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}");
}

#[test]
fn validate_ee_cert_path_with_prevalidated_issuer_covers_success_and_error_paths() {
    use rpki::data_model::common::BigUnsigned;
    use rpki::data_model::crl::RpkixCrl;
    use rpki::data_model::rc::ResourceCertificate;
    use rpki::validation::cert_path::validate_ee_cert_path_with_prevalidated_issuer;
    use std::collections::HashSet;
    use x509_parser::prelude::FromDer;
    use x509_parser::x509::SubjectPublicKeyInfo;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let issuer = ResourceCertificate::decode_der(&g.issuer_ca_der).expect("decode issuer");
    let ee = ResourceCertificate::decode_der(&g.ee_der).expect("decode ee");
    let issuer_crl = RpkixCrl::decode_der(&g.issuer_crl_der).expect("decode crl");
    let (rem, issuer_spki) = SubjectPublicKeyInfo::from_der(&issuer.tbs.subject_public_key_info)
        .expect("parse issuer spki");
    assert!(rem.is_empty());
    let now = time::OffsetDateTime::now_utc();

    validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &issuer,
        &issuer_spki,
        &issuer_crl,
        &HashSet::new(),
        Some("rsync://example.test/repo/issuer/issuer.cer"),
        Some("rsync://example.test/repo/issuer/issuer.crl"),
        now,
    )
    .expect("prevalidated ee path ok");

    let mut revoked = HashSet::new();
    revoked.insert(BigUnsigned::from_biguint(&ee.tbs.serial_number).bytes_be);
    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &issuer,
        &issuer_spki,
        &issuer_crl,
        &revoked,
        Some("rsync://example.test/repo/issuer/issuer.cer"),
        Some("rsync://example.test/repo/issuer/issuer.crl"),
        now,
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::EeRevoked), "{err}");
}

#[test]
fn validate_ee_cert_path_with_prevalidated_issuer_rejects_non_ee_and_non_ca_issuer() {
    use rpki::data_model::crl::RpkixCrl;
    use rpki::data_model::rc::ResourceCertificate;
    use rpki::validation::cert_path::validate_ee_cert_path_with_prevalidated_issuer;
    use std::collections::HashSet;
    use x509_parser::prelude::FromDer;
    use x509_parser::x509::SubjectPublicKeyInfo;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let issuer = ResourceCertificate::decode_der(&g.issuer_ca_der).expect("decode issuer");
    let ee = ResourceCertificate::decode_der(&g.ee_der).expect("decode ee");
    let issuer_crl = RpkixCrl::decode_der(&g.issuer_crl_der).expect("decode crl");
    let (rem, issuer_spki) = SubjectPublicKeyInfo::from_der(&issuer.tbs.subject_public_key_info)
        .expect("parse issuer spki");
    assert!(rem.is_empty());
    let now = time::OffsetDateTime::now_utc();

    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.issuer_ca_der,
        &issuer,
        &issuer_spki,
        &issuer_crl,
        &HashSet::new(),
        None,
        None,
        now,
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::EeNotEe), "{err}");

    let (rem, bad_spki) =
        SubjectPublicKeyInfo::from_der(&ee.tbs.subject_public_key_info).expect("parse ee spki");
    assert!(rem.is_empty());
    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &ee,
        &bad_spki,
        &issuer_crl,
        &HashSet::new(),
        None,
        None,
        now,
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::IssuerNotCa), "{err}");
}

#[test]
fn validate_ee_cert_path_with_prevalidated_issuer_rejects_mismatched_issuer_subject() {
    use rpki::data_model::crl::RpkixCrl;
    use rpki::data_model::rc::ResourceCertificate;
    use rpki::validation::cert_path::validate_ee_cert_path_with_prevalidated_issuer;
    use std::collections::HashSet;
    use x509_parser::prelude::FromDer;
    use x509_parser::x509::SubjectPublicKeyInfo;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let wrong_issuer_der = std::fs::read(
        "tests/fixtures/repository/ca.rg.net/rpki/RGnet-OU/R-lVU1XGsAeqzV1Fv0HjOD6ZFkE.cer",
    )
    .expect("read wrong issuer fixture");
    let wrong_issuer =
        ResourceCertificate::decode_der(&wrong_issuer_der).expect("decode wrong issuer");
    let issuer_crl = RpkixCrl::decode_der(&g.issuer_crl_der).expect("decode crl");
    let (rem, wrong_spki) =
        SubjectPublicKeyInfo::from_der(&wrong_issuer.tbs.subject_public_key_info)
            .expect("parse wrong issuer spki");
    assert!(rem.is_empty());

    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &wrong_issuer,
        &wrong_spki,
        &issuer_crl,
        &HashSet::new(),
        None,
        None,
        time::OffsetDateTime::now_utc(),
    )
    .unwrap_err();
    assert!(
        matches!(err, CertPathError::IssuerSubjectMismatch { .. }),
        "{err}"
    );
}

#[test]
fn validate_ee_cert_path_rejects_non_ee_and_non_ca_issuer() {
    use rpki::data_model::roa::RoaObject;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let roa_der =
        std::fs::read("tests/fixtures/repository/rpki.cernet.net/repo/cernet/0/AS4538.roa")
            .expect("read roa fixture");
    let roa = RoaObject::decode_der(&roa_der).expect("decode roa");
    let ee_from_roa = roa.signed_object.signed_data.certificates[0]
        .raw_der
        .clone();
    let now = time::OffsetDateTime::now_utc();

    let err = validate_ee_cert_path(
        &g.issuer_ca_der,
        &g.issuer_ca_der,
        &g.issuer_crl_der,
        None,
        None,
        now,
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::EeNotEe), "{err}");

    let err = validate_ee_cert_path(&g.ee_der, &ee_from_roa, &g.issuer_crl_der, None, None, now)
        .unwrap_err();
    assert!(matches!(err, CertPathError::IssuerNotCa), "{err}");
}

#[test]
fn validate_ee_cert_path_rejects_stale_crl() {
    use rpki::data_model::crl::RpkixCrl;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let crl = RpkixCrl::decode_der(&g.issuer_crl_der).expect("decode crl");
    let err = validate_ee_cert_path(
        &g.ee_der,
        &g.issuer_ca_der,
        &g.issuer_crl_der,
        None,
        None,
        crl.next_update.utc + time::Duration::seconds(1),
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::CrlNotValidAtTime), "{err}");
}

#[test]
fn validate_ee_cert_path_with_prevalidated_issuer_rejects_invalid_times() {
    use rpki::data_model::crl::RpkixCrl;
    use rpki::data_model::rc::ResourceCertificate;
    use rpki::validation::cert_path::validate_ee_cert_path_with_prevalidated_issuer;
    use std::collections::HashSet;
    use x509_parser::prelude::FromDer;
    use x509_parser::x509::SubjectPublicKeyInfo;

    let g = generate_issuer_ca_ee_and_crl(
        "keyUsage = critical, digitalSignature
",
    );
    let issuer = ResourceCertificate::decode_der(&g.issuer_ca_der).expect("decode issuer");
    let ee = ResourceCertificate::decode_der(&g.ee_der).expect("decode ee");
    let issuer_crl = RpkixCrl::decode_der(&g.issuer_crl_der).expect("decode crl");
    let (rem, issuer_spki) = SubjectPublicKeyInfo::from_der(&issuer.tbs.subject_public_key_info)
        .expect("parse issuer spki");
    assert!(rem.is_empty());

    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &issuer,
        &issuer_spki,
        &issuer_crl,
        &HashSet::new(),
        Some("rsync://example.test/repo/issuer/issuer.cer"),
        Some("rsync://example.test/repo/issuer/issuer.crl"),
        ee.tbs.validity_not_before - time::Duration::seconds(1),
    )
    .unwrap_err();
    assert!(
        matches!(err, CertPathError::CertificateNotValidAtTime),
        "{err}"
    );

    let err = validate_ee_cert_path_with_prevalidated_issuer(
        &g.ee_der,
        &issuer,
        &issuer_spki,
        &issuer_crl,
        &HashSet::new(),
        Some("rsync://example.test/repo/issuer/issuer.cer"),
        Some("rsync://example.test/repo/issuer/issuer.crl"),
        issuer_crl.next_update.utc + time::Duration::seconds(1),
    )
    .unwrap_err();
    assert!(matches!(err, CertPathError::CrlNotValidAtTime), "{err}");
}