Add ImageLoader and file discovery modules

pixstrip-core/src/loader.rs

@@ -0,0 +1,69 @@
+use std::path::Path;
+
+use crate::error::{PixstripError, Result};
+use crate::types::{Dimensions, ImageFormat};
+
+#[derive(Debug, Clone)]
+pub struct ImageInfo {
+    pub dimensions: Dimensions,
+    pub format: Option<ImageFormat>,
+    pub file_size: u64,
+}
+
+pub struct ImageLoader;
+
+impl ImageLoader {
+    pub fn new() -> Self {
+        Self
+    }
+
+    pub fn load_info(&self, path: &Path) -> Result<ImageInfo> {
+        let metadata = std::fs::metadata(path).map_err(|e| PixstripError::ImageLoad {
+            path: path.to_path_buf(),
+            reason: e.to_string(),
+        })?;
+
+        let reader =
+            image::ImageReader::open(path).map_err(|e| PixstripError::ImageLoad {
+                path: path.to_path_buf(),
+                reason: e.to_string(),
+            })?;
+
+        let reader = reader.with_guessed_format().map_err(|e| PixstripError::ImageLoad {
+            path: path.to_path_buf(),
+            reason: e.to_string(),
+        })?;
+
+        let img = reader.decode().map_err(|e| PixstripError::ImageLoad {
+            path: path.to_path_buf(),
+            reason: e.to_string(),
+        })?;
+
+        let format = path
+            .extension()
+            .and_then(|ext| ext.to_str())
+            .and_then(ImageFormat::from_extension);
+
+        Ok(ImageInfo {
+            dimensions: Dimensions {
+                width: img.width(),
+                height: img.height(),
+            },
+            format,
+            file_size: metadata.len(),
+        })
+    }
+
+    pub fn load_pixels(&self, path: &Path) -> Result<image::DynamicImage> {
+        image::open(path).map_err(|e| PixstripError::ImageLoad {
+            path: path.to_path_buf(),
+            reason: e.to_string(),
+        })
+    }
+}
+
+impl Default for ImageLoader {
+    fn default() -> Self {
+        Self::new()
+    }
+}