//! Code Name rama - Rede an mein Auto

use std::io::{Write, Read};
use std::process::{Command, Stdio};
use std::collections::HashMap;
use std::thread::sleep;
use std::time::{Duration, Instant};

const NEW_TEXT: &str = "NEW";
const CHANGED_TEXT: &str = " * ";
const OLD_TEXT: &str = "   ";

fn main() {
    sudo::escalate_if_needed().unwrap();
    let user_message_timeout = Duration::from_secs(10);
    
    let cmd = "candump";
    let args = ["can0"];
    //let mut db: HashMap<String, Vec<u8>> = HashMap::new();
    let mut db = HashMap::new();
    let mut db_last = HashMap::new();
    let command = Command::new(cmd)
        .args(args.iter())
        .stdout(Stdio::piped())
        .spawn();
    let mut zero_read_count = 0usize;
    let mut last_user_message = Instant::now();
    let mut last_can_data = Instant::now();
    if let Ok(mut child) = command {
        let stdout = child.stdout.as_mut().expect("Failed to open stdout");
        //let mut buf = String::new();
        let mut i = 0usize;
        loop {
            //debug!("DBG start");
        
            let mut buffer = [0; 1024];
            let len = stdout.read(&mut buffer).expect("unable to read");
            zero_read_count = if len == 0 {
                zero_read_count + 1
            } else {
                last_can_data = Instant::now();
                0
            };
            //debug!("DBG read");
            if zero_read_count > 50 {
                eprintln!("unable to read for {} cycles. Aborting!", zero_read_count);
                break;
            }
            let latest = String::from_utf8_lossy(&buffer[0..len]);
            //buf += latest;
            
            for line in latest.lines() {
                let mut parts = line.trim().split("  ");
                let (_dev, id, _len, data) = (parts.next().expect("no dev")
                                        , parts.next().expect("no id")
                                        , parts.next().expect("no len")
                                        , parts.next().expect("no data"));
                //db.entry(id.to_string()).or_insert(data.to_string());
                db.insert(id.to_string(), data.to_string());
            }
            
            if db_last != db {
                println!("{} (len: {}):", i, db.len());
                let mut db_sorted = db.iter().collect::<Vec<_>>();
                db_sorted.sort();
                for e in db_sorted {
                    let new_text = if db_last.contains_key(e.0) {
                        if db_last[e.0] == *e.1 {
                            OLD_TEXT
                        } else {
                            CHANGED_TEXT
                        }
                    } else {NEW_TEXT};
                    println!("{} {}: {}", new_text, e.0, e.1);
                    last_user_message = Instant::now();
                }
            }
            
            i += 1;
            sleep(Duration::from_millis(50));
            
            if last_user_message.elapsed() > user_message_timeout {
                println!("No new CAN data since {}", last_can_data.elapsed().as_secs());
                last_user_message = Instant::now();
            }
            db_last = db.clone();
        }
      
        child.wait().expect("command wasn't running");
        println!("Child has finished its execution!");
    } else {
        println!("{:?} command didn't start", cmd);
    }
}


// 180 : Fernlicht: 00 68 = nomal; 00 78 = Fernlicht
// 180 : [2] = 60 warnblinker; 04 = pipser
// 180 : [2] = 40 blink link, 20 blink rechts
// 2A0 : Geschwindigkeitsanzeige
//: watch -n 0 cansend can0 '2A0#80FF8001' # Tempo & Kilometer ohne Pipsen (8)
//: watch -n 0 cansend can0 '2A0#80FF0000' # Tempo
// 380 : [0] = 2x = Handbremse
// 380 : [0] = 4x = Bremsflüssigkeit
// 380 : [0] = 8x = Bremsbeläge abgenutzt
// 281 : Umdrehungen
///: Setzte ca. 2000 RPM: watch -n 0 cansend can0 '281#0000807C03BF3F00'
///: Ca. 900 rpm => 281: 00 00 40 73 02 04 1F 00
// 380 : [4] Nebelscheinwerfer
// 38A : 1100 Lüftung & Pipsen
// 545 : [3] Aktuelles Stück auf der CD
// 683 : 12 07 26 06
/// Uhrzeit & Datum: Hour Min Day Month