use std::{
    fs::{File, OpenOptions},
    io::{Read, Seek, SeekFrom},
    path::PathBuf,
    sync::mpsc::{channel, Receiver, Sender},
    time::Duration,
};

use notify::{event, Config, PollWatcher, RecursiveMode, Watcher, Event};
use regex::Regex;

#[cfg(target_os = "windows")]
use std::os::windows::fs::OpenOptionsExt;

struct LogFileReader {
    tx: Sender<String>,
    file_path: PathBuf,
    contents: Vec<u8>,
    position: u64,
}

impl Drop for LogFileReader {
    fn drop(&mut self) {
        log::debug!("LogFileReader dropped");
    }
}

#[cfg(target_os = "windows")]
fn share_mode(options: &mut OpenOptions) {
    options.share_mode(0x00000004 | 0x00000001 | 0x00000002);
}

#[cfg(not(target_os = "windows"))]
fn share_mode(options: &mut OpenOptions) {}

impl LogFileReader {
    fn new(file: &PathBuf, tx: Sender<String>) -> Result<Self, std::io::Error> {
        let mut lfr = LogFileReader {
            tx,
            file_path: file.to_path_buf(),
            contents: Vec::new(),
            position: 0,
        };

        let mut options = OpenOptions::new();

        options.read(true).write(false);

        share_mode(&mut options);

        let mut file = options.open(file)?;
        lfr.position = file
            .seek(SeekFrom::End(0))
            .expect("Could not start at end of file");

        Ok(lfr)
    }

    fn on_write_handler(&mut self) {
        self.contents.truncate(0);

        let mut options = OpenOptions::new();

        options.read(true).write(false);

        share_mode(&mut options);

        let mut file = options
            .open(&self.file_path)
            .expect("Could not re-open file");

        let _ = file.seek(SeekFrom::Start(self.position));

        self.position += file.read_to_end(&mut self.contents).unwrap() as u64;

        for line in String::from_utf8_lossy(&self.contents).lines() {
            let line = line.to_string();
            if !line.is_empty() {
                self.tx.send(line).expect("Could not send line to receiver");
            }
        }

        // do_process(contents)
    }
}

pub fn poe_client_log_receiver(path: PathBuf) -> (Receiver<String>, PollWatcher) {
    let (tx, rx) = channel();
    let mut lfr = LogFileReader::new(&path, tx).unwrap();

    (rx, watch_file_for_writes(path, Box::new(move || lfr.on_write_handler())))
}


const POE_STEAM_APP_ID: u32 = 238960;
pub fn get_poe_path() -> Option<PathBuf> {
    if let Some(mut steam_dir) = steamlocate::SteamDir::locate() {
        if let Some(app) = steam_dir.app(&POE_STEAM_APP_ID) {
            let mut path = app.path.clone();
            path.push("logs");
            path.push("Client.txt");
            return Some(path);
        }
    }

    None
}

#[allow(dead_code)]
fn entered_filtered_rx<'a>(rx: &'a Receiver<String>) -> impl Iterator<Item = String> + 'a {
    rx.iter().filter_map(|str| {
        if str.contains("You have entered ") {
            Some(str)
        } else {
            None
        }
    })
}

/// Returns an iterator of strings with the id
pub fn area_filtered_rx<'a>(rx: &'a Receiver<String>) -> impl Iterator<Item = String> + 'a {
    // Generating level 68 area "1_SideArea5_6" with seed 4103532853
    let reg = Regex::new("Generating level ([0-9]+) area \"(.+)\"").unwrap();
    let area_id_location = 2;
    rx.try_iter().filter_map(move |str| {
        let caps = reg.captures(&str);
        if let Some(caps) = caps {
            Some(caps[area_id_location].to_string())
        } else {
            None
        }
    })
}

pub fn filter_func(str : String) -> Option<String> {
    let reg = Regex::new("Generating level ([0-9]+) area \"(.+)\"").unwrap();
    let area_id_location = 2;

    let caps = reg.captures(&str);
    if let Some(caps) = caps {
        Some(caps[area_id_location].to_string())
    } else {
        None
    }
}

pub fn blocking_area_filtered_rx<'a>(rx: &'a Receiver<String>) -> impl Iterator<Item = String> + 'a {
    // Generating level 68 area "1_SideArea5_6" with seed 4103532853
    
    rx.iter()
}

fn watch_file_for_writes(path: PathBuf, mut on_write_handler: Box<dyn FnMut() + Send>)  -> PollWatcher

{

    // Create a watcher object, delivering debounced events.
    // The notification back-end is selected based on the platform.
    let config = Config::default().with_poll_interval(Duration::from_millis(150));
    let mut watcher = PollWatcher::new(
        move |e: Result<Event, _>| match e {
            Ok(e2) => {
                match e2.kind {
                
				notify::EventKind::Modify(_) => {
                    on_write_handler()
                },
                _ => (),

            }
        },

            e => log::error!("Error watching for file something something: {e:?}"),
        },
        config,
    )
    .unwrap();

    //let mut watcher = watcher(tx, Duration::from_millis(100)).unwrap();

    // Add a path to be watched. All files and directories at that path and
    // below will be monitored for changes.
    watcher
        .watch(path.as_path(), RecursiveMode::NonRecursive)
        .unwrap();
    watcher
}