1 files changed, 164 insertions, 0 deletions
diff --git a/azalea-core/src/identifier.rs b/azalea-core/src/identifier.rs
new file mode 100644
index 00000000..d1e46aef
--- /dev/null
+++ b/azalea-core/src/identifier.rs
@@ -0,0 +1,164 @@
+//! An arbitrary string identifier.
+
+use std::{
+    fmt,
+    io::{self, Cursor, Write},
+    str::FromStr,
+};
+
+use azalea_buf::{AzaleaRead, AzaleaWrite, BufReadError};
+use serde::{Deserialize, Deserializer, Serialize, Serializer, de};
+use simdnbt::{FromNbtTag, ToNbtTag, owned::NbtTag};
+
+/// An identifier, like `minecraft:stone` or `brigadier:number`.
+///
+/// This was formerly called a `ResourceLocation`.
+#[doc(alias = "ResourceLocation")]
+#[derive(Hash, Clone, PartialEq, Eq, Default)]
+pub struct Identifier {
+    pub namespace: String,
+    pub path: String,
+}
+
+static DEFAULT_NAMESPACE: &str = "minecraft";
+// static REALMS_NAMESPACE: &str = "realms";
+
+impl Identifier {
+    pub fn new(resource_string: &str) -> Identifier {
+        let sep_byte_position_option = resource_string.chars().position(|c| c == ':');
+        let (namespace, path) = if let Some(sep_byte_position) = sep_byte_position_option {
+            if sep_byte_position == 0 {
+                (DEFAULT_NAMESPACE, &resource_string[1..])
+            } else {
+                (
+                    &resource_string[..sep_byte_position],
+                    &resource_string[sep_byte_position + 1..],
+                )
+            }
+        } else {
+            (DEFAULT_NAMESPACE, resource_string)
+        };
+        Identifier {
+            namespace: namespace.to_string(),
+            path: path.to_string(),
+        }
+    }
+}
+
+impl fmt::Display for Identifier {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{}", self.namespace, self.path)
+    }
+}
+impl fmt::Debug for Identifier {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{}", self.namespace, self.path)
+    }
+}
+impl FromStr for Identifier {
+    type Err = &'static str;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Identifier::new(s))
+    }
+}
+impl From<&str> for Identifier {
+    fn from(s: &str) -> Self {
+        Identifier::new(s)
+    }
+}
+
+impl AzaleaRead for Identifier {
+    fn azalea_read(buf: &mut Cursor<&[u8]>) -> Result<Self, BufReadError> {
+        let location_string = String::azalea_read(buf)?;
+        Ok(Identifier::new(&location_string))
+    }
+}
+impl AzaleaWrite for Identifier {
+    fn azalea_write(&self, buf: &mut impl Write) -> io::Result<()> {
+        self.to_string().azalea_write(buf)
+    }
+}
+
+impl Serialize for Identifier {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for Identifier {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        if s.contains(':') {
+            Ok(Identifier::new(&s))
+        } else {
+            Err(de::Error::invalid_value(
+                de::Unexpected::Str(&s),
+                &"a valid Identifier",
+            ))
+        }
+    }
+}
+
+impl FromNbtTag for Identifier {
+    fn from_nbt_tag(tag: simdnbt::borrow::NbtTag) -> Option<Self> {
+        tag.string().and_then(|s| s.to_str().parse().ok())
+    }
+}
+
+impl ToNbtTag for Identifier {
+    fn to_nbt_tag(self) -> NbtTag {
+        NbtTag::String(self.to_string().into())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn basic_resource_location() {
+        let r = Identifier::new("abcdef:ghijkl");
+        assert_eq!(r.namespace, "abcdef");
+        assert_eq!(r.path, "ghijkl");
+    }
+    #[test]
+    fn no_namespace() {
+        let r = Identifier::new("azalea");
+        assert_eq!(r.namespace, "minecraft");
+        assert_eq!(r.path, "azalea");
+    }
+    #[test]
+    fn colon_start() {
+        let r = Identifier::new(":azalea");
+        assert_eq!(r.namespace, "minecraft");
+        assert_eq!(r.path, "azalea");
+    }
+    #[test]
+    fn colon_end() {
+        let r = Identifier::new("azalea:");
+        assert_eq!(r.namespace, "azalea");
+        assert_eq!(r.path, "");
+    }
+
+    #[test]
+    fn azbuf_resource_location() {
+        let mut buf = Vec::new();
+        Identifier::new("minecraft:dirt")
+            .azalea_write(&mut buf)
+            .unwrap();
+
+        let mut buf = Cursor::new(&buf[..]);
+
+        assert_eq!(
+            Identifier::azalea_read(&mut buf).unwrap(),
+            Identifier::new("minecraft:dirt")
+        );
+    }
+}