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use super::{Evaluator, Scope, ScopeKind};
use crate::{
ast::resolved::ResolvedNode,
ast::source::*,
ast::{PropValidation, Type, Value},
error::{NbclError, Result},
};
use std::collections::HashMap;
impl Evaluator {
pub(crate) fn resolve_node(&mut self, inv: NodeInvocation) -> Result<Vec<ResolvedNode>> {
// Try to find it as a Component
let component_def = self.registry.components.get(&inv.type_name).cloned();
if let Some(def) = component_def {
return self.expand_component(&def, inv);
}
let resolved_id = if let Some(id_expr) = &inv.id {
let val = self.eval_expr(id_expr)?;
match val {
Value::Str(s) => Some(s),
Value::Null => None,
_ => {
return Err(NbclError::Runtime {
message: format!("expected string for node ID, found {}", val.type_name()),
hint: Some(
"If you're passing a variable, ensure it contains a string.".into(),
),
span: Some(id_expr.span.clone()),
});
}
}
} else {
None
};
// Try to find it as a Native Node
if let Some(schema) = self.registry.native_nodes.get(&inv.type_name).cloned() {
// Check: Is an ID required by the schema?
if schema.enforce_id && resolved_id.is_none() {
return Err(NbclError::Runtime {
message: format!("node '{}' requires an #id", inv.type_name),
hint: Some(
"Try providing an id like this: 'Object \"id\" { ... }'.".to_string(),
),
span: Some(inv.span),
});
}
let mut props = HashMap::new();
let mut children = Vec::new();
self.resolve_node_items(inv.body, &mut props, &mut children)?;
// Check: Are these properties allowed and are their type correct?
if let PropValidation::Strict(allowed_map) = &schema.validation {
for (key, value) in props.iter() {
// Existence Check
if let Some(expected_type) = allowed_map.get(key) {
// Type Check
if expected_type.matches_value(value) {
return Err(NbclError::Runtime {
message: format!(
"type mismatch for '{}' on '{}': expected {:?}, found {:?}",
key,
inv.type_name,
expected_type,
value.type_name()
),
hint: None,
span: Some(inv.span.clone()),
});
}
} else {
// Key not found in the allowed map
let suggestion = crate::utils::find_best_match(key, allowed_map.keys());
let hint = suggestion.map(|s| format!("Did you mean \"{}\"?", s));
return Err(NbclError::Runtime {
message: format!(
"property '{}' is not allowed on node '{}'",
key, inv.type_name
),
hint,
span: Some(inv.span.clone()),
});
}
}
}
return Ok(vec![ResolvedNode {
type_name: inv.type_name,
id: resolved_id,
props,
children,
}]);
}
let all_node_names =
self.registry.native_nodes.keys().chain(self.registry.components.keys());
let suggestion = crate::utils::find_best_match(&inv.type_name, all_node_names);
let hint = suggestion.map(|s| format!("Did you mean \"{}\"?", s));
Err(NbclError::Runtime {
message: format!("unknown node or component: {}", inv.type_name),
hint,
span: Some(inv.span),
})
}
fn expand_component(
&mut self,
def: &ComponentDef,
inv: NodeInvocation,
) -> Result<Vec<ResolvedNode>> {
let resolved_id_val = if let Some(id_expr) = &inv.id {
let val = self.eval_expr(id_expr)?;
match val {
Value::Str(_) => val,
Value::Null => Value::Null,
_ => {
return Err(NbclError::Runtime {
message: "node ID must resolve to a string".into(),
hint: Some(format!("Got a {} instead.", val.type_name())),
span: Some(id_expr.span.clone()),
});
}
}
} else {
Value::Null
};
let mut component_scope = Scope::new(ScopeKind::Component);
// Resolve caller props once to avoid re-evaluating in different branches
let mut caller_props = HashMap::new();
let mut caller_children = Vec::new();
self.resolve_node_items(inv.body, &mut caller_props, &mut caller_children)?;
// Enforce properties
for item in &def.body {
match item {
NodeItem::Prop(key, expr) => {
let constraint_val = self.eval_expr(expr)?;
match key.as_str() {
"id_required" => {
if let Value::Bool(true) = constraint_val {
if resolved_id_val == Value::Null {
return Err(NbclError::Runtime {
message: format!(
"Component '{}' requires an ID.",
def.name
),
hint: Some(format!(
"Usage: {} \"my_id\" {{ ... }}",
def.name
)),
span: Some(inv.span.clone()),
});
}
}
}
"child_count" => {
let actual_count = caller_children.len() as i64;
match constraint_val {
// Case: child_count = 3 (Exact)
Value::Int(expected) => {
if actual_count != expected {
let maybe_pronoun = if expected == 1 {
"child"
} else {
"children"
};
return Err(NbclError::Runtime {
message: format!("Component '{}' requires exactly {} {}, but got {}.", def.name, expected, maybe_pronoun, actual_count),
hint: None,
span: Some(inv.span.clone()),
});
}
}
// Case: child_count = [1, 3] (Range)
Value::List(range) if range.len() == 2 => {
if let (Value::Int(min), Value::Int(max)) = (&range[0], &range[1]) {
if actual_count < *min || actual_count > *max {
return Err(NbclError::Runtime {
message: format!("Component '{}' requires between {} and {} children, but got {}.", def.name, min, max, actual_count),
hint: None,
span: Some(inv.span.clone()),
});
}
}
}
_ => return Err(NbclError::Runtime {
message: "Property 'child_count' must be an Integer or a List of 2 Integers.".into(),
hint: None,
span: Some(expr.span.clone()),
}),
}
}
_ => {}
}
}
_ => {}
}
}
// Generate component.* namspace
let mut meta_map = Vec::new();
meta_map.push(("id".to_string(), resolved_id_val));
meta_map.push(("children".to_string(), Value::Nodes(caller_children)));
component_scope.variables.insert("self".to_string(), Value::Map(meta_map));
match &def.interface {
ComponentInterface::Loose(name) => {
// Pack all props into a single Map value
let mut prop_list = Vec::new();
for (k, v) in caller_props {
prop_list.push((k, v));
}
component_scope.variables.insert(name.clone(), Value::Map(prop_list));
}
ComponentInterface::Strict(params) => {
for param in params {
let value = caller_props.remove(¶m.name);
match value {
Some(v) => {
// Validate Type Hint if it exists
if let Some(hint) = ¶m.type_hint {
if let Some(expected_type) = Type::from_str(hint) {
if !expected_type.matches_value(&v) {
return Err(NbclError::Runtime {
message: format!(
"component '{}' expected {} for prop '{}', got {}",
def.name,
hint,
param.name,
v.type_name()
),
hint: None,
span: Some(inv.span.clone()),
});
}
}
}
component_scope.variables.insert(param.name.clone(), v);
}
None => {
if !param.is_optional {
let suggestion =
crate::utils::find_best_match(¶m.name, caller_props.keys());
let hint = suggestion.map(|s|
format!("You provided \"{}\", which is not a parameter. Did you mean \"{}\"?", param.name, s)
);
return Err(NbclError::Runtime {
message: format!(
"missing required prop '{}' for component '{}'",
param.name, def.name
),
hint,
span: Some(inv.span.clone()),
});
}
component_scope.variables.insert(param.name.clone(), Value::Null);
}
}
}
if !caller_props.is_empty() {
let (extra_key, _) = caller_props.into_iter().next().unwrap();
let param_names = params.iter().map(|p| &p.name);
let suggestion = crate::utils::find_best_match(&extra_key, param_names);
let hint = suggestion.map(|s| format!("Did you mean \"{}\"?", s));
return Err(NbclError::Runtime {
message: format!(
"unexpected property '{}' for component '{}'.",
extra_key, def.name
),
hint,
span: Some(inv.span.clone()),
});
}
}
ComponentInterface::None => {}
}
self.scopes.push(component_scope);
let mut final_nodes = Vec::new();
let mut ignored_props = HashMap::new(); // Components usually don't "output" props, only nodes
// Use the recursive helper so components get 'if' and 'for' for free!
self.resolve_node_items(def.body.clone(), &mut ignored_props, &mut final_nodes)?;
self.scopes.pop();
Ok(final_nodes)
}
fn resolve_node_items(
&mut self,
items: Vec<NodeItem>,
props: &mut HashMap<String, Value>,
children: &mut Vec<ResolvedNode>,
) -> Result<()> {
for item in items {
match item {
NodeItem::Prop(key, expr) => {
props.insert(key, self.eval_expr(&expr)?);
}
NodeItem::Child(child_inv) => {
children.extend(self.resolve_node(child_inv)?);
}
NodeItem::Stmt(stmt) => {
let result = self.execute_stmt(stmt)?;
if let Value::Nodes(returned_nodes) = result {
children.extend(returned_nodes);
}
}
}
}
Ok(())
}
}