use std::sync::Arc;

use oxide_compiler::compiler::Compiler;
use oxide_compiler::DefaultCompilerService;
use oxide_kernel::kernel::{KernelConfig, KernelCore};
use oxide_parser::Allocator;
use oxide_vm::vm::Vm;

fn eval(source: &str) -> String {
    let allocator = Allocator::default();
    let program = match oxide_parser::parse(&allocator, source) {
        Ok(p) => p,
        Err(e) => return format!("parse error: {}", e[0].message),
    };
    let module = match Compiler::new().compile(&program) {
        Ok(m) => m,
        Err(e) => return format!("compile error: {e}"),
    };
    let mut vm = Vm::new();
    vm.set_compiler_service(Arc::new(DefaultCompilerService));
    match vm.run(&Arc::new(module)) {
        Ok(result) => format!("{result}"),
        Err(e) => format!("vm error: {e}"),
    }
}

fn eval_with_kernel(source: &str, kernel: Arc<KernelCore>) -> String {
    let allocator = Allocator::default();
    let program = match oxide_parser::parse(&allocator, source) {
        Ok(p) => p,
        Err(e) => return format!("parse error: {}", e[0].message),
    };
    let module = match Compiler::new().compile(&program) {
        Ok(m) => m,
        Err(e) => return format!("compile error: {e}"),
    };
    let mut vm = Vm::with_kernel_core(kernel);
    vm.set_compiler_service(Arc::new(DefaultCompilerService));
    match vm.run(&Arc::new(module)) {
        Ok(result) => format!("{result}"),
        Err(e) => format!("vm error: {e}"),
    }
}

#[test]
fn regression_to_boolean_empty_string() {
    assert_eq!(eval("!''"), "true", "NOT empty string should be true");
    assert_eq!(eval("if ('') { 1 } else { 2 }"), "2", "empty string should be falsy");
}

#[test]
fn regression_rerun_clears_ic_cache() {
    let allocator = Allocator::default();
    let source = "var o = {a: 1}; o.a";
    let program = oxide_parser::parse(&allocator, source).expect("parse");
    let module = Compiler::new().compile(&program).expect("compile");
    let mut vm = Vm::new();
    vm.set_compiler_service(Arc::new(DefaultCompilerService));
    assert_eq!(format!("{}", vm.run(&Arc::new(module)).unwrap()), "1");

    let source2 = "var o = {a: 2}; o.a";
    let program2 = oxide_parser::parse(&allocator, source2).expect("parse");
    let module2 = Compiler::new().compile(&program2).expect("compile");
    vm.run(&Arc::new(module2)).unwrap();
    assert_eq!(
        format!("{}", vm.rerun().unwrap()),
        "2",
        "rerun should re-read IC-cached property, not stale value from previous run"
    );
}

#[test]
fn regression_recursion_depth_limit() {
    let result = eval("function f(){f()} f()");
    assert!(result.contains("RangeError"), "expected RangeError, got: {result}");
    assert!(
        result.contains("Maximum call stack size exceeded"),
        "expected stack limit message, got: {result}"
    );
}

#[test]
fn regression_throw_statement_errors() {
    let result = eval("throw 'error'");
    assert!(result.contains("uncaught"), "expected uncaught, got: {result}");
    assert!(
        result.contains("uncaught Error"),
        "expected string throw to default to Error, got: {result}"
    );
}

#[test]
fn regression_throw_statement_preserves_type_error_kind() {
    assert_eq!(eval("try { throw new TypeError('boom') } catch (e) { e.name == 'TypeError' }"), "true");
    assert_eq!(eval("throw new TypeError('boom')"), "vm error: uncaught TypeError: boom");
}

#[test]
fn regression_throw_statement_preserves_syntax_error_kind() {
    assert_eq!(
        eval("try { throw new SyntaxError('boom') } catch (e) { e.name == 'SyntaxError' }"),
        "true"
    );
    assert_eq!(eval("throw new SyntaxError('boom')"), "vm error: uncaught SyntaxError: boom");
}

#[test]
fn regression_for_in_prototype_chain() {
    assert_eq!(
        eval("var c=0;for(var k in {a:1}){c=c+1;}c"),
        "1",
        "for-in must not include non-enumerable prototype properties like constructor"
    );
}

#[test]
fn regression_vm_step_limit_is_configurable() {
    let mut config = KernelConfig::minimal();
    config.max_steps = Some(5);
    let kernel = KernelCore::new(config);
    let result = eval_with_kernel("while (true) {}", kernel);
    assert!(
        result.contains("VM step limit exceeded"),
        "expected configurable step limit error, got: {result}"
    );
}

#[test]
fn regression_new_expression_native_constructor_error_is_catchable() {
    assert_eq!(
        eval("try { new RegExp('['); 0 } catch (e) { 1 }"),
        "1",
        "expected native constructor error to enter catch"
    );
}

#[test]
fn regression_new_expression_bytecode_constructor_error_is_catchable() {
    assert_eq!(
        eval("try { class C { constructor() { throw new Error('boom') } } new C(); 0 } catch (e) { 1 }"),
        "1",
        "expected bytecode class constructor error to enter catch"
    );
}

#[test]
fn regression_delete_static_property_returns_true() {
    assert_eq!(eval("var o={x:1}; delete o.x"), "true");
    assert_eq!(eval("var o={x:1}; delete o.x; o.x"), "undefined");
}

#[test]
fn regression_delete_dynamic_property_returns_true() {
    assert_eq!(eval("var o={x:1}; delete o['x']"), "true");
    assert_eq!(eval("var o={x:1}; var k='x'; delete o[k]; o.x"), "undefined");
}

#[test]
fn regression_large_expression_no_register_overflow() {
    let expr = std::iter::repeat("1").take(40).collect::<Vec<_>>().join(" + ");
    let source = format!("function f() {{ return {expr}; }} f()");
    assert_eq!(eval(&source), "40");
}

#[test]
fn regression_many_declarations_keep_stable_registers() {
    let decls = (0..120).map(|i| format!("var v{i} = {i};")).collect::<Vec<_>>().join("");
    let source = format!("{decls} v0 + v57 + v119");
    assert_eq!(eval(&source), "176");
}

#[test]
fn regression_method_call_receiver_survives_register_reuse() {
    assert_eq!(eval("var o = { x: 41, f: function() { return this.x + 1; } }; o.f()"), "42");
}

#[test]
fn test_recursive_getter_throws_range_error() {
    let result = eval("function f(){ return f(); } f()");
    assert!(
        result.contains("Maximum call stack size exceeded"),
        "expected catchable RangeError, got: {result}"
    );
}

/// 浅调用深度配置下执行源码：NEW/NEW_SPREAD 深递归无需堆满默认 1024 层即可命中
/// 深度上限，输出与 `eval` 同构（字符串结果取其内容）。
fn eval_shallow(source: &str, depth: usize) -> String {
    let allocator = Allocator::default();
    let program = oxide_parser::parse(&allocator, source).unwrap();
    let module = Compiler::new().compile(&program).unwrap();
    let mut cfg = KernelConfig::minimal();
    cfg.max_call_depth = depth;
    let mut vm = Vm::with_kernel_core(KernelCore::new(cfg));
    vm.set_compiler_service(Arc::new(DefaultCompilerService));
    match vm.run(&Arc::new(module)) {
        Ok(val) => {
            if val.is_string() {
                vm.lookup_str(val).unwrap_or_default().to_string()
            } else {
                format!("{val}")
            }
        }
        Err(e) => format!("vm error: {e}"),
    }
}

#[test]
fn test_new_deep_recursion_throws_catchable_range_error() {
    // NEW 深递归经统一压帧入口抛可捕获 RangeError：try/catch 能接住（非引擎错误）。
    let result = eval_shallow(
        "function f(){ return new f(); } try { f(); 'no-throw'; } catch(e){ 'caught:'+e.name; }",
        8,
    );
    assert_eq!(result, "caught:RangeError", "NEW 深递归应可捕获，got: {result}");
}

#[test]
fn test_new_spread_deep_recursion_throws_catchable_range_error() {
    // NEW_SPREAD 深递归与普通 NEW 同构：构造路径统一收敛到压帧入口的深度检查，
    // 不得再走显式引擎 Err（不可捕获）。spread 变体与普通路径行为须一致。
    let result = eval_shallow(
        "function f(){ return new f(...[1]); } try { f(); 'no-throw'; } catch(e){ 'caught:'+e.name; }",
        8,
    );
    assert_eq!(result, "caught:RangeError", "NEW_SPREAD 深递归应可捕获，got: {result}");
}

#[test]
fn test_array_length_range_error() {
    // 2^32-1 是合法数组长度：逻辑长度记覆盖位，物理区按稠密上限钳位。
    let result = eval("new Array(4294967295).length");
    assert_eq!(result, "4294967295", "2^32-1 合法长度，got: {result}");
    let result = eval("new Array(-1)");
    assert!(result.contains("Invalid array length"), "expected invalid length, got: {result}");
}

#[test]
fn test_huge_array_index_bounded() {
    let result = eval("var a=[]; a[2147483648]=1; 1");
    assert_eq!(result, "1");
}

#[test]
fn test_string_pad_bounded() {
    let result = eval("''.padStart(2147483648)");
    assert!(result.contains("Invalid string length"), "expected invalid string length, got: {result}");
    assert_eq!(eval("'x'.padStart(5,'0') == '0000x'"), "true");
}

#[test]
fn test_typed_array_survives_promote_reset() {
    assert_eq!(eval("var a=new Int32Array(4); a.fill(7); a.at(0)"), "7");
    assert_eq!(
        eval("var b=new ArrayBuffer(8); var d=new DataView(b); d.setInt32(0, 42); d.getInt32(0)"),
        "42"
    );
}

#[test]
fn test_flat_infinity_bounded() {
    assert_eq!(eval("[1,[2,[3,[4]]]].flat(Infinity).length"), "4");
}

#[test]
fn regression_bounded_object_numeric_coercion() {
    assert_eq!(eval("+new Number(1)"), "1");
    assert_eq!(eval("+new Boolean(true)"), "1");
    assert_eq!(eval("new Boolean(false) | 0"), "0");
    assert_eq!(eval("+({ valueOf: function() { return 7; } })"), "7");
    assert_eq!(eval("+({ toString: function() { return '9'; } })"), "9");
    assert_eq!(
        eval("+({ valueOf: function() { return {}; }, toString: function() { return {}; } })"),
        "vm error: uncaught TypeError: Cannot convert object to primitive value"
    );
    assert_eq!(
        eval("+({ valueOf: function() { throw new RangeError('coerce'); } })"),
        "vm error: uncaught RangeError: coerce"
    );
}