use std::str::FromStr;

use anyhow::Result;
use ethereum_types::U256;

use crate::cpu::kernel::aggregator::combined_kernel;
use crate::cpu::kernel::assembler::Kernel;
use crate::cpu::kernel::interpreter::run_with_kernel;
use crate::cpu::kernel::tests::u256ify;

fn test_valid_ecrecover(
    hash: &str,
    v: &str,
    r: &str,
    s: &str,
    expected: &str,
    kernel: &Kernel,
) -> Result<()> {
    let ecrecover = kernel.global_labels["ecrecover"];
    let initial_stack = u256ify(["0xdeadbeef", s, r, v, hash])?;
    let stack = run_with_kernel(kernel, ecrecover, initial_stack)?
        .stack()
        .to_vec();
    assert_eq!(stack[0], U256::from_str(expected).unwrap());

    Ok(())
}

fn test_invalid_ecrecover(hash: &str, v: &str, r: &str, s: &str, kernel: &Kernel) -> Result<()> {
    let ecrecover = kernel.global_labels["ecrecover"];
    let initial_stack = u256ify(["0xdeadbeef", s, r, v, hash])?;
    let stack = run_with_kernel(kernel, ecrecover, initial_stack)?
        .stack()
        .to_vec();
    assert_eq!(stack, vec![U256::MAX]);

    Ok(())
}

#[test]
fn test_ecrecover() -> Result<()> {
    let kernel = combined_kernel();

    test_valid_ecrecover(
        "0x55f77e8909b1f1c9531c4a309bb2d40388e9ed4b87830c8f90363c6b36255fb9",
        "0x1b",
        "0xd667c5a20fa899b253924099e10ae92998626718585b8171eb98de468bbebc",
        "0x58351f48ce34bf134ee611fb5bf255a5733f0029561d345a7d46bfa344b60ac0",
        "0x67f3c0Da351384838d7F7641AB0fCAcF853E1844",
        &kernel,
    )?;
    test_valid_ecrecover(
        "0x55f77e8909b1f1c9531c4a309bb2d40388e9ed4b87830c8f90363c6b36255fb9",
        "0x1c",
        "0xd667c5a20fa899b253924099e10ae92998626718585b8171eb98de468bbebc",
        "0x58351f48ce34bf134ee611fb5bf255a5733f0029561d345a7d46bfa344b60ac0",
        "0xaA58436DeABb64982a386B2De1A8015AA28fCCc0",
        &kernel,
    )?;
    test_valid_ecrecover(
        "0x0",
        "0x1c",
        "0x1",
        "0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
        "0x3344c6f6eeCA588be132142DB0a32C71ABFAAe7B",
        &kernel,
    )?;

    test_invalid_ecrecover(
        "0x0",
        "0x42", // v not in {27,28}
        "0x1",
        "0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
        &kernel,
    )?;
    test_invalid_ecrecover(
        "0x0",
        "0x42",
        "0xd667c5a20fa899b253924099e10ae92998626718585b8171eb98de468bbebc",
        "0x0", // s=0
        &kernel,
    )?;
    test_invalid_ecrecover(
        "0x0",
        "0x42",
        "0x0", // r=0
        "0xd667c5a20fa899b253924099e10ae92998626718585b8171eb98de468bbebc",
        &kernel,
    )?;
    test_invalid_ecrecover(
        "0x0",
        "0x1c",
        "0x3a18b21408d275dde53c0ea86f9c1982eca60193db0ce15008fa408d43024847", // r^3 + 7 isn't a square
        "0x5db9745f44089305b2f2c980276e7025a594828d878e6e36dd2abd34ca6b9e3d",
        &kernel,
    )?;

    Ok(())
}