perl-semantic-analyzer 0.13.3

//! Class model for Moose/Moo/Mouse/Class::Accessor intelligence.
//!
//! Provides a structured representation of Perl OOP class declarations,
//! including attributes, methods, inheritance, and role composition.
//! Built from AST traversal, reusing existing framework detection.

use crate::SourceLocation;
use crate::ast::{Node, NodeKind};
use std::collections::{HashMap, HashSet};

/// Which OO framework a package uses.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Framework {
    /// `use Moose;`
    Moose,
    /// `use Moo;`
    Moo,
    /// `use Mouse;`
    Mouse,
    /// `use Class::Accessor;` or `use parent 'Class::Accessor';`
    ClassAccessor,
    /// `use Object::Pad;`
    ObjectPad,
    /// Native Perl OOP (bless-based)
    Native,
    /// Native Perl 5.38+ class (use feature 'class')
    NativeClass,
    /// Plain OO via `use parent`, `use base`, or `@ISA` (no framework)
    PlainOO,
    /// `use Role::Tiny;` (package is a role) or `use Role::Tiny::With;` (package consumes roles)
    RoleTiny,
    /// No OO framework detected
    None,
}

/// Accessor mode from the `is` option.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum AccessorType {
    /// `is => 'ro'`
    Ro,
    /// `is => 'rw'`
    Rw,
    /// `is => 'lazy'` (Moo shorthand for `ro` + `lazy => 1`)
    Lazy,
    /// `is => 'bare'` (no accessor generated)
    Bare,
}

/// Method-resolution order for inherited method lookup.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum MethodResolutionOrder {
    /// Default Perl depth-first resolution order.
    #[default]
    Dfs,
    /// C3 linearization enabled via `use mro 'c3';`.
    C3,
}

/// A Moose/Moo attribute declared via `has`.
#[derive(Debug, Clone)]
pub struct Attribute {
    /// Attribute name (e.g., `name` from `has 'name' => (...)`)
    pub name: String,
    /// Accessor mode
    pub is: Option<AccessorType>,
    /// Type constraint string (e.g., `Str`, `ArrayRef[Int]`)
    pub isa: Option<String>,
    /// Whether a default value is specified
    pub default: bool,
    /// Whether `required => 1` is set
    pub required: bool,
    /// Name of the accessor method (may differ from attribute name)
    pub accessor_name: String,
    /// Source location of the `has` declaration
    pub location: SourceLocation,
    /// Builder method name. `builder => 1` derives `_build_<attr>`, a string names the method.
    pub builder: Option<String>,
    /// Whether a coercion is applied (`coerce => 1`)
    pub coerce: bool,
    /// Predicate method name. `predicate => 1` derives `has_<attr>`.
    pub predicate: Option<String>,
    /// Clearer method name. `clearer => 1` derives `clear_<attr>`.
    pub clearer: Option<String>,
    /// Whether a trigger is set (`trigger => \&sub`)
    pub trigger: bool,
}

/// An Object::Pad field declaration.
#[derive(Debug, Clone)]
pub struct FieldInfo {
    /// Field name (e.g., `name` from `field $name :param`)
    pub name: String,
    /// Source location of the field declaration
    pub location: SourceLocation,
    /// Raw field traits such as `param`, `reader`, and `writer`
    pub attributes: Vec<String>,
    /// Whether `:param` is present
    pub param: bool,
    /// Explicit or synthesized reader method name
    pub reader: Option<String>,
    /// Explicit or synthesized writer method name
    pub writer: Option<String>,
    /// Explicit or synthesized accessor method name
    pub accessor: Option<String>,
    /// Explicit or synthesized mutator method name
    pub mutator: Option<String>,
    /// Optional initializer expression summary
    pub default: Option<String>,
}

/// Information about a method modifier (`before`, `after`, `around`, `override`, `augment`).
#[derive(Debug, Clone)]
pub struct MethodModifier {
    /// Modifier type
    pub kind: ModifierKind,
    /// Name of the method being modified
    pub method_name: String,
    /// Source location
    pub location: SourceLocation,
}

/// The type of method modifier.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ModifierKind {
    /// `before 'method' => sub { ... }`
    Before,
    /// `after 'method' => sub { ... }`
    After,
    /// `around 'method' => sub { ... }`
    Around,
    /// `override 'method' => sub { ... }`
    Override,
    /// `augment 'method' => sub { ... }`
    Augment,
}

/// Synthetic accessor mode generated by `Class::Accessor`.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ClassAccessorMode {
    /// `mk_accessors(...)` or `mk_rw_accessors(...)`
    Rw,
    /// `mk_ro_accessors(...)`
    Ro,
    /// `mk_wo_accessors(...)`
    Wo,
}

/// Information about a method (subroutine) in a class.
#[derive(Debug, Clone)]
pub struct MethodInfo {
    /// Method name
    pub name: String,
    /// Source location of the sub declaration
    pub location: SourceLocation,
    /// Whether this method was synthesized from framework metadata.
    pub synthetic: bool,
    /// Accessor mode for `Class::Accessor`-generated methods.
    pub accessor_mode: Option<ClassAccessorMode>,
}

impl MethodInfo {
    /// Construct a regular declared method.
    pub fn new(name: String, location: SourceLocation) -> Self {
        Self { name, location, synthetic: false, accessor_mode: None }
    }

    /// Construct a synthetic method generated from framework metadata.
    pub fn synthetic(
        name: String,
        location: SourceLocation,
        accessor_mode: Option<ClassAccessorMode>,
    ) -> Self {
        Self { name, location, synthetic: true, accessor_mode }
    }
}

/// Structured model of a Perl OOP class or role.
#[derive(Debug, Clone)]
pub struct ClassModel {
    /// Package name (e.g., `MyApp::User`)
    pub name: String,
    /// Detected OO framework
    pub framework: Framework,
    /// Attributes declared via `has`
    pub attributes: Vec<Attribute>,
    /// Fields declared via Object::Pad `field`
    pub fields: Vec<FieldInfo>,
    /// Methods declared via `sub`
    pub methods: Vec<MethodInfo>,
    /// Object::Pad `ADJUST` blocks
    pub adjusts: Vec<MethodInfo>,
    /// Parent classes from `extends 'Parent'`, `use parent`, `use base`, or `@ISA`
    pub parents: Vec<String>,
    /// Method-resolution order for inherited method lookup.
    pub mro: MethodResolutionOrder,
    /// Roles consumed via `with 'Role'`
    pub roles: Vec<String>,
    /// Method modifiers (before/after/around/override/augment)
    pub modifiers: Vec<MethodModifier>,
    /// Names exported by default via `@EXPORT`
    pub exports: Vec<String>,
    /// Names available for explicit import via `@EXPORT_OK`
    pub export_ok: Vec<String>,
    /// Per-file Exporter metadata with subroutine resolution.
    pub exporter_metadata: Option<ExporterMetadata>,
}

/// Exporter-derived metadata captured for a package in a single file.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct ExporterMetadata {
    /// Names exported by default via `@EXPORT` that resolve to local subs.
    pub exports: Vec<ResolvedExport>,
    /// Names available for explicit import via `@EXPORT_OK` that resolve to local subs.
    pub export_ok: Vec<ResolvedExport>,
    /// `%EXPORT_TAGS` entries mapped to local subroutine definitions.
    pub export_tags: HashMap<String, Vec<ResolvedExport>>,
    /// Export names referenced in export declarations but not defined as local subs.
    pub unresolved: Vec<String>,
}

/// Export symbol that resolves to a same-package subroutine definition.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct ResolvedExport {
    /// Exported symbol name (without sigil).
    pub name: String,
    /// Location of the matching subroutine definition in this file/package.
    pub location: SourceLocation,
}

impl ClassModel {
    /// Returns true if this class uses any OO framework.
    pub fn has_framework(&self) -> bool {
        !matches!(self.framework, Framework::None)
    }

    /// Return the names of Object::Pad fields that participate in constructor parameters.
    pub fn object_pad_param_field_names(&self) -> impl Iterator<Item = &str> {
        self.fields.iter().filter(|field| field.param).map(|field| field.name.as_str())
    }
}

/// Builds `ClassModel` instances by walking an AST.
pub struct ClassModelBuilder {
    models: Vec<ClassModel>,
    current_package: String,
    current_framework: Framework,
    current_attributes: Vec<Attribute>,
    current_fields: Vec<FieldInfo>,
    current_methods: Vec<MethodInfo>,
    current_adjusts: Vec<MethodInfo>,
    current_parents: Vec<String>,
    current_mro: MethodResolutionOrder,
    current_roles: Vec<String>,
    current_modifiers: Vec<MethodModifier>,
    current_exports: Vec<String>,
    current_export_ok: Vec<String>,
    current_export_tags: HashMap<String, Vec<String>>,
    current_uses_exporter: bool,
    current_package_aliases: HashSet<String>,
    /// Track which packages have framework detection applied
    framework_map: HashMap<String, Framework>,
}

impl Default for ClassModelBuilder {
    fn default() -> Self {
        Self::new()
    }
}

impl ClassModelBuilder {
    /// Create a new builder.
    pub fn new() -> Self {
        Self {
            models: Vec::new(),
            current_package: "main".to_string(),
            current_framework: Framework::None,
            current_attributes: Vec::new(),
            current_fields: Vec::new(),
            current_methods: Vec::new(),
            current_adjusts: Vec::new(),
            current_parents: Vec::new(),
            current_mro: MethodResolutionOrder::Dfs,
            current_roles: Vec::new(),
            current_modifiers: Vec::new(),
            current_exports: Vec::new(),
            current_export_ok: Vec::new(),
            current_export_tags: HashMap::new(),
            current_uses_exporter: false,
            current_package_aliases: HashSet::new(),
            framework_map: HashMap::new(),
        }
    }

    /// Build class models from an AST.
    pub fn build(mut self, node: &Node) -> Vec<ClassModel> {
        self.visit_node(node);
        self.flush_current_package();
        self.models
    }

    /// Flush the current package's accumulated data into a ClassModel.
    fn flush_current_package(&mut self) {
        let framework = self.current_framework;
        // Produce a ClassModel if the package uses a framework, has attributes, or has parents
        let has_oo_indicator = framework != Framework::None
            || !self.current_attributes.is_empty()
            || !self.current_fields.is_empty()
            || !self.current_parents.is_empty()
            || !self.current_adjusts.is_empty()
            || !self.current_exports.is_empty()
            || !self.current_export_ok.is_empty()
            || !self.current_export_tags.is_empty();
        if has_oo_indicator {
            let exporter_metadata = self.build_exporter_metadata_for_current_package();
            let model = ClassModel {
                name: self.current_package.clone(),
                framework,
                attributes: std::mem::take(&mut self.current_attributes),
                fields: std::mem::take(&mut self.current_fields),
                methods: std::mem::take(&mut self.current_methods),
                adjusts: std::mem::take(&mut self.current_adjusts),
                parents: std::mem::take(&mut self.current_parents),
                mro: self.current_mro,
                roles: std::mem::take(&mut self.current_roles),
                modifiers: std::mem::take(&mut self.current_modifiers),
                exports: std::mem::take(&mut self.current_exports),
                export_ok: std::mem::take(&mut self.current_export_ok),
                exporter_metadata,
            };
            self.models.push(model);
            self.current_package_aliases.clear();
        } else {
            // Reset accumulators even if we don't produce a model
            self.current_attributes.clear();
            self.current_fields.clear();
            self.current_methods.clear();
            self.current_adjusts.clear();
            self.current_parents.clear();
            self.current_mro = MethodResolutionOrder::Dfs;
            self.current_roles.clear();
            self.current_modifiers.clear();
            self.current_exports.clear();
            self.current_export_ok.clear();
            self.current_export_tags.clear();
            self.current_uses_exporter = false;
            self.current_package_aliases.clear();
        }
    }

    fn visit_node(&mut self, node: &Node) {
        match &node.kind {
            NodeKind::Program { statements } => {
                self.visit_statement_list(statements);
            }

            NodeKind::Package { name, block, .. } => {
                // Flush previous package
                self.flush_current_package();

                self.current_package = name.clone();
                self.current_framework =
                    self.framework_map.get(name).copied().unwrap_or(Framework::None);
                self.current_mro = MethodResolutionOrder::Dfs;
                self.current_uses_exporter = false;

                if let Some(block) = block {
                    self.visit_node(block);
                }
            }

            NodeKind::Block { statements, .. } => {
                self.visit_statement_list(statements);
            }

            NodeKind::Subroutine { name, body, .. } => {
                if let Some(sub_name) = name {
                    self.current_methods.push(MethodInfo::new(sub_name.clone(), node.location));
                }
                self.visit_node(body);
            }

            NodeKind::Use { module, args, .. } => {
                self.detect_framework(module, args);
            }

            NodeKind::No { module, .. } if module == "mro" => {
                self.current_mro = MethodResolutionOrder::Dfs;
            }

            // `our @ISA = qw(Parent1 Parent2);` / `our @EXPORT = qw(...);` / `our @EXPORT_OK = qw(...);`
            NodeKind::VariableDeclaration { variable, initializer, .. } => {
                if let NodeKind::Variable { sigil, name } = &variable.kind {
                    if sigil == "$"
                        && let Some(init) = initializer
                        && self.initializer_is_current_package(init)
                    {
                        self.current_package_aliases.insert(name.clone());
                    }

                    if sigil == "@"
                        && let Some(init) = initializer
                    {
                        match name.as_str() {
                            "ISA" => self.extract_isa_from_node(init),
                            "EXPORT" => {
                                self.current_exports.extend(collect_symbol_names(init));
                            }
                            "EXPORT_OK" => {
                                self.current_export_ok.extend(collect_symbol_names(init));
                            }
                            _ => {}
                        }
                    }
                    if sigil == "%"
                        && name == "EXPORT_TAGS"
                        && let Some(init) = initializer
                    {
                        merge_export_tags(&mut self.current_export_tags, collect_export_tags(init));
                    }
                }
            }

            // `@ISA = qw(...);` / `@EXPORT = qw(...);` / `@EXPORT_OK = qw(...);` (bare assignment without `our`)
            NodeKind::Assignment { lhs, rhs, .. } => {
                if let NodeKind::Variable { sigil, name } = &lhs.kind
                    && sigil == "@"
                {
                    match name.as_str() {
                        "ISA" => self.extract_isa_from_node(rhs),
                        "EXPORT" => {
                            self.current_exports.extend(collect_symbol_names(rhs));
                        }
                        "EXPORT_OK" => {
                            self.current_export_ok.extend(collect_symbol_names(rhs));
                        }
                        _ => {}
                    }
                }
                if let NodeKind::Variable { sigil, name } = &lhs.kind
                    && sigil == "%"
                    && name == "EXPORT_TAGS"
                {
                    merge_export_tags(&mut self.current_export_tags, collect_export_tags(rhs));
                }
            }

            // `push @ISA, 'Parent';` or `push @ISA, 'Base1', 'Base2';`
            // Also recurse into the inner expression so that assignments like
            // `@EXPORT_OK = qw(...)` (wrapped in ExpressionStatement) are still handled.
            NodeKind::ExpressionStatement { expression } => {
                if let NodeKind::FunctionCall { name, args } = &expression.kind
                    && name == "push"
                {
                    if let Some(first_arg) = args.first() {
                        if let NodeKind::Variable { sigil, name: var_name } = &first_arg.kind
                            && sigil == "@"
                            && var_name == "ISA"
                        {
                            for arg in args.iter().skip(1) {
                                self.extract_isa_from_node(arg);
                            }
                            return;
                        }
                    }
                }
                // Fall through: visit the inner expression for assignments, etc.
                self.visit_node(expression);
            }

            NodeKind::Class { name, parents, body } => {
                self.flush_current_package();
                self.current_package = name.clone();
                self.current_framework = if self.current_framework == Framework::ObjectPad {
                    Framework::ObjectPad
                } else {
                    Framework::NativeClass
                };
                self.current_mro = MethodResolutionOrder::Dfs;
                self.framework_map.insert(name.clone(), self.current_framework);
                self.current_package_aliases.clear();
                // Populate parent classes from `:isa(Parent)` attributes
                self.current_parents.extend(parents.iter().cloned());
                self.visit_node(body);
            }

            NodeKind::Method { name, body, .. } => {
                self.current_methods.push(MethodInfo::new(name.clone(), node.location));
                self.visit_node(body);
            }

            NodeKind::Error { partial, .. } => {
                if let Some(partial) = partial {
                    self.visit_node(partial);
                }
            }

            _ => {
                // Recurse into children for other node types
                self.visit_children(node);
            }
        }
    }

    fn visit_children(&mut self, node: &Node) {
        match &node.kind {
            NodeKind::ExpressionStatement { expression } => {
                self.visit_node(expression);
            }
            NodeKind::Block { statements, .. } => {
                self.visit_statement_list(statements);
            }
            NodeKind::If { condition, then_branch, else_branch, .. } => {
                self.visit_node(condition);
                self.visit_node(then_branch);
                if let Some(else_node) = else_branch {
                    self.visit_node(else_node);
                }
            }
            _ => {}
        }
    }

    fn visit_statement_list(&mut self, statements: &[Node]) {
        let mut idx = 0;
        while idx < statements.len() {
            // First, check for `use` declarations to detect frameworks
            if let NodeKind::Use { module, args, .. } = &statements[idx].kind {
                self.detect_mro(module, args);
                self.detect_framework(module, args);
                idx += 1;
                continue;
            }

            let is_framework_package = self.current_framework != Framework::None;

            if is_framework_package {
                if self.current_framework == Framework::ObjectPad
                    && let Some(consumed) = self.try_extract_object_pad_constructs(statements, idx)
                {
                    idx += consumed;
                    continue;
                }
                if self.current_framework == Framework::ClassAccessor
                    && let Some(consumed) = self.try_extract_class_accessor_methods(statements, idx)
                {
                    idx += consumed;
                    continue;
                }
                // Try to extract `has` declarations
                if let Some(consumed) = self.try_extract_has(statements, idx) {
                    idx += consumed;
                    continue;
                }
                // Try to extract method modifiers
                if let Some(consumed) = self.try_extract_modifier(statements, idx) {
                    idx += consumed;
                    continue;
                }
                // Try to extract extends/with
                if let Some(consumed) = self.try_extract_extends_with(statements, idx) {
                    idx += consumed;
                    continue;
                }
            }

            // Recurse into the statement for subroutines etc.
            self.visit_node(&statements[idx]);
            idx += 1;
        }
    }

    /// Detect framework from a `use` statement.
    fn detect_framework(&mut self, module: &str, args: &[String]) {
        let framework = match module {
            "Exporter" => {
                self.current_uses_exporter = true;
                return;
            }
            "Moose" | "Moose::Role" => Framework::Moose,
            "Moo" | "Moo::Role" => Framework::Moo,
            "Mouse" | "Mouse::Role" => Framework::Mouse,
            "Role::Tiny" | "Role::Tiny::With" => Framework::RoleTiny,
            "Class::Accessor" => Framework::ClassAccessor,
            "Object::Pad" => Framework::ObjectPad,
            "base" | "parent" => {
                // Capture parent class names, skipping -norequire flag and Class::Accessor sentinel.
                // args may be:
                //   - A quoted string: "'Parent'"
                //   - A qw-string:     "qw(Base1 Base2)"  (single arg, space-separated inside)
                //   - A bare flag:     "-norequire"
                let mut has_class_accessor = false;
                let mut captured_parents: Vec<String> = Vec::new();

                for arg in args {
                    let trimmed = arg.trim();
                    if trimmed.starts_with('-') || trimmed.is_empty() {
                        // Skip flags like -norequire
                        continue;
                    }
                    // Expand qw(...) into individual names
                    let names = expand_arg_to_names(trimmed);
                    for name in names {
                        if name == "Class::Accessor" {
                            has_class_accessor = true;
                        } else if name == "Exporter" {
                            self.current_uses_exporter = true;
                        } else {
                            captured_parents.push(name);
                        }
                    }
                }

                self.current_parents.extend(captured_parents);

                if has_class_accessor {
                    Framework::ClassAccessor
                } else if self.current_framework == Framework::None {
                    // Only promote to PlainOO if no stronger framework already detected
                    Framework::PlainOO
                } else {
                    // Already a Moose/Moo/etc. package — keep existing framework
                    return;
                }
            }
            _ => return,
        };

        self.current_framework = framework;
        self.framework_map.insert(self.current_package.clone(), framework);
    }

    /// Detect `use mro 'c3'` / `use mro 'dfs'` for the current package.
    fn detect_mro(&mut self, module: &str, args: &[String]) {
        if module != "mro" {
            return;
        }

        if args.is_empty() {
            self.current_mro = MethodResolutionOrder::Dfs;
            return;
        }

        for arg in args {
            let trimmed = arg.trim().trim_matches('\'').trim_matches('"');
            match trimmed {
                "c3" => {
                    self.current_mro = MethodResolutionOrder::C3;
                    return;
                }
                "dfs" => {
                    self.current_mro = MethodResolutionOrder::Dfs;
                    return;
                }
                _ => {}
            }
        }
    }

    /// Extract Moo/Moose `has` declarations.
    ///
    /// Mirrors the two-statement pattern from `SymbolExtractor::try_extract_moo_has_declaration`.
    fn try_extract_has(&mut self, statements: &[Node], idx: usize) -> Option<usize> {
        let first = &statements[idx];

        // Form A: two statements
        // 1) ExpressionStatement(Identifier("has"))
        // 2) ExpressionStatement(HashLiteral(...)) or ExpressionStatement(ArrayLiteral([..., HashLiteral]))
        if idx + 1 < statements.len() {
            let second = &statements[idx + 1];
            let is_has_marker = matches!(
                &first.kind,
                NodeKind::ExpressionStatement { expression }
                    if matches!(&expression.kind, NodeKind::Identifier { name } if name == "has")
            );

            if is_has_marker {
                if let NodeKind::ExpressionStatement { expression } = &second.kind {
                    let has_location =
                        SourceLocation { start: first.location.start, end: second.location.end };

                    match &expression.kind {
                        NodeKind::HashLiteral { pairs } => {
                            self.extract_has_from_pairs(pairs, has_location, false);
                            return Some(2);
                        }
                        NodeKind::ArrayLiteral { elements } => {
                            if let Some(Node { kind: NodeKind::HashLiteral { pairs }, .. }) =
                                elements.last()
                            {
                                let mut names = Vec::new();
                                for el in elements.iter().take(elements.len() - 1) {
                                    names.extend(collect_symbol_names(el));
                                }
                                if !names.is_empty() {
                                    self.extract_has_with_names(&names, pairs, has_location);
                                    return Some(2);
                                }
                            }
                        }
                        _ => {}
                    }
                }
            }
        }

        // Form B: single statement with embedded `has` marker
        if let NodeKind::ExpressionStatement { expression } = &first.kind
            && let NodeKind::HashLiteral { pairs } = &expression.kind
        {
            let has_embedded = pairs.iter().any(|(key_node, _)| {
                matches!(
                    &key_node.kind,
                    NodeKind::Binary { op, left, .. }
                        if op == "[]" && matches!(&left.kind, NodeKind::Identifier { name } if name == "has")
                )
            });

            if has_embedded {
                self.extract_has_from_pairs(pairs, first.location, true);
                return Some(1);
            }
        }

        // Form C: FunctionCall { name: "has", args: [name_expr, HashLiteral { ... }] }
        // Produced when the parser recognises `has 'name' => (is => 'ro', ...)` as a bare call.
        if let NodeKind::ExpressionStatement { expression } = &first.kind
            && let NodeKind::FunctionCall { name, args } = &expression.kind
            && name == "has"
            && !args.is_empty()
        {
            // The last arg that is a HashLiteral holds the options.
            let options_hash_idx =
                args.iter().rposition(|a| matches!(a.kind, NodeKind::HashLiteral { .. }));
            if let Some(opts_idx) = options_hash_idx {
                if let NodeKind::HashLiteral { pairs } = &args[opts_idx].kind {
                    let names: Vec<String> =
                        args[..opts_idx].iter().flat_map(collect_symbol_names).collect();
                    if !names.is_empty() {
                        self.extract_has_with_names(&names, pairs, first.location);
                        return Some(1);
                    }
                }
            } else {
                let names: Vec<String> = args.iter().flat_map(collect_symbol_names).collect();
                if !names.is_empty() {
                    self.extract_has_with_names(&names, &[], first.location);
                    return Some(1);
                }
            }
        }

        None
    }

    /// Extract attributes from parsed `has` key/value pairs.
    fn extract_has_from_pairs(
        &mut self,
        pairs: &[(Node, Node)],
        location: SourceLocation,
        require_embedded: bool,
    ) {
        for (attr_expr, options_expr) in pairs {
            let attr_expr = if let NodeKind::Binary { op, left, right } = &attr_expr.kind
                && op == "[]"
                && matches!(&left.kind, NodeKind::Identifier { name } if name == "has")
            {
                right.as_ref()
            } else if require_embedded {
                continue;
            } else {
                attr_expr
            };

            let names = collect_symbol_names(attr_expr);
            if names.is_empty() {
                continue;
            }

            if let NodeKind::HashLiteral { pairs: option_pairs } = &options_expr.kind {
                self.extract_has_with_names(&names, option_pairs, location);
            }
        }
    }

    /// Build Attribute structs from attribute names and option pairs.
    fn extract_has_with_names(
        &mut self,
        names: &[String],
        option_pairs: &[(Node, Node)],
        location: SourceLocation,
    ) {
        let options = extract_hash_options(option_pairs);

        let is = options.get("is").and_then(|v| match v.as_str() {
            "ro" => Some(AccessorType::Ro),
            "rw" => Some(AccessorType::Rw),
            "lazy" => Some(AccessorType::Lazy),
            "bare" => Some(AccessorType::Bare),
            _ => None,
        });

        let isa = options.get("isa").cloned();
        let default = options.contains_key("default")
            || options.contains_key("builder")
            || is == Some(AccessorType::Lazy);
        let required = options.get("required").is_some_and(|v| v == "1" || v == "true");
        let coerce = options.get("coerce").is_some_and(|v| v == "1" || v == "true");
        let trigger = options.contains_key("trigger");

        // Determine accessor name: explicit accessor/reader overrides default
        let explicit_accessor = options.get("accessor").or_else(|| options.get("reader")).cloned();

        for raw_name in names {
            let Some(name) = normalize_attribute_name(raw_name) else { continue };
            let accessor_name = explicit_accessor.clone().unwrap_or_else(|| name.clone());

            // builder => 1 derives `_build_<attr>`; a string value names the method directly
            let builder = options
                .get("builder")
                .map(|v| if v == "1" { format!("_build_{name}") } else { v.clone() });

            // predicate => 1 derives `has_<attr>`; a string value is used directly
            let predicate = options
                .get("predicate")
                .map(|v| if v == "1" { format!("has_{name}") } else { v.clone() });

            // clearer => 1 derives `clear_<attr>`; a string value is used directly
            let clearer = options
                .get("clearer")
                .map(|v| if v == "1" { format!("clear_{name}") } else { v.clone() });

            self.current_attributes.push(Attribute {
                name: name.clone(),
                is,
                isa: isa.clone(),
                default,
                required,
                accessor_name,
                location,
                builder,
                coerce,
                predicate,
                clearer,
                trigger,
            });
        }
    }

    /// Extract method modifiers (before/after/around/override/augment).
    fn try_extract_modifier(&mut self, statements: &[Node], idx: usize) -> Option<usize> {
        let first = &statements[idx];

        // FunctionCall form: `before 'save' => sub { }` parsed as a bare call.
        if let NodeKind::ExpressionStatement { expression } = &first.kind
            && let NodeKind::FunctionCall { name, args } = &expression.kind
        {
            let modifier_kind = modifier_kind_from_name(name);
            if let Some(modifier_kind) = modifier_kind {
                // args[0] is the method name (String or ArrayLiteral), rest is the impl.
                let method_names: Vec<String> =
                    args.first().map(collect_symbol_names).unwrap_or_default();
                if !method_names.is_empty() {
                    for method_name in method_names {
                        self.current_modifiers.push(MethodModifier {
                            kind: modifier_kind,
                            method_name,
                            location: first.location,
                        });
                    }
                    return Some(1);
                }
            }
        }

        // Two-statement legacy form:
        // 1) ExpressionStatement(Identifier("before"/"after"/"around"))
        // 2) ExpressionStatement(HashLiteral((method_name, Subroutine)))
        if idx + 1 >= statements.len() {
            return None;
        }
        let second = &statements[idx + 1];

        let modifier_kind = match &first.kind {
            NodeKind::ExpressionStatement { expression } => match &expression.kind {
                NodeKind::Identifier { name } => modifier_kind_from_name(name),
                _ => None,
            },
            _ => None,
        };

        let modifier_kind = modifier_kind?;

        let NodeKind::ExpressionStatement { expression } = &second.kind else {
            return None;
        };
        let NodeKind::HashLiteral { pairs } = &expression.kind else {
            return None;
        };

        let location = SourceLocation { start: first.location.start, end: second.location.end };

        for (key_node, _) in pairs {
            let method_names = collect_symbol_names(key_node);
            for method_name in method_names {
                self.current_modifiers.push(MethodModifier {
                    kind: modifier_kind,
                    method_name,
                    location,
                });
            }
        }

        Some(2)
    }

    /// Extract `extends 'Parent'` and `with 'Role'` declarations.
    fn try_extract_extends_with(&mut self, statements: &[Node], idx: usize) -> Option<usize> {
        let first = &statements[idx];

        // Form: FunctionCall { name: "extends"/"with", args: [...] }
        // Produced when `extends 'Parent'` / `with 'Role'` are parsed as bare calls.
        if let NodeKind::ExpressionStatement { expression } = &first.kind
            && let NodeKind::FunctionCall { name, args } = &expression.kind
            && matches!(name.as_str(), "extends" | "with")
        {
            let names: Vec<String> = args.iter().flat_map(collect_symbol_names).collect();
            if !names.is_empty() {
                if name == "extends" {
                    self.current_parents.extend(names);
                } else {
                    self.current_roles.extend(names);
                }
                return Some(1);
            }
        }

        // Two-statement form (legacy parser output):
        // 1) ExpressionStatement(Identifier("extends"/"with"))
        // 2) ExpressionStatement(String/ArrayLiteral)
        if idx + 1 >= statements.len() {
            return None;
        }
        let second = &statements[idx + 1];

        let keyword = match &first.kind {
            NodeKind::ExpressionStatement { expression } => match &expression.kind {
                NodeKind::Identifier { name } if matches!(name.as_str(), "extends" | "with") => {
                    name.as_str()
                }
                _ => return None,
            },
            _ => return None,
        };

        let NodeKind::ExpressionStatement { expression } = &second.kind else {
            return None;
        };

        let names = collect_symbol_names(expression);
        if names.is_empty() {
            return None;
        }

        if keyword == "extends" {
            self.current_parents.extend(names);
        } else {
            self.current_roles.extend(names);
        }

        Some(2)
    }

    /// Extract `Class::Accessor` generated methods from `mk_*_accessors` calls.
    fn try_extract_class_accessor_methods(
        &mut self,
        statements: &[Node],
        idx: usize,
    ) -> Option<usize> {
        let first = &statements[idx];

        let NodeKind::ExpressionStatement { expression } = &first.kind else {
            return None;
        };

        let NodeKind::MethodCall { object, method, args } = &expression.kind else {
            return None;
        };

        let accessor_mode = match method.as_str() {
            "mk_accessors" | "mk_rw_accessors" => ClassAccessorMode::Rw,
            "mk_ro_accessors" => ClassAccessorMode::Ro,
            "mk_wo_accessors" => ClassAccessorMode::Wo,
            _ => return None,
        };

        if !self.class_accessor_target_matches_current_package(object) {
            return None;
        }

        let mut accessor_names = Vec::new();
        let mut seen = HashSet::new();
        for arg in args {
            for name in collect_accessor_names(arg) {
                if seen.insert(name.clone()) {
                    accessor_names.push(name);
                }
            }
        }

        if accessor_names.is_empty() {
            return None;
        }

        for name in accessor_names {
            self.current_methods.push(MethodInfo::synthetic(
                name,
                first.location,
                Some(accessor_mode),
            ));
        }

        Some(1)
    }

    /// Extract Object::Pad field declarations and `ADJUST` blocks.
    fn try_extract_object_pad_constructs(
        &mut self,
        statements: &[Node],
        idx: usize,
    ) -> Option<usize> {
        let statement = &statements[idx];

        if let Some(field) = Self::object_pad_field_from_statement(statement) {
            let location = field.location;
            let field_name = field.name.clone();
            let traits = field.attributes.clone();

            self.current_fields.push(field);

            if let Some(reader) = Self::object_pad_reader_name(&field_name, &traits) {
                self.current_methods.push(MethodInfo::synthetic(reader, location, None));
            }
            if let Some(writer) = Self::object_pad_writer_name(&field_name, &traits) {
                self.current_methods.push(MethodInfo::synthetic(writer, location, None));
            }
            if let Some(accessor) = Self::object_pad_accessor_name(&field_name, &traits) {
                self.current_methods.push(MethodInfo::synthetic(accessor, location, None));
            }
            if let Some(mutator) = Self::object_pad_mutator_name(&field_name, &traits) {
                self.current_methods.push(MethodInfo::synthetic(mutator, location, None));
            }

            return Some(1);
        }

        match &statement.kind {
            NodeKind::Method { name, body, .. } if name == "ADJUST" => {
                self.record_object_pad_adjust(statement.location);
                self.visit_node(body);
                return Some(1);
            }
            NodeKind::Subroutine { name, body, .. } if name.as_deref() == Some("ADJUST") => {
                self.record_object_pad_adjust(statement.location);
                self.visit_node(body);
                return Some(1);
            }
            _ => {}
        }

        None
    }

    fn record_object_pad_adjust(&mut self, location: SourceLocation) {
        self.current_adjusts.push(MethodInfo::synthetic("ADJUST".to_string(), location, None));
    }

    fn object_pad_field_from_statement(statement: &Node) -> Option<FieldInfo> {
        let NodeKind::VariableDeclaration { declarator, variable, attributes, initializer } =
            &statement.kind
        else {
            return None;
        };
        if declarator != "field" {
            return None;
        }

        let NodeKind::Variable { sigil, name } = &variable.kind else {
            return None;
        };
        if sigil != "$" {
            return None;
        }

        let mut param = false;
        let mut traits = Vec::new();
        for attr in attributes {
            let attr_name = attr.trim().to_string();
            if attr_name == "param" {
                param = true;
            }
            traits.push(attr_name);
        }

        let mut field = FieldInfo {
            name: name.clone(),
            location: statement.location,
            attributes: traits,
            param,
            reader: None,
            writer: None,
            accessor: None,
            mutator: None,
            default: initializer.as_ref().map(|node| Self::value_summary(node)),
        };

        field.reader = Self::object_pad_reader_name(&field.name, &field.attributes);
        field.writer = Self::object_pad_writer_name(&field.name, &field.attributes);
        field.accessor = Self::object_pad_accessor_name(&field.name, &field.attributes);
        field.mutator = Self::object_pad_mutator_name(&field.name, &field.attributes);

        Some(field)
    }

    fn object_pad_reader_name(field_name: &str, traits: &[String]) -> Option<String> {
        if traits.iter().any(|trait_name| trait_name == "reader") {
            Some(Self::object_pad_public_name(field_name).to_string())
        } else {
            None
        }
    }

    fn object_pad_writer_name(field_name: &str, traits: &[String]) -> Option<String> {
        if traits.iter().any(|trait_name| trait_name == "writer") {
            Some(format!("set_{}", Self::object_pad_public_name(field_name)))
        } else {
            None
        }
    }

    fn object_pad_accessor_name(field_name: &str, traits: &[String]) -> Option<String> {
        if traits.iter().any(|trait_name| trait_name == "accessor") {
            Some(Self::object_pad_public_name(field_name).to_string())
        } else {
            None
        }
    }

    fn object_pad_mutator_name(field_name: &str, traits: &[String]) -> Option<String> {
        if traits.iter().any(|trait_name| trait_name == "mutator") {
            Some(Self::object_pad_public_name(field_name).to_string())
        } else {
            None
        }
    }

    fn object_pad_public_name(field_name: &str) -> &str {
        field_name.strip_prefix('_').unwrap_or(field_name)
    }

    /// Return true when a `Class::Accessor` call targets the current package.
    fn class_accessor_target_matches_current_package(&self, object: &Node) -> bool {
        match &object.kind {
            NodeKind::Identifier { name } => name == "__PACKAGE__" || name == &self.current_package,
            NodeKind::String { value, .. } => {
                normalize_symbol_name(value).is_some_and(|name| name == self.current_package)
            }
            NodeKind::Variable { sigil, name } if sigil == "$" => {
                self.current_package_aliases.contains(name)
            }
            _ => false,
        }
    }

    /// Extract parent class names from an `@ISA` RHS node (ArrayLiteral or qw-word-list).
    fn extract_isa_from_node(&mut self, node: &Node) {
        let parents = collect_symbol_names(node);
        if !parents.is_empty() {
            if parents.iter().any(|parent| parent == "Exporter") {
                self.current_uses_exporter = true;
            }
            // Promote to PlainOO if no stronger framework is already set
            if self.current_framework == Framework::None {
                self.current_framework = Framework::PlainOO;
                self.framework_map.insert(self.current_package.clone(), Framework::PlainOO);
            }
            self.current_parents.extend(parents);
        }
    }

    fn build_exporter_metadata_for_current_package(&mut self) -> Option<ExporterMetadata> {
        if !self.current_uses_exporter {
            self.current_export_tags.clear();
            return None;
        }

        let method_map: HashMap<&str, SourceLocation> = self
            .current_methods
            .iter()
            .map(|method| (method.name.as_str(), method.location))
            .collect();

        let (exports, unresolved_exports) = resolve_exports(&self.current_exports, &method_map);
        let (export_ok, unresolved_export_ok) =
            resolve_exports(&self.current_export_ok, &method_map);

        let mut export_tags: HashMap<String, Vec<ResolvedExport>> = HashMap::new();
        let mut unresolved = unresolved_exports;
        unresolved.extend(unresolved_export_ok);

        for (tag, names) in std::mem::take(&mut self.current_export_tags) {
            let (resolved, unresolved_names) = resolve_exports(&names, &method_map);
            if !resolved.is_empty() {
                export_tags.insert(tag, resolved);
            }
            unresolved.extend(unresolved_names);
        }

        dedupe_preserve_order(&mut unresolved);

        Some(ExporterMetadata { exports, export_ok, export_tags, unresolved })
    }

    /// Return true if a variable initializer resolves to the current package name.
    fn initializer_is_current_package(&self, node: &Node) -> bool {
        match &node.kind {
            NodeKind::Identifier { name } => name == "__PACKAGE__" || name == &self.current_package,
            NodeKind::FunctionCall { name, args } if name == "__PACKAGE__" && args.is_empty() => {
                true
            }
            NodeKind::String { value, .. } => {
                normalize_symbol_name(value).is_some_and(|name| name == self.current_package)
            }
            _ => false,
        }
    }

    fn value_summary(node: &Node) -> String {
        match &node.kind {
            NodeKind::String { value, .. } => {
                normalize_symbol_name(value).unwrap_or_else(|| value.clone())
            }
            NodeKind::Identifier { name } => name.clone(),
            NodeKind::Number { value } => value.clone(),
            NodeKind::Undef => "undef".to_string(),
            NodeKind::Variable { sigil, name } => format!("{sigil}{name}"),
            _ => "expr".to_string(),
        }
    }
}

// ---- Helper functions (parallel to SymbolExtractor's private helpers) ----

fn collect_symbol_names(node: &Node) -> Vec<String> {
    match &node.kind {
        NodeKind::String { value, .. } => normalize_symbol_name(value).into_iter().collect(),
        NodeKind::Identifier { name } => normalize_symbol_name(name).into_iter().collect(),
        NodeKind::ArrayLiteral { elements } => {
            elements.iter().flat_map(collect_symbol_names).collect()
        }
        _ => Vec::new(),
    }
}

fn collect_export_tags(node: &Node) -> HashMap<String, Vec<String>> {
    let mut tags: HashMap<String, Vec<String>> = HashMap::new();
    match &node.kind {
        NodeKind::HashLiteral { pairs } => {
            for (key, value) in pairs {
                let Some(tag_name) = collect_single_symbol_name(key) else { continue };
                let Some(symbols) = collect_static_symbol_names(value) else { continue };
                if symbols.is_empty() {
                    continue;
                }
                tags.entry(tag_name).or_default().extend(symbols);
            }
        }
        NodeKind::ArrayLiteral { elements } => {
            for pair in elements.chunks_exact(2) {
                let Some(tag_name) = collect_single_symbol_name(&pair[0]) else { continue };
                let Some(symbols) = collect_static_symbol_names(&pair[1]) else { continue };
                if symbols.is_empty() {
                    continue;
                }
                tags.entry(tag_name).or_default().extend(symbols);
            }
        }
        NodeKind::Binary { op, .. } if op == "," => {
            let mut flattened = Vec::new();
            flatten_comma_expression(node, &mut flattened);
            for element in flattened {
                if let NodeKind::Binary { op, left, right } = &element.kind
                    && op == "=>"
                {
                    let Some(tag_name) = collect_single_symbol_name(left) else { continue };
                    let Some(symbols) = collect_static_symbol_names(right) else { continue };
                    if symbols.is_empty() {
                        continue;
                    }
                    tags.entry(tag_name).or_default().extend(symbols);
                }
            }
        }
        _ => {}
    }

    for symbols in tags.values_mut() {
        dedupe_preserve_order(symbols);
    }
    tags
}

fn collect_single_symbol_name(node: &Node) -> Option<String> {
    let mut names = collect_static_symbol_names(node)?;
    dedupe_preserve_order(&mut names);
    names.into_iter().next()
}

fn collect_static_symbol_names(node: &Node) -> Option<Vec<String>> {
    match &node.kind {
        NodeKind::String { value, .. } => Some(expand_export_name_list(value)),
        NodeKind::Identifier { name } => Some(expand_export_name_list(name)),
        NodeKind::ArrayLiteral { elements } => {
            let mut names = Vec::new();
            for element in elements {
                let mut element_names = collect_static_symbol_names(element)?;
                names.append(&mut element_names);
            }
            Some(names)
        }
        NodeKind::Binary { op, left, right } if op == "," => {
            let mut names = collect_static_symbol_names(left)?;
            let mut right_names = collect_static_symbol_names(right)?;
            names.append(&mut right_names);
            Some(names)
        }
        _ => None,
    }
}

fn resolve_exports(
    names: &[String],
    method_map: &HashMap<&str, SourceLocation>,
) -> (Vec<ResolvedExport>, Vec<String>) {
    let mut resolved = Vec::new();
    let mut unresolved = Vec::new();
    for raw_name in names {
        for name in expand_export_name_list(raw_name) {
            if let Some(location) = method_map.get(name.as_str()) {
                resolved.push(ResolvedExport { name, location: *location });
            } else {
                unresolved.push(name);
            }
        }
    }
    dedupe_resolved_exports(&mut resolved);
    dedupe_preserve_order(&mut unresolved);
    (resolved, unresolved)
}

fn dedupe_resolved_exports(exports: &mut Vec<ResolvedExport>) {
    let mut seen = HashSet::new();
    exports.retain(|item| seen.insert(item.name.clone()));
}

fn dedupe_preserve_order(items: &mut Vec<String>) {
    let mut seen = HashSet::new();
    items.retain(|item| seen.insert(item.clone()));
}

fn merge_export_tags(
    target: &mut HashMap<String, Vec<String>>,
    updates: HashMap<String, Vec<String>>,
) {
    for (tag, mut symbols) in updates {
        target.entry(tag).or_default().append(&mut symbols);
    }
}

fn flatten_comma_expression<'a>(node: &'a Node, out: &mut Vec<&'a Node>) {
    if let NodeKind::Binary { op, left, right } = &node.kind
        && op == ","
    {
        flatten_comma_expression(left, out);
        flatten_comma_expression(right, out);
    } else {
        out.push(node);
    }
}

fn expand_export_name_list(raw: &str) -> Vec<String> {
    expand_symbol_list(raw).into_iter().filter_map(|name| normalize_export_name(&name)).collect()
}

fn normalize_export_name(raw: &str) -> Option<String> {
    let normalized = normalize_symbol_name(raw)?;
    let stripped = normalized
        .strip_prefix('&')
        .or_else(|| normalized.strip_prefix('$'))
        .or_else(|| normalized.strip_prefix('@'))
        .or_else(|| normalized.strip_prefix('%'))
        .unwrap_or(&normalized)
        .to_string();
    if stripped.is_empty() { None } else { Some(stripped) }
}

fn collect_accessor_names(node: &Node) -> Vec<String> {
    match &node.kind {
        NodeKind::String { value, .. } => expand_symbol_list(value),
        NodeKind::Identifier { name } => expand_symbol_list(name),
        NodeKind::ArrayLiteral { elements } => {
            elements.iter().flat_map(collect_accessor_names).collect()
        }
        _ => Vec::new(),
    }
}

fn modifier_kind_from_name(name: &str) -> Option<ModifierKind> {
    match name {
        "before" => Some(ModifierKind::Before),
        "after" => Some(ModifierKind::After),
        "around" => Some(ModifierKind::Around),
        "override" => Some(ModifierKind::Override),
        "augment" => Some(ModifierKind::Augment),
        _ => None,
    }
}

fn normalize_symbol_name(raw: &str) -> Option<String> {
    let trimmed = raw.trim().trim_matches('\'').trim_matches('"').trim();
    if trimmed.is_empty() { None } else { Some(trimmed.to_string()) }
}

fn normalize_attribute_name(raw: &str) -> Option<String> {
    let trimmed = raw.trim();
    let without_override_prefix = trimmed.strip_prefix('+').unwrap_or(trimmed);
    normalize_symbol_name(without_override_prefix)
}

fn expand_symbol_list(raw: &str) -> Vec<String> {
    let raw = raw.trim();

    if raw.starts_with("qw(") && raw.ends_with(')') {
        let content = &raw[3..raw.len() - 1];
        return content
            .split_whitespace()
            .filter(|s| !s.is_empty())
            .map(|s| s.to_string())
            .collect();
    }

    if raw.starts_with("qw") && raw.len() > 2 {
        let open = raw.chars().nth(2).unwrap_or(' ');
        let close = match open {
            '(' => ')',
            '{' => '}',
            '[' => ']',
            '<' => '>',
            c => c,
        };
        if let (Some(start), Some(end)) = (raw.find(open), raw.rfind(close))
            && start < end
        {
            let content = &raw[start + 1..end];
            return content
                .split_whitespace()
                .filter(|s| !s.is_empty())
                .map(|s| s.to_string())
                .collect();
        }
    }

    normalize_symbol_name(raw).into_iter().collect()
}

/// Expand a single `use parent`/`use base` arg string into individual class names.
///
/// The parser stores qw-lists as a single string like `"qw(Base1 Base2)"`.
/// This function splits those into `["Base1", "Base2"]`.
/// Plain quoted strings like `"'Parent'"` return `["Parent"]`.
fn expand_arg_to_names(arg: &str) -> Vec<String> {
    let arg = arg.trim();
    // qw(...) — any delimiter variant that the parser normalised to qw(...)
    if arg.starts_with("qw(") && arg.ends_with(')') {
        let content = &arg[3..arg.len() - 1];
        return content
            .split_whitespace()
            .filter(|s| !s.is_empty())
            .map(|s| s.to_string())
            .collect();
    }
    // Other qw variants: qw{...}, qw[...], qw/.../ etc.
    if arg.starts_with("qw") && arg.len() > 2 {
        let open = arg.chars().nth(2).unwrap_or(' ');
        let close = match open {
            '(' => ')',
            '{' => '}',
            '[' => ']',
            '<' => '>',
            c => c,
        };
        if let (Some(start), Some(end)) = (arg.find(open), arg.rfind(close)) {
            if start < end {
                let content = &arg[start + 1..end];
                return content
                    .split_whitespace()
                    .filter(|s| !s.is_empty())
                    .map(|s| s.to_string())
                    .collect();
            }
        }
    }
    // Quoted string or bare identifier
    normalize_symbol_name(arg).into_iter().collect()
}

fn extract_hash_options(pairs: &[(Node, Node)]) -> HashMap<String, String> {
    let mut options = HashMap::new();
    for (key_node, value_node) in pairs {
        let Some(key_name) = collect_symbol_names(key_node).into_iter().next() else {
            continue;
        };
        let value_text = value_summary(value_node);
        options.insert(key_name, value_text);
    }
    options
}

fn value_summary(node: &Node) -> String {
    match &node.kind {
        NodeKind::String { value, .. } => {
            normalize_symbol_name(value).unwrap_or_else(|| value.clone())
        }
        NodeKind::Identifier { name } => name.clone(),
        NodeKind::Number { value } => value.clone(),
        _ => "expr".to_string(),
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::parser::Parser;
    use perl_tdd_support::must;
    use std::collections::HashSet;

    fn build_models(code: &str) -> Vec<ClassModel> {
        let mut parser = Parser::new(code);
        let ast = must(parser.parse());
        ClassModelBuilder::new().build(&ast)
    }

    fn find_model<'a>(models: &'a [ClassModel], name: &str) -> Option<&'a ClassModel> {
        models.iter().find(|m| m.name == name)
    }

    fn has_method(
        model: &ClassModel,
        name: &str,
        synthetic: bool,
        accessor_mode: Option<ClassAccessorMode>,
    ) -> bool {
        model.methods.iter().any(|method| {
            method.name == name
                && method.synthetic == synthetic
                && method.accessor_mode == accessor_mode
        })
    }

    #[test]
    fn basic_moo_class() {
        let models = build_models(
            r#"
package MyApp::User;
use Moo;

has 'name' => (is => 'ro', isa => 'Str');
has 'age' => (is => 'rw', required => 1);

sub greet { }
"#,
        );

        let model = find_model(&models, "MyApp::User");
        assert!(model.is_some(), "expected ClassModel for MyApp::User");
        let model = model.unwrap();

        assert_eq!(model.framework, Framework::Moo);
        assert_eq!(model.attributes.len(), 2);

        let name_attr = model.attributes.iter().find(|a| a.name == "name");
        assert!(name_attr.is_some());
        let name_attr = name_attr.unwrap();
        assert_eq!(name_attr.is, Some(AccessorType::Ro));
        assert_eq!(name_attr.isa.as_deref(), Some("Str"));
        assert!(!name_attr.required);
        assert_eq!(name_attr.accessor_name, "name");

        let age_attr = model.attributes.iter().find(|a| a.name == "age");
        assert!(age_attr.is_some());
        let age_attr = age_attr.unwrap();
        assert_eq!(age_attr.is, Some(AccessorType::Rw));
        assert!(age_attr.required);

        assert!(model.methods.iter().any(|m| m.name == "greet"));
    }

    #[test]
    fn moose_extends_and_with() {
        let models = build_models(
            r#"
package MyApp::Admin;
use Moose;
extends 'MyApp::User';
with 'MyApp::Printable', 'MyApp::Serializable';

has 'level' => (is => 'ro');
"#,
        );

        let model = find_model(&models, "MyApp::Admin");
        assert!(model.is_some());
        let model = model.unwrap();

        assert_eq!(model.framework, Framework::Moose);
        assert!(model.parents.contains(&"MyApp::User".to_string()));
        assert_eq!(model.roles, vec!["MyApp::Printable", "MyApp::Serializable"]);
        assert_eq!(model.attributes.len(), 1);
    }

    #[test]
    fn mro_pragma_tracks_c3_and_reset() {
        let models = build_models(
            r#"
package Example::Child;
use parent 'Example::Base';
use mro 'c3';
sub greet { }

package Example::Sibling;
use parent 'Example::Base';
no mro;
sub greet { }
"#,
        );

        let child = find_model(&models, "Example::Child").expect("expected ClassModel for Child");
        assert_eq!(child.mro, MethodResolutionOrder::C3);

        let sibling =
            find_model(&models, "Example::Sibling").expect("expected ClassModel for Sibling");
        assert_eq!(sibling.mro, MethodResolutionOrder::Dfs);
    }

    #[test]
    fn method_modifiers() {
        let models = build_models(
            r#"
package MyApp::User;
use Moo;
before 'save' => sub { };
after 'save' => sub { };
around 'validate' => sub { };
override 'dispatch' => sub { super(); };
augment 'serialize' => sub { inner(); };
"#,
        );

        let model = find_model(&models, "MyApp::User");
        assert!(model.is_some());
        let model = model.unwrap();

        assert_eq!(model.modifiers.len(), 5);
        assert!(
            model
                .modifiers
                .iter()
                .any(|m| m.kind == ModifierKind::Before && m.method_name == "save")
        );
        assert!(
            model
                .modifiers
                .iter()
                .any(|m| m.kind == ModifierKind::After && m.method_name == "save")
        );
        assert!(
            model
                .modifiers
                .iter()
                .any(|m| m.kind == ModifierKind::Around && m.method_name == "validate")
        );
        assert!(
            model
                .modifiers
                .iter()
                .any(|m| m.kind == ModifierKind::Override && m.method_name == "dispatch")
        );
        assert!(
            model
                .modifiers
                .iter()
                .any(|m| m.kind == ModifierKind::Augment && m.method_name == "serialize")
        );
    }

    #[test]
    fn class_accessor_generates_synthetic_methods_for_all_variants() {
        let models = build_models(
            r#"
package Example::Accessors;
use parent 'Class::Accessor';
__PACKAGE__->mk_accessors(qw(foo bar));
__PACKAGE__->mk_rw_accessors(qw(baz));
sub other_method { }

package Example::ReadOnly;
use parent 'Class::Accessor';
my $package = __PACKAGE__;
$package->mk_ro_accessors('id');

package Example::WriteOnly;
use parent 'Class::Accessor';
my $package = 'Example::WriteOnly';
$package->mk_wo_accessors([qw(token)]);
"#,
        );

        let accessors = find_model(&models, "Example::Accessors")
            .expect("expected ClassModel for Example::Accessors");
        assert!(has_method(accessors, "foo", true, Some(ClassAccessorMode::Rw)));
        assert!(has_method(accessors, "bar", true, Some(ClassAccessorMode::Rw)));
        assert!(has_method(accessors, "baz", true, Some(ClassAccessorMode::Rw)));
        assert!(has_method(accessors, "other_method", false, None));

        let read_only = find_model(&models, "Example::ReadOnly")
            .expect("expected ClassModel for Example::ReadOnly");
        assert!(has_method(read_only, "id", true, Some(ClassAccessorMode::Ro)));

        let write_only = find_model(&models, "Example::WriteOnly")
            .expect("expected ClassModel for Example::WriteOnly");
        assert!(has_method(write_only, "token", true, Some(ClassAccessorMode::Wo)));
    }

    #[test]
    fn no_model_for_plain_package() {
        let models = build_models(
            r#"
package MyApp::Utils;
sub helper { 1 }
"#,
        );

        assert!(
            find_model(&models, "MyApp::Utils").is_none(),
            "plain package should not produce a ClassModel"
        );
    }

    #[test]
    fn multiple_packages() {
        let models = build_models(
            r#"
package MyApp::User;
use Moo;
has 'name' => (is => 'ro');

package MyApp::Admin;
use Moose;
extends 'MyApp::User';
has 'level' => (is => 'rw');

package MyApp::Utils;
sub helper { 1 }
"#,
        );

        assert_eq!(models.len(), 2, "expected 2 ClassModels (User + Admin, not Utils)");
        assert!(find_model(&models, "MyApp::User").is_some());
        assert!(find_model(&models, "MyApp::Admin").is_some());
        assert!(find_model(&models, "MyApp::Utils").is_none());
    }

    #[test]
    fn qw_attribute_list() {
        let models = build_models(
            r#"
use Moo;
has [qw(first_name last_name)] => (is => 'ro');
"#,
        );

        assert_eq!(models.len(), 1);
        let model = &models[0];
        assert_eq!(model.attributes.len(), 2);

        let names: HashSet<_> = model.attributes.iter().map(|a| a.name.as_str()).collect();
        assert!(names.contains("first_name"));
        assert!(names.contains("last_name"));
    }

    #[test]
    fn has_framework_helper() {
        let models = build_models(
            r#"
package MyApp::User;
use Moo;
has 'name' => (is => 'ro');
"#,
        );

        let model = find_model(&models, "MyApp::User").unwrap();
        assert!(model.has_framework());
    }

    #[test]
    fn accessor_type_lazy() {
        let models = build_models(
            r#"
use Moo;
has 'config' => (is => 'lazy');
"#,
        );

        let model = &models[0];
        assert_eq!(model.attributes[0].is, Some(AccessorType::Lazy));
        assert!(model.attributes[0].default, "lazy implies default");
    }

    #[test]
    fn explicit_accessor_name() {
        let models = build_models(
            r#"
use Moo;
has 'name' => (is => 'ro', reader => 'get_name');
"#,
        );

        let model = &models[0];
        assert_eq!(model.attributes[0].accessor_name, "get_name");
    }

    #[test]
    fn inherited_attribute_override_strips_plus_prefix() {
        let models = build_models(
            r#"
use Moo;
has '+name' => (is => 'ro', builder => 1, predicate => 1, clearer => 1);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(attr.name, "name");
        assert_eq!(attr.accessor_name, "name");
        assert_eq!(attr.builder.as_deref(), Some("_build_name"));
        assert_eq!(attr.predicate.as_deref(), Some("has_name"));
        assert_eq!(attr.clearer.as_deref(), Some("clear_name"));
    }

    #[test]
    fn default_via_builder_option() {
        let models = build_models(
            r#"
use Moo;
has 'config' => (is => 'ro', builder => 1);
"#,
        );

        let model = &models[0];
        assert!(model.attributes[0].default, "builder option implies default");
    }

    #[test]
    fn lazy_builder_with_string_name() {
        let models = build_models(
            r#"
use Moo;
has 'config' => (is => 'ro', lazy => 1, builder => '_build_config');
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.builder.as_deref(),
            Some("_build_config"),
            "builder string should be captured"
        );
        assert!(attr.default, "named builder implies default");
    }

    #[test]
    fn lazy_builder_with_numeric_one_generates_default_name() {
        let models = build_models(
            r#"
use Moo;
has 'profile' => (is => 'ro', builder => 1);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.builder.as_deref(),
            Some("_build_profile"),
            "builder => 1 should derive builder name as '_build_<attr>'"
        );
    }

    #[test]
    fn predicate_with_string_name() {
        let models = build_models(
            r#"
use Moo;
has 'name' => (is => 'ro', predicate => 'has_name');
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.predicate.as_deref(),
            Some("has_name"),
            "predicate string name should be captured"
        );
    }

    #[test]
    fn predicate_with_numeric_one_generates_default_name() {
        let models = build_models(
            r#"
use Moo;
has 'name' => (is => 'ro', predicate => 1);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.predicate.as_deref(),
            Some("has_name"),
            "predicate => 1 should derive predicate name as 'has_<attr>'"
        );
    }

    #[test]
    fn clearer_with_string_name() {
        let models = build_models(
            r#"
use Moo;
has 'name' => (is => 'rw', clearer => 'clear_name');
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.clearer.as_deref(),
            Some("clear_name"),
            "clearer string name should be captured"
        );
    }

    #[test]
    fn clearer_with_numeric_one_generates_default_name() {
        let models = build_models(
            r#"
use Moo;
has 'name' => (is => 'rw', clearer => 1);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(
            attr.clearer.as_deref(),
            Some("clear_name"),
            "clearer => 1 should derive clearer name as 'clear_<attr>'"
        );
    }

    #[test]
    fn coerce_flag_true() {
        let models = build_models(
            r#"
use Moose;
has 'age' => (is => 'rw', isa => 'Int', coerce => 1);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert!(attr.coerce, "coerce => 1 should set coerce flag");
    }

    #[test]
    fn coerce_flag_false_when_absent() {
        let models = build_models(
            r#"
use Moose;
has 'age' => (is => 'rw', isa => 'Int');
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert!(!attr.coerce, "coerce should be false when not specified");
    }

    #[test]
    fn trigger_flag_true() {
        let models = build_models(
            r#"
use Moose;
has 'name' => (is => 'rw', trigger => \&_on_name_change);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert!(attr.trigger, "trigger option should set trigger flag");
    }

    #[test]
    fn trigger_flag_false_when_absent() {
        let models = build_models(
            r#"
use Moose;
has 'name' => (is => 'rw');
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert!(!attr.trigger, "trigger should be false when not specified");
    }

    // ── Bug 4 tests: NativeClass framework (must fail before fix) ─────────

    #[test]
    fn native_class_produces_model() {
        let models = build_models(
            r#"
class MyApp::Point {
    field $x :param = 0;
    field $y :param = 0;
    method get_x { return $x; }
    method get_y { return $y; }
}
"#,
        );
        assert_eq!(models.len(), 1, "expected one ClassModel for MyApp::Point");
        let model = &models[0];
        assert_eq!(model.name, "MyApp::Point");
        assert_eq!(model.framework, Framework::NativeClass);
        assert_eq!(model.methods.len(), 2);
        assert!(model.methods.iter().any(|m| m.name == "get_x"));
        assert!(model.methods.iter().any(|m| m.name == "get_y"));
    }

    #[test]
    fn native_class_and_moo_class_do_not_interfere() {
        let models = build_models(
            r#"
class Native::Point {
    field $x :param = 0;
    method get_x { return $x; }
}

package Moo::User;
use Moo;
has 'name' => (is => 'ro');
"#,
        );
        assert_eq!(models.len(), 2, "expected 2 ClassModels: Native::Point and Moo::User");
        let native = models.iter().find(|m| m.name == "Native::Point");
        assert!(native.is_some(), "expected Native::Point model");
        let native = native.unwrap();
        assert_eq!(native.framework, Framework::NativeClass);
        let moo = models.iter().find(|m| m.name == "Moo::User");
        assert!(moo.is_some(), "expected Moo::User model");
        let moo = moo.unwrap();
        assert_eq!(moo.framework, Framework::Moo);
    }

    #[test]
    fn object_pad_fields_and_accessors_are_tracked() {
        let models = build_models(
            r#"
use Object::Pad;

class Point {
    field $x :param :reader = 0;
    field $y :param :writer = 1;

    method move { }
}
"#,
        );

        assert!(
            !models.is_empty(),
            "expected at least one model, got {:?}",
            models.iter().map(|m| (&m.name, m.framework)).collect::<Vec<_>>()
        );
        let model = find_model(&models, "Point").expect("Point model");
        assert_eq!(model.framework, Framework::ObjectPad);
        assert_eq!(model.fields.len(), 2);
        assert!(has_method(model, "x", true, None));
        assert!(has_method(model, "set_y", true, None));
        assert!(has_method(model, "move", false, None));

        let x = model.fields.iter().find(|field| field.name == "x").unwrap();
        assert!(x.param);
        assert_eq!(x.reader.as_deref(), Some("x"));
        assert_eq!(x.default.as_deref(), Some("0"));

        let y = model.fields.iter().find(|field| field.name == "y").unwrap();
        assert!(y.param);
        assert_eq!(y.writer.as_deref(), Some("set_y"));
        assert_eq!(y.default.as_deref(), Some("1"));

        let param_names: Vec<_> = model.object_pad_param_field_names().collect();
        assert_eq!(param_names, vec!["x", "y"]);
    }

    #[test]
    fn object_pad_adjust_blocks_are_tracked() {
        let models = build_models(
            r#"
use Object::Pad;

class Config {
    ADJUST {
        my $tmp = 1;
    }
}
"#,
        );

        let model = find_model(&models, "Config").expect("Config model");
        assert_eq!(model.framework, Framework::ObjectPad);
        assert_eq!(model.adjusts.len(), 1, "expected one ADJUST block");
        assert_eq!(model.adjusts[0].name, "ADJUST");
        assert!(model.adjusts[0].synthetic, "ADJUST should be modeled as synthetic");
    }

    #[test]
    fn object_pad_param_field_names_exclude_non_param_fields() {
        let models = build_models(
            r#"
use Object::Pad;

class Config {
    field $name :param;
    field $cache = 1;
}
"#,
        );

        let model = find_model(&models, "Config").expect("Config model");
        let param_names: Vec<_> = model.object_pad_param_field_names().collect();
        assert_eq!(param_names, vec!["name"]);
    }

    #[test]
    fn object_pad_generated_names_follow_documented_defaults() {
        let models = build_models(
            r#"
use Object::Pad;

class Defaults {
    field $_secret :reader :writer :accessor :mutator;
}
"#,
        );

        let model = find_model(&models, "Defaults").expect("Defaults model");
        let field = model.fields.iter().find(|field| field.name == "_secret").unwrap();

        assert_eq!(field.reader.as_deref(), Some("secret"));
        assert_eq!(field.writer.as_deref(), Some("set_secret"));
        assert_eq!(field.accessor.as_deref(), Some("secret"));
        assert_eq!(field.mutator.as_deref(), Some("secret"));

        assert!(has_method(model, "secret", true, None));
        assert!(has_method(model, "set_secret", true, None));
    }

    #[test]
    fn all_advanced_options_together() {
        let models = build_models(
            r#"
use Moo;
has 'status' => (
    is        => 'rw',
    isa       => 'Str',
    builder   => '_build_status',
    coerce    => 1,
    predicate => 'has_status',
    clearer   => 'clear_status',
    trigger   => \&_on_status_change,
);
"#,
        );

        let model = &models[0];
        let attr = &model.attributes[0];
        assert_eq!(attr.builder.as_deref(), Some("_build_status"));
        assert!(attr.coerce);
        assert_eq!(attr.predicate.as_deref(), Some("has_status"));
        assert_eq!(attr.clearer.as_deref(), Some("clear_status"));
        assert!(attr.trigger);
    }

    // ── Phase 1 tests: plain OO inheritance detection ─────────────────────

    #[test]
    fn use_parent_plain_oo() {
        let code = "package Child; use parent 'Parent'; sub greet { } 1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert_eq!(model.framework, Framework::PlainOO);
        assert!(model.parents.contains(&"Parent".to_string()), "parents should contain 'Parent'");
    }

    #[test]
    fn use_parent_multiple() {
        let code = "package Child; use parent qw(Base1 Base2); 1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert_eq!(model.framework, Framework::PlainOO);
        assert!(model.parents.contains(&"Base1".to_string()), "parents should contain Base1");
        assert!(model.parents.contains(&"Base2".to_string()), "parents should contain Base2");
    }

    #[test]
    fn isa_array_assignment() {
        let code = "package Child; our @ISA = qw(Parent); sub greet { } 1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert!(
            model.parents.contains(&"Parent".to_string()),
            "parents should contain 'Parent' from @ISA"
        );
    }

    #[test]
    fn use_parent_norequire() {
        // use parent -norequire, 'Base' — the -norequire flag must not prevent parent capture
        let code = "package Child; use parent -norequire, 'Base'; 1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert!(
            model.parents.contains(&"Base".to_string()),
            "parents should contain 'Base' even with -norequire"
        );
    }

    #[test]
    fn use_base_plain_oo() {
        let code = "package Child; use base 'Parent'; sub greet { } 1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert_eq!(model.framework, Framework::PlainOO);
        assert!(
            model.parents.contains(&"Parent".to_string()),
            "parents should contain 'Parent' from use base"
        );
    }

    #[test]
    fn plain_oo_does_not_regress_moose_extends() {
        // Moose classes should still work and use parent field from extends
        let models = build_models(
            r#"
package MyApp::Admin;
use Moose;
extends 'MyApp::User';
has 'level' => (is => 'ro');
"#,
        );
        let model = find_model(&models, "MyApp::Admin").expect("Admin model");
        assert_eq!(model.framework, Framework::Moose);
        assert!(
            model.parents.contains(&"MyApp::User".to_string()),
            "Moose extends should still populate parents"
        );
    }

    // ---- Gap 1: Export surface ----

    #[test]
    fn export_array_captured() {
        let code = "package MyUtils;\nour @EXPORT = qw(foo bar);\nour @EXPORT_OK = qw(baz);\nsub foo {}\nsub bar {}\nsub baz {}\n1;";
        let models = build_models(code);
        let model = find_model(&models, "MyUtils").expect("MyUtils model");
        assert_eq!(model.exports, vec!["foo".to_string(), "bar".to_string()]);
        assert_eq!(model.export_ok, vec!["baz".to_string()]);
    }

    #[test]
    fn export_non_oo_package_produces_model() {
        let code = "package MyUtils;\nour @EXPORT = qw(helper);\nsub helper { 1 }\n1;";
        let models = build_models(code);
        assert!(
            find_model(&models, "MyUtils").is_some(),
            "export-only package must produce a model"
        );
    }

    #[test]
    fn export_ok_assignment_without_our() {
        let code = "package MyLib;\n@EXPORT_OK = qw(util_a util_b);\n1;";
        let models = build_models(code);
        let model = find_model(&models, "MyLib").expect("MyLib model");
        assert_eq!(model.export_ok, vec!["util_a".to_string(), "util_b".to_string()]);
    }

    #[test]
    fn export_assignment_without_our() {
        // Symmetric to export_ok_assignment_without_our: bare `@EXPORT = qw(...)` form.
        let code = "package MyLib;\n@EXPORT = qw(func_a func_b);\n1;";
        let models = build_models(code);
        let model = find_model(&models, "MyLib").expect("MyLib model");
        assert_eq!(model.exports, vec!["func_a".to_string(), "func_b".to_string()]);
    }

    #[test]
    fn exporter_metadata_resolves_export_and_export_ok() {
        let code = r#"
package MyUtils;
use Exporter 'import';
our @EXPORT = qw(foo missing_default);
our @EXPORT_OK = ('bar', "missing_ok");
sub foo { 1 }
sub bar { 1 }
1;
"#;
        let models = build_models(code);
        let model = find_model(&models, "MyUtils").expect("MyUtils model");
        let metadata = model.exporter_metadata.as_ref().expect("exporter metadata");

        assert_eq!(
            metadata.exports.iter().map(|item| item.name.as_str()).collect::<Vec<_>>(),
            vec!["foo"]
        );
        assert_eq!(
            metadata.export_ok.iter().map(|item| item.name.as_str()).collect::<Vec<_>>(),
            vec!["bar"]
        );
        assert!(metadata.unresolved.contains(&"missing_default".to_string()));
        assert!(metadata.unresolved.contains(&"missing_ok".to_string()));
    }

    #[test]
    fn exporter_metadata_resolves_export_tags() {
        let code = r#"
package MyTags;
use parent 'Exporter';
our %EXPORT_TAGS = (
    util => [qw(one two missing)],
    misc => ['three'],
);
sub one { 1 }
sub two { 1 }
sub three { 1 }
1;
"#;
        let models = build_models(code);
        let model = find_model(&models, "MyTags").expect("MyTags model");
        let metadata = model.exporter_metadata.as_ref().expect("exporter metadata");

        let util_names = metadata
            .export_tags
            .get("util")
            .expect("util tag")
            .iter()
            .map(|item| item.name.as_str())
            .collect::<Vec<_>>();
        let misc_names = metadata
            .export_tags
            .get("misc")
            .expect("misc tag")
            .iter()
            .map(|item| item.name.as_str())
            .collect::<Vec<_>>();

        assert_eq!(util_names, vec!["one", "two"]);
        assert_eq!(misc_names, vec!["three"]);
        assert!(metadata.unresolved.contains(&"missing".to_string()));
    }

    #[test]
    fn export_lists_without_exporter_usage_do_not_produce_exporter_metadata() {
        let code = r#"
package NoExporter;
our @EXPORT = qw(foo);
our @EXPORT_OK = qw(bar);
our %EXPORT_TAGS = (all => [qw(foo bar)]);
sub foo { 1 }
sub bar { 1 }
1;
"#;
        let models = build_models(code);
        let model = find_model(&models, "NoExporter").expect("NoExporter model");
        assert!(model.exporter_metadata.is_none());
    }

    // ---- Gap 2: push @ISA ----

    #[test]
    fn push_isa_single_parent() {
        let code = "package Child;\npush @ISA, 'Parent';\n1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert!(model.parents.contains(&"Parent".to_string()), "push @ISA must capture parent");
        assert_eq!(model.framework, Framework::PlainOO);
    }

    #[test]
    fn push_isa_multiple_parents() {
        let code = "package Child;\npush @ISA, 'Base1', 'Base2';\n1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert!(model.parents.contains(&"Base1".to_string()));
        assert!(model.parents.contains(&"Base2".to_string()));
    }

    #[test]
    fn push_isa_does_not_downgrade_moose_framework() {
        // If a package already uses Moose, push @ISA must not overwrite to PlainOO.
        let code = "package Child;\nuse Moose;\nextends 'Base';\npush @ISA, 'Extra';\n1;";
        let models = build_models(code);
        let model = find_model(&models, "Child").expect("Child model");
        assert_eq!(model.framework, Framework::Moose, "Moose must not be downgraded to PlainOO");
        assert!(
            model.parents.contains(&"Extra".to_string()),
            "push @ISA parent must still be captured"
        );
    }

    // ── Issue #3540: Native Perl 5.38 class :isa(Parent) inheritance ──────────

    #[test]
    fn native_class_with_isa_has_correct_parent() {
        let models = build_models(
            r#"
class Point3D :isa(Point) {
    field $z :param = 0;
    method get_z { return $z; }
}
"#,
        );
        assert_eq!(models.len(), 1, "expected one ClassModel for Point3D");
        let model = &models[0];
        assert_eq!(model.name, "Point3D");
        assert_eq!(model.framework, Framework::NativeClass);
        assert!(
            model.parents.contains(&"Point".to_string()),
            "native class :isa(Point) must populate parents, got {:?}",
            model.parents
        );
    }

    #[test]
    fn native_class_with_multiple_isa_has_all_parents() {
        let models = build_models(
            r#"
class Shape3D :isa(Shape) :isa(Printable) {
    field $z :param = 0;
}
"#,
        );
        assert_eq!(models.len(), 1, "expected one ClassModel for Shape3D");
        let model = &models[0];
        assert_eq!(model.framework, Framework::NativeClass);
        assert!(
            model.parents.contains(&"Shape".to_string()),
            "expected 'Shape' in parents, got {:?}",
            model.parents
        );
        assert!(
            model.parents.contains(&"Printable".to_string()),
            "expected 'Printable' in parents, got {:?}",
            model.parents
        );
    }

    #[test]
    fn native_class_without_isa_has_no_parents() {
        let models = build_models(
            r#"
class Point {
    field $x :param = 0;
    field $y :param = 0;
}
"#,
        );
        assert_eq!(models.len(), 1);
        let model = &models[0];
        assert_eq!(model.framework, Framework::NativeClass);
        assert!(
            model.parents.is_empty(),
            "class without :isa must have no parents, got {:?}",
            model.parents
        );
    }

    #[test]
    fn native_class_with_qualified_isa_has_qualified_parent() {
        let models = build_models(
            r#"
class MyApp::Point3D :isa(MyApp::Point) {
    field $z :param = 0;
}
"#,
        );
        assert_eq!(models.len(), 1);
        let model = &models[0];
        assert_eq!(model.name, "MyApp::Point3D");
        assert!(
            model.parents.contains(&"MyApp::Point".to_string()),
            "qualified :isa must preserve qualified name, got {:?}",
            model.parents
        );
    }

    #[test]
    fn second_class_without_isa_does_not_inherit_first_class_parents() {
        // Regression guard: parents from the first class must not bleed into the second.
        // flush_current_package() uses mem::take so current_parents is reset between classes.
        let models = build_models(
            r#"
class Point3D :isa(Point) {
    field $z :param = 0;
}
class Standalone {
    field $x :param = 0;
}
"#,
        );
        let standalone = models.iter().find(|m| m.name == "Standalone").expect("Standalone model");
        assert!(
            standalone.parents.is_empty(),
            "Standalone class must have no parents, but got {:?}",
            standalone.parents
        );
    }
}