use dbus::arg::{RefArg, Variant};
use dbus::blocking::Connection;
use dbus::message::MatchRule;
use dbus::strings::Interface;
use dbus::MessageType::Signal;
use dbus::{Message, Path};
use std::collections::HashMap;
use std::fmt;
use std::time::Duration;

// Structure of a notification
struct Notif {
    app_name: String,
    replace_id: Option<u32>,
    ico: String,
    summary: String,
    body: String,
    actions: Vec<(String, String)>,
    hints: HashMap<String, String>,
    expir_timeout: Option<u32>,
}

// Function to print the contents of the notification
impl fmt::Display for Notif {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        writeln!(f, "AppName: {}", &self.app_name)?;
        match self.replace_id {
            Some(notif_id) => writeln!(f, "ReplaceId: {notif_id}")?,
            None => writeln!(f, "None")?,
        }
        write!(
            f,
            "Icon: {}\nSummary: {}\nBody: {}\nActions:\n",
            &self.ico, &self.summary, &self.body
        )?;
        for (key, label) in &self.actions {
            writeln!(f, "\t{key}: {label}")?;
        }
        writeln!(f, "Hints:")?;
        for (key, value) in &self.hints {
            writeln!(f, "\t{key}: {value}")?;
        }
        match self.expir_timeout {
            Some(millisec) => writeln!(f, "Expiration Timeout: {millisec}")?,
            None => writeln!(f, "None")?,
        }
        Ok(()) // Return Ok to indicate success
    }
}

// Summary should be generally <= 40 chars, as per the specification.
fn truncate_summary(notif: &mut Notif) {
    if notif.summary.len() > 40 {
        notif.summary.truncate(39);
        notif.summary.push('…');
    }
}

// Callback function
fn handle_notif(signal: &dbus::Message) -> Result<(), dbus::Error> {
    // Extract all items as variants
    let items = signal.get_items();

    // Helper functions to safely extract data
    let get_string = |item: &dyn RefArg| item.as_str().unwrap_or_default().to_string();
    let get_u32 = |item: &dyn RefArg| item.as_u64().unwrap_or_default() as u32;
    let get_i32 = |item: &dyn RefArg| item.as_i64().unwrap_or_default() as i32;

    // Extract the fields from the message
    let app_name = get_string(&items[0]);
    let replace_id = get_u32(&items[1]);
    let ico = get_string(&items[2]);
    let summary = get_string(&items[3]);
    let body = get_string(&items[4]);

    // Extract actions as Vec<String>
    let actions = items[5].as_array().unwrap_or(&[]).iter()
        .filter_map(|v| v.as_str().map(|s| s.to_string()))
        .collect();

    // Extract hints as HashMap<String, String>
    let hints = items[6].as_dict().unwrap_or(&[]).iter()
        .map(|(k, v)| (get_string(k), get_string(v)))
        .collect();

    let expir_timeout = get_i32(&items[7]);

    // Convert actions from Vec<String> to Vec<(String, String)>
    let notif_actions = actions.chunks(2)
        .map(|chunk| if chunk.len() == 2 { (chunk[0].clone(), chunk[1].clone()) } else { (chunk[0].clone(), "".to_string()) })
        .collect();

    let mut notif = Notif {
        app_name,
        replace_id: Some(replace_id),
        ico,
        summary,
        body,
        actions: notif_actions,
        hints: notif_hints,
        expir_timeout: if expir_timeout >= 0 {
            Some(expir_timeout as u32)
        } else {
            None
        },
    };

    truncate_summary(&mut notif);

    println!("{}", notif);

    Ok(())
}

fn main() -> Result<(), dbus::Error> {
    // Connect to the system bus
    let conn = Connection::new_session()?;

    // Get the object path of the notification service
    //let object_path = "/org/freedesktop/Notifications";
    //let member = "Notify";

    // Get the interface name of the notification service
    //let interface_name = "org.freedesktop.Notifications".to_string();

    // Create a match rule to listen for the notifications
    let match_rule = MatchRule::new_signal("org.freedesktop.Notifications".into(), "Notify".into());

    // Add the match rule to the connection
    conn.add_match(match_rule, |msg, _conn, _| {
        if let Err(e) = handle_notif(&msg) {
            eprintln!("Error handling notification: {:?}", e);
        }
        true // Returning true keeps the callback active
    })?;

    // Wait for signals
    loop {
        conn.process(Duration::from_millis(1000))?;
    }

    Ok(())
}