// client/src/input/inputs.rs

#[cfg(not(coverage))]
use anyhow::bail;
use anyhow::{Context, Result};
use evdev::{AbsoluteAxisCode, Device, EventType, KeyCode, RelativeAxisCode};
use std::collections::HashSet;
use std::time::Instant;
use tokio::{
    sync::broadcast::Sender,
    time::{Duration, interval},
};
use tracing::{debug, info, warn};

use lesavka_common::lesavka::{KeyboardReport, MouseReport};

use super::{keyboard::KeyboardAggregator, mouse::MouseAggregator};
use crate::layout::{Layout, apply as apply_layout};
use tokio::sync::mpsc::UnboundedSender;

pub struct InputAggregator {
    kbd_tx: Sender<KeyboardReport>,
    mou_tx: Sender<MouseReport>,
    dev_mode: bool,
    released: bool,
    magic_active: bool,
    pending_release: bool,
    pending_kill: bool,
    pending_keys: HashSet<KeyCode>,
    paste_tx: Option<UnboundedSender<String>>,
    keyboards: Vec<KeyboardAggregator>,
    mice: Vec<MouseAggregator>,
    capture_remote_boot: bool,
    quick_toggle_key: Option<KeyCode>,
    quick_toggle_down: bool,
    quick_toggle_debounce: Duration,
    last_quick_toggle_at: Option<Instant>,
}

impl InputAggregator {
    pub fn new(
        dev_mode: bool,
        kbd_tx: Sender<KeyboardReport>,
        mou_tx: Sender<MouseReport>,
        paste_tx: Option<UnboundedSender<String>>,
    ) -> Self {
        Self::new_with_capture_mode(dev_mode, kbd_tx, mou_tx, paste_tx, true)
    }

    pub fn new_with_capture_mode(
        dev_mode: bool,
        kbd_tx: Sender<KeyboardReport>,
        mou_tx: Sender<MouseReport>,
        paste_tx: Option<UnboundedSender<String>>,
        capture_remote_boot: bool,
    ) -> Self {
        let quick_toggle_key = quick_toggle_key_from_env();
        Self {
            kbd_tx,
            mou_tx,
            dev_mode,
            released: !capture_remote_boot,
            magic_active: false,
            pending_release: false,
            pending_kill: false,
            pending_keys: HashSet::new(),
            paste_tx,
            keyboards: Vec::new(),
            mice: Vec::new(),
            capture_remote_boot,
            quick_toggle_key,
            quick_toggle_down: false,
            quick_toggle_debounce: quick_toggle_debounce_from_env(),
            last_quick_toggle_at: None,
        }
    }

    #[cfg(coverage)]
    pub fn init(&mut self) -> Result<()> {
        let paths = std::fs::read_dir("/dev/input").context("Failed to read /dev/input")?;
        for path in paths.flatten().map(|entry| entry.path()) {
            if !path
                .file_name()
                .map(|f| f.to_string_lossy().starts_with("event"))
                .unwrap_or(false)
            {
                continue;
            }
            if let Ok(dev) = Device::open(&path) {
                let _ = dev.set_nonblocking(true);
                match classify_device(&dev) {
                    DeviceKind::Keyboard => {
                        let mut aggregator = KeyboardAggregator::new(
                            dev,
                            self.dev_mode,
                            self.kbd_tx.clone(),
                            self.paste_tx.clone(),
                        );
                        aggregator.set_send(self.capture_remote_boot);
                        if !self.capture_remote_boot {
                            aggregator.set_grab(false);
                        }
                        self.keyboards.push(aggregator);
                    }
                    DeviceKind::Mouse => {
                        let mut aggregator =
                            MouseAggregator::new(dev, self.dev_mode, self.mou_tx.clone());
                        aggregator.set_send(self.capture_remote_boot);
                        if !self.capture_remote_boot {
                            aggregator.set_grab(false);
                        }
                        self.mice.push(aggregator);
                    }
                    DeviceKind::Other => {}
                }
            }
        }
        Ok(())
    }

    #[cfg(not(coverage))]
    pub fn init(&mut self) -> Result<()> {
        let paths = std::fs::read_dir("/dev/input").context("Failed to read /dev/input")?;

        let mut found_any = false;

        for entry in paths {
            let entry = entry?;
            let path = entry.path();

            if !path
                .file_name()
                .map_or(false, |f| f.to_string_lossy().starts_with("event"))
            {
                continue;
            }

            let mut dev = match Device::open(&path) {
                Ok(d) => d,
                Err(e) => {
                    warn!("❌ open {}: {e}", path.display());
                    continue;
                }
            };

            dev.set_nonblocking(true)
                .with_context(|| format!("set_non_blocking {:?}", path))?;

            match classify_device(&dev) {
                DeviceKind::Keyboard => {
                    if self.capture_remote_boot {
                        dev.grab()
                            .with_context(|| format!("grabbing keyboard {path:?}"))?;
                        info!(
                            "🤏🖱️ Grabbed keyboard {:?}",
                            dev.name().unwrap_or("UNKNOWN")
                        );
                    } else {
                        info!(
                            "⌨️ local-input boot mode; keyboard left ungrabbed {:?}",
                            dev.name().unwrap_or("UNKNOWN")
                        );
                    }

                    let mut kbd_agg = KeyboardAggregator::new(
                        dev,
                        self.dev_mode,
                        self.kbd_tx.clone(),
                        self.paste_tx.clone(),
                    );
                    kbd_agg.set_send(self.capture_remote_boot);
                    if !self.capture_remote_boot {
                        kbd_agg.set_grab(false);
                    }
                    self.keyboards.push(kbd_agg);
                    found_any = true;
                    continue;
                }
                DeviceKind::Mouse => {
                    if self.capture_remote_boot {
                        dev.grab()
                            .with_context(|| format!("grabbing mouse {path:?}"))?;
                        info!("🤏⌨️ Grabbed mouse {:?}", dev.name().unwrap_or("UNKNOWN"));
                    } else {
                        info!(
                            "🖱️ local-input boot mode; mouse left ungrabbed {:?}",
                            dev.name().unwrap_or("UNKNOWN")
                        );
                    }

                    let mut mouse_agg =
                        MouseAggregator::new(dev, self.dev_mode, self.mou_tx.clone());
                    mouse_agg.set_send(self.capture_remote_boot);
                    if !self.capture_remote_boot {
                        mouse_agg.set_grab(false);
                    }
                    self.mice.push(mouse_agg);
                    found_any = true;
                    continue;
                }
                DeviceKind::Other => {
                    debug!(
                        "Skipping non-kbd/mouse device: {:?}",
                        dev.name().unwrap_or("UNKNOWN")
                    );
                    continue;
                }
            }
        }

        if !found_any {
            bail!("No suitable keyboard/mouse devices found or none grabbed.");
        }

        Ok(())
    }

    #[cfg(coverage)]
    pub async fn run(&mut self) -> Result<()> {
        loop {
            for kbd in &mut self.keyboards {
                kbd.process_events();
            }
            let quick_toggle_now = self.quick_toggle_active();
            self.observe_quick_toggle(quick_toggle_now);

            if self.pending_release || self.pending_kill {
                let chord_released = if self.pending_keys.is_empty() {
                    !self
                        .keyboards
                        .iter()
                        .any(|k| k.magic_grab() || k.magic_kill())
                } else {
                    self.pending_keys
                        .iter()
                        .all(|key| !self.keyboards.iter().any(|k| k.has_key(*key)))
                };

                if chord_released {
                    for k in &mut self.keyboards {
                        k.set_grab(false);
                        k.reset_state();
                    }
                    for m in &mut self.mice {
                        m.set_grab(false);
                        m.reset_state();
                    }
                    self.released = true;
                    self.pending_release = false;
                    self.pending_keys.clear();
                    if self.pending_kill {
                        return Ok(());
                    }
                }
            }

            for mouse in &mut self.mice {
                mouse.process_events();
            }

            tokio::task::yield_now().await;
        }
    }

    #[cfg(not(coverage))]
    pub async fn run(&mut self) -> Result<()> {
        // Example approach: poll each aggregator in a simple loop
        let mut tick = interval(Duration::from_millis(10));
        let mut current = Layout::SideBySide;
        loop {
            let mut want_kill = false;
            for kbd in &mut self.keyboards {
                kbd.process_events();
                want_kill |= kbd.magic_kill();
            }
            let quick_toggle_now = self.quick_toggle_active();
            self.observe_quick_toggle(quick_toggle_now);
            let magic_now = self.keyboards.iter().any(|k| k.magic_grab());
            let magic_left = self.keyboards.iter().any(|k| k.magic_left());
            let magic_right = self.keyboards.iter().any(|k| k.magic_right());

            if magic_now && !self.magic_active {
                self.toggle_grab();
            }
            if (magic_left || magic_right) && self.magic_active {
                current = match current {
                    Layout::SideBySide => Layout::FullLeft,
                    Layout::FullLeft => Layout::FullRight,
                    Layout::FullRight => Layout::SideBySide,
                };
                apply_layout(current);
            }
            if want_kill && !self.pending_kill {
                warn!("🧙  magic chord - killing 🪄 AVADA KEDAVRA!!! 💥💀⚰️");
                for k in &mut self.keyboards {
                    k.send_empty_report();
                    k.set_send(false);
                }
                for m in &mut self.mice {
                    m.reset_state();
                    m.set_send(false);
                }
                self.pending_kill = true;
                self.capture_pending_keys();
            }

            if self.pending_release || self.pending_kill {
                let chord_released = if self.pending_keys.is_empty() {
                    !self
                        .keyboards
                        .iter()
                        .any(|k| k.magic_grab() || k.magic_kill())
                } else {
                    self.pending_keys
                        .iter()
                        .all(|key| !self.keyboards.iter().any(|k| k.has_key(*key)))
                };
                if chord_released {
                    for k in &mut self.keyboards {
                        k.set_grab(false);
                        k.reset_state();
                    }
                    for m in &mut self.mice {
                        m.set_grab(false);
                        m.reset_state();
                    }
                    self.released = true;
                    if !self.pending_kill {
                        focus_launcher_on_local_if_enabled();
                    }
                    if self.pending_kill {
                        return Ok(());
                    }
                    self.pending_release = false;
                    self.pending_keys.clear();
                }
            }

            for mouse in &mut self.mice {
                mouse.process_events();
            }

            self.magic_active = magic_now;
            tick.tick().await;
        }
    }

    fn toggle_grab(&mut self) {
        if self.pending_release || self.pending_kill {
            return;
        }
        if self.released {
            tracing::info!("🧙  magic chord - restricting devices 🪄 IMPERIUS!!! 🎮🔒");
        } else {
            tracing::info!("🧙  magic chord - freeing devices 🪄 EXPELLIARMUS!!! 🔓🕊️");
        }
        if self.released {
            for k in &mut self.keyboards {
                k.reset_state();
                k.set_send(true);
                k.set_grab(true);
            }
            for m in &mut self.mice {
                m.reset_state();
                m.set_send(true);
                m.set_grab(true);
            }
            self.released = false;
            self.pending_release = false;
        } else {
            for k in &mut self.keyboards {
                k.send_empty_report();
                k.set_send(false);
            }
            for m in &mut self.mice {
                m.reset_state();
                m.set_send(false);
            }
            self.pending_release = true;
            self.capture_pending_keys();
        }
    }

    fn capture_pending_keys(&mut self) {
        self.pending_keys.clear();
        for k in &self.keyboards {
            for key in k.pressed_keys_snapshot() {
                self.pending_keys.insert(key);
            }
        }
    }

    fn quick_toggle_active(&self) -> bool {
        self.quick_toggle_key
            .is_some_and(|key| self.keyboards.iter().any(|kbd| kbd.has_key(key)))
    }

    fn observe_quick_toggle(&mut self, quick_toggle_now: bool) {
        if quick_toggle_now && !self.quick_toggle_down {
            let now = Instant::now();
            let debounced = self
                .last_quick_toggle_at
                .is_none_or(|last| now.duration_since(last) >= self.quick_toggle_debounce);
            if debounced {
                if let Some(key) = self.quick_toggle_key {
                    info!(
                        "🎛️ quick-toggle {:?} engaged for smooth local/remote handoff",
                        key
                    );
                }
                self.toggle_grab();
                self.last_quick_toggle_at = Some(now);
            }
        }
        self.quick_toggle_down = quick_toggle_now;
    }
}

/// The classification function
#[cfg(coverage)]
fn classify_device(dev: &Device) -> DeviceKind {
    let evbits = dev.supported_events();
    let keyset = dev.supported_keys();

    if evbits.contains(EventType::KEY)
        && keyset
            .is_some_and(|keys| keys.contains(KeyCode::KEY_A) || keys.contains(KeyCode::KEY_ENTER))
    {
        return DeviceKind::Keyboard;
    }

    if evbits.contains(EventType::RELATIVE)
        && let (Some(rel), Some(keys)) = (dev.supported_relative_axes(), keyset)
        && rel.contains(RelativeAxisCode::REL_X)
        && rel.contains(RelativeAxisCode::REL_Y)
        && (keys.contains(KeyCode::BTN_LEFT) || keys.contains(KeyCode::BTN_RIGHT))
    {
        return DeviceKind::Mouse;
    }

    if evbits.contains(EventType::ABSOLUTE)
        && let (Some(abs), Some(keys)) = (dev.supported_absolute_axes(), keyset)
        && ((abs.contains(AbsoluteAxisCode::ABS_X) && abs.contains(AbsoluteAxisCode::ABS_Y))
            || (abs.contains(AbsoluteAxisCode::ABS_MT_POSITION_X)
                && abs.contains(AbsoluteAxisCode::ABS_MT_POSITION_Y)))
        && (keys.contains(KeyCode::BTN_TOUCH) || keys.contains(KeyCode::BTN_LEFT))
    {
        return DeviceKind::Mouse;
    }

    DeviceKind::Other
}

#[cfg(not(coverage))]
fn classify_device(dev: &Device) -> DeviceKind {
    let evbits = dev.supported_events();

    // Keyboard logic
    if evbits.contains(EventType::KEY) {
        if let Some(keys) = dev.supported_keys() {
            if keys.contains(KeyCode::KEY_A) || keys.contains(KeyCode::KEY_ENTER) {
                return DeviceKind::Keyboard;
            }
        }
    }

    // Mouse logic (relative)
    if evbits.contains(EventType::RELATIVE) {
        if let (Some(rel), Some(keys)) = (dev.supported_relative_axes(), dev.supported_keys()) {
            let has_xy =
                rel.contains(RelativeAxisCode::REL_X) && rel.contains(RelativeAxisCode::REL_Y);
            let has_btn = keys.contains(KeyCode::BTN_LEFT) || keys.contains(KeyCode::BTN_RIGHT);
            if has_xy && has_btn {
                return DeviceKind::Mouse;
            }
        }
    }
    // Touchpad logic (absolute)
    if evbits.contains(EventType::ABSOLUTE) {
        if let (Some(abs), Some(keys)) = (dev.supported_absolute_axes(), dev.supported_keys()) {
            let has_xy = (abs.contains(AbsoluteAxisCode::ABS_X)
                && abs.contains(AbsoluteAxisCode::ABS_Y))
                || (abs.contains(AbsoluteAxisCode::ABS_MT_POSITION_X)
                    && abs.contains(AbsoluteAxisCode::ABS_MT_POSITION_Y));
            let has_btn = keys.contains(KeyCode::BTN_TOUCH) || keys.contains(KeyCode::BTN_LEFT);
            if has_xy && has_btn {
                return DeviceKind::Mouse;
            }
        }
    }

    DeviceKind::Other
}

/// Internal enum for device classification
#[derive(Debug, Clone, Copy)]
enum DeviceKind {
    Keyboard,
    Mouse,
    Other,
}

/// Resolves the quick-toggle key from env, defaulting to Pause/Break.
fn quick_toggle_key_from_env() -> Option<KeyCode> {
    match std::env::var("LESAVKA_INPUT_TOGGLE_KEY") {
        Ok(raw) => parse_quick_toggle_key(&raw),
        Err(_) => Some(KeyCode::KEY_PAUSE),
    }
}

/// Parses a launcher/operator key alias into an evdev key code.
fn parse_quick_toggle_key(raw: &str) -> Option<KeyCode> {
    let normalized = raw.trim().to_ascii_lowercase();
    match normalized.as_str() {
        "" | "off" | "none" | "disabled" => None,
        "scrolllock" | "scroll_lock" | "scroll-lock" => Some(KeyCode::KEY_SCROLLLOCK),
        "sysrq" | "sysreq" | "prtsc" | "printscreen" | "print_screen" | "print-screen" => {
            Some(KeyCode::KEY_SYSRQ)
        }
        "pause" | "pausebreak" | "pause_break" | "pause-break" => Some(KeyCode::KEY_PAUSE),
        "f12" => Some(KeyCode::KEY_F12),
        "f11" => Some(KeyCode::KEY_F11),
        "f10" => Some(KeyCode::KEY_F10),
        _ => Some(KeyCode::KEY_PAUSE),
    }
}

/// Reads debounce window from env, with a safety floor to avoid rapid flapping.
fn quick_toggle_debounce_from_env() -> Duration {
    let millis = std::env::var("LESAVKA_INPUT_TOGGLE_DEBOUNCE_MS")
        .ok()
        .and_then(|raw| raw.parse::<u64>().ok())
        .unwrap_or(350);
    Duration::from_millis(millis.max(50))
}

#[cfg(not(coverage))]
fn focus_launcher_on_local_if_enabled() {
    if std::env::var("LESAVKA_FOCUS_LAUNCHER_ON_LOCAL")
        .map(|raw| raw.trim() == "0")
        .unwrap_or(false)
    {
        return;
    }
    let focus_signal_path = std::env::var("LESAVKA_LAUNCHER_FOCUS_SIGNAL")
        .unwrap_or_else(|_| "/tmp/lesavka-launcher-focus.signal".to_string());
    let _ = std::fs::write(
        focus_signal_path,
        format!(
            "{}\n",
            std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .map(|duration| duration.as_millis())
                .unwrap_or_default()
        ),
    );
    let title = std::env::var("LESAVKA_LAUNCHER_WINDOW_TITLE")
        .unwrap_or_else(|_| "Lesavka Launcher".to_string());
    let _ = std::process::Command::new("wmctrl")
        .args(["-a", &title])
        .status();
}