//! Hyprland IPC client: socket1 request/response (JSON) and socket2 path
//! resolution.
//!
//! The socket-path resolution + raw request/response round trip was
//! duplicated near-verbatim in `breadbox/src/main.rs` (`get_active_workspace`,
//! lines 26-42) and `breadclip/src/position.rs` (`hyprctl_json`, lines
//! 58-71) — same `HYPRLAND_INSTANCE_SIGNATURE`/`XDG_RUNTIME_DIR` env lookup,
//! same `.socket.sock` path format, same connect/write/shutdown-write/
//! read-to-string sequence. `breadmon/src/main.rs`'s `hyprland_socket2_path`
//! duplicates just the path-resolution half for the event socket.
//!
//! `active_window`'s `fullscreen` field deserializes leniently as either a
//! JSON bool or integer: Hyprland has changed this field's type across
//! versions (older releases emit a bool, `0`/`1`; newer ones emit an
//! integer fullscreen *mode* — `0` none, `1` maximized, `2` fullscreen), and
//! a client hard-coded to one shape silently misreads the other instead of
//! erroring. `breadclip`'s own version (`as_i64().unwrap_or(0) != 0`) only
//! handles the integer shape; a bool `true` would `.as_i64()` to `None` and
//! silently read as "not fullscreen".

use serde::Deserialize;
use std::env;
use std::io::{Read, Write};
use std::os::unix::net::UnixStream;
use std::path::PathBuf;

/// Which of Hyprland's two IPC sockets: `.socket.sock` (request/response) or
/// `.socket2.sock` (event stream).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Socket {
    Request,
    Events,
}

/// Resolve the path to one of Hyprland's IPC sockets from
/// `HYPRLAND_INSTANCE_SIGNATURE` + `XDG_RUNTIME_DIR`. Returns `None` if
/// `HYPRLAND_INSTANCE_SIGNATURE` isn't set (Hyprland isn't running, or we're
/// not inside a Hyprland session) — `XDG_RUNTIME_DIR` falls back to
/// `/run/user/1000` if unset, matching `breadmon`'s existing fallback.
pub fn socket_path(kind: Socket) -> Option<PathBuf> {
    let sig = env::var("HYPRLAND_INSTANCE_SIGNATURE").ok()?;
    let rt = env::var("XDG_RUNTIME_DIR").unwrap_or_else(|_| "/run/user/1000".to_string());
    let file = match kind {
        Socket::Request => ".socket.sock",
        Socket::Events => ".socket2.sock",
    };
    Some(PathBuf::from(format!("{rt}/hypr/{sig}/{file}")))
}

/// Send `request` (e.g. `"j/activewindow"`, `"j/monitors"`) to the socket1
/// IPC socket and return the raw response body. Blocking/synchronous — this
/// matches every current consumer (breadbox, breadclip), which call it from
/// non-async GTK app code.
///
/// Read/write timeouts are set on the socket (both original hand-rolled
/// implementations this replaces — breadbox's `get_active_workspace`,
/// breadclip's `hyprctl_json` — had none): a Hyprland instance that's
/// wedged or mid-reload could otherwise hang this call, and every current
/// caller runs it on the GTK main thread, so a hang here freezes the whole
/// UI, not just this query.
const REQUEST_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(2);

pub fn request(request: &str) -> Option<String> {
    let socket = socket_path(Socket::Request)?;
    let mut stream = UnixStream::connect(&socket).ok()?;
    stream.set_read_timeout(Some(REQUEST_TIMEOUT)).ok()?;
    stream.set_write_timeout(Some(REQUEST_TIMEOUT)).ok()?;
    stream.write_all(request.as_bytes()).ok()?;
    stream.shutdown(std::net::Shutdown::Write).ok()?;

    let mut buf = String::new();
    stream.read_to_string(&mut buf).ok()?;
    Some(buf)
}

/// Like [`request`], parsed as JSON. `request` should already carry the `j/`
/// prefix Hyprland expects for JSON responses (e.g. `"j/activewindow"`).
pub fn request_json(request_str: &str) -> Option<serde_json::Value> {
    serde_json::from_str(&request(request_str)?).ok()
}

/// Connect to the socket2 event stream. Callers read newline-delimited
/// `EVENT>>DATA` lines from the returned stream themselves — event framing
/// and reconnect/backoff policy are genuinely per-consumer (see
/// `breadmon`'s hotplug listener), so this only replaces the duplicated
/// path-resolution + connect boilerplate, not a full event-loop
/// abstraction.
pub fn connect_events() -> Option<UnixStream> {
    let socket = socket_path(Socket::Events)?;
    UnixStream::connect(&socket).ok()
}

/// Hyprland's `fullscreen` field, tolerant of either representation it has
/// shipped across versions: a plain bool, or an integer fullscreen mode
/// (`0` = none, nonzero = some fullscreen mode).
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct FullscreenState(bool);

impl FullscreenState {
    pub fn is_fullscreen(self) -> bool {
        self.0
    }
}

impl<'de> Deserialize<'de> for FullscreenState {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        #[derive(Deserialize)]
        #[serde(untagged)]
        enum Repr {
            Bool(bool),
            Int(i64),
        }
        Ok(match Repr::deserialize(deserializer)? {
            Repr::Bool(b) => FullscreenState(b),
            Repr::Int(i) => FullscreenState(i != 0),
        })
    }
}

#[derive(Debug, Clone, Deserialize)]
pub struct ActiveWindow {
    #[serde(default)]
    pub class: String,
    #[serde(default)]
    pub fullscreen: FullscreenState,
    pub at: (i32, i32),
    pub size: (i32, i32),
}

impl ActiveWindow {
    pub fn x(&self) -> i32 {
        self.at.0
    }
    pub fn y(&self) -> i32 {
        self.at.1
    }
    pub fn width(&self) -> i32 {
        self.size.0
    }
    pub fn height(&self) -> i32 {
        self.size.1
    }
}

#[derive(Debug, Clone, Deserialize)]
pub struct Monitor {
    pub name: String,
    pub x: i32,
    pub y: i32,
    pub width: i32,
    pub height: i32,
    #[serde(default)]
    pub focused: bool,
}

/// Query the currently active (focused) window. Returns `None` if the
/// window is fullscreen or no window is focused — same "centre the popup
/// instead" contract `breadclip`'s original `get_active_window` had.
pub fn active_window() -> Option<ActiveWindow> {
    let win: ActiveWindow = serde_json::from_value(request_json("j/activewindow")?).ok()?;
    if win.fullscreen.is_fullscreen() || win.class.is_empty() {
        return None;
    }
    Some(win)
}

/// Query all monitors and return the focused one (or the first, if none
/// report as focused).
pub fn focused_monitor() -> Option<Monitor> {
    let monitors: Vec<Monitor> = serde_json::from_value(request_json("j/monitors")?).ok()?;
    monitors
        .iter()
        .find(|m| m.focused)
        .or_else(|| monitors.first())
        .cloned()
}

/// The active workspace's name (e.g. `"1"`, `"special:scratch"`).
pub fn active_workspace_name() -> Option<String> {
    request_json("j/activeworkspace")?
        .get("name")
        .and_then(|v| v.as_str())
        .map(str::to_string)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn fullscreen_state_deserializes_from_bool() {
        let s: FullscreenState = serde_json::from_str("true").unwrap();
        assert!(s.is_fullscreen());
        let s: FullscreenState = serde_json::from_str("false").unwrap();
        assert!(!s.is_fullscreen());
    }

    #[test]
    fn fullscreen_state_deserializes_from_int() {
        let s: FullscreenState = serde_json::from_str("0").unwrap();
        assert!(!s.is_fullscreen());
        let s: FullscreenState = serde_json::from_str("2").unwrap();
        assert!(s.is_fullscreen());
    }

    #[test]
    fn active_window_parses_bool_fullscreen_shape() {
        let json = r#"{"class":"kitty","fullscreen":true,"at":[10,20],"size":[300,400]}"#;
        let win: ActiveWindow = serde_json::from_str(json).unwrap();
        assert!(win.fullscreen.is_fullscreen());
        assert_eq!(win.x(), 10);
        assert_eq!(win.height(), 400);
    }

    #[test]
    fn active_window_parses_int_fullscreen_shape() {
        let json = r#"{"class":"kitty","fullscreen":1,"at":[0,0],"size":[100,100]}"#;
        let win: ActiveWindow = serde_json::from_str(json).unwrap();
        assert!(win.fullscreen.is_fullscreen());
    }

    // Both env-var-dependent cases share one test function: `set_var`/
    // `remove_var` are process-global, and cargo runs tests in parallel
    // threads by default, so two separate #[test] fns racing on the same
    // vars would be flaky.
    #[test]
    fn socket_path_env_var_behavior() {
        let _lock = crate::env_test_lock().lock().unwrap_or_else(|e| e.into_inner());
        unsafe { env::remove_var("HYPRLAND_INSTANCE_SIGNATURE") };
        assert!(socket_path(Socket::Request).is_none());

        unsafe {
            env::set_var("HYPRLAND_INSTANCE_SIGNATURE", "test-sig");
            env::set_var("XDG_RUNTIME_DIR", "/run/user/9999");
        }
        assert_eq!(
            socket_path(Socket::Request).unwrap(),
            PathBuf::from("/run/user/9999/hypr/test-sig/.socket.sock")
        );
        assert_eq!(
            socket_path(Socket::Events).unwrap(),
            PathBuf::from("/run/user/9999/hypr/test-sig/.socket2.sock")
        );
        unsafe {
            env::remove_var("HYPRLAND_INSTANCE_SIGNATURE");
            env::remove_var("XDG_RUNTIME_DIR");
        }
    }
}