1 files changed, 99 insertions, 0 deletions
diff --git a/crates/nres/src/error.rs b/crates/nres/src/error.rs
new file mode 100644
index 0000000..a6f078f
--- /dev/null
+++ b/crates/nres/src/error.rs
@@ -0,0 +1,99 @@
+use core::fmt;
+
+#[derive(Debug)]
+#[non_exhaustive]
+pub enum Error {
+    Io(std::io::Error),
+
+    InvalidMagic {
+        got: [u8; 4],
+    },
+    UnsupportedVersion {
+        got: u32,
+    },
+    TotalSizeMismatch {
+        header: u32,
+        actual: u64,
+    },
+
+    InvalidEntryCount {
+        got: i32,
+    },
+    DirectoryOutOfBounds {
+        directory_offset: u64,
+        directory_len: u64,
+        file_len: u64,
+    },
+
+    EntryIdOutOfRange {
+        id: u32,
+        entry_count: u32,
+    },
+    EntryDataOutOfBounds {
+        id: u32,
+        offset: u64,
+        size: u32,
+        directory_offset: u64,
+    },
+    NameTooLong {
+        got: usize,
+        max: usize,
+    },
+    NameContainsNul,
+    BadNameEncoding,
+
+    IntegerOverflow,
+
+    RawModeDisallowsOperation(&'static str),
+}
+
+impl From<std::io::Error> for Error {
+    fn from(value: std::io::Error) -> Self {
+        Self::Io(value)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::Io(e) => write!(f, "I/O error: {e}"),
+            Error::InvalidMagic { got } => write!(f, "invalid NRes magic: {got:02X?}"),
+            Error::UnsupportedVersion { got } => {
+                write!(f, "unsupported NRes version: {got:#x}")
+            }
+            Error::TotalSizeMismatch { header, actual } => {
+                write!(f, "NRes total_size mismatch: header={header}, actual={actual}")
+            }
+            Error::InvalidEntryCount { got } => write!(f, "invalid entry_count: {got}"),
+            Error::DirectoryOutOfBounds {
+                directory_offset,
+                directory_len,
+                file_len,
+            } => write!(
+                f,
+                "directory out of bounds: off={directory_offset}, len={directory_len}, file={file_len}"
+            ),
+            Error::EntryIdOutOfRange { id, entry_count } => {
+                write!(f, "entry id out of range: id={id}, count={entry_count}")
+            }
+            Error::EntryDataOutOfBounds {
+                id,
+                offset,
+                size,
+                directory_offset,
+            } => write!(
+                f,
+                "entry data out of bounds: id={id}, off={offset}, size={size}, dir_off={directory_offset}"
+            ),
+            Error::NameTooLong { got, max } => write!(f, "name too long: {got} > {max}"),
+            Error::NameContainsNul => write!(f, "name contains NUL byte"),
+            Error::BadNameEncoding => write!(f, "bad name encoding"),
+            Error::IntegerOverflow => write!(f, "integer overflow"),
+            Error::RawModeDisallowsOperation(op) => {
+                write!(f, "operation not allowed in raw mode: {op}")
+            }
+        }
+    }
+}
+
+impl std::error::Error for Error {}