use crate::ffi;
use foreign_types::{ForeignType, ForeignTypeRef};
use libc::{c_int, c_uint, c_ulong, time_t};
use openssl_macros::corresponds;
use std::net::IpAddr;

use crate::error::ErrorStack;
use crate::{cvt, cvt_p};

bitflags! {
    /// Flags used to check an `X509` certificate.
    #[derive(Debug, PartialEq, Eq, Clone, Copy, PartialOrd, Ord, Hash)]
    #[repr(transparent)]
    pub struct X509CheckFlags: c_uint {
        const ALWAYS_CHECK_SUBJECT = ffi::X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT as _;
        const NO_WILDCARDS = ffi::X509_CHECK_FLAG_NO_WILDCARDS as _;
        const NO_PARTIAL_WILDCARDS = ffi::X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS as _;
        const MULTI_LABEL_WILDCARDS = ffi::X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS as _;
        const SINGLE_LABEL_SUBDOMAINS = ffi::X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS as _;
        const NEVER_CHECK_SUBJECT = ffi::X509_CHECK_FLAG_NEVER_CHECK_SUBJECT as _;
        #[cfg(feature = "underscore-wildcards")]
        const UNDERSCORE_WILDCARDS = ffi::X509_CHECK_FLAG_UNDERSCORE_WILDCARDS as _;
    }
}

bitflags! {
    /// Flags used to check an `X509` certificate.
    #[derive(Debug, PartialEq, Eq, Clone, Copy, PartialOrd, Ord, Hash)]
    #[repr(transparent)]
    #[doc(alias = "X509Flags")]
    pub struct X509VerifyFlags: c_ulong {
        const CB_ISSUER_CHECK = ffi::X509_V_FLAG_CB_ISSUER_CHECK as _;
        const USE_CHECK_TIME = ffi::X509_V_FLAG_USE_CHECK_TIME as _;
        const CRL_CHECK = ffi::X509_V_FLAG_CRL_CHECK as _;
        const CRL_CHECK_ALL = ffi::X509_V_FLAG_CRL_CHECK_ALL as _;
        const IGNORE_CRITICAL = ffi::X509_V_FLAG_IGNORE_CRITICAL as _;
        const X509_STRICT = ffi::X509_V_FLAG_X509_STRICT as _;
        const ALLOW_PROXY_CERTS = ffi::X509_V_FLAG_ALLOW_PROXY_CERTS as _;
        const POLICY_CHECK = ffi::X509_V_FLAG_POLICY_CHECK as _;
        const EXPLICIT_POLICY = ffi::X509_V_FLAG_EXPLICIT_POLICY as _;
        const INHIBIT_ANY = ffi::X509_V_FLAG_INHIBIT_ANY as _;
        const INHIBIT_MAP = ffi::X509_V_FLAG_INHIBIT_MAP as _;
        const NOTIFY_POLICY = ffi::X509_V_FLAG_NOTIFY_POLICY as _;
        const EXTENDED_CRL_SUPPORT = ffi::X509_V_FLAG_EXTENDED_CRL_SUPPORT as _;
        const USE_DELTAS = ffi::X509_V_FLAG_USE_DELTAS as _;
        const CHECK_SS_SIGNATURE = ffi::X509_V_FLAG_CHECK_SS_SIGNATURE as _;
        const TRUSTED_FIRST = ffi::X509_V_FLAG_TRUSTED_FIRST as _;
        const PARTIAL_CHAIN = ffi::X509_V_FLAG_PARTIAL_CHAIN as _;
        const NO_ALT_CHAINS = ffi::X509_V_FLAG_NO_ALT_CHAINS as _;
    }
}

foreign_type_and_impl_send_sync! {
    type CType = ffi::X509_VERIFY_PARAM;
    fn drop = ffi::X509_VERIFY_PARAM_free;

    /// Adjust parameters associated with certificate verification.
    pub struct X509VerifyParam;
}

impl X509VerifyParam {
    /// Create an X509VerifyParam
    #[corresponds(X509_VERIFY_PARAM_new)]
    pub fn new() -> Result<Self, ErrorStack> {
        unsafe {
            ffi::init();
            let handle = cvt_p(ffi::X509_VERIFY_PARAM_new())?;
            Ok(Self::from_ptr(handle))
        }
    }
}

impl X509VerifyParamRef {
    /// Set verification flags.
    #[corresponds(X509_VERIFY_PARAM_set_flags)]
    pub fn set_flags(&mut self, flags: X509VerifyFlags) {
        unsafe {
            cvt(ffi::X509_VERIFY_PARAM_set_flags(
                self.as_ptr(),
                flags.bits(),
            ))
            .unwrap();
        }
    }

    /// Clear verification flags.
    #[corresponds(X509_VERIFY_PARAM_clear_flags)]
    pub fn clear_flags(&mut self, flags: X509VerifyFlags) {
        unsafe {
            cvt(ffi::X509_VERIFY_PARAM_clear_flags(
                self.as_ptr(),
                flags.bits(),
            ))
            .unwrap();
        }
    }

    ///
    /// Set the host flags.
    #[corresponds(X509_VERIFY_PARAM_set_hostflags)]
    pub fn set_hostflags(&mut self, hostflags: X509CheckFlags) {
        unsafe {
            ffi::X509_VERIFY_PARAM_set_hostflags(self.as_ptr(), hostflags.bits());
        }
    }

    /// Gets verification flags.
    #[corresponds(X509_VERIFY_PARAM_get_flags)]
    #[must_use]
    pub fn flags(&self) -> X509VerifyFlags {
        let bits = unsafe { ffi::X509_VERIFY_PARAM_get_flags(self.as_ptr()) };
        X509VerifyFlags::from_bits_retain(bits)
    }

    /// Set the expected DNS hostname.
    #[corresponds(X509_VERIFY_PARAM_set1_host)]
    pub fn set_host(&mut self, host: &str) -> Result<(), ErrorStack> {
        unsafe {
            // len == 0 means "run strlen" :(
            let raw_host = if host.is_empty() { "\0" } else { host };
            cvt(ffi::X509_VERIFY_PARAM_set1_host(
                self.as_ptr(),
                raw_host.as_ptr().cast(),
                host.len(),
            ))
        }
    }

    /// Set the expected email address.
    #[corresponds(X509_VERIFY_PARAM_set1_email)]
    pub fn set_email(&mut self, email: &str) -> Result<(), ErrorStack> {
        unsafe {
            // len == 0 means "run strlen" :(
            let raw_email = if email.is_empty() { "\0" } else { email };
            cvt(ffi::X509_VERIFY_PARAM_set1_email(
                self.as_ptr(),
                raw_email.as_ptr().cast(),
                email.len(),
            ))
        }
    }

    /// Set the expected IPv4 or IPv6 address.
    #[corresponds(X509_VERIFY_PARAM_set1_ip)]
    pub fn set_ip(&mut self, ip: IpAddr) -> Result<(), ErrorStack> {
        unsafe {
            let mut buf = [0; 16];
            let len = match ip {
                IpAddr::V4(addr) => {
                    buf[..4].copy_from_slice(&addr.octets());
                    4
                }
                IpAddr::V6(addr) => {
                    buf.copy_from_slice(&addr.octets());
                    16
                }
            };
            cvt(ffi::X509_VERIFY_PARAM_set1_ip(
                self.as_ptr(),
                buf.as_ptr().cast(),
                len,
            ))
        }
    }

    /// Set the verification time, where time is of type time_t, traditionaly defined as seconds since the epoch
    #[corresponds(X509_VERIFY_PARAM_set_time)]
    pub fn set_time(&mut self, time: time_t) {
        unsafe { ffi::X509_VERIFY_PARAM_set_time(self.as_ptr(), time) }
    }

    /// Set the verification depth
    #[corresponds(X509_VERIFY_PARAM_set_depth)]
    pub fn set_depth(&mut self, depth: c_int) {
        unsafe { ffi::X509_VERIFY_PARAM_set_depth(self.as_ptr(), depth) }
    }

    /// Copies parameters from `src`.
    ///
    /// If a parameter is unset in `src`, the existing value in `self`` is preserved.
    #[corresponds(X509_VERIFY_PARAM_set1)]
    pub fn copy_from(&mut self, src: &Self) -> Result<(), ErrorStack> {
        unsafe { cvt(ffi::X509_VERIFY_PARAM_set1(self.as_ptr(), src.as_ptr())) }
    }
}
