#[cfg(test)]
mod tests {
    use crate::ast::parser::Parser;
    use crate::ast::types::Value;
    use crate::ast::nodes::UntypedKind;
    use crate::ast::environment::Environment;

    #[test]
    fn test_parse_integer_constant() {
        let source = "123";
        let mut parser = Parser::new(source).expect("Failed to create parser");
        let ast = parser.parse_expression().expect("Failed to parse");
        
        if let UntypedKind::Constant(Value::Int(val)) = ast.kind {
            assert_eq!(val, 123);
        } else {
            panic!("Expected Integer constant, got {:?}", ast.kind);
        }
    }

    #[test]
    fn test_parse_negative_integer() {
        let source = "-42";
        let mut parser = Parser::new(source).expect("Failed to create parser");
        let ast = parser.parse_expression().expect("Failed to parse");
        
        if let UntypedKind::Constant(Value::Int(val)) = ast.kind {
            assert_eq!(val, -42);
        } else {
            panic!("Expected Integer constant, got {:?}", ast.kind);
        }
    }

    #[test]
    fn test_parse_float_constant() {
        let source = "123.45";
        let mut parser = Parser::new(source).expect("Failed to create parser");
        let ast = parser.parse_expression().expect("Failed to parse");
        
        if let UntypedKind::Constant(Value::Float(val)) = ast.kind {
            assert_eq!(val, 123.45);
        } else {
            panic!("Expected Float constant, got {:?}", ast.kind);
        }
    }

    #[test]
    fn test_parse_negative_float() {
        let source = "-10.5";
        let mut parser = Parser::new(source).expect("Failed to create parser");
        let ast = parser.parse_expression().expect("Failed to parse");
        
        if let UntypedKind::Constant(Value::Float(val)) = ast.kind {
            assert_eq!(val, -10.5);
        } else {
            panic!("Expected Float constant, got {:?}", ast.kind);
        }
    }

    #[test]
    fn test_closure_modification_from_source() {
        let source = r#"
        (do
            (def x 10)
            (def f (fn [] (assign x 20)))
            (f)
            x
        )
        "#;

        let env = Environment::new();
        let compiled = env.compile(source).expect("Failed to compile");
        let linked = env.link(compiled);
        let result = env.run(&linked);

        match result {
            Ok(Value::Int(val)) => assert_eq!(val, 20, "Closure should modify outer variable"),
            Ok(val) => panic!("Expected Int(20), got {:?}", val),
            Err(e) => panic!("VM Error: {}", e),
        }
    }

    #[test]
    fn test_examples() {
        let results = crate::utils::tester::run_functional_tests();
        for res in results {
            assert!(res.success, "Example {} failed: {}", res.name, res.message);
        }
    }

    #[test]
    fn test_debug_mode_logging() {
        let env = Environment::new();
        let source = "(+ 10 20)";
        let result = env.run_debug(source).expect("Failed to run debug");
        
        let (val, logs) = result;
        
        // 1. Check value
        match val {
            Ok(Value::Int(30)) => (),
            _ => panic!("Expected Int(30), got {:?}", val),
        }

        // 2. Check logs (should have entries for + and constants)
        assert!(!logs.is_empty(), "Logs should not be empty");
        
        // Look for typical trace patterns
        let has_call = logs.iter().any(|l| l.contains("CALL"));
        let has_const = logs.iter().any(|l| l.contains("CONST(10)"));
        let has_result = logs.iter().any(|l| l.contains("} -> 30"));

        assert!(has_call, "Logs should contain CALL");
        assert!(has_const, "Logs should contain CONST(10)");
        assert!(has_result, "Logs should contain result 30");
    }

    #[test]
    fn test_rtl_operators() {
        let env = Environment::new();
        
        // --- Arithmetic ---
        assert_eq!(format!("{}", env.run_script("(+ 10 20)").unwrap()), "30");
        assert_eq!(format!("{}", env.run_script("(- 20 10)").unwrap()), "10");
        assert_eq!(format!("{}", env.run_script("(* 10 20)").unwrap()), "200");
        assert_eq!(format!("{}", env.run_script("(/ 20 10)").unwrap()), "2");
        assert_eq!(format!("{}", env.run_script("(// 20 3)").unwrap()), "6"); // 20 // 3 = 6
        assert_eq!(format!("{}", env.run_script("(% 20 3)").unwrap()), "2"); // 20 % 3 = 2
        
        // --- Logic / Bitwise ---
        assert_eq!(format!("{}", env.run_script("(and true false)").unwrap()), "false");
        assert_eq!(format!("{}", env.run_script("(or true false)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(xor true false)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(not true)").unwrap()), "false");
        
        assert_eq!(format!("{}", env.run_script("(<< 1 2)").unwrap()), "4"); // 1 << 2 = 4
        assert_eq!(format!("{}", env.run_script("(>> 4 1)").unwrap()), "2"); // 4 >> 1 = 2
        assert_eq!(format!("{}", env.run_script("(and 3 1)").unwrap()), "1"); // 3 & 1 = 1
        
        // --- Comparison ---
        assert_eq!(format!("{}", env.run_script("(= 10 10)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(= 10 20)").unwrap()), "false");
        assert_eq!(format!("{}", env.run_script("(<> 10 20)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(< 10 20)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(> 10 20)").unwrap()), "false");
        assert_eq!(format!("{}", env.run_script("(<= 10 10)").unwrap()), "true");
        assert_eq!(format!("{}", env.run_script("(>= 10 10)").unwrap()), "true");

        // --- NaN ---
        assert_eq!(format!("{}", env.run_script("NaN").unwrap()), "NaN");
    }

    #[test]
    fn test_date_parsing() {
        let env = Environment::new();
        let res = env.run_script("(date \"2023-01-01\")").unwrap();
        if let Value::DateTime(_) = res {
            // OK
        } else {
            panic!("Expected DateTime, got {:?}", res);
        }
    }

    #[test]
    fn test_dynamic_call_destructuring_underflow() {
        let env = Environment::new();
        let source = "(do 
            (def call-dynamic (fn [f data] (f data)))
            (def data [10 [20 30]])
            (def x (fn [[a [b c]]] (+ a (+ b c))))
            (call-dynamic x data))";
        
        let result = env.run_script(source);
        if let Err(e) = &result {
             panic!("Failed: {}", e);
        }
        assert_eq!(format!("{}", result.unwrap()), "60");
    }
}