feat: implement entry header parsing (#5)

feat: add #![warn(clippy::pedantic)]

feat: add `#[derive(Debug, PartialEq)]` to types for easier testing.

---------

Co-authored-by: nenikitov <nenikitov@mail.ru>

lib/src/lib.rs

@@ -1,4 +1,5 @@
 #![allow(unused)] // FIX(Unavailable): just testing :)
 #![warn(unused_imports)]
+#![warn(clippy::pedantic)]
 
 mod packfile;

lib/src/packfile/mod.rs

@@ -2,25 +2,35 @@
 
 mod nom;
 
+#[allow(clippy::wildcard_imports)]
 use nom::*;
 
+#[derive(Debug, PartialEq)]
 enum EntryKind {}
 
+#[derive(Debug, PartialEq)]
 pub struct EntryData {
     bytes: Vec<u8>,
     kind: EntryKind,
 }
 
+#[derive(Debug, PartialEq)]
 pub struct PackFile {
     copyright: String,
     entries: Vec<EntryData>,
 }
 
+#[derive(Debug, PartialEq)]
+struct EntryHeader {
+    offset: u32,
+    size: u32,
+}
+
 impl PackFile {
     const HEADER: &'static str = "PMAN";
     const COPYRIGHT_LENGTH: usize = 56;
 
-    fn new(bytes: &[u8]) -> Result<()> {
+    pub fn new(bytes: &[u8]) -> Result<Self> {
         todo!()
     }
 
@@ -36,6 +46,24 @@ impl PackFile {
 
         Ok((input, (copyright, total_entries)))
     }
+
+    fn entries(input: &[u8], total_entries: u32) -> Result<Vec<EntryHeader>> {
+        fn entry(input: &[u8]) -> Result<EntryHeader> {
+            // TODO(nenikitov): add check for `asset_kind == 0`
+            let (input, asset_kind) = number::le_u32(input)?;
+
+            let (input, offset) = number::le_u32(input)?;
+
+            let (input, size) = number::le_u32(input)?;
+
+            // TODO(nenikitov): add check for `reserved == 0`
+            let (input, reserved) = number::le_u32(input)?;
+
+            Ok((input, EntryHeader { offset, size }))
+        }
+
+        multi::count(entry, total_entries as usize)(input)
+    }
 }
 
 #[cfg(test)]
@@ -51,4 +79,40 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn packfile_entries_works() -> eyre::Result<()> {
+        #[rustfmt::skip]
+        let (_, entries) = PackFile::entries(
+            &[
+                // File 1
+                0x00, 0x00, 0x00, 0x00,
+                0x20, 0x0A, 0x00, 0x00,
+                0x00, 0x65, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                // File 2
+                0x00, 0x00, 0x00, 0x00,
+                0x20, 0x6F, 0x00, 0x00,
+                0x00, 0x80, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+            ],
+            2
+        )?;
+
+        assert_eq!(
+            entries,
+            [
+                EntryHeader {
+                    offset: 0x0A20,
+                    size: 0x6500,
+                },
+                EntryHeader {
+                    offset: 0x6F20,
+                    size: 0x8000,
+                },
+            ]
+        );
+
+        Ok(())
+    }
 }

lib/src/packfile/nom.rs

@@ -13,4 +13,8 @@ re_export!(bytes);
 re_export!(character);
 re_export!(number);
 
+pub mod multi {
+    pub use nom::multi::*;
+}
+
 pub type Result<'a, T> = nom::IResult<&'a [u8], T>;