use std::process::Command;

use rpki::validation::cert_path::{CertPathError, validate_ee_cert_path};

fn openssl_available() -> bool {
    Command::new("openssl")
        .arg("version")
        .output()
        .map(|o| o.status.success())
        .unwrap_or(false)
}

fn run(cmd: &mut Command) {
    let out = cmd.output().expect("run command");
    if !out.status.success() {
        panic!(
            "command failed: {:?}\nstdout={}\nstderr={}",
            cmd,
            String::from_utf8_lossy(&out.stdout),
            String::from_utf8_lossy(&out.stderr)
        );
    }
}

struct Generated {
    issuer_ca_der: Vec<u8>,
    ee_der: Vec<u8>,
    issuer_crl_der: Vec<u8>,
}

fn generate_issuer_ca_ee_and_crl(ee_ext: &str) -> Generated {
    assert!(openssl_available(), "openssl is required for this test");

    let td = tempfile::tempdir().expect("tempdir");
    let dir = td.path();

    std::fs::create_dir_all(dir.join("newcerts")).expect("newcerts");
    std::fs::write(dir.join("index.txt"), b"").expect("index");
    std::fs::write(dir.join("serial"), b"1000\n").expect("serial");
    std::fs::write(dir.join("crlnumber"), b"1000\n").expect("crlnumber");

    let cnf = format!(
        r#"
[ ca ]
default_ca = CA_default

[ CA_default ]
dir = {dir}
database = $dir/index.txt
new_certs_dir = $dir/newcerts
certificate = $dir/issuer.pem
private_key = $dir/issuer.key
serial = $dir/serial
crlnumber = $dir/crlnumber
default_md = sha256
default_days = 365
default_crl_days = 1
policy = policy_any
x509_extensions = v3_issuer_ca
crl_extensions = crl_ext
unique_subject = no
copy_extensions = none

[ policy_any ]
commonName = supplied

[ req ]
prompt = no
distinguished_name = dn

[ dn ]
CN = Test Issuer CA

[ v3_issuer_ca ]
basicConstraints = critical,CA:true
keyUsage = critical, keyCertSign, cRLSign
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always

[ v3_ee ]
basicConstraints = critical,CA:false
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always
crlDistributionPoints = URI:rsync://example.test/repo/issuer/issuer.crl
authorityInfoAccess = caIssuers;URI:rsync://example.test/repo/issuer/issuer.cer
{ee_ext}

[ crl_ext ]
authorityKeyIdentifier = keyid:always
"#,
        dir = dir.display(),
        ee_ext = ee_ext
    );
    std::fs::write(dir.join("openssl.cnf"), cnf.as_bytes()).expect("write cnf");

    run(
        Command::new("openssl")
            .arg("genrsa")
            .arg("-out")
            .arg(dir.join("issuer.key"))
            .arg("2048"),
    );
    run(
        Command::new("openssl")
            .arg("req")
            .arg("-new")
            .arg("-x509")
            .arg("-sha256")
            .arg("-days")
            .arg("365")
            .arg("-key")
            .arg(dir.join("issuer.key"))
            .arg("-config")
            .arg(dir.join("openssl.cnf"))
            .arg("-extensions")
            .arg("v3_issuer_ca")
            .arg("-out")
            .arg(dir.join("issuer.pem")),
    );

    run(
        Command::new("openssl")
            .arg("genrsa")
            .arg("-out")
            .arg(dir.join("ee.key"))
            .arg("2048"),
    );
    run(
        Command::new("openssl")
            .arg("req")
            .arg("-new")
            .arg("-key")
            .arg(dir.join("ee.key"))
            .arg("-subj")
            .arg("/CN=Test EE")
            .arg("-out")
            .arg(dir.join("ee.csr")),
    );

    run(
        Command::new("openssl")
            .arg("ca")
            .arg("-batch")
            .arg("-config")
            .arg(dir.join("openssl.cnf"))
            .arg("-in")
            .arg(dir.join("ee.csr"))
            .arg("-extensions")
            .arg("v3_ee")
            .arg("-out")
            .arg(dir.join("ee.pem")),
    );

    run(
        Command::new("openssl")
            .arg("x509")
            .arg("-in")
            .arg(dir.join("issuer.pem"))
            .arg("-outform")
            .arg("DER")
            .arg("-out")
            .arg(dir.join("issuer.cer")),
    );
    run(
        Command::new("openssl")
            .arg("x509")
            .arg("-in")
            .arg(dir.join("ee.pem"))
            .arg("-outform")
            .arg("DER")
            .arg("-out")
            .arg(dir.join("ee.cer")),
    );

    run(
        Command::new("openssl")
            .arg("ca")
            .arg("-gencrl")
            .arg("-config")
            .arg(dir.join("openssl.cnf"))
            .arg("-out")
            .arg(dir.join("issuer.crl.pem")),
    );
    run(
        Command::new("openssl")
            .arg("crl")
            .arg("-in")
            .arg(dir.join("issuer.crl.pem"))
            .arg("-outform")
            .arg("DER")
            .arg("-out")
            .arg(dir.join("issuer.crl")),
    );

    Generated {
        issuer_ca_der: std::fs::read(dir.join("issuer.cer")).expect("read issuer der"),
        ee_der: std::fs::read(dir.join("ee.cer")).expect("read ee der"),
        issuer_crl_der: std::fs::read(dir.join("issuer.crl")).expect("read crl der"),
    }
}

#[test]
fn ee_key_usage_digital_signature_only_is_accepted() {
    let g = generate_issuer_ca_ee_and_crl("keyUsage = critical, digitalSignature\n");
    let now = time::OffsetDateTime::now_utc();
    validate_ee_cert_path(&g.ee_der, &g.issuer_ca_der, &g.issuer_crl_der, None, None, now)
        .expect("valid EE path");
}

#[test]
fn ee_key_usage_missing_is_rejected() {
    let g = generate_issuer_ca_ee_and_crl("");
    let now = time::OffsetDateTime::now_utc();
    let err = validate_ee_cert_path(&g.ee_der, &g.issuer_ca_der, &g.issuer_crl_der, None, None, now)
        .unwrap_err();
    assert!(matches!(err, CertPathError::KeyUsageMissing), "{err}");
}

#[test]
fn ee_key_usage_not_critical_is_rejected() {
    let g = generate_issuer_ca_ee_and_crl("keyUsage = digitalSignature\n");
    let now = time::OffsetDateTime::now_utc();
    let err = validate_ee_cert_path(&g.ee_der, &g.issuer_ca_der, &g.issuer_crl_der, None, None, now)
        .unwrap_err();
    assert!(matches!(err, CertPathError::KeyUsageNotCritical), "{err}");
}

#[test]
fn ee_key_usage_wrong_bits_is_rejected() {
    let g = generate_issuer_ca_ee_and_crl("keyUsage = critical, digitalSignature, keyEncipherment\n");
    let now = time::OffsetDateTime::now_utc();
    let err = validate_ee_cert_path(&g.ee_der, &g.issuer_ca_der, &g.issuer_crl_der, None, None, now)
        .unwrap_err();
    assert!(matches!(err, CertPathError::KeyUsageInvalidBits), "{err}");
}