use std::sync::Arc;

use oxide_compiler::compiler::Compiler;
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();
    match vm.run(&Arc::new(module)) {
        Ok(result) => format!("{result}"),
        Err(e) => format!("vm error: {e}"),
    }
}

/// 求值并取字符串结果内容（字符串值走 lookup_str，非字符串走 Display）。
fn eval_str(source: &str) -> String {
    let allocator = Allocator::default();
    let program = oxide_parser::parse(&allocator, source).expect("parse ok");
    let module = Compiler::new().compile(&program).expect("compile ok");
    let mut vm = Vm::new();
    let val = vm.run(&Arc::new(module)).expect("run ok");
    if val.is_string() {
        vm.lookup_str(val).unwrap_or_default()
    } else {
        format!("{val}")
    }
}

#[test]
fn eval_arithmetic_add() {
    assert_eq!(eval("1 + 2"), "3");
}

#[test]
fn eval_arithmetic_sub() {
    assert_eq!(eval("5 - 3"), "2");
}

#[test]
fn eval_arithmetic_mul() {
    assert_eq!(eval("3 * 4"), "12");
}

#[test]
fn eval_arithmetic_div() {
    assert_eq!(eval("10 / 2"), "5");
}

#[test]
fn eval_arithmetic_mod() {
    assert_eq!(eval("7 % 3"), "1");
}

#[test]
fn eval_precedence() {
    assert_eq!(eval("1 * 2 + 3"), "5");
}

#[test]
fn eval_negation() {
    assert_eq!(eval("-5"), "-5");
}

#[test]
fn eval_division_by_zero() {
    assert_eq!(eval("1 / 0"), "Infinity");
}

#[test]
fn eval_string_concat() {
    assert_eq!(eval("1 + 2 + 3"), "6");
}

#[test]
fn eval_string_concat_negative_double_appends() {
    // 非空缓冲 + ryu 路径负数：负号紧跟当前数值追加，不插到整个结果最前。
    assert_eq!(eval_str("\"a\" + -1.5"), "a-1.5");
    assert_eq!(eval_str("\"a\" + (-1e21)"), "a-1e+21");
    // 整数负数（int 直写）与整数 double 快路径负数同样追加正确。
    assert_eq!(eval_str("\"a\" + -42"), "a-42");
    assert_eq!(eval_str("\"a\" + (-42.0)"), "a-42");
    // ≥2^53 可精确表示整数负数（2^53+2）落 ryu 定点路径，追加语义保持一致。
    assert_eq!(eval_str("\"a\" + -9007199254740994"), "a-9007199254740994");
}

#[test]
fn eval_compound_add() {
    assert_eq!(eval("var x=5; x+=3; x"), "8");
}

#[test]
fn eval_compound_sub() {
    assert_eq!(eval("var x=10; x-=4; x"), "6");
}

#[test]
fn eval_compound_mul() {
    assert_eq!(eval("var x=2; x*=3; x"), "6");
}

#[test]
fn eval_compound_div() {
    assert_eq!(eval("var x=10; x/=2; x"), "5");
}

#[test]
fn eval_compound_mod() {
    assert_eq!(eval("var x=7; x%=3; x"), "1");
}

#[test]
fn eval_compound_exp() {
    assert_eq!(eval("var x=2; x**=3; x"), "8");
}

#[test]
fn eval_binary_exp() {
    assert_eq!(eval("2 ** 3"), "8");
    assert_eq!(eval("2 ** 10"), "1024");
    assert_eq!(eval("2 ** -1"), "0.5");
    assert_eq!(eval("4 ** 0.5"), "2");
}

#[test]
fn eval_exp_edge_cases() {
    assert_eq!(eval("0 ** 0"), "1");
    assert_eq!(eval("(-2) ** 3"), "-8");
    assert_eq!(eval("(-2) ** 2"), "4");
    assert_eq!(eval("(-2) ** 0.5"), "NaN");
    assert_eq!(eval("NaN ** 0"), "1");
    assert_eq!(eval("2 ** Infinity"), "Infinity");
    assert_eq!(eval("2.5 ** 2"), "6.25");
}

#[test]
fn eval_exp_bigint() {
    assert_eq!(eval("2n ** 3n"), "BigInt(8)");
    assert_eq!(eval("2n ** 0n"), "BigInt(1)");
    assert_eq!(eval("0n ** 0n"), "BigInt(1)");
}

#[test]
fn eval_exp_bigint_negative_exponent_throws() {
    // BigInt::exponentiate 禁止负指数，抛 RangeError（规范 §6.1.6.1.19）。
    let err = eval("2n ** -1n");
    assert!(err.contains("RangeError"), "expected RangeError, got: {err}");
}

#[test]
fn eval_exp_mixed_bigint_number_throws() {
    // ToNumeric 类型不一致：Number 与 BigInt 混合幂抛 TypeError（与 ADD/SUB 同）。
    let err = eval("2 ** 2n");
    assert!(err.contains("TypeError"), "expected TypeError, got: {err}");
    let err2 = eval("2n ** 2");
    assert!(err2.contains("TypeError"), "expected TypeError, got: {err2}");
}

#[test]
fn eval_exp_compound_bigint() {
    // 复合 **= 与二元 ** 共享幂语义（BigInt 结果保持 BigInt，不再降 f64）。
    assert_eq!(eval("var x = 2n; x **= 3n; x"), "BigInt(8)");
    let err = eval("var x = 2n; x **= 3; x");
    assert!(err.contains("TypeError"), "expected TypeError, got: {err}");
}

#[test]
fn eval_compound_add_expr_value() {
    assert_eq!(eval("var x=5; x+=3"), "8");
}

#[test]
fn eval_compound_undefined() {
    assert_eq!(eval("var x; x+=1; x"), "NaN");
}

#[test]
fn eval_bitwise_direct_ops() {
    assert_eq!(eval("5 & 3"), "1");
    assert_eq!(eval("5 | 2"), "7");
    assert_eq!(eval("5 ^ 1"), "4");
    assert_eq!(eval("1 << 3"), "8");
    assert_eq!(eval("-8 >> 1"), "-4");
    assert_eq!(eval("-1 >>> 0"), "4294967295");
    assert_eq!(eval("~0"), "-1");
}

#[test]
fn eval_bitwise_coercion() {
    assert_eq!(eval("'3' | 0"), "3");
    assert_eq!(eval("'x' | 0"), "0");
    assert_eq!(eval("undefined | 0"), "0");
    assert_eq!(eval("NaN | 0"), "0");
    assert_eq!(eval("1.9 | 0"), "1");
    assert_eq!(eval("-1.9 | 0"), "-1");
}

#[test]
fn eval_shift_masking() {
    assert_eq!(eval("1 << 32"), "1");
    assert_eq!(eval("1 << 33"), "2");
    assert_eq!(eval("8 >> 33"), "4");
}

#[test]
fn eval_ushr_boundaries() {
    assert_eq!(eval("2147483647 >>> 0"), "2147483647");
    assert_eq!(eval("2147483648 >>> 0"), "2147483648");
    assert_eq!(eval("-1 >>> 1"), "2147483647");
}

#[test]
fn eval_compound_bitwise_ops() {
    assert_eq!(eval("var x=5; x &= 3; x"), "1");
    assert_eq!(eval("var x=5; x |= 2; x"), "7");
    assert_eq!(eval("var x=5; x ^= 1; x"), "4");
    assert_eq!(eval("var x=1; x <<= 5; x"), "32");
    assert_eq!(eval("var x=-8; x >>= 1; x"), "-4");
    assert_eq!(eval("var x=-1; x >>>= 0; x"), "4294967295");
}

#[test]
fn eval_bitwise_in_control_flow() {
    assert_eq!(eval("var x=3; if ((x & 1) == 1) { 7 } else { 9 }"), "7");
}