/*!
 * EXTREME TDD AST Node Tests - ACTOR-003 (Syntactic Structure)
 *
 * CRITICAL: ALL AST node definitions MUST be tested FIRST before ANY AST implementation.
 * These tests define the EXACT syntactic structure for actor system constructs.
 *
 * Following Toyota Way: Build quality in from the start.
 * Following EXTREME TDD: 100% AST coverage before any syntax tree code exists.
 *
 * Complexity Budget: Each test function ≤5 cyclomatic, ≤8 cognitive
 * Coverage Target: 100% AST node coverage
 * Test Ratio: 3:1 test-to-implementation ratio
 */

use ruchy::common::types::{ActorRef, Type, TypeRef};
use ruchy::frontend::ast::{
    ActorDef, ActorState, Expression, Hook, HookType, MessagePattern, Pattern, PatternGuard,
    ReceiveArm, ReceiveBlock, RestartStrategy, SendExpr, SpawnExpr, Statement, SupervisorDef,
};
use ruchy::frontend::tokens::{Span, TokenKind};

#[cfg(test)]
mod actor_ast_tests {
    use super::*;
    use proptest::prelude::*;
    use std::collections::HashMap;

    /// Test infrastructure for AST validation
    struct ASTTestContext {
        nodes: Vec<Box<dyn ASTNode>>,
        type_context: HashMap<String, Type>,
    }

    trait ASTNode {
        fn node_type(&self) -> &'static str;
        fn validate(&self) -> bool;
        fn children(&self) -> Vec<&dyn ASTNode>;
        fn span(&self) -> Span;
    }

    impl ASTTestContext {
        fn new() -> Self {
            Self {
                nodes: Vec::new(),
                type_context: HashMap::new(),
            }
        }

        fn add_node<T: ASTNode + 'static>(&mut self, node: T) {
            self.nodes.push(Box::new(node));
        }

        fn validate_tree(&self) -> bool {
            self.nodes.iter().all(|node| node.validate())
        }
    }

    // =================================================================
    // ACTOR DEFINITION AST TESTS (Core Actor Structure)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_actor_def_basic_structure() {
        let actor_def = ActorDef {
            name: "ChatAgent".to_string(),
            type_params: vec![],
            state_params: vec![],
            body: vec![],
            span: Span::new(0, 20),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        assert_eq!(actor_def.name, "ChatAgent");
        assert!(actor_def.state_params.is_empty());
        assert!(actor_def.body.is_empty());
        assert!(actor_def.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_actor_def_with_state_params() {
        let state_param = StateParam {
            name: "count".to_string(),
            param_type: Type::Int32,
            default_value: Some(Expression::IntLiteral(0)),
            mutability: Mutability::Mutable,
            span: Span::new(0, 10),
        };

        let actor_def = ActorDef {
            name: "Counter".to_string(),
            type_params: vec![],
            state_params: vec![state_param],
            body: vec![],
            span: Span::new(0, 30),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        assert_eq!(actor_def.state_params.len(), 1);
        assert_eq!(actor_def.state_params[0].name, "count");
        assert_eq!(actor_def.state_params[0].param_type, Type::Int32);
        assert!(actor_def.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_actor_def_with_generic_params() {
        let type_param = TypeParam {
            name: "T".to_string(),
            bounds: vec![TypeBound::Send, TypeBound::Sync],
            default_type: None,
            span: Span::new(0, 1),
        };

        let actor_def = ActorDef {
            name: "GenericActor".to_string(),
            type_params: vec![type_param],
            state_params: vec![],
            body: vec![],
            span: Span::new(0, 25),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        assert_eq!(actor_def.type_params.len(), 1);
        assert_eq!(actor_def.type_params[0].name, "T");
        assert_eq!(actor_def.type_params[0].bounds.len(), 2);
        assert!(actor_def.validate());
    }

    // =================================================================
    // RECEIVE BLOCK AST TESTS (Message Pattern Matching)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_receive_block_basic_structure() {
        let pattern = Pattern::Identifier {
            name: "Increment".to_string(),
            span: Span::new(0, 9),
        };

        let expression = Expression::FieldAccess {
            object: Box::new(Expression::Identifier {
                name: "self".to_string(),
                span: Span::new(13, 17),
            }),
            field: "count".to_string(),
            span: Span::new(13, 23),
        };

        let receive_arm = ReceiveArm {
            pattern,
            guard: None,
            body: expression,
            span: Span::new(0, 23),
        };

        let receive_block = ReceiveBlock {
            arms: vec![receive_arm],
            is_exhaustive: false,
            timeout: None,
            span: Span::new(0, 30),
        };

        assert_eq!(receive_block.arms.len(), 1);
        assert!(!receive_block.is_exhaustive);
        assert!(receive_block.timeout.is_none());
        assert!(receive_block.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_receive_arm_with_pattern_destructuring() {
        let pattern = Pattern::Struct {
            name: "SendMessage".to_string(),
            fields: vec![FieldPattern {
                name: "content".to_string(),
                pattern: Box::new(Pattern::Identifier {
                    name: "msg".to_string(),
                    span: Span::new(0, 3),
                }),
                span: Span::new(0, 10),
            }],
            span: Span::new(0, 20),
        };

        let body = Expression::FunctionCall {
            function: Box::new(Expression::Identifier {
                name: "handle_message".to_string(),
                span: Span::new(0, 14),
            }),
            args: vec![Expression::Identifier {
                name: "msg".to_string(),
                span: Span::new(15, 18),
            }],
            span: Span::new(0, 19),
        };

        let receive_arm = ReceiveArm {
            pattern,
            guard: None,
            body,
            span: Span::new(0, 40),
        };

        assert!(matches!(receive_arm.pattern, Pattern::Struct { .. }));
        assert!(receive_arm.guard.is_none());
        assert!(receive_arm.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_receive_arm_with_pattern_guard() {
        let pattern = Pattern::Struct {
            name: "SetValue".to_string(),
            fields: vec![FieldPattern {
                name: "value".to_string(),
                pattern: Box::new(Pattern::Identifier {
                    name: "v".to_string(),
                    span: Span::new(0, 1),
                }),
                span: Span::new(0, 8),
            }],
            span: Span::new(0, 15),
        };

        let guard = PatternGuard {
            condition: Expression::BinaryOp {
                op: BinaryOperator::GreaterThan,
                left: Box::new(Expression::Identifier {
                    name: "v".to_string(),
                    span: Span::new(0, 1),
                }),
                right: Box::new(Expression::IntLiteral(0)),
                span: Span::new(0, 5),
            },
            span: Span::new(0, 5),
        };

        let receive_arm = ReceiveArm {
            pattern,
            guard: Some(guard),
            body: Expression::Unit,
            span: Span::new(0, 25),
        };

        assert!(receive_arm.guard.is_some());
        assert!(receive_arm.validate());
    }

    // =================================================================
    // HOOK DEFINITION AST TESTS (Lifecycle Events)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_hook_on_start_structure() {
        let hook = Hook {
            hook_type: HookType::OnStart,
            body: vec![Statement::Expression(Expression::FunctionCall {
                function: Box::new(Expression::Identifier {
                    name: "println".to_string(),
                    span: Span::new(0, 7),
                }),
                args: vec![Expression::StringLiteral {
                    value: "Actor starting".to_string(),
                    span: Span::new(8, 24),
                }],
                span: Span::new(0, 25),
            })],
            span: Span::new(0, 30),
            is_async: false,
        };

        assert_eq!(hook.hook_type, HookType::OnStart);
        assert_eq!(hook.body.len(), 1);
        assert!(!hook.is_async);
        assert!(hook.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_hook_on_error_with_error_param() {
        let hook = Hook {
            hook_type: HookType::OnError {
                error_param: Some("error".to_string()),
            },
            body: vec![Statement::Expression(Expression::FunctionCall {
                function: Box::new(Expression::Identifier {
                    name: "log_error".to_string(),
                    span: Span::new(0, 9),
                }),
                args: vec![Expression::Identifier {
                    name: "error".to_string(),
                    span: Span::new(10, 15),
                }],
                span: Span::new(0, 16),
            })],
            span: Span::new(0, 20),
            is_async: false,
        };

        assert!(matches!(hook.hook_type, HookType::OnError { .. }));
        if let HookType::OnError { error_param } = &hook.hook_type {
            assert_eq!(error_param.as_ref().unwrap(), "error");
        }
        assert!(hook.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_all_hook_types_coverage() {
        let hook_types = vec![
            HookType::OnStart,
            HookType::OnStop,
            HookType::OnError { error_param: None },
            HookType::OnRestart {
                reason_param: Some("reason".to_string()),
            },
        ];

        for hook_type in hook_types {
            let hook = Hook {
                hook_type,
                body: vec![],
                span: Span::new(0, 10),
                is_async: false,
            };

            assert!(hook.validate());
        }
    }

    // =================================================================
    // MESSAGE SEND AST TESTS (Actor Communication)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_send_expression_basic() {
        let send_expr = SendExpr {
            receiver: Box::new(Expression::Identifier {
                name: "actor_ref".to_string(),
                span: Span::new(0, 9),
            }),
            message: Box::new(Expression::Identifier {
                name: "Increment".to_string(),
                span: Span::new(12, 21),
            }),
            send_type: SendType::Fire, // Fire and forget
            span: Span::new(0, 21),
        };

        assert!(matches!(send_expr.send_type, SendType::Fire));
        assert!(send_expr.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_send_expression_with_message_data() {
        let message = Expression::FunctionCall {
            function: Box::new(Expression::Identifier {
                name: "SendMessage".to_string(),
                span: Span::new(0, 11),
            }),
            args: vec![Expression::StringLiteral {
                value: "Hello World".to_string(),
                span: Span::new(12, 25),
            }],
            span: Span::new(0, 26),
        };

        let send_expr = SendExpr {
            receiver: Box::new(Expression::Identifier {
                name: "chat_agent".to_string(),
                span: Span::new(0, 10),
            }),
            message: Box::new(message),
            send_type: SendType::Fire,
            span: Span::new(0, 35),
        };

        assert!(send_expr.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_send_expression_call_pattern() {
        let send_expr = SendExpr {
            receiver: Box::new(Expression::Identifier {
                name: "calculator".to_string(),
                span: Span::new(0, 10),
            }),
            message: Box::new(Expression::FunctionCall {
                function: Box::new(Expression::Identifier {
                    name: "Add".to_string(),
                    span: Span::new(0, 3),
                }),
                args: vec![Expression::IntLiteral(1), Expression::IntLiteral(2)],
                span: Span::new(0, 10),
            }),
            send_type: SendType::Call {
                timeout: Some(5000),
            }, // Request-response with timeout
            span: Span::new(0, 25),
        };

        assert!(matches!(send_expr.send_type, SendType::Call { .. }));
        if let SendType::Call { timeout } = send_expr.send_type {
            assert_eq!(timeout, Some(5000));
        }
        assert!(send_expr.validate());
    }

    // =================================================================
    // SPAWN EXPRESSION AST TESTS (Actor Creation)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_spawn_expression_no_args() {
        let spawn_expr = SpawnExpr {
            actor_type: "ChatAgent".to_string(),
            args: vec![],
            supervisor: None,
            spawn_options: SpawnOptions::default(),
            span: Span::new(0, 17),
        };

        assert_eq!(spawn_expr.actor_type, "ChatAgent");
        assert!(spawn_expr.args.is_empty());
        assert!(spawn_expr.supervisor.is_none());
        assert!(spawn_expr.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_spawn_expression_with_args() {
        let spawn_expr = SpawnExpr {
            actor_type: "Counter".to_string(),
            args: vec![
                Expression::IntLiteral(0),
                Expression::StringLiteral {
                    value: "counter1".to_string(),
                    span: Span::new(0, 10),
                },
            ],
            supervisor: None,
            spawn_options: SpawnOptions::default(),
            span: Span::new(0, 25),
        };

        assert_eq!(spawn_expr.args.len(), 2);
        assert!(matches!(spawn_expr.args[0], Expression::IntLiteral(0)));
        assert!(spawn_expr.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_spawn_expression_with_supervisor() {
        let spawn_expr = SpawnExpr {
            actor_type: "Worker".to_string(),
            args: vec![],
            supervisor: Some("MainSupervisor".to_string()),
            spawn_options: SpawnOptions {
                restart_strategy: Some(RestartStrategy::OneForOne),
                max_restarts: Some(3),
                restart_period: Some(60000),  // 1 minute
                shutdown_timeout: Some(5000), // 5 seconds
            },
            span: Span::new(0, 30),
        };

        assert_eq!(spawn_expr.supervisor.as_ref().unwrap(), "MainSupervisor");
        assert!(matches!(
            spawn_expr.spawn_options.restart_strategy,
            Some(RestartStrategy::OneForOne)
        ));
        assert!(spawn_expr.validate());
    }

    // =================================================================
    // SUPERVISOR DEFINITION AST TESTS (Fault Tolerance)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_supervisor_def_basic() {
        let supervisor_def = SupervisorDef {
            name: "ChatSupervisor".to_string(),
            strategy: RestartStrategy::OneForOne,
            child_specs: vec![],
            max_restarts: 3,
            max_seconds: 60,
            span: Span::new(0, 40),
        };

        assert_eq!(supervisor_def.name, "ChatSupervisor");
        assert!(matches!(
            supervisor_def.strategy,
            RestartStrategy::OneForOne
        ));
        assert_eq!(supervisor_def.max_restarts, 3);
        assert_eq!(supervisor_def.max_seconds, 60);
        assert!(supervisor_def.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_supervisor_with_child_specs() {
        let child_spec = ChildSpec {
            id: "worker1".to_string(),
            actor_type: "Worker".to_string(),
            args: vec![Expression::IntLiteral(1)],
            restart_type: RestartType::Permanent,
            shutdown_type: ShutdownType::Timeout(5000),
            span: Span::new(0, 20),
        };

        let supervisor_def = SupervisorDef {
            name: "WorkerSupervisor".to_string(),
            strategy: RestartStrategy::OneForAll,
            child_specs: vec![child_spec],
            max_restarts: 5,
            max_seconds: 300,
            span: Span::new(0, 60),
        };

        assert_eq!(supervisor_def.child_specs.len(), 1);
        assert_eq!(supervisor_def.child_specs[0].id, "worker1");
        assert!(matches!(
            supervisor_def.child_specs[0].restart_type,
            RestartType::Permanent
        ));
        assert!(supervisor_def.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_restart_strategies_coverage() {
        let strategies = vec![
            RestartStrategy::OneForOne,
            RestartStrategy::OneForAll,
            RestartStrategy::RestForOne,
            RestartStrategy::SimpleOneForOne,
        ];

        for strategy in strategies {
            let supervisor = SupervisorDef {
                name: "TestSupervisor".to_string(),
                strategy,
                child_specs: vec![],
                max_restarts: 3,
                max_seconds: 60,
                span: Span::new(0, 20),
            };

            assert!(supervisor.validate());
        }
    }

    // =================================================================
    // PATTERN AST TESTS (Message Pattern Matching)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_pattern_identifier() {
        let pattern = Pattern::Identifier {
            name: "Increment".to_string(),
            span: Span::new(0, 9),
        };

        if let Pattern::Identifier { name, .. } = pattern {
            assert_eq!(name, "Increment");
        } else {
            panic!("Expected identifier pattern");
        }
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_pattern_struct_destructuring() {
        let pattern = Pattern::Struct {
            name: "Point".to_string(),
            fields: vec![
                FieldPattern {
                    name: "x".to_string(),
                    pattern: Box::new(Pattern::Identifier {
                        name: "px".to_string(),
                        span: Span::new(0, 2),
                    }),
                    span: Span::new(0, 5),
                },
                FieldPattern {
                    name: "y".to_string(),
                    pattern: Box::new(Pattern::Identifier {
                        name: "py".to_string(),
                        span: Span::new(0, 2),
                    }),
                    span: Span::new(0, 5),
                },
            ],
            span: Span::new(0, 15),
        };

        if let Pattern::Struct { name, fields, .. } = pattern {
            assert_eq!(name, "Point");
            assert_eq!(fields.len(), 2);
            assert_eq!(fields[0].name, "x");
            assert_eq!(fields[1].name, "y");
        } else {
            panic!("Expected struct pattern");
        }
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_pattern_tuple_destructuring() {
        let pattern = Pattern::Tuple {
            elements: vec![
                Pattern::Identifier {
                    name: "first".to_string(),
                    span: Span::new(0, 5),
                },
                Pattern::Identifier {
                    name: "second".to_string(),
                    span: Span::new(7, 13),
                },
                Pattern::Wildcard {
                    span: Span::new(15, 16),
                },
            ],
            span: Span::new(0, 17),
        };

        if let Pattern::Tuple { elements, .. } = pattern {
            assert_eq!(elements.len(), 3);
            assert!(matches!(elements[0], Pattern::Identifier { .. }));
            assert!(matches!(elements[1], Pattern::Identifier { .. }));
            assert!(matches!(elements[2], Pattern::Wildcard { .. }));
        } else {
            panic!("Expected tuple pattern");
        }
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_pattern_literal_matching() {
        let patterns = vec![
            Pattern::IntLiteral {
                value: 42,
                span: Span::new(0, 2),
            },
            Pattern::StringLiteral {
                value: "hello".to_string(),
                span: Span::new(0, 7),
            },
            Pattern::BoolLiteral {
                value: true,
                span: Span::new(0, 4),
            },
        ];

        for pattern in patterns {
            // Each literal pattern should validate
            match pattern {
                Pattern::IntLiteral { value, .. } => assert_eq!(value, 42),
                Pattern::StringLiteral { value, .. } => assert_eq!(value, "hello"),
                Pattern::BoolLiteral { value, .. } => assert!(value),
                _ => {}
            }
        }
    }

    // =================================================================
    // PROPERTY-BASED AST TESTS (Structural Invariants)
    // =================================================================

    proptest! {
        #[test]
        #[ignore] // EXTREME TDD: Property tests first, no implementation yet
        fn prop_actor_name_must_be_pascal_case(
            name in r"[A-Z][a-zA-Z0-9_]*"
        ) {
            let actor_def = ActorDef {
                name: name.clone(),
                type_params: vec![],
                state_params: vec![],
                body: vec![],
                span: Span::new(0, name.len()),
                visibility: Visibility::Public,
                attributes: vec![],
            };

            // Property: Actor names must start with uppercase
            prop_assert!(name.chars().next().unwrap().is_uppercase());
            prop_assert!(actor_def.validate());
        }

        #[test]
        #[ignore] // EXTREME TDD: Property tests first, no implementation yet
        fn prop_receive_block_exhaustiveness(
            patterns in prop::collection::vec(r"[A-Z][a-zA-Z0-9_]*", 1..10)
        ) {
            let mut receive_arms = Vec::new();
            for pattern_name in patterns {
                let arm = ReceiveArm {
                    pattern: Pattern::Identifier {
                        name: pattern_name,
                        span: Span::new(0, 10),
                    },
                    guard: None,
                    body: Expression::Unit,
                    span: Span::new(0, 20),
                };
                receive_arms.push(arm);
            }

            let receive_block = ReceiveBlock {
                arms: receive_arms,
                is_exhaustive: false,
                timeout: None,
                span: Span::new(0, 50),
            };

            // Property: Receive blocks with patterns are valid
            prop_assert!(!receive_block.arms.is_empty());
            prop_assert!(receive_block.validate());
        }

        #[test]
        #[ignore] // EXTREME TDD: Property tests first, no implementation yet
        fn prop_spawn_options_consistency(
            max_restarts in 0u32..100,
            restart_period in 1000u64..86400000 // 1 second to 1 day
        ) {
            let spawn_options = SpawnOptions {
                restart_strategy: Some(RestartStrategy::OneForOne),
                max_restarts: Some(max_restarts),
                restart_period: Some(restart_period),
                shutdown_timeout: Some(5000),
            };

            // Property: Restart period should be reasonable relative to max restarts
            if max_restarts > 0 {
                prop_assert!(restart_period >= 1000); // At least 1 second
            }

            let spawn_expr = SpawnExpr {
                actor_type: "TestActor".to_string(),
                args: vec![],
                supervisor: None,
                spawn_options,
                span: Span::new(0, 20),
            };

            prop_assert!(spawn_expr.validate());
        }
    }

    // =================================================================
    // AST TRAVERSAL AND VISITOR TESTS (Tree Navigation)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_ast_visitor_pattern() {
        trait ASTVisitor {
            fn visit_actor_def(&mut self, actor: &ActorDef) -> bool;
            fn visit_receive_block(&mut self, receive: &ReceiveBlock) -> bool;
            fn visit_hook(&mut self, hook: &Hook) -> bool;
            fn visit_expression(&mut self, expr: &Expression) -> bool;
        }

        struct CountingVisitor {
            actor_count: usize,
            receive_count: usize,
            hook_count: usize,
            expr_count: usize,
        }

        impl ASTVisitor for CountingVisitor {
            fn visit_actor_def(&mut self, _actor: &ActorDef) -> bool {
                self.actor_count += 1;
                true // Continue traversal
            }

            fn visit_receive_block(&mut self, _receive: &ReceiveBlock) -> bool {
                self.receive_count += 1;
                true
            }

            fn visit_hook(&mut self, _hook: &Hook) -> bool {
                self.hook_count += 1;
                true
            }

            fn visit_expression(&mut self, _expr: &Expression) -> bool {
                self.expr_count += 1;
                true
            }
        }

        // Test visitor pattern implementation
        let mut visitor = CountingVisitor {
            actor_count: 0,
            receive_count: 0,
            hook_count: 0,
            expr_count: 0,
        };

        // This would traverse a sample AST and count nodes
        assert_eq!(visitor.actor_count, 0); // Before traversal
    }

    // =================================================================
    // AST SERIALIZATION TESTS (Persistence and Debugging)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_ast_debug_representation() {
        let actor_def = ActorDef {
            name: "TestActor".to_string(),
            type_params: vec![],
            state_params: vec![],
            body: vec![],
            span: Span::new(0, 15),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        let debug_output = format!("{:?}", actor_def);
        assert!(debug_output.contains("TestActor"));
        assert!(debug_output.contains("ActorDef"));
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_ast_clone_semantics() {
        let original = ActorDef {
            name: "ClonableActor".to_string(),
            type_params: vec![],
            state_params: vec![],
            body: vec![],
            span: Span::new(0, 20),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        let cloned = original.clone();
        assert_eq!(original.name, cloned.name);
        assert_eq!(original.span, cloned.span);

        // Verify deep clone behavior
        assert_eq!(original.type_params.len(), cloned.type_params.len());
        assert_eq!(original.state_params.len(), cloned.state_params.len());
    }

    // =================================================================
    // AST VALIDATION TESTS (Semantic Correctness)
    // =================================================================

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_ast_semantic_validation() {
        // Test cases for invalid AST structures that should fail validation
        let invalid_cases = vec![
            // Actor with empty name
            ActorDef {
                name: "".to_string(),
                type_params: vec![],
                state_params: vec![],
                body: vec![],
                span: Span::new(0, 0),
                visibility: Visibility::Public,
                attributes: vec![],
            },
            // Actor with invalid span (end before start)
            ActorDef {
                name: "InvalidSpan".to_string(),
                type_params: vec![],
                state_params: vec![],
                body: vec![],
                span: Span::new(10, 5), // Invalid: start > end
                visibility: Visibility::Public,
                attributes: vec![],
            },
        ];

        for invalid_actor in invalid_cases {
            assert!(!invalid_actor.validate());
        }
    }

    #[test]
    #[ignore] // EXTREME TDD: Test first, no implementation yet
    fn test_ast_consistency_checks() {
        // Test cross-node consistency requirements

        // Test: Send expression target must be valid actor reference
        let invalid_send = SendExpr {
            receiver: Box::new(Expression::IntLiteral(42)), // Invalid: not an actor ref
            message: Box::new(Expression::Identifier {
                name: "TestMessage".to_string(),
                span: Span::new(0, 11),
            }),
            send_type: SendType::Fire,
            span: Span::new(0, 20),
        };

        assert!(!invalid_send.validate());

        // Test: Receive pattern must match message type expectations
        let type_mismatch_receive = ReceiveArm {
            pattern: Pattern::IntLiteral {
                value: 42,
                span: Span::new(0, 2),
            },
            guard: None,
            body: Expression::Unit,
            span: Span::new(0, 10),
        };

        // This would require type context to validate properly
        // For now, just ensure structure is correct
        assert!(type_mismatch_receive.span.start < type_mismatch_receive.span.end);
    }
}

// =================================================================
// AST PERFORMANCE AND MEMORY TESTS
// =================================================================

#[cfg(test)]
mod ast_performance_tests {
    use super::*;
    use std::time::Instant;

    #[test]
    #[ignore] // EXTREME TDD: Performance tests first, no implementation yet
    fn test_large_ast_construction_performance() {
        let start = Instant::now();

        // Create large AST with many nested structures
        let mut large_body = Vec::new();
        for i in 0..1000 {
            let receive_block = ReceiveBlock {
                arms: vec![ReceiveArm {
                    pattern: Pattern::Identifier {
                        name: format!("Message{}", i),
                        span: Span::new(0, 10),
                    },
                    guard: None,
                    body: Expression::FunctionCall {
                        function: Box::new(Expression::Identifier {
                            name: format!("handler{}", i),
                            span: Span::new(0, 10),
                        }),
                        args: vec![],
                        span: Span::new(0, 15),
                    },
                    span: Span::new(0, 25),
                }],
                is_exhaustive: false,
                timeout: None,
                span: Span::new(0, 30),
            };
            large_body.push(ActorBodyItem::Receive(receive_block));
        }

        let large_actor = ActorDef {
            name: "LargeActor".to_string(),
            type_params: vec![],
            state_params: vec![],
            body: large_body,
            span: Span::new(0, 50000),
            visibility: Visibility::Public,
            attributes: vec![],
        };

        let duration = start.elapsed();

        // Performance requirement: Large AST construction <100ms
        assert!(duration.as_millis() < 100);
        assert_eq!(large_actor.body.len(), 1000);
        assert!(large_actor.validate());
    }

    #[test]
    #[ignore] // EXTREME TDD: Memory tests first, no implementation yet
    fn test_ast_memory_efficiency() {
        use std::mem;

        // Verify AST nodes have reasonable memory footprint
        assert!(mem::size_of::<ActorDef>() < 1024); // <1KB per actor def
        assert!(mem::size_of::<ReceiveBlock>() < 512); // <512B per receive block
        assert!(mem::size_of::<Hook>() < 256); // <256B per hook
        assert!(mem::size_of::<Pattern>() < 128); // <128B per pattern

        // Test memory usage of deeply nested expressions
        let nested_expr = create_deeply_nested_expression(100);
        let size_estimate = estimate_expression_size(&nested_expr);

        // Should scale linearly, not exponentially
        assert!(size_estimate < 100 * 200); // <20KB for 100 levels
    }

    fn create_deeply_nested_expression(depth: usize) -> Expression {
        if depth == 0 {
            Expression::IntLiteral(42)
        } else {
            Expression::BinaryOp {
                op: BinaryOperator::Add,
                left: Box::new(create_deeply_nested_expression(depth - 1)),
                right: Box::new(Expression::IntLiteral(1)),
                span: Span::new(0, depth),
            }
        }
    }

    fn estimate_expression_size(expr: &Expression) -> usize {
        // Rough estimation of expression memory usage
        match expr {
            Expression::IntLiteral(_) => mem::size_of::<i64>(),
            Expression::BinaryOp { left, right, .. } => {
                mem::size_of::<Expression>()
                    + estimate_expression_size(left)
                    + estimate_expression_size(right)
            }
            _ => mem::size_of::<Expression>(),
        }
    }
}

impl ASTNode for ActorDef {
    fn node_type(&self) -> &'static str {
        "ActorDef"
    }
    fn validate(&self) -> bool {
        !self.name.is_empty() && self.span.start <= self.span.end
    }
    fn children(&self) -> Vec<&dyn ASTNode> {
        vec![]
    }
    fn span(&self) -> Span {
        self.span
    }
}

impl ASTNode for ReceiveBlock {
    fn node_type(&self) -> &'static str {
        "ReceiveBlock"
    }
    fn validate(&self) -> bool {
        !self.arms.is_empty() && self.span.start <= self.span.end
    }
    fn children(&self) -> Vec<&dyn ASTNode> {
        vec![]
    }
    fn span(&self) -> Span {
        self.span
    }
}

impl ASTNode for Hook {
    fn node_type(&self) -> &'static str {
        "Hook"
    }
    fn validate(&self) -> bool {
        self.span.start <= self.span.end
    }
    fn children(&self) -> Vec<&dyn ASTNode> {
        vec![]
    }
    fn span(&self) -> Span {
        self.span
    }
}

impl ASTNode for SendExpr {
    fn node_type(&self) -> &'static str {
        "SendExpr"
    }
    fn validate(&self) -> bool {
        self.span.start <= self.span.end
    }
    fn children(&self) -> Vec<&dyn ASTNode> {
        vec![]
    }
    fn span(&self) -> Span {
        self.span
    }
}

impl ASTNode for SpawnExpr {
    fn node_type(&self) -> &'static str {
        "SpawnExpr"
    }
    fn validate(&self) -> bool {
        !self.actor_type.is_empty() && self.span.start <= self.span.end
    }
    fn children(&self) -> Vec<&dyn ASTNode> {
        vec![]
    }
    fn span(&self) -> Span {
        self.span
    }
}
