import json
import time

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from nettacker import logger
from nettacker.api.helpers import structure
from nettacker.config import Config
from nettacker.core.messages import messages
from nettacker.database.models import HostsLog, Report, TempEvents

config = Config()
log = logger.get_logger()


def db_inputs(connection_type):
    """
    a function to determine the type of database the user wants to work with and
    selects the corresponding connection to the db

    Args:
        connection_type: type of db we are working with

    Returns:
        corresponding command to connect to the db
    """
    context = Config.db.as_dict()
    return {
        "postgres": "postgresql+psycopg2://{username}:{password}@{host}:{port}/{name}?sslmode={ssl_mode}".format(
            **context
        ),
        "mysql": "mysql+pymysql://{username}:{password}@{host}:{port}/{name}".format(**context),
        "sqlite": "sqlite:///{name}".format(**context),
    }[connection_type]


def create_connection():
    """
    a function to create connections to db with pessimistic approach

    Returns:
        connection if success otherwise False
    """
    connection_args = {}

    if Config.db.engine.startswith("sqlite"):
        connection_args["check_same_thread"] = False

    db_engine = create_engine(
        db_inputs(Config.db.engine),
        connect_args=connection_args,
        pool_size=50,
        pool_pre_ping=True,
    )
    Session = sessionmaker(bind=db_engine)

    return Session()


def send_submit_query(session):
    """
    a function to send submit based queries to db
    (such as insert and update or delete), it retries 100 times if
    connection returned an error.

    Args:
        session: session to commit

    Returns:
        True if submitted success otherwise False
    """
    try:
        for _ in range(1, 100):
            try:
                session.commit()
                return True
            except Exception:
                time.sleep(0.1)
    except Exception:
        log.warn(messages("database_connect_fail"))
        return False
    return False


def submit_report_to_db(event):
    """
    this function created to submit the generated reports into db, the
    files are not stored in db, just the path!

    Args:
        event: event log

    Returns:
        return True if submitted otherwise False
    """
    log.verbose_info(messages("inserting_report_db"))
    session = create_connection()
    session.add(
        Report(
            date=event["date"],
            scan_unique_id=event["scan_id"],
            report_path_filename=event["options"]["report_path_filename"],
            options=json.dumps(event["options"]),
        )
    )
    return send_submit_query(session)


def remove_old_logs(options):
    """
    this function remove old events (and duplicated)
    from nettacker.database based on target, module, scan_id

    Args:
        options: identifiers

    Returns:
        True if success otherwise False
    """
    session = create_connection()
    session.query(HostsLog).filter(
        HostsLog.target == options["target"],
        HostsLog.module_name == options["module_name"],
        HostsLog.scan_unique_id != options["scan_id"],
        HostsLog.scan_unique_id != options["scan_compare_id"],
        # Don't remove old logs if they are to be used for the scan reports
    ).delete(synchronize_session=False)
    return send_submit_query(session)


def submit_logs_to_db(log):
    """
    this function created to submit new events into database

    Args:
        log: log event in JSON type

    Returns:
        True if success otherwise False
    """
    if isinstance(log, dict):
        session = create_connection()
        session.add(
            HostsLog(
                target=log["target"],
                date=log["date"],
                module_name=log["module_name"],
                scan_unique_id=log["scan_id"],
                port=json.dumps(log["port"]),
                event=json.dumps(log["event"]),
                json_event=json.dumps(log["json_event"]),
            )
        )
        return send_submit_query(session)
    else:
        log.warn(messages("invalid_json_type_to_db").format(log))
        return False


def submit_temp_logs_to_db(log):
    """
    this function created to submit new events into database

    Args:
        log: log event in JSON type

    Returns:
        True if success otherwise False
    """
    if isinstance(log, dict):
        session = create_connection()
        session.add(
            TempEvents(
                target=log["target"],
                date=log["date"],
                module_name=log["module_name"],
                scan_unique_id=log["scan_id"],
                event_name=log["event_name"],
                port=json.dumps(log["port"]),
                event=json.dumps(log["event"]),
                data=json.dumps(log["data"]),
            )
        )
        return send_submit_query(session)
    else:
        log.warn(messages("invalid_json_type_to_db").format(log))
        return False


def find_temp_events(target, module_name, scan_id, event_name):
    """
    select all events by scan_unique id, target, module_name

    Args:
        target: target
        module_name: module name
        scan_id: unique scan identifier
        event_name: event_name

    Returns:
        an array with JSON events or an empty array
    """
    session = create_connection()
    try:
        for _ in range(1, 100):
            try:
                return (
                    session.query(TempEvents)
                    .filter(
                        TempEvents.target == target,
                        TempEvents.module_name == module_name,
                        TempEvents.scan_unique_id == scan_id,
                        TempEvents.event_name == event_name,
                    )
                    .first()
                )
            except Exception:
                time.sleep(0.1)
    except Exception:
        log.warn(messages("database_connect_fail"))
        return False
    return False


def find_events(target, module_name, scan_id):
    """
    select all events by scan_unique id, target, module_name

    Args:
        target: target
        module_name: module name
        scan_id: unique scan identifier

    Returns:
        an array with JSON events or an empty array
    """
    session = create_connection()
    return (
        session.query(HostsLog)
        .filter(
            HostsLog.target == target,
            HostsLog.module_name == module_name,
            HostsLog.scan_unique_id == scan_id,
        )
        .all()
    )


def select_reports(page):
    """
    this function created to crawl into submitted results,
    it shows last 10 results submitted in the database.
    you may change the page (default 1) to go to next/previous page.

    Args:
        page: page number

    Returns:
        list of events in array and JSON type, otherwise an error in JSON type.
    """
    selected = []
    session = create_connection()
    try:
        search_data = (
            session.query(Report).order_by(Report.id.desc()).offset((page * 10) - 10).limit(10)
        )
        for data in search_data:
            tmp = {
                "id": data.id,
                "date": data.date,
                "scan_id": data.scan_unique_id,
                "report_path_filename": data.report_path_filename,
                "options": json.loads(data.options),
            }
            selected.append(tmp)
    except Exception:
        return structure(status="error", msg="database error!")
    return selected


def get_scan_result(id):
    """
    this function created to download results by the result ID.

    Args:
        id: scan id

    Returns:
        result file content (TEXT, HTML, JSON) if success otherwise and error in JSON type.
    """
    session = create_connection()
    filename = session.query(Report).filter_by(id=id).first().report_path_filename

    return filename, open(str(filename), "rb").read()


def last_host_logs(page):
    """
    this function created to select the last 10 events from the database.
    you can goto next page by changing page value.

    Args:
        page: page number

    Returns:
        an array of events in JSON type if success otherwise an error in JSON type
    """
    session = create_connection()
    hosts = [
        {
            "target": host.target,
            "info": {
                "module_name": [
                    _.module_name
                    for _ in session.query(HostsLog)
                    .filter(HostsLog.target == host.target)
                    .group_by(HostsLog.module_name)
                    .all()
                ],
                "date": session.query(HostsLog)
                .filter(HostsLog.target == host.target)
                .order_by(HostsLog.id.desc())
                .first()
                .date,
                # "options": [  # unnecessary data?
                #     _.options for _ in session.query(HostsLog).filter(
                #         HostsLog.target == host.target
                #     ).all()
                # ],
                "events": [
                    _.event
                    for _ in session.query(HostsLog).filter(HostsLog.target == host.target).all()
                ],
            },
        }
        for host in session.query(HostsLog)
        .group_by(HostsLog.target)
        .order_by(HostsLog.id.desc())
        .offset((page * 10) - 10)
        .limit(10)
    ]
    if len(hosts) == 0:
        return structure(status="finished", msg="No more search results")
    return hosts


def get_logs_by_scan_id(scan_id):
    """
    select all events by scan id hash

    Args:
        scan_id: scan id hash

    Returns:
        an array with JSON events or an empty array
    """
    session = create_connection()
    return [
        {
            "scan_id": scan_id,
            "target": log.target,
            "module_name": log.module_name,
            "date": str(log.date),
            "port": json.loads(log.port),
            "event": json.loads(log.event),
            "json_event": log.json_event,
        }
        for log in session.query(HostsLog).filter(HostsLog.scan_unique_id == scan_id).all()
    ]


def get_options_by_scan_id(scan_id):
    """
    select all stored options of the scan by scan id hash
    Args:
        scan_id: scan id hash
    Returns:
        an array with a dict with stored options or an empty array
    """
    session = create_connection()
    return [
        {"options": log.options}
        for log in session.query(Report).filter(Report.scan_unique_id == scan_id).all()
    ]


def logs_to_report_json(target):
    """
    select all reports of a host

    Args:
        host: the host to search

    Returns:
        an array with JSON events or an empty array
    """
    try:
        session = create_connection()
        return_logs = []
        logs = session.query(HostsLog).filter(HostsLog.target == target)
        for log in logs:
            data = {
                "scan_id": log.scan_unique_id,
                "target": log.target,
                "port": json.loads(log.port),
                "event": json.loads(log.event),
                "json_event": json.loads(log.json_event),
            }
            return_logs.append(data)
        return return_logs
    except Exception:
        return []


def logs_to_report_html(target):
    """
    generate HTML report with d3_tree_v2_graph for a host

    Args:
        target: the target

    Returns:
        HTML report
    """
    from nettacker.core.graph import build_graph
    from nettacker.lib.html_log import log_data

    session = create_connection()
    logs = [
        {
            "date": log.date,
            "target": log.target,
            "module_name": log.module_name,
            "scan_id": log.scan_unique_id,
            "port": log.port,
            "event": log.event,
            "json_event": log.json_event,
        }
        for log in session.query(HostsLog).filter(HostsLog.target == target).all()
    ]
    html_graph = build_graph("d3_tree_v2_graph", logs)

    html_content = log_data.table_title.format(
        html_graph,
        log_data.css_1,
        "date",
        "target",
        "module_name",
        "scan_id",
        "port",
        "event",
        "json_event",
    )
    for event in logs:
        html_content += log_data.table_items.format(
            event["date"],
            event["target"],
            event["module_name"],
            event["scan_id"],
            event["port"],
            event["event"],
            event["json_event"],
        )
    html_content += (
        log_data.table_end + '<p class="footer">' + messages("nettacker_report") + "</p>"
    )
    return html_content


def search_logs(page, query):
    """
    search in events (host, date, port, module, category, description,
    username, password, scan_id, scan_cmd)

    Args:
        page: page number
        query: query to search

    Returns:
        an array with JSON structure of founded events or an empty array
    """
    session = create_connection()
    selected = []
    try:
        for host in (
            session.query(HostsLog)
            .filter(
                (HostsLog.target.like("%" + str(query) + "%"))
                | (HostsLog.date.like("%" + str(query) + "%"))
                | (HostsLog.module_name.like("%" + str(query) + "%"))
                | (HostsLog.port.like("%" + str(query) + "%"))
                | (HostsLog.event.like("%" + str(query) + "%"))
                | (HostsLog.scan_unique_id.like("%" + str(query) + "%"))
            )
            .group_by(HostsLog.target)
            .order_by(HostsLog.id.desc())
            .offset((page * 10) - 10)
            .limit(10)
        ):
            for data in (
                session.query(HostsLog)
                .filter(HostsLog.target == str(host.target))
                .group_by(
                    HostsLog.module_name,
                    HostsLog.port,
                    HostsLog.scan_unique_id,
                    HostsLog.event,
                )
                .order_by(HostsLog.id.desc())
                .all()
            ):
                n = 0
                capture = None
                for selected_data in selected:
                    if selected_data["target"] == host.target:
                        capture = n
                    n += 1
                if capture is None:
                    tmp = {
                        "target": data.target,
                        "info": {
                            "module_name": [],
                            "port": [],
                            "date": [],
                            "event": [],
                            "json_event": [],
                        },
                    }
                    selected.append(tmp)
                    n = 0
                    for selected_data in selected:
                        if selected_data["target"] == host.target:
                            capture = n
                        n += 1
                if data.target == selected[capture]["target"]:
                    if data.module_name not in selected[capture]["info"]["module_name"]:
                        selected[capture]["info"]["module_name"].append(data.module_name)
                    if data.date not in selected[capture]["info"]["date"]:
                        selected[capture]["info"]["date"].append(data.date)
                    if data.port not in selected[capture]["info"]["port"]:
                        selected[capture]["info"]["port"].append(json.loads(data.port))
                    if data.event not in selected[capture]["info"]["event"]:
                        selected[capture]["info"]["event"].append(json.loads(data.event))
                    if data.json_event not in selected[capture]["info"]["json_event"]:
                        selected[capture]["info"]["json_event"].append(json.loads(data.json_event))
    except Exception:
        return structure(status="error", msg="database error!")
    if len(selected) == 0:
        return structure(status="finished", msg="No more search results")
    return selected