file system and file donload

client-network/src/data.rs

@@ -1,7 +1,13 @@
 use rand::{Rng, rng};
+use sha2::{Digest, Sha256};
 use std::collections::HashMap;
 use std::hash::{DefaultHasher, Hash, Hasher};
 
+use std::fs::{File, OpenOptions, create_dir};
+use std::io::{self, Write};
+
+use std::env;
+
 // --- Constants ---
 pub const MAX_CHUNK_DATA_SIZE: usize = 1024;
 pub const MAX_DIRECTORY_ENTRIES: usize = 16;
@@ -176,3 +182,336 @@ impl MerkleNode {
         bytes
     }
 }
+
+fn hash(data: &[u8]) -> NodeHash {
+    let root_hash = Sha256::digest(&data);
+    println!("root hash: {:?}", root_hash);
+    let res: NodeHash = root_hash.try_into().expect("incorrect size");
+    res
+    /*let mut hasher = DefaultHasher::new();
+    data.hash(&mut hasher);
+    let hash_u64 = hasher.finish();
+
+    let mut hash_array = [0u8; FILENAME_HASH_SIZE];
+    // Simple way to spread a 64-bit hash across 32 bytes for a unique-ish ID
+    for i in 0..8 {
+        hash_array[i] = (hash_u64 >> (i * 8)) as u8;
+    }
+    hash_array // The rest remains 0, satisfying the 32-byte requirement
+    */
+}
+
+fn generate_random_filename() -> [u8; FILENAME_HASH_SIZE] {
+    let mut rng = rand::rng();
+    let mut filename_bytes = [0; FILENAME_HASH_SIZE];
+
+    // Generate a random length for the base name
+    let name_len = rng.random_range(5..21);
+
+    // Generate random alphanumeric characters
+    for i in 0..name_len {
+        let char_code = rng.random_range(97..123); // 'a' through 'z'
+        if i < FILENAME_HASH_SIZE {
+            filename_bytes[i] = char_code as u8;
+        }
+    }
+
+    // Append a common extension
+    let ext = if rng.random_bool(0.5) { ".txt" } else { ".dat" };
+    let ext_bytes = ext.as_bytes();
+    let start_index = name_len.min(FILENAME_HASH_SIZE - ext_bytes.len());
+    if start_index < FILENAME_HASH_SIZE {
+        filename_bytes[start_index..(start_index + ext_bytes.len())].copy_from_slice(ext_bytes);
+    }
+
+    filename_bytes
+}
+
+fn generate_random_file_node(
+    storage: &mut HashMap<NodeHash, MerkleNode>,
+) -> Result<NodeHash, String> {
+    let mut rng = rng();
+    let is_big = rng.random_bool(0.2); // 20% chance of being a big file
+
+    if !is_big {
+        // Generate a simple Chunk Node
+        let node = MerkleNode::Chunk(ChunkNode::new_random());
+        let hash = hash(&node.serialize());
+        storage.insert(hash, node);
+        Ok(hash)
+    } else {
+        // Generate a Big Node (a file composed of chunks)
+        let num_children = rng.random_range(MIN_BIG_CHILDREN..=MAX_BIG_CHILDREN.min(8)); // Limit complexity
+        let mut children_hashes = Vec::with_capacity(num_children);
+
+        for _ in 0..num_children {
+            // Children must be Chunk or Big; for simplicity, we only generate Chunk children here.
+            let chunk_node = MerkleNode::Chunk(ChunkNode::new_random());
+            let chunk_hash = hash(&chunk_node.serialize());
+            storage.insert(chunk_hash, chunk_node);
+            children_hashes.push(chunk_hash);
+        }
+
+        let node = MerkleNode::Big(BigNode::new(children_hashes)?);
+        let hash = hash(&node.serialize());
+        storage.insert(hash, node);
+        Ok(hash)
+    }
+}
+
+fn generate_random_directory_node(
+    depth: u32,
+    max_depth: u32,
+    storage: &mut HashMap<NodeHash, MerkleNode>,
+) -> Result<NodeHash, String> {
+    let mut rng = rng();
+    let current_depth = depth + 1;
+    let is_big_dir = rng.random_bool(0.3) && current_depth < max_depth;
+
+    if !is_big_dir || current_depth >= max_depth {
+        // Generate a simple Directory Node (leaf level directory)
+        let num_entries = rng.random_range(1..=MAX_DIRECTORY_ENTRIES.min(5)); // Limit directory size for testing
+        let mut entries = Vec::with_capacity(num_entries);
+
+        for _ in 0..num_entries {
+            if rng.random_bool(0.7) {
+                // 70% chance of creating a file (Chunk/Big)
+                let file_hash = generate_random_file_node(storage)?;
+                let entry = DirectoryEntry {
+                    filename: generate_random_filename(),
+                    content_hash: file_hash,
+                };
+                entries.push(entry);
+            } else if current_depth < max_depth {
+                // 30% chance of creating a subdirectory
+                let dir_hash = generate_random_directory_node(current_depth, max_depth, storage)?;
+
+                // Create a basic directory entry name
+                let mut filename_bytes = [0; 32];
+                let subdir_name = format!("dir_{}", current_depth);
+                filename_bytes[..subdir_name.len()].copy_from_slice(subdir_name.as_bytes());
+
+                let entry = DirectoryEntry {
+                    filename: filename_bytes,
+                    content_hash: dir_hash,
+                };
+                entries.push(entry);
+            }
+        }
+
+        let node = MerkleNode::Directory(DirectoryNode::new(entries)?);
+        let hash = hash(&node.serialize());
+        storage.insert(hash, node);
+        Ok(hash)
+    } else {
+        // Generate a BigDirectory Node (internal directory structure)
+        let num_children = rng.random_range(MIN_BIG_CHILDREN..=MAX_BIG_CHILDREN.min(4)); // Limit children count
+        let mut children = Vec::with_capacity(num_children);
+
+        for _ in 0..num_children {
+            // Children must be Directory or BigDirectory
+            let child_hash = generate_random_directory_node(current_depth, max_depth, storage)?;
+            children.push(child_hash);
+        }
+
+        let node = MerkleNode::BigDirectory(BigDirectoryNode::new(children)?);
+        let hash = hash(&node.serialize());
+        storage.insert(hash, node);
+        Ok(hash)
+    }
+}
+
+pub fn generate_random_tree(
+    max_depth: u32,
+) -> Result<(NodeHash, HashMap<NodeHash, MerkleNode>), String> {
+    let mut storage = HashMap::new();
+
+    // Start tree generation from the root directory at depth 0
+    let root_hash = generate_random_directory_node(0, max_depth, &mut storage)?;
+
+    Ok((root_hash, storage))
+}
+
+pub fn generate_base_tree() -> MerkleTree {
+    let mut res = HashMap::new();
+
+    let bob_content = "where is bob".to_string().into_bytes();
+    let alice_content = "alice".to_string().into_bytes();
+    let oscar_content = "oscar is the opponent".to_string().into_bytes();
+
+    let mut children_nodes = Vec::new();
+    for i in 0..10 {
+        let mut i_nodes = Vec::new();
+        for j in 0..10 {
+            let node1 = MerkleNode::Chunk(ChunkNode::new(bob_content.clone()).unwrap());
+            let hash = hash(&node1.serialize());
+            i_nodes.push(hash);
+            res.insert(hash, node1);
+        }
+        let bignode = MerkleNode::Big(BigNode::new(i_nodes).unwrap());
+        let hashbig = hash(&bignode.serialize());
+        children_nodes.push(hashbig);
+        res.insert(hashbig, bignode);
+    }
+
+    let bignode = MerkleNode::Big(BigNode::new(children_nodes).unwrap());
+    let hashbig = hash(&bignode.serialize());
+
+    let node1 = MerkleNode::Chunk(ChunkNode::new(bob_content).unwrap());
+    let hash1 = hash(&node1.serialize());
+
+    let node2 = MerkleNode::Chunk(ChunkNode::new(alice_content).unwrap());
+    let hash2 = hash(&node2.serialize());
+
+    //res.insert(hash1, node1);
+    //res.insert(hash2, node2);
+    res.insert(hashbig, bignode);
+
+    let node3 = MerkleNode::Chunk(ChunkNode::new(oscar_content).unwrap());
+    let hash3 = hash(&node3.serialize());
+
+    //res.insert(hash3, node3);
+
+    let dir1 = MerkleNode::Directory(DirectoryNode {
+        entries: [DirectoryEntry {
+            filename: generate_random_filename(),
+            content_hash: hash3,
+        }]
+        .to_vec(),
+    });
+    let hash_dir1 = hash(&dir1.serialize());
+
+    //res.insert(hash_dir1, dir1);
+
+    let root = MerkleNode::Directory(DirectoryNode {
+        entries: [
+            DirectoryEntry {
+                filename: generate_random_filename(),
+                content_hash: hashbig,
+            },
+            /*DirectoryEntry {
+                filename: generate_random_filename(),
+                content_hash: hash2,
+            },
+            DirectoryEntry {
+                filename: generate_random_filename(),
+                content_hash: hash_dir1,
+            },*/
+        ]
+        .to_vec(),
+    });
+
+    let root_hash = Sha256::digest(&root.serialize());
+    println!("root hash: {:?}", root_hash);
+    res.insert(root_hash.try_into().expect("incorrect size"), root);
+
+    MerkleTree::new(res, root_hash.try_into().expect("incorrect size"))
+}
+
+pub fn node_to_file(tree: &MerkleTree, node: &MerkleNode, path: String, i: u8) {
+    match node.clone() {
+        MerkleNode::Directory(dir) => {
+            if i != 0 {
+                let new_path = format!("{}/fold_{}", path.clone(), i);
+                match create_dir(new_path.clone()) {
+                    Ok(_) => println!("Directory created successfully!"),
+                    Err(e) => println!("Failed to create directory: {}", e),
+                }
+            }
+            for entry in dir.entries {
+                // creer un fichier pour chaque entry
+                if let Ok(filename_str) = String::from_utf8(entry.filename.to_vec()) {
+                    let new_name = format!("{}{}", path.clone(), remove_null_bytes(&filename_str));
+
+                    println!("new_name: {}", new_name);
+                    let file = OpenOptions::new()
+                        .append(true)
+                        .create(true)
+                        .open(new_name.clone());
+                    match file {
+                        Ok(mut fileok) => {
+                            if let Some(current) = tree.data.get(&entry.content_hash) {
+                                big_or_chunk_to_file(&tree, &current, &mut fileok);
+                            }
+                        }
+                        Err(e) => {
+                            eprintln!("error creaation file: {}", e);
+                        }
+                    }
+                }
+            }
+        }
+        MerkleNode::BigDirectory(bigdir) => {
+            for entry in bigdir.children_hashes.iter() {
+                if let Some(current) = tree.data.get(entry) {
+                    node_to_file(tree, current, path.clone(), i + 1);
+                }
+            }
+        }
+        _ => {
+            eprintln!("invalid type of dir");
+        }
+    }
+}
+
+pub fn remove_null_bytes(input: &str) -> String {
+    input.chars().filter(|&c| c != '\0').collect()
+}
+
+pub fn big_or_chunk_to_file(tree: &MerkleTree, node: &MerkleNode, file: &mut File) {
+    match node {
+        MerkleNode::Big(big) => {
+            for entry in big.children_hashes.iter() {
+                if let Some(current) = tree.data.get(entry) {
+                    big_or_chunk_to_file(tree, current, file);
+                }
+            }
+        }
+        MerkleNode::Chunk(chunk) => {
+            println!("wrote data");
+            let _ = file.write_all(&chunk.data);
+        }
+        _ => {
+            println!("invalid type of file");
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    ///
+    /// creates a cryptographic signature
+    ///
+    #[test]
+    fn test_saving_tree() {
+        if let Ok(current_dir) = env::current_dir() {
+            println!("Current working directory: {:?}", current_dir);
+        }
+
+        println!("--------- tree test starts ------------");
+
+        match create_dir("../Download/") {
+            Ok(_) => println!("Directory created successfully!"),
+            Err(e) => println!("Failed to create directory: {}", e),
+        }
+        let tree = generate_base_tree();
+
+        println!("--------- test tree created ------------");
+        if let Some(root_node) = tree.data.get(&tree.root) {
+            node_to_file(&tree, root_node, "../Download/".to_string(), 0);
+        }
+    }
+
+    /*#[test]
+    fn signing_message() {
+        let username = String::from("gamixtreize");
+        let crypto_pair = CryptographicSignature::new(username.clone());
+        let handshake = HandshakeMessage::hello(0, 12, username);
+        let ser = handshake.serialize();
+        let signed_message = sign_message(&crypto_pair, &ser);
+        println!("unsigned_message: {:?}", ser);
+        println!("signed_message: {:?}", signed_message);
+    }*/
+}