Add file.rs for local file input

src/input/file.rs

@@ -0,0 +1,65 @@
+//! 本地檔案輸入
+
+use anyhow::Result;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Clone)]
+pub enum MediaType {
+    Video,
+    Audio,
+    Image,
+    Document,
+    Unknown,
+}
+
+impl MediaType {
+    pub fn from_extension(ext: &str) -> Self {
+        match ext.to_lowercase().as_str() {
+            "mp4" | "avi" | "mkv" | "mov" | "webm" | "flv" => MediaType::Video,
+            "mp3" | "wav" | "flac" | "aac" | "ogg" | "m4a" => MediaType::Audio,
+            "jpg" | "jpeg" | "png" | "gif" | "webp" | "bmp" => MediaType::Image,
+            "md" | "markdown" | "pdf" | "html" | "htm" => MediaType::Document,
+            _ => MediaType::Unknown,
+        }
+    }
+}
+
+pub struct FileInput {
+    path: Option<PathBuf>,
+    media_type: MediaType,
+}
+
+impl FileInput {
+    pub fn new() -> Self {
+        Self {
+            path: None,
+            media_type: MediaType::Unknown,
+        }
+    }
+
+    pub fn open(&mut self, path: &str) -> Result<MediaType> {
+        let path = Path::new(path);
+        
+        if !path.exists() {
+            anyhow::bail!("File not found: {:?}", path);
+        }
+        
+        let ext = path.extension()
+            .and_then(|e| e.to_str())
+            .unwrap_or("");
+        
+        let media_type = MediaType::from_extension(ext);
+        self.path = Some(path.to_path_buf());
+        self.media_type = media_type.clone();
+        
+        Ok(media_type)
+    }
+
+    pub fn get_path(&self) -> Option<&Path> {
+        self.path.as_deref()
+    }
+
+    pub fn get_media_type(&self) -> &MediaType {
+        &self.media_type
+    }
+}