Enable support for writing the file info format

This is the first step in enabling write support for a format! I wanted
to see how binwrite works with one of the game's simplest formats.

Cargo.lock

@@ -443,6 +443,7 @@ dependencies = [
  "paste",
  "serde",
  "serde_json",
+ "sha1_smol",
 ]
 
 [[package]]
@@ -603,6 +604,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "sha1_smol"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
+
 [[package]]
 name = "syn"
 version = "1.0.99"

Cargo.toml

@@ -44,3 +44,6 @@ hard-xml = "1.13.0"
 # needed for textools skel parsing
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
+
+# needed for file info (fiin)
+sha1_smol = "1.0.0"

src/fiin.rs

@@ -1,33 +1,42 @@
 use std::ffi::CString;
+use std::fs::read;
 use std::io::Cursor;
-use binrw::binread;
+use binrw::binrw;
 use crate::gamedata::MemoryBuffer;
 use binrw::BinRead;
 
-#[binread]
-#[br(magic = b"FileInfo")]
+#[binrw]
+#[brw(magic = b"FileInfo")]
 #[derive(Debug)]
 pub struct FileInfo {
-    #[br(pad_before = 20)]
+    #[brw(pad_before = 16)]
+    #[br(ignore)]
+    #[bw(calc = 1024)]
+    unknown : i32,
+
     #[br(temp)]
+    #[bw(calc = (entries.len() * 96) as i32)]
     entries_size : i32,
 
-    #[br(pad_before = 992)]
+    #[brw(pad_before = 992)]
     #[br(count = entries_size / 96)]
     entries : Vec<FIINEntry>
 }
 
-#[binread]
+#[binrw]
 #[derive(Debug)]
 pub struct FIINEntry {
     file_size : i32,
 
-    #[br(pad_before = 4)]
+    #[brw(pad_before = 4)]
     #[br(count = 64)]
     #[br(map = | x: Vec < u8 > | String::from_utf8(x).unwrap())]
+    #[bw(map = | x : &String | x.as_bytes().to_vec())]
+    #[bw(pad_size_to = 64)]
     file_name: String,
 
     #[br(count = 24)]
+    #[bw(pad_size_to = 24)]
     sha1 : Vec<u8>
 }
 
@@ -36,4 +45,22 @@ impl FileInfo {
         let mut cursor = Cursor::new(buffer);
         Some(FileInfo::read(&mut cursor).ok()?)
     }
+
+    pub fn new(file_names : Vec<&str>) -> Option<FileInfo> {
+        let mut entries = vec![];
+
+        for name in file_names {
+            let file = &read(&name).expect("Cannot read file.");
+            
+            entries.push(FIINEntry {
+                file_size: file.len() as i32,
+                file_name: name.to_string(),
+                sha1: sha1_smol::Sha1::from(file).digest().bytes().to_vec()
+            });
+        }
+
+        Some(FileInfo {
+            entries
+        })
+    }
 }