// SPDX-License-Identifier: GPL-3.0-or-later
// src/application/services/cache_service.rs
//
// Cache service: manages document and thumbnail caching.
// Reserved for future caching layer implementation.

#![allow(dead_code)]

use std::path::Path;

use cosmic::widget::image::Handle as ImageHandle;
use image::DynamicImage;

use crate::infrastructure::cache::ThumbnailCache;

/// Cache service for managing document caches.
///
/// Provides high-level caching operations for the application layer.
pub struct CacheService;

impl CacheService {
    /// Create a new cache service.
    #[must_use]
    pub fn new() -> Self {
        Self
    }

    /// Load a thumbnail from cache.
    ///
    /// Returns None if the thumbnail is not cached or the cache is invalid.
    #[must_use]
    pub fn get_thumbnail(&self, path: &Path, page: usize) -> Option<ImageHandle> {
        ThumbnailCache::load(path, page)
    }

    /// Save a thumbnail to cache.
    ///
    /// Returns true if the thumbnail was successfully cached.
    pub fn put_thumbnail(&self, path: &Path, page: usize, image: &DynamicImage) -> bool {
        ThumbnailCache::save(path, page, image).is_some()
    }

    /// Clear all cached thumbnails.
    ///
    /// This operation is not yet implemented.
    pub fn clear_cache(&self) -> Result<(), String> {
        ThumbnailCache::clear_cache().map_err(|e| e.to_string())
    }

    /// Get the size of the cache directory.
    ///
    /// Returns the total size in bytes, or None if it cannot be determined.
    #[must_use]
    pub fn cache_size(&self) -> Option<u64> {
        // TODO: Implement cache size calculation
        None
    }
}

impl Default for CacheService {
    fn default() -> Self {
        Self::new()
    }
}

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

    #[test]
    fn test_cache_service_creation() {
        let service = CacheService::new();
        assert!(std::ptr::eq(&service, &service)); // Dummy test
    }

    #[test]
    fn test_cache_service_default() {
        let service = CacheService::default();
        assert!(std::ptr::eq(&service, &service)); // Dummy test
    }
}