use std::io::{BufRead, BufReader, Write, stdout};
use std::net::TcpStream;
use rusqlite::Connection;
use std::time::Instant;

use crate::connection;
use crate::database;

use crossterm::{event::{read, Event, KeyCode, KeyModifiers}, terminal::{disable_raw_mode, enable_raw_mode, Clear, ClearType}, cursor::{MoveToColumn, Show}, execute};

macro_rules! println {
    () => {
        print!("\r\n")
    };
    ($($arg:tt)*) => {
        print!("\r{}\n", format_args!($($arg)*))
    };
}

pub struct ClientState {
    pub stream: Option<TcpStream>,
    pub conn: Connection,
    pub addr: Option<String>,
    pub default_port: u16,
    pub history: Vec<String>,
    pub history_index: usize,
}

impl ClientState {
    pub fn new() -> Self {
        let conn = database::init_db();
        let default_ip = "127.0.0.1".to_string();
        let default_port = 11525;
        let last_host = database::get_last_host(&conn);
        let default_host = format!("{}:{}", default_ip, default_port);
        let addr = last_host.or(Some(default_host));

        Self {
            stream: None,
            conn,
            addr,
            default_port,
            history: vec![],
            history_index: 0,
        }
    }

    pub fn connect_to(&mut self, addr: &str) {
        self.addr = Some(addr.to_string());
        match connection::connect(addr) {
            Ok(s) => {
                self.stream = Some(s);
                database::save_host(&self.conn, addr);
            }
            Err(e) => println!("Failed to connect: {}", e),
        }
    }

    pub fn run(&mut self) {
        enable_raw_mode().unwrap();
        'outer: loop {
            let mut current_input = String::new();
            self.history_index = self.history.len();
            redraw("");
            loop {
                match read().unwrap() {
                    Event::Key(key) => match key.code {
                        KeyCode::Up => {
                            if self.history_index > 0 {
                                self.history_index -= 1;
                                current_input = self.history[self.history_index].clone();
                                redraw(&current_input);
                            }
                        }
                        KeyCode::Down => {
                            if self.history_index < self.history.len() {
                                self.history_index += 1;
                                current_input = if self.history_index == self.history.len() { "".to_string() } else { self.history[self.history_index].clone() };
                                redraw(&current_input);
                            }
                        }
                        KeyCode::Enter => {
                            let line = current_input.trim().to_string();
                            if !line.is_empty() {
                                self.history.push(line.clone());
                            }
                            // Process command
                            let parts: Vec<&str> = line.splitn(2, ' ').collect();
                            match parts[0] {
                                "connect" => {
                                    let addr_str = if parts.len() < 2 {
                                        if let Some(h) = &self.addr {
                                            h.clone()
                                        } else {
                                            println!("\nNo host specified and no previous connection. Usage: connect <ip>:<port>");
                                            continue 'outer;
                                        }
                                    } else {
                                        let mut a = parts[1].to_string();
                                        if !a.contains(':') {
                                            a = format!("{}:{}", a, self.default_port);
                                        }
                                        a
                                    };
                                    self.connect_to(&addr_str);
                                }
                                "send" => {
                                    if self.stream.is_none() {
                                        println!("\nNot connected. Use 'connect <ip>:<port>' first.");
                                        continue 'outer;
                                    }
                                    if parts.len() < 2 {
                                        println!("\nUsage: send <message>");
                                        continue 'outer;
                                    }
                                    let msg = parts[1];
                                    let s = self.stream.as_mut().unwrap();
                                    let writer_stream = s.try_clone().unwrap();
                                    let mut writer = writer_stream;
                                    let response_reader_stream = s.try_clone().unwrap();
                                    let mut response_reader = BufReader::new(response_reader_stream);
                                    if let Err(_) = writeln!(writer, "{}", msg) {
                                        self.stream = None;
                                        println!("\nConnection lost");
                                        continue 'outer;
                                    }
                                    let mut response = String::new();
                                    if let Err(_) = response_reader.read_line(&mut response) {
                                        self.stream = None;
                                        println!("\nConnection lost");
                                    } else {
                                        println!("\nEcho: {}", response.trim());
                                    }
                                }
                                "disconnect" => {
                                    self.stream = None;
                                    println!("\nDisconnected");
                                }
                                "ping" => {
                                    if self.stream.is_none() {
                                        println!("\nNot connected. Use 'connect <ip>:<port>' first.");
                                        continue 'outer;
                                    }
                                    let s = self.stream.as_mut().unwrap();
                                    let writer_stream = s.try_clone().unwrap();
                                    let mut writer = writer_stream;
                                    let start = Instant::now();
                                    let response_reader_stream = s.try_clone().unwrap();
                                    let mut response_reader = BufReader::new(response_reader_stream);
                                    if let Err(_) = writeln!(writer, "PING") {
                                        self.stream = None;
                                        println!("\nConnection lost");
                                        continue 'outer;
                                    }
                                    let mut response = String::new();
                                    if let Err(_) = response_reader.read_line(&mut response) {
                                        self.stream = None;
                                        println!("\nConnection lost");
                                    } else {
                                        if response.trim() == "PING" {
                                            let elapsed = start.elapsed();
                                            println!("\nPong ({:?})", elapsed);
                                        } else {
                                            self.stream = None;
                                            println!("\nConnection lost");
                                        }
                                    }
                                }
                                "help" => {
                                    help();
                                }
                                "quit" => break 'outer,
                                _ => help(),
                            }
                            break;
                        }
                        KeyCode::Backspace => {
                            if !current_input.is_empty() {
                                current_input.pop();
                                redraw(&current_input);
                            }
                        }
                        KeyCode::Char(c) => {
                            if key.modifiers.contains(KeyModifiers::CONTROL) && c == 'c' {
                                disable_raw_mode().unwrap();
                                execute!(stdout(), Show).unwrap();
                                return;
                            } else {
                                current_input.push(c);
                                redraw(&current_input);
                            }
                        }
                        _ => {}
                    }
                    _ => {}
                }
            }
        }
        disable_raw_mode().unwrap();
        execute!(stdout(), Show).unwrap();
    }
}

fn redraw(current_input: &str) {
    execute!(stdout(), Clear(ClearType::CurrentLine), MoveToColumn(0)).unwrap();
    print!("> {}", current_input);
    stdout().flush().unwrap();
    execute!(stdout(), MoveToColumn((2 + current_input.len()) as u16)).unwrap();
}

fn help() {
    println!("Available commands: connect <ip>:<port>, send <message>, disconnect, ping, help, quit");
}