// EXTREME Coverage Test Suite for Runtime Environment
// Target: Maximum runtime coverage
// Sprint 80: ALL NIGHT Coverage Marathon Phase 12

use ruchy::runtime::{Binding, Environment, Scope, Value};
use std::collections::HashMap;
use std::rc::Rc;

// Environment tests
#[test]
fn test_environment_new() {
    let _env = Environment::new();
    assert!(true);
}

#[test]
fn test_environment_default() {
    let _env = Environment::default();
    assert!(true);
}

#[test]
fn test_environment_with_capacity() {
    let _env = Environment::with_capacity(100);
    assert!(true);
}

// Binding tests
#[test]
fn test_binding_immutable() {
    let binding = Binding {
        value: Value::Integer(42),
        mutable: false,
    };
    assert!(!binding.mutable);
    assert_eq!(binding.value, Value::Integer(42));
}

#[test]
fn test_binding_mutable() {
    let binding = Binding {
        value: Value::String(Rc::new("hello".to_string())),
        mutable: true,
    };
    assert!(binding.mutable);
}

// Scope tests
#[test]
fn test_scope_new() {
    let _scope = Scope::new();
    assert!(true);
}

#[test]
fn test_scope_with_parent() {
    let parent = Rc::new(Scope::new());
    let _child = Scope::with_parent(parent);
    assert!(true);
}

// Define and lookup
#[test]
fn test_define_and_lookup() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(42), false);

    let value = env.lookup("x");
    assert!(value.is_some());
    assert_eq!(value, Some(&Value::Integer(42)));
}

#[test]
fn test_define_mutable() {
    let mut env = Environment::new();
    env.define("mut_var", Value::Bool(true), true);

    let value = env.lookup("mut_var");
    assert_eq!(value, Some(&Value::Bool(true)));
}

#[test]
fn test_lookup_undefined() {
    let env = Environment::new();
    let value = env.lookup("undefined");
    assert_eq!(value, None);
}

// Set value
#[test]
fn test_set_mutable_binding() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(1), true);

    let result = env.set("x", Value::Integer(2));
    assert!(result.is_ok());

    let value = env.lookup("x");
    assert_eq!(value, Some(&Value::Integer(2)));
}

#[test]
fn test_set_immutable_binding() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(1), false);

    let result = env.set("x", Value::Integer(2));
    assert!(result.is_err());
}

#[test]
fn test_set_undefined_variable() {
    let mut env = Environment::new();
    let result = env.set("undefined", Value::Integer(42));
    assert!(result.is_err());
}

// Scoping
#[test]
fn test_push_scope() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(1), false);

    env.push_scope();
    env.define("x", Value::Integer(2), false);

    let value = env.lookup("x");
    assert_eq!(value, Some(&Value::Integer(2)));
}

#[test]
fn test_pop_scope() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(1), false);

    env.push_scope();
    env.define("x", Value::Integer(2), false);
    env.pop_scope();

    let value = env.lookup("x");
    assert_eq!(value, Some(&Value::Integer(1)));
}

#[test]
fn test_nested_scopes() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(0), false);

    for i in 1..=5 {
        env.push_scope();
        env.define("x", Value::Integer(i), false);
    }

    for i in (1..=5).rev() {
        let value = env.lookup("x");
        assert_eq!(value, Some(&Value::Integer(i)));
        env.pop_scope();
    }

    let value = env.lookup("x");
    assert_eq!(value, Some(&Value::Integer(0)));
}

// Value types
#[test]
fn test_value_integer() {
    let val = Value::Integer(42);
    assert_eq!(val, Value::Integer(42));
}

#[test]
fn test_value_float() {
    let val = Value::Float(3.14);
    assert_eq!(val, Value::Float(3.14));
}

#[test]
fn test_value_string() {
    let val = Value::String(Rc::new("hello".to_string()));
    assert_eq!(val, Value::String(Rc::new("hello".to_string())));
}

#[test]
fn test_value_bool() {
    let val = Value::Bool(true);
    assert_eq!(val, Value::Bool(true));
}

#[test]
fn test_value_unit() {
    let val = Value::Unit;
    assert_eq!(val, Value::Unit);
}

#[test]
fn test_value_list() {
    let list = vec![Value::Integer(1), Value::Integer(2), Value::Integer(3)];
    let val = Value::List(Rc::new(list));
    assert!(matches!(val, Value::List(_)));
}

#[test]
fn test_value_object() {
    let mut map = HashMap::new();
    map.insert("x".to_string(), Value::Integer(10));
    map.insert("y".to_string(), Value::Integer(20));
    let val = Value::Object(Rc::new(map));
    assert!(matches!(val, Value::Object(_)));
}

#[test]
fn test_value_function() {
    let func = |_args: Vec<Value>| -> Result<Value, String> { Ok(Value::Integer(42)) };
    let val = Value::Function(Rc::new(func));
    assert!(matches!(val, Value::Function(_)));
}

// Value operations
#[test]
fn test_value_equality() {
    assert_eq!(Value::Integer(42), Value::Integer(42));
    assert_ne!(Value::Integer(42), Value::Integer(43));
    assert_ne!(Value::Integer(42), Value::String(Rc::new("42".to_string())));
}

#[test]
fn test_value_display() {
    let val = Value::Integer(42);
    let s = format!("{}", val);
    assert!(s.contains("42"));
}

// Environment with multiple bindings
#[test]
fn test_multiple_bindings() {
    let mut env = Environment::new();

    for i in 0..100 {
        env.define(&format!("var{}", i), Value::Integer(i), false);
    }

    for i in 0..100 {
        let value = env.lookup(&format!("var{}", i));
        assert_eq!(value, Some(&Value::Integer(i)));
    }
}

// Shadow bindings
#[test]
fn test_shadowing() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(1), false);
    env.define("x", Value::Integer(2), false);

    let value = env.lookup("x");
    assert_eq!(value, Some(&Value::Integer(2)));
}

// Clear environment
#[test]
fn test_clear_environment() {
    let mut env = Environment::new();
    env.define("x", Value::Integer(42), false);
    env.define("y", Value::String(Rc::new("hello".to_string())), false);

    env.clear();

    assert_eq!(env.lookup("x"), None);
    assert_eq!(env.lookup("y"), None);
}

// Stress tests
#[test]
fn test_deep_scope_nesting() {
    let mut env = Environment::new();

    for i in 0..1000 {
        env.push_scope();
        env.define("x", Value::Integer(i), false);
    }

    for _ in 0..1000 {
        env.pop_scope();
    }

    assert!(true);
}

#[test]
fn test_many_environments() {
    let mut envs = vec![];
    for _ in 0..100 {
        envs.push(Environment::new());
    }
    assert_eq!(envs.len(), 100);
}

#[test]
fn test_large_object() {
    let mut map = HashMap::new();
    for i in 0..1000 {
        map.insert(format!("key{}", i), Value::Integer(i));
    }
    let val = Value::Object(Rc::new(map));
    assert!(matches!(val, Value::Object(_)));
}

// Scope chain
#[test]
fn test_scope_chain_lookup() {
    let mut env = Environment::new();
    env.define("global", Value::Integer(0), false);

    env.push_scope();
    env.define("level1", Value::Integer(1), false);

    env.push_scope();
    env.define("level2", Value::Integer(2), false);

    assert_eq!(env.lookup("global"), Some(&Value::Integer(0)));
    assert_eq!(env.lookup("level1"), Some(&Value::Integer(1)));
    assert_eq!(env.lookup("level2"), Some(&Value::Integer(2)));
}

// Function closures
#[test]
fn test_closure_environment() {
    let mut env = Environment::new();
    env.define("captured", Value::Integer(42), false);

    let closure = move |_args: Vec<Value>| -> Result<Value, String> {
        // Would capture the environment
        Ok(Value::Integer(42))
    };

    let val = Value::Function(Rc::new(closure));
    assert!(matches!(val, Value::Function(_)));
}
