extern crate lazy_static;
use crate::detections::configs;
use crate::detections::utils;
use crate::detections::utils::get_serde_number_to_string;
use chrono::{DateTime, Local, TimeZone, Utc};
use lazy_static::lazy_static;
use linecount::count_lines;
use regex::Regex;
use serde_json::Value;
use std::collections::BTreeMap;
use std::collections::HashMap;
use std::env;
use std::fs::create_dir;
use std::fs::remove_file;
use std::fs::File;
use std::io::BufWriter;
use std::io::{self, Write};
use std::path::Path;
use std::sync::Mutex;

#[derive(Debug)]
pub struct Message {
    map: BTreeMap<DateTime<Utc>, Vec<DetectInfo>>,
}

#[derive(Debug, Clone)]
pub struct DetectInfo {
    pub filepath: String,
    pub rulepath: String,
    pub level: String,
    pub computername: String,
    pub eventid: String,
    pub alert: String,
    pub detail: String,
}

pub struct AlertMessage {}

lazy_static! {
    pub static ref MESSAGES: Mutex<Message> = Mutex::new(Message::new());
    pub static ref ALIASREGEX: Regex = Regex::new(r"%[a-zA-Z0-9-_]+%").unwrap();
    pub static ref ERROR_LOG_PATH: String = format!(
        "./logs/errorlog-{}.log",
        Local::now().format("%Y%m%d_%H%M%S")
    );
    pub static ref QUIERT_ERRORS_FLAG: bool = configs::CONFIG
        .read()
        .unwrap()
        .args
        .is_present("quiet-errors");
}

#[derive(Copy, Clone)]
/// エラーログに出力したエラー回数を保持した構造体
pub struct Counter {
    pub count: u128,
}

impl Counter {
    pub fn new() -> Self {
        Counter { count: 0 }
    }
    /// エラーログに出力したエラー回数を1増やす
    pub fn countup(mut self) {
        self.count += 1;
    }
}

impl Message {
    pub fn new() -> Self {
        let messages: BTreeMap<DateTime<Utc>, Vec<DetectInfo>> = BTreeMap::new();
        Message { map: messages }
    }

    /// メッセージの設定を行う関数。aggcondition対応のためrecordではなく出力をする対象時間がDatetime形式での入力としている
    pub fn insert_message(
        &mut self,
        target_file: String,
        rule_path: String,
        event_time: DateTime<Utc>,
        level: String,
        computername: String,
        eventid: String,
        event_title: String,
        event_detail: String,
    ) {
        let detect_info = DetectInfo {
            filepath: target_file,
            rulepath: rule_path,
            level: level,
            computername: computername,
            eventid: eventid,
            alert: event_title,
            detail: event_detail,
        };

        match self.map.get_mut(&event_time) {
            Some(v) => {
                v.push(detect_info);
            }
            None => {
                let m = vec![detect_info; 1];
                self.map.insert(event_time, m);
            }
        }
    }

    /// メッセージを設定
    pub fn insert(
        &mut self,
        target_file: String,
        rule_path: String,
        event_record: &Value,
        level: String,
        computername: String,
        eventid: String,
        event_title: String,
        output: String,
    ) {
        let message = &self.parse_message(event_record, output);
        let default_time = Utc.ymd(1970, 1, 1).and_hms(0, 0, 0);
        let time = Message::get_event_time(event_record).unwrap_or(default_time);
        self.insert_message(
            target_file,
            rule_path,
            time,
            level,
            computername,
            eventid,
            event_title,
            message.to_string(),
        )
    }

    fn parse_message(&mut self, event_record: &Value, output: String) -> String {
        let mut return_message: String = output;
        let mut hash_map: HashMap<String, String> = HashMap::new();
        for caps in ALIASREGEX.captures_iter(&return_message) {
            let full_target_str = &caps[0];
            let target_length = full_target_str.chars().count() - 2; // The meaning of 2 is two percent
            let target_str = full_target_str
                .chars()
                .skip(1)
                .take(target_length)
                .collect::<String>();

            if let Some(array_str) = configs::EVENTKEY_ALIAS.get_event_key(&target_str) {
                let split: Vec<&str> = array_str.split(".").collect();
                let mut is_exist_event_key = false;
                let mut tmp_event_record: &Value = event_record.into();
                for s in split {
                    if let Some(record) = tmp_event_record.get(s) {
                        is_exist_event_key = true;
                        tmp_event_record = record;
                    }
                }
                if is_exist_event_key {
                    let hash_value = get_serde_number_to_string(tmp_event_record);
                    if hash_value.is_some() {
                        hash_map.insert(full_target_str.to_string(), hash_value.unwrap());
                    }
                }
            }
        }

        for (k, v) in &hash_map {
            return_message = return_message.replace(k, v);
        }

        return_message
    }

    /// メッセージを返す
    pub fn get(&self, time: DateTime<Utc>) -> Vec<DetectInfo> {
        match self.map.get(&time) {
            Some(v) => v.to_vec(),
            None => Vec::new(),
        }
    }

    /// Messageのなかに入っているメッセージすべてを表示する
    pub fn debug(&self) {
        println!("{:?}", self.map);
    }

    /// 最後に表示を行う
    pub fn print(&self) {
        let mut detect_count = 0;
        for (key, detect_infos) in self.map.iter() {
            for detect_info in detect_infos.iter() {
                println!("{} <{}> {}", key, detect_info.alert, detect_info.detail);
            }
            detect_count += detect_infos.len();
        }
        println!("");
        println!("Total events:{:?}", detect_count);
    }

    pub fn iter(&self) -> &BTreeMap<DateTime<Utc>, Vec<DetectInfo>> {
        &self.map
    }

    pub fn get_event_time(event_record: &Value) -> Option<DateTime<Utc>> {
        let system_time = &event_record["Event"]["System"]["TimeCreated_attributes"]["SystemTime"];
        return utils::str_time_to_datetime(system_time.as_str().unwrap_or(""));
    }

    /// message内のマップをクリアする。テストする際の冪等性の担保のため作成。
    pub fn clear(&mut self) {
        self.map.clear();
    }
}

impl AlertMessage {
    //対象のディレクトリが存在することを確認後、最初の定型文を追加して、ファイルのbufwriterを返す関数
    pub fn create_error_log(path_str: String) {
        let path = Path::new(&path_str);
        if !path.parent().unwrap().exists() {
            create_dir(path.parent().unwrap()).ok();
        }
        // 1行目は必ず実行したコマンド情報を入れておく。
        let mut ret = BufWriter::new(File::create(path).unwrap());

        ret.write(
            format!(
                "user input: {:?}\n",
                format_args!(
                    "{}",
                    env::args()
                        .map(|arg| arg)
                        .collect::<Vec<String>>()
                        .join(" ")
                )
            )
            .as_bytes(),
        )
        .unwrap();
        ret.flush().ok();
    }

    /// ERRORメッセージを表示する関数。error_log_flagでfalseの場合は外部へのエラーログの書き込みは行わずに指定されたwを用いた出力のみ行う。trueの場合はwを用いた出力を行わずにエラーログへの出力を行う
    pub fn alert<W: Write>(w: &mut W, contents: String) -> io::Result<()> {
        if QUIERT_ERRORS_FLAG {
            writeln!(w, "[ERROR] {}", contents)
        } else {
            ok()
        }
    }

    // WARNメッセージを表示する関数
    pub fn warn<W: Write>(w: &mut W, contents: String) -> io::Result<()> {
        if QUIERT_ERRORS_FLAG {
            writeln!(w, "[WARN] {}", contents)
        } else {
            ok()
        }
    }

    /// エラーログへのERRORメッセージの出力数を確認して、0であったらファイルを削除する。1以上あればエラーを書き出した旨を標準出力に表示する
    pub fn output_error_log_exist() {
        let error_log_path_str = ERROR_LOG_PATH.to_string();
        // 1行しかなかった場合は最初に書いたコマンド情報のみと判断して削除する
        if count_lines(File::open(&error_log_path_str).unwrap()).unwrap() == 1 {
            if remove_file(&error_log_path_str).is_err() {
                AlertMessage::alert(
                    &mut std::io::stderr().lock(),
                    format!("failed to remove file. filepath:{}", &error_log_path_str),
                )
                .ok();
            }
            return;
        }
        println!(
            "Generated error was output to {}. Please see the file for details.",
            &error_log_path_str
        );
    }
}

#[cfg(test)]
mod tests {
    use crate::detections::print::{AlertMessage, Message};
    use serde_json::Value;

    #[test]
    fn test_create_and_append_message() {
        let mut message = Message::new();
        let json_str_1 = r##"
        {
            "Event": {
                "EventData": {
                    "CommandLine": "hoge"
                },
                "System": {
                    "TimeCreated_attributes": {
                        "SystemTime": "1996-02-27T01:05:01Z"
                    }
                }
            }
        }
    "##;
        let event_record_1: Value = serde_json::from_str(json_str_1).unwrap();
        message.insert(
            "a".to_string(),
            "test_rule".to_string(),
            &event_record_1,
            "high".to_string(),
            "testcomputer1".to_string(),
            "1".to_string(),
            "test1".to_string(),
            "CommandLine1: %CommandLine%".to_string(),
        );

        let json_str_2 = r##"
    {
        "Event": {
            "EventData": {
                "CommandLine": "hoge"
            },
            "System": {
                "TimeCreated_attributes": {
                    "SystemTime": "1996-02-27T01:05:01Z"
                }
            }
        }
    }
    "##;
        let event_record_2: Value = serde_json::from_str(json_str_2).unwrap();
        message.insert(
            "a".to_string(),
            "test_rule2".to_string(),
            &event_record_2,
            "high".to_string(),
            "testcomputer2".to_string(),
            "2".to_string(),
            "test2".to_string(),
            "CommandLine2: %CommandLine%".to_string(),
        );

        let json_str_3 = r##"
    {
        "Event": {
            "EventData": {
                "CommandLine": "hoge"
            },
            "System": {
                "TimeCreated_attributes": {
                    "SystemTime": "2000-01-21T09:06:01Z"
                }
            }
        }
    }
    "##;
        let event_record_3: Value = serde_json::from_str(json_str_3).unwrap();
        message.insert(
            "a".to_string(),
            "test_rule3".to_string(),
            &event_record_3,
            "high".to_string(),
            "testcomputer3".to_string(),
            "3".to_string(),
            "test3".to_string(),
            "CommandLine3: %CommandLine%".to_string(),
        );

        let json_str_4 = r##"
    {
        "Event": {
            "EventData": {
                "CommandLine": "hoge"
            }
        }
    }
    "##;
        let event_record_4: Value = serde_json::from_str(json_str_4).unwrap();
        message.insert(
            "a".to_string(),
            "test_rule4".to_string(),
            &event_record_4,
            "medium".to_string(),
            "testcomputer4".to_string(),
            "4".to_string(),
            "test4".to_string(),
            "CommandLine4: %CommandLine%".to_string(),
        );

        let display = format!("{}", format_args!("{:?}", message));
        println!("display::::{}", display);
        let expect = "Message { map: {1970-01-01T00:00:00Z: [DetectInfo { filepath: \"a\", rulepath: \"test_rule4\", level: \"medium\", computername: \"testcomputer4\", eventid: \"4\", alert: \"test4\", detail: \"CommandLine4: hoge\" }], 1996-02-27T01:05:01Z: [DetectInfo { filepath: \"a\", rulepath: \"test_rule\", level: \"high\", computername: \"testcomputer1\", eventid: \"1\", alert: \"test1\", detail: \"CommandLine1: hoge\" }, DetectInfo { filepath: \"a\", rulepath: \"test_rule2\", level: \"high\", computername: \"testcomputer2\", eventid: \"2\", alert: \"test2\", detail: \"CommandLine2: hoge\" }], 2000-01-21T09:06:01Z: [DetectInfo { filepath: \"a\", rulepath: \"test_rule3\", level: \"high\", computername: \"testcomputer3\", eventid: \"3\", alert: \"test3\", detail: \"CommandLine3: hoge\" }]} }";
        assert_eq!(display, expect);
    }

    #[test]
    fn test_error_message() {
        let input = "TEST!";
        let stdout = std::io::stdout();
        let mut stdout = stdout.lock();
        AlertMessage::alert(&mut stdout, input.to_string()).expect("[ERROR] TEST!");
    }

    #[test]
    fn test_warn_message() {
        let input = "TESTWarn!";
        let stdout = std::io::stdout();
        let mut stdout = stdout.lock();
        AlertMessage::alert(&mut stdout, input.to_string()).expect("[WARN] TESTWarn!");
    }

    #[test]
    /// outputで指定されているキー(eventkey_alias.txt内で設定済み)から対象のレコード内の情報でメッセージをパースしているか確認する関数
    fn test_parse_message() {
        let mut message = Message::new();
        let json_str = r##"
        {
            "Event": {
                "EventData": {
                    "CommandLine": "parsetest1"
                },
                "System": {
                    "Computer": "testcomputer1",
                    "TimeCreated_attributes": {
                        "SystemTime": "1996-02-27T01:05:01Z"
                    }
                }
            }
        }
    "##;
        let event_record: Value = serde_json::from_str(json_str).unwrap();
        let expected = "commandline:parsetest1 computername:testcomputer1";
        assert_eq!(
            message.parse_message(
                &event_record,
                "commandline:%CommandLine% computername:%ComputerName%".to_owned()
            ),
            expected,
        );
    }
    #[test]
    /// outputで指定されているキーが、eventkey_alias.txt内で設定されていない場合の出力テスト
    fn test_parse_message_not_exist_key_in_output() {
        let mut message = Message::new();
        let json_str = r##"
        {
            "Event": {
                "EventData": {
                    "CommandLine": "parsetest2"
                },
                "System": {
                    "TimeCreated_attributes": {
                        "SystemTime": "1996-02-27T01:05:01Z"
                    }
                }
            }
        }
    "##;
        let event_record: Value = serde_json::from_str(json_str).unwrap();
        let expected = "NoExistKey:%TESTNoExistKey%";
        assert_eq!(
            message.parse_message(&event_record, "NoExistKey:%TESTNoExistKey%".to_owned()),
            expected,
        );
    }
    #[test]
    /// outputで指定されているキー(eventkey_alias.txt内で設定済み)が対象のレコード内に該当する情報がない場合の出力テスト
    fn test_parse_message_not_exist_value_in_record() {
        let mut message = Message::new();
        let json_str = r##"
        {
            "Event": {
                "EventData": {
                    "CommandLine": "parsetest3"
                },
                "System": {
                    "TimeCreated_attributes": {
                        "SystemTime": "1996-02-27T01:05:01Z"
                    }
                }
            }
        }
    "##;
        let event_record: Value = serde_json::from_str(json_str).unwrap();
        let expected = "commandline:parsetest3 computername:%ComputerName%";
        assert_eq!(
            message.parse_message(
                &event_record,
                "commandline:%CommandLine% computername:%ComputerName%".to_owned()
            ),
            expected,
        );
    }
}