From 89b2b480ced9cd358e102ff4cf8ade2bbee393a9 Mon Sep 17 00:00:00 2001
From: CodeSteak <codesteak@shellf.art>
Date: Thu, 9 May 2019 20:13:15 +0200
Subject: [PATCH] implement image preview

---
 .../src/persistency/image_convert/mod.rs      | 34 +++++++++++--------
 .../src/persistency/mod.rs                    | 29 ++++++++++++----
 .../texture-sync-server/src/server_state.rs   | 13 ++-----
 3 files changed, 45 insertions(+), 31 deletions(-)

diff --git a/server/texture-sync-server/src/persistency/image_convert/mod.rs b/server/texture-sync-server/src/persistency/image_convert/mod.rs
index 3b7d6be..2c609de 100644
--- a/server/texture-sync-server/src/persistency/image_convert/mod.rs
+++ b/server/texture-sync-server/src/persistency/image_convert/mod.rs
@@ -1,19 +1,23 @@
-// TODO: remove on implementation
-#![allow(unused_imports)]
-#![allow(unused_variables)]
-#![allow(dead_code)]
-
-
 use crate::model::*;
+use ::image::*;
 
-pub struct ConvertConfig {
-    pub desired_size: (usize, usize),
-}
+// TODO: Deside on ::image::FilterType;
+// TODO: Think about size; Hard Code??
 
-pub fn generate_preview(
-    input: &[u8],
-    format: TextureFormat,
-    config: &ConvertConfig,
-) -> ::image::ImageResult<Vec<u8>> {
-    unimplemented!()
+const RESIZE: u32 = 256;
+
+pub fn generate_preview(input: &[u8], format: TextureFormat) -> ImageResult<Vec<u8>> {
+    // Yes, this guesses the format :D
+    // Also the resize function takes a maximum size and preservs the ratio.
+    let img =
+        ::image::load_from_memory(input)?.resize(RESIZE, RESIZE, ::image::FilterType::Lanczos3);
+
+    let mut out: Vec<u8> = Vec::new();
+
+    match format {
+        TextureFormat::JPEG => img.write_to(&mut out, ImageOutputFormat::JPEG(95))?,
+        TextureFormat::PNG => img.write_to(&mut out, ImageOutputFormat::PNG)?,
+    }
+
+    Ok(out)
 }
diff --git a/server/texture-sync-server/src/persistency/mod.rs b/server/texture-sync-server/src/persistency/mod.rs
index 8339025..33c900b 100644
--- a/server/texture-sync-server/src/persistency/mod.rs
+++ b/server/texture-sync-server/src/persistency/mod.rs
@@ -7,6 +7,7 @@ use std::path::{Path, PathBuf};
 mod image_convert;
 mod metadata_file;
 
+/*
 pub type TextureFileResult = Result<Vec<u8>, TextureFileError>;
 pub enum TextureFileError {
     NotFound,
@@ -25,6 +26,7 @@ impl From<::image::ImageError> for TextureFileError {
         TextureFileError::ImageError(err)
     }
 }
+*/
 
 pub struct DataStore {
     //data_path: PathBuf,
@@ -35,7 +37,7 @@ pub struct DataStore {
     id_index: HashMap<String, Texture>,
     name_index: HashMap<String, Texture>,
 
-    _preview_cache: HashMap<(TextureFormat, Sha256), Vec<u8>>,
+    preview_cache: HashMap<(TextureFormat, Sha256), Vec<u8>>,
 }
 
 impl DataStore {
@@ -65,7 +67,7 @@ impl DataStore {
             id_index: Default::default(),
             name_index: Default::default(),
 
-            _preview_cache: Default::default(),
+            preview_cache: Default::default(),
         };
 
         let metadata_file = metadata_file::MetadataFile::load(&store.index_file_path())?;
@@ -172,10 +174,25 @@ impl DataStore {
 
     pub fn get_texture_preview(
         &mut self,
-        _hash: &Sha256,
-        _desired_format: TextureFormat,
-    ) -> TextureFileResult {
-        unimplemented!();
+        hash: &Sha256,
+        desired_format: TextureFormat,
+    ) -> io::Result<Vec<u8>> {
+        let key = (desired_format.clone(), hash.clone());
+
+        if let Some(preview) = self.preview_cache.get(&key) {
+            return Ok(preview.clone());
+        }
+
+        let original = self.read_texture_file_by_hash(&hash)?;
+
+        let preview =
+            image_convert::generate_preview(&original[..], desired_format).map_err(|_e| {
+                io::Error::new(io::ErrorKind::InvalidData, "Invalid Texture Image on Disk.")
+            })?;
+
+        self.preview_cache.insert(key, preview.clone());
+
+        Ok(preview)
     }
 
     pub fn borrow_textures(&self) -> impl Iterator<Item = &Texture> {
diff --git a/server/texture-sync-server/src/server_state.rs b/server/texture-sync-server/src/server_state.rs
index 0c619e6..09ef116 100644
--- a/server/texture-sync-server/src/server_state.rs
+++ b/server/texture-sync-server/src/server_state.rs
@@ -56,16 +56,9 @@ impl ProtocolHandler for ServerState {
     ) -> ProtocolResult<Vec<u8>> {
         let mut data_store = self.data_store.write().unwrap();
 
-        match data_store.get_texture_preview(&hash, format) {
-            Ok(data) => Ok(data),
-            Err(TextureFileError::NotFound) => Err(ProtocolError::FileNotFound(
-                "Texture not found!".to_string(),
-            )),
-            Err(TextureFileError::ImageError(_)) => Err(ProtocolError::FileNotFound(
-                "Didn't Find valid Texture File".to_string(),
-            )),
-            Err(TextureFileError::IoError(err)) => Err(ProtocolError::InternalServerError(err)),
-        }
+        let preview = data_store.get_texture_preview(&hash, format)?;
+
+        Ok(preview)
     }
 
     fn replace_texture(