nautilus-orm-schema 0.1.3

//! Semantic token provider for `.nautilus` schema files.
//!
//! Produces a list of [`SemanticToken`]s by walking the AST and resolving
//! every `UserType` field reference to either a model or an enum, using
//! the parsed token stream to recover the exact source span.

use crate::ast::{Declaration, FieldType, Schema};
use crate::span::Span;
use crate::token::{Token, TokenKind};
use std::collections::HashSet;

/// The semantic category of a type reference.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SemanticKind {
    /// Reference to a `model` declaration.
    ModelRef,
    /// Reference to an `enum` declaration.
    EnumRef,
    /// Reference to a `type` (composite type) declaration.
    CompositeTypeRef,
}

/// A single semantic token: a source span and its semantic kind.
#[derive(Debug, Clone)]
pub struct SemanticToken {
    /// The source span of the token.
    pub span: Span,
    /// The semantic kind (model or enum reference).
    pub kind: SemanticKind,
}

/// Walk `ast` and return semantic tokens for every user-type field reference.
///
/// The `tokens` slice (from the lexer) is used to recover the precise span of
/// each type name — the AST's `FieldType::UserType` only stores the name string.
pub fn semantic_tokens(ast: &Schema, tokens: &[Token]) -> Vec<SemanticToken> {
    let model_names: HashSet<&str> = ast.models().map(|m| m.name.value.as_str()).collect();
    let enum_names: HashSet<&str> = ast.enums().map(|e| e.name.value.as_str()).collect();
    let type_names: HashSet<&str> = ast.types().map(|t| t.name.value.as_str()).collect();

    let mut result = Vec::new();

    for decl in &ast.declarations {
        if let Declaration::Model(model) = decl {
            for field in &model.fields {
                if let FieldType::UserType(type_name) = &field.field_type {
                    let kind = if type_names.contains(type_name.as_str()) {
                        SemanticKind::CompositeTypeRef
                    } else if model_names.contains(type_name.as_str()) {
                        SemanticKind::ModelRef
                    } else if enum_names.contains(type_name.as_str()) {
                        SemanticKind::EnumRef
                    } else {
                        continue;
                    };

                    // Find the Ident token whose text matches `type_name`, within
                    // the field's span, skipping the field name token itself.
                    if let Some(tok) = tokens.iter().find(|t| {
                        matches!(&t.kind, TokenKind::Ident(name) if name == type_name)
                            && t.span.start >= field.span.start
                            && t.span.end <= field.span.end
                            && t.span.start != field.name.span.start
                    }) {
                        result.push(SemanticToken {
                            span: tok.span,
                            kind,
                        });
                    }
                }
            }
        }
    }

    result.sort_by_key(|t| t.span.start);
    result
}