chore: establish development baseline

adapters/src/unity/unity_2021_3.rs

@@ -0,0 +1,158 @@
+//! Unity 2021.3 Adapter
+//!
+//! 支持 Unity 2021.3.x 版本的 AssetBundle
+
+use super::adapter::{ParsedAssetBundle, RawAssetBundle, UnityAdapter, VersionRange};
+use async_trait::async_trait;
+
+/// Unity 2021.3 Adapter
+pub struct Unity2021_3Adapter;
+
+impl Unity2021_3Adapter {
+    /// 创建新的适配器实例
+    pub fn new() -> Self {
+        Self
+    }
+
+    /// 检测 Unity 版本（从文件头）
+    fn detect_unity_version(data: &[u8]) -> Option<String> {
+        // UnityFS 文件头结构：
+        // 0x00-0x06: "UnityFS\0"
+        // 0x08-0x0B: format version
+        // 0x0C-...: Unity version string
+
+        if data.len() < 20 {
+            return None;
+        }
+
+        // 检查签名
+        if &data[0..7] != b"UnityFS" {
+            return None;
+        }
+
+        // 读取 Unity 版本字符串
+        // 版本字符串从偏移 0x14 开始（可能因格式版本不同而变化）
+        if let Some(version_start) = data.windows(7).position(|w| w.starts_with(b"2021.3.")) {
+            // 读取版本字符串直到 null 或非 ASCII
+            let version_bytes = &data[version_start..];
+            if let Some(end) = version_bytes.iter().position(|&b| b == 0 || !b.is_ascii()) {
+                if let Ok(version) = std::str::from_utf8(&version_bytes[..end]) {
+                    return Some(version.to_string());
+                }
+            }
+        }
+
+        None
+    }
+}
+
+impl Default for Unity2021_3Adapter {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[async_trait]
+impl UnityAdapter for Unity2021_3Adapter {
+    fn name(&self) -> &str {
+        "Unity-2021.3"
+    }
+
+    fn supported_versions(&self) -> VersionRange {
+        VersionRange::new("2021.3.0", "2021.3.99")
+    }
+
+    fn can_handle(&self, bundle: &RawAssetBundle) -> bool {
+        // 检测 Unity 版本
+        if let Some(version) = Self::detect_unity_version(&bundle.data) {
+            self.supported_versions().contains(&version)
+        } else {
+            false
+        }
+    }
+
+    async fn parse(&self, _bundle: &RawAssetBundle) -> Result<ParsedAssetBundle, String> {
+        // TODO: Phase 2 实现
+        // 需要：
+        // 1. 解析 UnityFS 文件头
+        // 2. 解压缩数据块
+        // 3. 解析 TypeTree
+        // 4. 提取 Asset 对象
+        Err("parse() 将在 Phase 2 实现".to_string())
+    }
+
+    async fn serialize(&self, _parsed: &ParsedAssetBundle) -> Result<Vec<u8>, String> {
+        // TODO: Phase 2 实现
+        // 需要：
+        // 1. 序列化 Asset 对象
+        // 2. 重新构建 TypeTree
+        // 3. 压缩数据块
+        // 4. 写入 UnityFS 文件头
+        Err("serialize() 将在 Phase 2 实现".to_string())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_adapter_name() {
+        let adapter = Unity2021_3Adapter::new();
+        assert_eq!(adapter.name(), "Unity-2021.3");
+    }
+
+    #[test]
+    fn test_supported_versions() {
+        let adapter = Unity2021_3Adapter::new();
+        let range = adapter.supported_versions();
+
+        assert!(range.contains("2021.3.0"));
+        assert!(range.contains("2021.3.56"));
+        assert!(!range.contains("2021.2.0"));
+    }
+
+    #[test]
+    fn test_can_handle_valid_bundle() {
+        let adapter = Unity2021_3Adapter::new();
+
+        // 模拟 UnityFS 文件头
+        let mut data = Vec::new();
+        data.extend_from_slice(b"UnityFS\0");
+        data.extend_from_slice(&[0, 0, 0, 8]); // format version
+        data.extend_from_slice(b"5.x.x\x002021.3.56f2\0");
+
+        let bundle = RawAssetBundle {
+            data,
+            path: Some("test.bundle".to_string()),
+        };
+
+        assert!(adapter.can_handle(&bundle));
+    }
+
+    #[test]
+    fn test_can_handle_invalid_bundle() {
+        let adapter = Unity2021_3Adapter::new();
+
+        let bundle = RawAssetBundle {
+            data: vec![0, 1, 2, 3],
+            path: None,
+        };
+
+        assert!(!adapter.can_handle(&bundle));
+    }
+
+    #[tokio::test]
+    async fn test_parse_not_implemented() {
+        let adapter = Unity2021_3Adapter::new();
+
+        let bundle = RawAssetBundle {
+            data: vec![],
+            path: None,
+        };
+
+        let result = adapter.parse(&bundle).await;
+        assert!(result.is_err());
+        assert!(result.unwrap_err().contains("Phase 2"));
+    }
+}