use log::{info, warn};
use serde::{Deserialize, Serialize};
use std::time::Duration;
use tauri::{AppHandle, Emitter, Manager};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct UpdateInfo {
    pub current_version: String,
    pub latest_version: String,
    pub release_notes: String,
    pub download_url: String,
    pub is_update_available: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReleaseInfo {
    pub version: String,
    pub published_at: String,
    pub prerelease: bool,
    pub assets: Vec<ReleaseAsset>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReleaseAsset {
    pub name: String,
    pub browser_download_url: String,
    pub size: u64,
}

pub async fn check_for_updates(app_handle: AppHandle) -> Result<UpdateInfo, String> {
    info!("Checking for updates");

    let current_version = app_handle
        .package_info()
        .version
        .to_string();

    // In production, this would check a remote API
    // For now, we'll simulate a check
    let latest_version = current_version.clone();
    let is_update_available = false;

    let update_info = UpdateInfo {
        current_version,
        latest_version,
        release_notes: "Initial release".to_string(),
        download_url: String::new(),
        is_update_available,
    };

    if is_update_available {
        info!("Update available: {}", update_info.latest_version);
        
        // Emit event to frontend
        if let Err(e) = app_handle.emit("update-available", &update_info) {
            warn!("Failed to emit update event: {}", e);
        }
    } else {
        info!("Already on latest version");
    }

    Ok(update_info)
}

pub async fn download_update(app_handle: AppHandle, download_url: String) -> Result<String, String> {
    info!("Downloading update from: {}", download_url);

    // Simulate download
    let client = reqwest::Client::builder()
        .timeout(Duration::from_secs(300))
        .build()
        .map_err(|e| e.to_string())?;

    let response = client
        .get(&download_url)
        .send()
        .await
        .map_err(|e| format!("Download failed: {}", e))?;

    let bytes = response
        .bytes()
        .await
        .map_err(|e| format!("Failed to read bytes: {}", e))?;

    info!("Downloaded {} bytes", bytes.len());

    // Save to temp location
    let temp_dir = std::env::temp_dir();
    let installer_path = temp_dir.join("frenocorp-updater-installer");
    
    std::fs::write(&installer_path, &bytes)
        .map_err(|e| format!("Failed to write installer: {}", e))?;

    Ok(installer_path.to_string_lossy().to_string())
}

pub async fn install_update(app_handle: AppHandle, installer_path: String) -> Result<(), String> {
    info!("Installing update from: {}", installer_path);

    // Platform-specific installation
    #[cfg(target_os = "macos")]
    {
        // For macOS, we'd use Sparkle or similar
        info!("macOS installation would happen here");
    }

    #[cfg(target_os = "windows")]
    {
        // For Windows, use WiX or InnoSetup
        info!("Windows installation would happen here");
    }

    #[cfg(target_os = "linux")]
    {
        // For Linux, use AppImage or deb/rpm
        info!("Linux installation would happen here");
    }

    // Emit update installed event
    if let Err(e) = app_handle.emit("update-installed", &installer_path) {
        warn!("Failed to emit installed event: {}", e);
    }

    Ok(())
}

pub fn schedule_periodic_check(app_handle: AppHandle, interval_secs: u64) {
    info!("Scheduling periodic update check every {} seconds", interval_secs);

    let interval = Duration::from_secs(interval_secs);
    
    tokio::spawn(async move {
        let mut interval_tick = tokio::time::interval(interval);
        
        loop {
            interval_tick.tick().await;
            
            info!("Running scheduled update check");
            
            match check_for_updates(app_handle.clone()).await {
                Ok(update_info) => {
                    if update_info.is_update_available {
                        info!("Scheduled check found update: {}", update_info.latest_version);
                    }
                }
                Err(e) => {
                    warn!("Scheduled update check failed: {}", e);
                }
            }
        }
    });
}