feat: add project & registry parsing /w commands

1 files changed, 263 insertions, 0 deletions

diff --git a/src/command.rs b/src/command.rs
new file mode 100644
index 0000000..c7ada95
--- /dev/null
+++ b/src/command.rs
@@ -0,0 +1,263 @@
+//! OpenGL command.
+use crate::xml::element::{Elements, FromElements};
+
+/// A command.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Command
+{
+    prototype: Prototype,
+    parameters: Vec<Parameter>,
+}
+
+impl Command
+{
+    /// Returns a new `Command`.
+    pub fn new(
+        prototype: Prototype,
+        parameters: impl IntoIterator<Item = Parameter>,
+    ) -> Self
+    {
+        Self {
+            prototype,
+            parameters: parameters.into_iter().collect(),
+        }
+    }
+
+    /// Returns the command prototype.
+    #[must_use]
+    pub fn prototype(&self) -> &Prototype
+    {
+        &self.prototype
+    }
+
+    /// Returns the command parameters.
+    #[must_use]
+    pub fn parameters(&self) -> &[Parameter]
+    {
+        &self.parameters
+    }
+}
+
+impl FromElements for Command
+{
+    type Error = Error;
+
+    fn from_elements(
+        elements: &crate::xml::element::Elements,
+    ) -> Result<Self, Self::Error>
+    {
+        let proto_element = elements
+            .get_first_tagged_element("proto")
+            .ok_or(Self::Error::MissingPrototype)?;
+
+        let prototype = Prototype::from_elements(proto_element.child_elements())?;
+
+        let parameters = elements
+            .get_all_tagged_elements_with_name("param")
+            .into_iter()
+            .map(|param_element| Parameter::from_elements(param_element.child_elements()))
+            .collect::<Result<Vec<_>, _>>()?;
+
+        Ok(Self {
+            prototype,
+            parameters,
+        })
+    }
+}
+
+/// [`Command`] error.
+#[derive(Debug, thiserror::Error)]
+pub enum Error
+{
+    /// No 'proto' element was found.
+    #[error("No 'proto' element was found")]
+    MissingPrototype,
+
+    /// Invalid prototype.
+    #[error("Invalid prototype")]
+    InvalidPrototype(#[from] PrototypeError),
+
+    /// Invalid parameter.
+    #[error("Invalid parameter")]
+    InvalidParameter(#[from] ParameterError),
+}
+
+/// A command prototype.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Prototype
+{
+    name: String,
+    return_type: String,
+}
+
+impl Prototype
+{
+    /// Returns a new `Prototype`.
+    pub fn new(name: impl Into<String>, return_type: impl Into<String>) -> Self
+    {
+        Self {
+            name: name.into(),
+            return_type: return_type.into(),
+        }
+    }
+
+    /// Returns the command prototype name.
+    #[must_use]
+    pub fn name(&self) -> &str
+    {
+        &self.name
+    }
+
+    /// Returns the command prototype return type.
+    #[must_use]
+    pub fn return_type(&self) -> &str
+    {
+        &self.return_type
+    }
+}
+
+impl FromElements for Prototype
+{
+    type Error = PrototypeError;
+
+    fn from_elements(
+        elements: &crate::xml::element::Elements,
+    ) -> Result<Self, Self::Error>
+    {
+        let name = elements
+            .get_first_tagged_element("name")
+            .ok_or(Self::Error::MissingName)?
+            .child_elements()
+            .get_first_text_element()
+            .cloned()
+            .unwrap_or_default();
+
+        let return_type = find_type(elements);
+
+        Ok(Self { name, return_type })
+    }
+}
+
+/// [`Prototype`] error.
+#[derive(Debug, thiserror::Error)]
+pub enum PrototypeError
+{
+    /// No 'name' element was found.
+    #[error("No 'name' element was found")]
+    MissingName,
+}
+
+/// A command parameter.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Parameter
+{
+    name: String,
+    ty: String,
+}
+
+impl Parameter
+{
+    /// Returns a new `Parameter`.
+    pub fn new(name: impl Into<String>, ty: impl Into<String>) -> Self
+    {
+        Self {
+            name: name.into(),
+            ty: ty.into(),
+        }
+    }
+
+    /// Returns the name of the command parameter.
+    #[must_use]
+    pub fn name(&self) -> &str
+    {
+        &self.name
+    }
+
+    /// Returns the type of the command parameter.
+    #[must_use]
+    pub fn get_type(&self) -> &str
+    {
+        &self.ty
+    }
+}
+
+impl FromElements for Parameter
+{
+    type Error = ParameterError;
+
+    fn from_elements(elements: &Elements) -> Result<Self, Self::Error>
+    {
+        let name = elements
+            .get_first_tagged_element("name")
+            .ok_or(Self::Error::MissingName)?
+            .child_elements()
+            .get_first_text_element()
+            .cloned()
+            .unwrap_or_default();
+
+        let ty = find_type(elements);
+
+        Ok(Self { name, ty })
+    }
+}
+
+/// [`Parameter`] error.
+#[derive(Debug, thiserror::Error)]
+pub enum ParameterError
+{
+    /// No 'name' element was found.
+    #[error("No 'name' element was found")]
+    MissingName,
+}
+
+fn find_type(elements: &Elements) -> String
+{
+    let text_type_parts = elements
+        .get_all_text_elements()
+        .into_iter()
+        .map(|text_type_part| text_type_part.trim())
+        .filter(|text_type_part| !text_type_part.is_empty())
+        .collect::<Vec<_>>();
+
+    let opt_ptype_text = get_ptype_text(elements);
+
+    opt_ptype_text.map_or_else(
+        || join_space_strs(text_type_parts.iter()),
+        |ptype_text| {
+            let Some(first_part) = text_type_parts.first() else {
+                return ptype_text.clone();
+            };
+
+            let before = if *first_part == "const" { "const " } else { "" };
+
+            let after_start_index = usize::from(*first_part == "const");
+
+            format!(
+                "{before}{ptype_text} {}",
+                text_type_parts
+                    .get(after_start_index..)
+                    .map(|parts| join_space_strs(parts.iter()))
+                    .unwrap_or_default()
+            )
+        },
+    )
+}
+
+fn get_ptype_text(elements: &Elements) -> Option<&String>
+{
+    let ptype_element = elements.get_first_tagged_element("ptype")?;
+
+    ptype_element.child_elements().get_first_text_element()
+}
+
+fn join_space_strs<Strings, StrItem>(strings: Strings) -> String
+where
+    Strings: Iterator<Item = StrItem>,
+    StrItem: ToString,
+{
+    strings
+        .into_iter()
+        .map(|string| string.to_string())
+        .collect::<Vec<_>>()
+        .join(" ")
+}