wayle-wallpaper 0.1.2

use std::{collections::HashMap, sync::Arc, time::Instant};

use tokio::sync::broadcast;
use tokio_util::sync::CancellationToken;
use tracing::{debug, info};
use wayle_core::Property;
use wayle_traits::ServiceMonitoring;
use zbus::Connection;

use crate::{
    backend::{TransitionConfig, spawn_daemon_if_needed},
    dbus::{SERVICE_NAME, SERVICE_PATH, WallpaperDaemon},
    error::Error,
    service::WallpaperService,
    tasks::{spawn_color_extractor, spawn_output_watcher},
    types::ColorExtractorConfig,
};

/// Builder for configuring a WallpaperService.
#[derive(Debug)]
pub struct WallpaperServiceBuilder {
    color_extractor: ColorExtractorConfig,
    transition: TransitionConfig,
    theming_monitor: Option<String>,
    shared_cycle: bool,
    engine_active: bool,
}

impl Default for WallpaperServiceBuilder {
    fn default() -> Self {
        Self {
            color_extractor: ColorExtractorConfig::default(),
            transition: TransitionConfig::default(),
            theming_monitor: None,
            shared_cycle: false,
            engine_active: true,
        }
    }
}

impl WallpaperServiceBuilder {
    /// Creates a new builder with default values.
    pub fn new() -> Self {
        Self::default()
    }

    /// Builds and initializes the WallpaperService.
    ///
    /// # Errors
    ///
    /// Returns error if D-Bus connection fails or service registration fails.
    #[allow(clippy::cognitive_complexity)]
    pub async fn build(self) -> Result<Arc<WallpaperService>, Error> {
        let start = Instant::now();
        self.spawn_daemon_if_enabled();

        let connection = Self::connect_session_bus().await?;
        debug!(elapsed_ms = start.elapsed().as_millis(), "D-Bus connected");

        let service = self.create_service(&connection);
        Self::register_dbus(&connection, Arc::clone(&service)).await?;
        debug!(elapsed_ms = start.elapsed().as_millis(), "D-Bus registered");

        Self::start_background_tasks(&service).await?;
        debug!(
            elapsed_ms = start.elapsed().as_millis(),
            "Monitoring started"
        );

        info!("Wallpaper service registered at {SERVICE_NAME}");

        Ok(service)
    }

    /// Sets the color extraction configuration.
    pub fn color_extractor(mut self, config: ColorExtractorConfig) -> Self {
        self.color_extractor = config;
        self
    }

    /// Sets the transition animation configuration.
    pub fn transition(mut self, transition: TransitionConfig) -> Self {
        self.transition = transition;
        self
    }

    /// Sets which monitor's wallpaper drives color extraction.
    pub fn theming_monitor(mut self, monitor: Option<String>) -> Self {
        self.theming_monitor = monitor;
        self
    }

    /// Synchronizes cycling across all monitors in shuffle mode.
    pub fn shared_cycle(mut self, shared: bool) -> Self {
        self.shared_cycle = shared;
        self
    }

    /// Enables or disables the awww wallpaper engine.
    pub fn engine_active(mut self, active: bool) -> Self {
        self.engine_active = active;
        self
    }

    fn spawn_daemon_if_enabled(&self) {
        if self.engine_active {
            spawn_daemon_if_needed();
        }
    }

    async fn connect_session_bus() -> Result<Connection, Error> {
        Connection::session().await.map_err(|error| {
            Error::ServiceInitializationFailed(format!("D-Bus connection failed: {error}"))
        })
    }

    fn create_service(self, connection: &Connection) -> Arc<WallpaperService> {
        let cancellation_token = CancellationToken::new();
        let (extraction_complete, _) = broadcast::channel(16);

        Arc::new(WallpaperService {
            cancellation_token,
            _connection: connection.clone(),
            last_extracted_wallpaper: Property::new(None),
            extraction_complete,
            theming_monitor: Property::new(self.theming_monitor),
            cycling: Property::new(None),
            monitors: Property::new(HashMap::new()),
            color_extractor: Property::new(self.color_extractor),
            transition: Property::new(self.transition),
            shared_cycle: Property::new(self.shared_cycle),
            engine_active: Property::new(self.engine_active),
        })
    }

    async fn register_dbus(
        connection: &Connection,
        service: Arc<WallpaperService>,
    ) -> Result<(), Error> {
        let daemon = WallpaperDaemon { service };

        connection
            .object_server()
            .at(SERVICE_PATH, daemon)
            .await
            .map_err(|error| {
                Error::ServiceInitializationFailed(format!(
                    "cannot register D-Bus object at '{SERVICE_PATH}': {error}"
                ))
            })?;

        connection
            .request_name(SERVICE_NAME)
            .await
            .map_err(|error| {
                Error::ServiceInitializationFailed(format!(
                    "cannot acquire D-Bus name '{SERVICE_NAME}': {error}"
                ))
            })?;

        Ok(())
    }

    async fn start_background_tasks(service: &Arc<WallpaperService>) -> Result<(), Error> {
        service.start_monitoring().await?;
        spawn_output_watcher(Arc::clone(service));
        spawn_color_extractor(Arc::clone(service));
        Ok(())
    }
}