list()
        for root, dirs, files in os.walk(self.PATH_TO_WORKDIR):
            if self.LOG_NAME in files:
                if not self.__check_ignore(currentPath=root[len(self.PATH_TO_WORKDIR) + 1:]):
                    fuzz_stats.append([root[len(self.PATH_TO_WORKDIR) + 1:], os.path.join(root, self.LOG_NAME)])
        logging.debug("Get fuzz path - " + str(fuzz_stats))
        return fuzz_stats

    def __get_log(self, path_2log) -> list:
        with open(path_2log, 'r') as file:
            return file.readlines()

    def __re_log(self, search_list: list, sfx: str) -> list:  # search by regular expression in list
        l = list()
        for search_string in search_list:
            res = re.findall(self.REGEXP, search_string)
            if res:
                for i in res:
                    # creating a nested list with the name of metric [0] and its value [1]
                    # in the name of the metric replace all characters with - "_" for correct display in Prometheus
                    if not i[0] or not i[1]:
                        continue
                    l.append([re.sub("\W", "_", i[0]+"_"+sfx), i[1]])
        return l

    def get_metrics(self):
        metrics = list()

        self.__check_valid_dir()

        for i in self.__search_fuzz_stats():
            for j in self.__re_log(self.__get_log(path_2log=i[1]), i[0]):
                metrics.append(j)

        logging.debug("Metrics updated")
        return metrics


@dataclasses.dataclass
class GracefulKiller:
  kill_now: bool

  def __init__(self):
    self.kill_now = False
    signal.signal(signal.SIGINT, self.exit_gracefully)
    signal.signal(signal.SIGTERM, self.exit_gracefully)

  def exit_gracefully(self, *args):
    self.kill_now = True


if __name__ == "__main__":
    # set env
    logging.info("Init environments")
    env1 = Environment()
    env1.check_system_env()

    # init killer by SIGTERM
    killer = GracefulKiller()

    # Start listen exporter
    exporter1 = Exporter(env1)
    exporter_listen_t = threading.Thread(target=exporter1.listen)
    exporter_listen_t.setDaemon(True)
    exporter_listen_t.start()
    logging.info("Exporter started")

    # Start update metrics
    parser1 = Parser(env1)
    logging.info("Start update metrics")
    while not killer.kill_now:
        try:
            exporter1.update_metric_list(parser1.get_metrics())
            time.sleep(env1.CHECK_INTERVAL)

            # Check exporter thread
            if not exporter_listen_t.is_alive():
                logging.error("Exporter thread is down")
                exit(1)

        except Exception as e:
            logging.warning(f"Stop running by {e}")
            exit(1)