rama-ua 0.3.0

use rama_core::error::BoxErrorExt as _;
use std::borrow::Cow;

use rama_core::{
    Layer, Service,
    error::{BoxError, ErrorContext},
    extensions::{Extension, ExtensionsRef},
    telemetry::tracing,
};
use rama_http::headers::{ClientHint, all_client_hints};
use rama_http::{
    HeaderMap, HeaderName, HeaderValue, Method, Request, Version,
    conn::{H2ClientContextParams, Http1ClientContextParams},
    header::{CONTENT_TYPE, REFERER, SEC_WEBSOCKET_VERSION, USER_AGENT},
};
use rama_net::{
    AuthorityInputExt, Protocol, ProtocolInputExt,
    address::{Host, HostWithOptPort},
    client::{ConnectorService, EstablishedClientConnection},
    uri::Uri,
};
use rama_utils::str::{starts_with_ignore_ascii_case, submatch_ignore_ascii_case};

use crate::{
    HttpAgent, UserAgent,
    profile::{
        CUSTOM_HEADER_MARKER, HttpHeadersProfile, HttpProfile, PreserveHeaderUserAgent,
        RequestClientHints, RequestInitiator,
    },
};

use super::{SelectedUserAgentProfile, UserAgentProvider, UserAgentSelectFallback};

/// Service to select a [`UserAgentProfile`] and inject its info into the input [`Extensions`].
///
/// Note that actual http emulation is done by also ensuring a service
/// such as [`UserAgentEmulateHttpRequestModifier`] and [`UserAgentEmulateHttpConnectModifier`] is in use within your connector stack.
/// Tls emulation is facilitated by a tls client connector which respects
/// the injected (tls) client profile.
///
/// See the implementation of[`EasyHttpWebClient`] for the reference implementation of how
/// one can make use of this profile to emulate a user agent on the tls layer.
///
/// [`UserAgentProfile`]: crate::profile::UserAgentProfile
/// [`Extensions`]: rama_core::extensions::Extensions
/// [`EasyHttpWebClient`]: https://ramaproxy.org/docs/rama/http/client/struct.EasyHttpWebClient.html
#[derive(Debug, Clone)]
pub struct UserAgentEmulateService<S, P> {
    inner: S,
    provider: P,
    optional: bool,
    try_auto_detect_user_agent: bool,
    input_header_order: Option<HeaderName>,
    select_fallback: Option<UserAgentSelectFallback>,
}

impl<S, P> UserAgentEmulateService<S, P> {
    /// Create a new [`UserAgentEmulateService`] with the given inner service and provider.
    ///
    /// Provider is implicitly expected to be a [`UserAgentProvider`].
    pub fn new(inner: S, provider: P) -> Self {
        Self {
            inner,
            provider,
            optional: false,
            try_auto_detect_user_agent: false,
            input_header_order: None,
            select_fallback: None,
        }
    }

    rama_utils::macros::generate_set_and_with! {
        /// When no user agent profile was found it will
        /// fail the request unless optional is true. In case of
        /// the latter the service will do nothing.
        pub fn is_optional(mut self, optional: bool) -> Self {
            self.optional = optional;
            self
        }
    }

    rama_utils::macros::generate_set_and_with! {
        /// If true, the service will try to auto-detect the user agent from the request,
        /// but only in case that info is not yet found in the context.
        pub fn try_auto_detect_user_agent(mut self, try_auto_detect_user_agent: bool) -> Self {
            self.try_auto_detect_user_agent = try_auto_detect_user_agent;
            self
        }
    }

    rama_utils::macros::generate_set_and_with! {
        /// Define a header that if present is to contain a CSV header name list,
        /// that allows you to define the desired header order for the (extra) headers
        /// found in the input (http) request.
        ///
        /// Extra meaning any headers not considered a base header and already defined
        /// by the (selected) User Agent Profile.
        ///
        /// This can be useful because your http client might not respect the header casing
        /// and/or order of the headers taken together. Using this metadata allows you to
        /// communicate this data through anyway. If however your http client does respect
        /// casing and order, or you don't care about some of it, you might not need it.
        pub fn input_header_order(mut self, name: Option<HeaderName>) -> Self {
            self.input_header_order = name;
            self
        }
    }

    rama_utils::macros::generate_set_and_with! {
        /// Choose what to do in case no profile could be selected
        /// using the regular pre-conditions as specified by the provider.
        pub fn select_fallback(mut self, fb: Option<UserAgentSelectFallback>) -> Self {
            self.select_fallback = fb;
            self
        }
    }
}

impl<Body, S, P> Service<Request<Body>> for UserAgentEmulateService<S, P>
where
    Body: Send + Sync + 'static,
    S: Service<Request<Body>, Error: Into<BoxError>>,
    P: UserAgentProvider,
{
    type Output = S::Output;
    type Error = BoxError;

    async fn serve(&self, req: Request<Body>) -> Result<Self::Output, Self::Error> {
        if let Some(fallback) = self.select_fallback {
            req.extensions().insert(fallback);
        }

        if self.try_auto_detect_user_agent && !req.extensions().contains::<UserAgent>() {
            match req
                .headers()
                .get(USER_AGENT)
                .and_then(|ua| ua.to_str().ok())
            {
                Some(ua_str) => {
                    let user_agent = UserAgent::new(ua_str);
                    tracing::trace!(
                        user_agent.original = %ua_str,
                        "user agent {user_agent} auto-detected from request"
                    );
                    req.extensions().insert(user_agent);
                }
                None => {
                    tracing::debug!(
                        "user agent auto-detection not possible: no user agent header present"
                    );
                }
            }
        }

        if let Some(header) = self
            .input_header_order
            .as_ref()
            .and_then(|name| req.headers().get(name))
        {
            let s = header.to_str().context("interpret header as a utf-8 str")?;
            let headers = s
                .split(',')
                .map(str::trim)
                .filter(|s| !s.is_empty())
                .map(|s| s.parse().context("parse header part as h1 header name"))
                .collect::<Result<Vec<HeaderName>, BoxError>>()?;
            req.extensions().insert(InputHeaderOrder(headers));
        }

        let Some(profile) = self.provider.select_user_agent_profile(req.extensions()) else {
            return if self.optional {
                Ok(self.inner.serve(req).await.into_box_error()?)
            } else {
                Err(BoxError::from_static_str(
                    "requirement not fulfilled: user agent profile could not be selected",
                ))
            };
        };

        tracing::debug!(
            user_agent.kind = %profile.ua_kind,
            user_agent.version = ?profile.ua_version,
            user_agent.platform = ?profile.platform,
            "user agent profile selected for emulation"
        );

        let preserve_http = matches!(
            req.extensions()
                .get_ref::<UserAgent>()
                .and_then(|ua| ua.http_agent()),
            Some(HttpAgent::Preserve),
        );

        if preserve_http {
            tracing::trace!(
                user_agent.kind = %profile.ua_kind,
                user_agent.version = ?profile.ua_version,
                user_agent.platform = ?profile.platform,
                "user agent emulation: skip http settings as http is instructed to be preserved"
            );
        } else {
            tracing::trace!(
                user_agent.kind = %profile.ua_kind,
                user_agent.version = ?profile.ua_version,
                user_agent.platform = ?profile.platform,
                "user agent emulation: inject http context data to prepare for HTTP emulation"
            );
            req.extensions().insert_arc(profile.http.clone());
        }

        #[cfg(feature = "tls")]
        {
            use crate::TlsAgent;

            let preserve_tls = matches!(
                req.extensions()
                    .get_ref::<UserAgent>()
                    .and_then(|ua| ua.tls_agent()),
                Some(TlsAgent::Preserve),
            );
            if preserve_tls {
                tracing::trace!(
                    user_agent.kind = %profile.ua_kind,
                    user_agent.version = ?profile.ua_version,
                    user_agent.platform = ?profile.platform,
                    "user agent emulation: skip tls settings as tls is instructed to be preserved"
                );
            } else {
                req.extensions().insert_arc(profile.tls.clone());
                tracing::trace!(
                    user_agent.kind = %profile.ua_kind,
                    user_agent.version = ?profile.ua_version,
                    user_agent.platform = ?profile.platform,
                    "user agent emulation: tls profile injected in ctx"
                );
            }
        }

        // inject the selected user agent profile into the context
        req.extensions()
            .insert(SelectedUserAgentProfile::from(profile));

        // serve emulated http(s) request via inner service
        self.inner.serve(req).await.into_box_error()
    }
}

#[derive(Debug, Clone, Default)]
// A connector which is to be used in combination
// with the [`UserAgentEmulateService`] to facilitate the
// http emulation based on the injected http profile.
pub struct UserAgentEmulateHttpConnectModifier<S> {
    inner: S,
}

impl<S> UserAgentEmulateHttpConnectModifier<S> {
    #[inline]
    /// Create a new [`UserAgentEmulateHttpConnectModifier`].
    #[must_use]
    pub fn new(inner: S) -> Self {
        Self { inner }
    }
}

impl<S, ReqBody> Service<Request<ReqBody>> for UserAgentEmulateHttpConnectModifier<S>
where
    S: ConnectorService<Request<ReqBody>, Error: Into<BoxError>>,
    ReqBody: Send + 'static,
{
    type Error = BoxError;
    type Output = EstablishedClientConnection<S::Connection, Request<ReqBody>>;

    async fn serve(&self, req: Request<ReqBody>) -> Result<Self::Output, Self::Error> {
        let EstablishedClientConnection { conn, input: req } =
            self.inner.connect(req).await.into_box_error()?;

        match req
            .extensions()
            .clone_to_if_absent::<HttpProfile>(conn.extensions())
        {
            Some(http_profile) => {
                tracing::trace!(
                    http.version = ?req.version(),
                    "http profile found in context to use for http connection emulation, proceed",
                );
                emulate_http_connect_settings(&req, &http_profile);
            }
            None => {
                tracing::trace!(
                    http.version = ?req.version(),
                    "no http profile found in context to use for http connection emulation, request is passed through as-is",
                );
            }
        }
        Ok(EstablishedClientConnection { input: req, conn })
    }
}

#[non_exhaustive]
#[derive(Debug, Default, Clone)]
pub struct UserAgentEmulateHttpConnectModifierLayer;

impl<S> Layer<S> for UserAgentEmulateHttpConnectModifierLayer {
    type Service = UserAgentEmulateHttpConnectModifier<S>;

    fn layer(&self, inner: S) -> Self::Service {
        UserAgentEmulateHttpConnectModifier::new(inner)
    }
}

fn emulate_http_connect_settings<Body>(req: &Request<Body>, profile: &HttpProfile) {
    match req.version() {
        Version::HTTP_09 | Version::HTTP_10 | Version::HTTP_11 => {
            tracing::trace!("UA emulation add http1-specific settings",);
            req.extensions().insert(Http1ClientContextParams {
                title_header_case: profile.h1.settings.title_case_headers,
            });
        }
        Version::HTTP_2 => {
            let pseudo_headers = profile.h2.settings.http_pseudo_headers.clone();
            let early_frames = profile.h2.settings.early_frames.clone();

            if pseudo_headers.is_some() || early_frames.is_some() {
                tracing::trace!(
                    "user agent emulation: insert h2 settings into extensions: (pseudo headers = {:?} ; early frames: {:?})",
                    pseudo_headers,
                    early_frames,
                );
                req.extensions().insert(H2ClientContextParams {
                    headers_pseudo_order: pseudo_headers,
                    early_frames,
                    ..Default::default()
                });
            }
        }
        Version::HTTP_3 => tracing::debug!(
            "UA emulation not yet supported for h3: not applying anything h3-specific"
        ),
        // defensive forward-compat arm; native Version is currently exhaustive
        #[expect(
            unreachable_patterns,
            reason = "forward-compat fallback for future Version variants"
        )]
        _ => tracing::debug!(
            http.version = ?req.version(),
            "UA emulation not supported for unknown http version: not applying anything version-specific",
        ),
    }
}

#[derive(Debug, Clone, Default)]
#[non_exhaustive]
// A http service which is to be used in combination
// with the [`UserAgentEmulateService`] to facilitate the
// http emulation based on the injected http profile.
pub struct UserAgentEmulateHttpRequestModifier<S> {
    inner: S,
}

impl<S> UserAgentEmulateHttpRequestModifier<S> {
    #[inline]
    #[must_use]
    /// Create a new [`UserAgentEmulateHttpRequestModifier`].
    pub fn new(inner: S) -> Self {
        Self { inner }
    }
}

impl<S, ReqBody> Service<Request<ReqBody>> for UserAgentEmulateHttpRequestModifier<S>
where
    S: Service<Request<ReqBody>, Error: Into<BoxError>>,
    ReqBody: Send + 'static,
{
    type Error = BoxError;
    type Output = S::Output;

    async fn serve(&self, mut req: Request<ReqBody>) -> Result<Self::Output, Self::Error> {
        match req.extensions().get_arc() {
            Some(http_profile) => {
                tracing::trace!(
                    http.version = ?req.version(),
                    "http profile found in context to use for emulation, proceed",
                );

                match get_base_http_headers(&req, &http_profile) {
                    Some(base_http_headers) => {
                        let original_http_header_order =
                            req.extensions().get_ref::<InputHeaderOrder>().cloned();
                        let original_headers = req.headers().clone();

                        let preserve_ua_header =
                            req.extensions().contains::<PreserveHeaderUserAgent>();

                        let authority = req.authority().map(Cow::Owned);
                        let protocol = req.protocol().map(Cow::Borrowed);

                        let output_headers = merge_http_headers(
                            base_http_headers,
                            original_http_header_order,
                            original_headers,
                            preserve_ua_header,
                            authority,
                            protocol,
                            Some(req.method()),
                            req.extensions()
                                .get_ref::<RequestClientHints>()
                                .map(AsRef::as_ref),
                        );

                        tracing::trace!("user agent emulation: http emulated");
                        *req.headers_mut() = output_headers;
                    }
                    None => {
                        tracing::debug!(
                            "user agent emulation: no http headers to emulate: no base http headers found"
                        );
                    }
                }

                if req.version() == Version::HTTP_2 {
                    let pseudo_headers = http_profile.h2.settings.http_pseudo_headers.clone();

                    tracing::trace!(
                        "user agent emulation: insert h2 pseudo headers into request extensions: {pseudo_headers:?}"
                    );

                    if let Some(pseudo_headers) = pseudo_headers {
                        req.extensions().insert(pseudo_headers);
                    }
                }
            }
            None => {
                tracing::trace!(
                    http.version = ?req.version(),
                    "no http profile found in context to use for emulation, request is passed through as-is",
                );
            }
        }

        let resp = self.inner.serve(req).await.into_box_error()?;
        Ok(resp)
    }
}

#[derive(Debug, Clone, Default)]
#[non_exhaustive]
// A http layer which is to be used in combination
// with the [`UserAgentEmulateService`] to facilitate the
// http emulation based on the injected http profile.
pub struct UserAgentEmulateHttpRequestModifierLayer;

impl<S> Layer<S> for UserAgentEmulateHttpRequestModifierLayer {
    type Service = UserAgentEmulateHttpRequestModifier<S>;

    fn layer(&self, inner: S) -> Self::Service {
        UserAgentEmulateHttpRequestModifier::new(inner)
    }
}

fn get_base_http_headers<'a, Body>(
    req: &Request<Body>,
    profile: &'a HttpProfile,
) -> Option<&'a HeaderMap> {
    let headers_profile = match req.version() {
        Version::HTTP_09 | Version::HTTP_10 | Version::HTTP_11 => &profile.h1.headers,
        Version::HTTP_2 => &profile.h2.headers,
        _ => {
            tracing::debug!(
                http.version = ?req.version(),
                "UA emulation not supported for unknown http version: not applying anything version-specific",
            );
            return None;
        }
    };
    match req.extensions().get_ref::<RequestInitiator>().copied() {
        Some(req_init) => {
            tracing::trace!(
                "base http headers defined based on hint from UserAgent (overwrite): {req_init}"
            );
            get_base_http_headers_from_req_init(req_init, headers_profile)
        }
        // NOTE: the primitive checks below are pretty bad,
        // feel free to help improve. Just need to make sure it has good enough fallbacks,
        // and that they are cheap enough to check.
        None => match *req.method() {
            Method::GET => {
                let req_init = if headers_contains_partial_value(
                    req.headers(),
                    &X_REQUESTED_WITH,
                    "XmlHttpRequest",
                ) {
                    RequestInitiator::Xhr
                } else if headers_contains_partial_value(
                    req.headers(),
                    &SEC_WEBSOCKET_VERSION,
                    "13",
                ) {
                    RequestInitiator::Ws
                } else {
                    RequestInitiator::Navigate
                };
                tracing::trace!(
                    "base http headers defined based on Get=XhrOrWsOrNavigate assumption: {req_init}"
                );
                get_base_http_headers_from_req_init(req_init, headers_profile)
            }
            Method::POST => {
                let req_init = if headers_contains_partial_value(
                    req.headers(),
                    &X_REQUESTED_WITH,
                    "XmlHttpRequest",
                ) {
                    RequestInitiator::Xhr
                } else if headers_contains_partial_value(req.headers(), &CONTENT_TYPE, "form-") {
                    RequestInitiator::Form
                } else {
                    RequestInitiator::Fetch
                };
                tracing::trace!(
                    "base http headers defined based on Post=FormOrFetch assumption: {req_init}"
                );
                get_base_http_headers_from_req_init(req_init, headers_profile)
            }
            _ => {
                let req_init = if headers_contains_partial_value(
                    req.headers(),
                    &X_REQUESTED_WITH,
                    "XmlHttpRequest",
                ) {
                    RequestInitiator::Xhr
                } else if req.version() == Version::HTTP_2
                    && req.method() == Method::CONNECT
                    && headers_contains_partial_value(req.headers(), &SEC_WEBSOCKET_VERSION, "13")
                {
                    RequestInitiator::Ws
                } else {
                    RequestInitiator::Fetch
                };
                tracing::trace!(
                    "base http headers defined based on XhrOrWsOrFetch assumption: {req_init}"
                );
                get_base_http_headers_from_req_init(req_init, headers_profile)
            }
        },
    }
}

static X_REQUESTED_WITH: HeaderName = HeaderName::from_static("x-requested-with");

fn headers_contains_partial_value(headers: &HeaderMap, name: &HeaderName, value: &str) -> bool {
    headers
        .get(name)
        .and_then(|value| value.to_str().ok())
        .map(|s| submatch_ignore_ascii_case(s, value))
        .unwrap_or_default()
}

fn get_base_http_headers_from_req_init(
    req_init: RequestInitiator,
    headers: &HttpHeadersProfile,
) -> Option<&HeaderMap> {
    match req_init {
        RequestInitiator::Navigate => Some(&headers.navigate),
        RequestInitiator::Form => Some(headers.form.as_ref().unwrap_or(&headers.navigate)),
        RequestInitiator::Xhr => Some(
            headers
                .xhr
                .as_ref()
                .or(headers.fetch.as_ref())
                .unwrap_or(&headers.navigate),
        ),
        RequestInitiator::Fetch => Some(
            headers
                .fetch
                .as_ref()
                .or(headers.xhr.as_ref())
                .unwrap_or(&headers.navigate),
        ),
        RequestInitiator::Ws => headers.ws.as_ref(),
    }
}

const SEC_FETCH_SITE: HeaderName = HeaderName::from_static("sec-fetch-site");

#[derive(Debug, Clone, Extension)]
#[extension(tags(http))]
struct InputHeaderOrder(Vec<HeaderName>);

#[expect(clippy::too_many_arguments, clippy::needless_pass_by_value)]
fn merge_http_headers<'a>(
    base_http_headers: &HeaderMap,
    original_http_header_order: Option<InputHeaderOrder>,
    original_headers: HeaderMap,
    preserve_ua_header: bool,
    request_authority: Option<Cow<'a, HostWithOptPort>>,
    protocol: Option<Cow<'a, Protocol>>,
    method: Option<&Method>,
    requested_client_hints: Option<&[ClientHint]>,
) -> HeaderMap {
    let original_header_referer_value = original_headers.get(&REFERER).cloned();
    let is_secure_request = protocol.as_ref().map(|p| p.is_secure()).unwrap_or_default();

    let mut original_headers: Vec<_> = original_headers.into_ordered_iter().collect();

    let remove_original_header = |headers: &mut Vec<(HeaderName, HeaderValue)>,
                                  name: &HeaderName| {
        headers
            .iter()
            .position(|(header_name, _)| header_name == name)
            .map(|index| headers.remove(index).1)
    };

    // to support clients that pass in client hints as well. We'll ignore their
    // header values, but can still take the hint none the less
    let original_client_hints: Vec<_> = all_client_hints()
        .filter(|p| {
            p.iter_header_names()
                .filter_map(|name| remove_original_header(&mut original_headers, &name).map(|_| 1))
                .sum::<u16>()
                > 0
        })
        .collect();

    let mut output_headers_a = Vec::new();
    let mut output_headers_b = Vec::new();

    let mut output_headers_ref = &mut output_headers_a;

    let is_header_allowed = |header_name: &HeaderName| {
        if let Some(hint) = ClientHint::match_header_name(header_name) {
            is_secure_request
                && (hint.is_low_entropy()
                    || requested_client_hints
                        .map(|hints| hints.contains(&hint))
                        .unwrap_or_default()
                    || original_client_hints.contains(&hint))
        } else {
            is_secure_request || !starts_with_ignore_ascii_case(header_name.as_str(), "sec-fetch")
        }
    };

    // put all "base" headers in correct order, and with proper name casing
    for (base_name, base_value) in base_http_headers.clone().into_ordered_iter() {
        let base_header_name = &base_name;
        let original_value = remove_original_header(&mut original_headers, base_header_name);
        match base_header_name.standard() {
            Some(
                rama_http::header::StandardHeader::Accept
                | rama_http::header::StandardHeader::AcceptLanguage
                | rama_http::header::StandardHeader::SecWebSocketExtensions,
            ) => {
                let value = original_value.unwrap_or(base_value);
                output_headers_ref.push((base_name, value));
            }
            Some(
                rama_http::header::StandardHeader::Referer
                | rama_http::header::StandardHeader::Cookie
                | rama_http::header::StandardHeader::Authorization
                | rama_http::header::StandardHeader::Host
                | rama_http::header::StandardHeader::Origin
                | rama_http::header::StandardHeader::ContentLength
                | rama_http::header::StandardHeader::ContentType
                | rama_http::header::StandardHeader::SecWebSocketProtocol
                | rama_http::header::StandardHeader::SecWebSocketKey,
            ) => {
                if let Some(value) = original_value {
                    output_headers_ref.push((base_name, value));
                }
            }
            Some(rama_http::header::StandardHeader::UserAgent) => {
                if preserve_ua_header {
                    let value = original_value.unwrap_or(base_value);
                    output_headers_ref.push((base_name, value));
                } else {
                    output_headers_ref.push((base_name, base_value));
                }
            }
            _ => {
                if base_header_name == CUSTOM_HEADER_MARKER {
                    output_headers_ref = &mut output_headers_b;
                } else if is_header_allowed(base_header_name) {
                    if base_header_name == SEC_FETCH_SITE {
                        // assumption: is_header_allowed ensures that this only
                        // is reached in a secure context :)
                        let value = compute_sec_fetch_site_value(
                            original_header_referer_value.as_ref(),
                            method,
                            protocol.as_deref(),
                            request_authority.as_deref(),
                        );
                        output_headers_ref.push((base_name, value));
                    } else {
                        output_headers_ref.push((base_name, base_value));
                    }
                }
            }
        }
    }

    // respect original header order of original headers where possible
    for header_name in original_http_header_order
        .into_iter()
        .flat_map(|order| order.0)
    {
        if let Some(value) = remove_original_header(&mut original_headers, &header_name)
            && is_header_allowed(&header_name)
            && ClientHint::match_header_name(&header_name).is_none()
        {
            output_headers_a.push((header_name, value));
        }
    }

    let original_headers_iter = original_headers
        .into_iter()
        .filter(|(header_name, _)| is_header_allowed(header_name));

    HeaderMap::from_iter(
        output_headers_a
            .into_iter()
            .chain(original_headers_iter) // add all remaining original headers in any order within the right loc
            .chain(output_headers_b),
    )
}

fn compute_sec_fetch_site_value(
    original_header_referer_value: Option<&HeaderValue>,
    _method: Option<&Method>,
    protocol: Option<&Protocol>,
    request_authority: Option<&HostWithOptPort>,
) -> HeaderValue {
    match &original_header_referer_value {
        Some(referer_value) => {
            match referer_value
                .to_str()
                .context("turn referer into str")
                .and_then(|s| {
                    // Referer is usually a full URL; fall back to authority-form
                    // so a bare/degenerate host is still treated as an origin.
                    Uri::parse(s)
                        .or_else(|_| Uri::parse_authority_form(s))
                        .context("turn referer header value str into http Uri")
                }) {
                Ok(uri) => {
                    let referer_protocol = uri.scheme().cloned();

                    let default_port = uri
                        .port_u16()
                        .or_else(|| referer_protocol.as_ref().and_then(|p| p.default_port()));

                    let maybe_authority = uri.host().map(|h| {
                        let h = h.into_owned();
                        if let Some(default_port) = default_port {
                            tracing::trace!(url.full = %uri, "detected host {h} from (abs) referer uri");
                            HostWithOptPort::new_with_port(h, default_port)
                        } else {
                            tracing::trace!(url.full = %uri, "detected host {h} from (abs) referer uri: but no (default) port available");
                            HostWithOptPort::new(h)
                        }
                    });

                    if let Some(authority) = maybe_authority {
                        if referer_protocol.as_ref() == protocol {
                            if Some(&authority) == request_authority {
                                HeaderValue::from_static("same-origin")
                            } else if let Some(request_host) =
                                request_authority.as_ref().map(|a| &a.host)
                            {
                                let is_same_registrable_domain =
                                    match (&authority.host, request_host) {
                                        (Host::Name(a), Host::Name(b)) => {
                                            a.have_same_registrable_domain(b)
                                        }
                                        (Host::Address(a), Host::Address(b)) => a == b,
                                        _ => false,
                                    };
                                if is_same_registrable_domain {
                                    HeaderValue::from_static("same-site")
                                } else {
                                    HeaderValue::from_static("cross-site")
                                }
                            } else {
                                tracing::debug!(
                                    http.request.header.referer = ?referer_value,
                                    "missing request authority, returning none as default",
                                );
                                HeaderValue::from_static("none")
                            }
                        } else {
                            HeaderValue::from_static("cross-site")
                        }
                    } else {
                        tracing::debug!(
                            http.request.header.referer = ?referer_value,
                            "invalid referer value (failed to extract authority from uri value)",
                        );
                        HeaderValue::from_static("none")
                    }
                }
                Err(err) => {
                    tracing::debug!(
                        http.request.header.referer = ?referer_value,
                        "invalid referer value (expected a valid uri, defaulting to none): {err:?}",
                    );
                    HeaderValue::from_static("none")
                }
            }
        }
        None => HeaderValue::from_static("none"),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    use std::{convert::Infallible, str::FromStr, sync::Arc};

    use itertools::Itertools as _;
    use rama_core::extensions::Extensions;
    use rama_core::{Layer, service::service_fn};
    use rama_http::{Body, HeaderMap, HeaderName, HeaderValue, header::ETAG};
    use rama_net::address::{Domain, Host};

    use crate::layer::emulate::UserAgentEmulateLayer;
    use crate::profile::{
        Http1Profile, Http1Settings, Http2Profile, Http2Settings, HttpHeadersProfile, HttpProfile,
        UserAgentProfile,
    };

    #[test]
    fn test_merge_http_headers() {
        struct TestCase {
            description: &'static str,
            base_http_headers: Vec<(&'static str, &'static str)>,
            original_http_header_order: Option<Vec<&'static str>>,
            original_headers: Vec<(&'static str, &'static str)>,
            preserve_ua_header: bool,
            request_authority: HostWithOptPort,
            protocol: Protocol,
            requested_client_hints: Option<Vec<&'static str>>,
            expected: Vec<(&'static str, &'static str)>,
        }

        let test_cases = [
            TestCase {
                description: "empty",
                base_http_headers: vec![],
                original_http_header_order: None,
                original_headers: vec![],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![],
            },
            TestCase {
                description: "base headers only",
                base_http_headers: vec![
                    ("Accept", "text/html"),
                    ("Content-Type", "application/json"),
                ],
                original_http_header_order: None,
                original_headers: vec![],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![("Accept", "text/html")],
            },
            TestCase {
                description: "base headers only with content-type",
                base_http_headers: vec![
                    ("Accept", "text/html"),
                    ("Content-Type", "application/json"),
                ],
                original_http_header_order: None,
                original_headers: vec![("content-type", "text/xml")],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![("Accept", "text/html"), ("Content-Type", "text/xml")],
            },
            TestCase {
                description: "original headers only",
                base_http_headers: vec![],
                original_http_header_order: None,
                original_headers: vec![("accept", "text/html")],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![("accept", "text/html")],
            },
            TestCase {
                description: "original and base headers, no conflicts",
                base_http_headers: vec![("accept", "text/html"), ("user-agent", "python/3.10")],
                original_http_header_order: None,
                original_headers: vec![("content-type", "application/json")],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("user-agent", "python/3.10"),
                    ("content-type", "application/json"),
                ],
            },
            TestCase {
                description: "original and base headers, with conflicts",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("content-type", "text/html"),
                    ("user-agent", "python/3.10"),
                ],
                original_http_header_order: Some(vec!["content-type", "user-agent"]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("content-type", "application/json"),
                    ("user-agent", "python/3.10"),
                ],
            },
            TestCase {
                description: "original and base headers, with conflicts, preserve ua header",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("content-type", "text/html"),
                    ("user-agent", "python/3.10"),
                ],
                original_http_header_order: Some(vec!["content-type", "user-agent"]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
                preserve_ua_header: true,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
            },
            TestCase {
                description: "no opt-in base headers defined",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 1234567890"),
                    ("cookie", "session=1234567890"),
                    ("referer", "https://example.com"),
                ],
                original_http_header_order: Some(vec!["content-type", "user-agent"]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_http(),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
            },
            TestCase {
                description: "some opt-in base headers defined",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 1234567890"),
                    ("cookie", "session=1234567890"),
                    ("referer", "https://example.com"),
                ],
                original_http_header_order: Some(vec![
                    "content-type",
                    "cookie",
                    "user-agent",
                    "referer",
                ]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("cookie", "foo=bar"),
                    ("user-agent", "php/8.0"),
                    ("referer", "https://ramaproxy.org"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("ramaproxy.org")),
                    Protocol::HTTPS_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTPS,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("cookie", "foo=bar"),
                    ("referer", "https://ramaproxy.org"),
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
            },
            TestCase {
                description: "all opt-in base headers defined",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 1234567890"),
                    ("cookie", "session=1234567890"),
                    ("referer", "https://example.com"),
                ],
                original_http_header_order: Some(vec![
                    "content-type",
                    "cookie",
                    "user-agent",
                    "referer",
                    "authorization",
                ]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("cookie", "foo=bar"),
                    ("user-agent", "php/8.0"),
                    ("referer", "https://ramaproxy.org"),
                    ("authorization", "Bearer 42"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::example_domain_https(),
                protocol: Protocol::HTTPS,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 42"),
                    ("cookie", "foo=bar"),
                    ("referer", "https://ramaproxy.org"),
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                ],
            },
            TestCase {
                description: "all opt-in base headers defined, with custom header marker",
                base_http_headers: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 1234567890"),
                    ("x-rama-custom-header-marker", "1"),
                    ("cookie", "session=1234567890"),
                    ("referer", "https://example.com"),
                ],
                original_http_header_order: Some(vec![
                    "content-type",
                    "cookie",
                    "user-agent",
                    "referer",
                    "authorization",
                ]),
                original_headers: vec![
                    ("content-type", "application/json"),
                    ("cookie", "foo=bar"),
                    ("user-agent", "php/8.0"),
                    ("referer", "https://ramaproxy.org"),
                    ("authorization", "Bearer 42"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("ramaproxy.org")),
                    Protocol::HTTPS_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTPS,
                requested_client_hints: None,
                expected: vec![
                    ("accept", "text/html"),
                    ("authorization", "Bearer 42"),
                    ("content-type", "application/json"),
                    ("user-agent", "php/8.0"),
                    ("cookie", "foo=bar"),
                    ("referer", "https://ramaproxy.org"),
                ],
            },
            TestCase {
                description: "realistic browser example",
                base_http_headers: vec![
                    ("Host", "www.google.com"),
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "en-US,en;q=0.9"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Referer", "https://www.google.com/"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-rama-custom-header-marker", "1"),
                    ("Cookie", "rama-ua-test=1"),
                    ("Sec-Fetch-Dest", "document"),
                    ("Sec-Fetch-Mode", "navigate"),
                    ("Sec-Fetch-Site", "cross-site"),
                    ("Sec-Fetch-User", "?1"),
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
                original_http_header_order: Some(vec![
                    "x-show-price",
                    "x-show-price-currency",
                    "accept-language",
                    "cookie",
                ]),
                original_headers: vec![
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("accept-language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("cookie", "session=on; foo=bar"),
                    ("x-requested-with", "XMLHttpRequest"),
                    ("host", "www.example.com"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("www.google.com")),
                    Protocol::HTTP_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTP,
                requested_client_hints: None,
                expected: vec![
                    ("Host", "www.example.com"),
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("x-requested-with", "XMLHttpRequest"),
                    ("Cookie", "session=on; foo=bar"),
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
            },
            TestCase {
                description: "realistic browser example over tls",
                base_http_headers: vec![
                    ("Host", "www.google.com"),
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "en-US,en;q=0.9"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Referer", "https://www.google.com/"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-rama-custom-header-marker", "1"),
                    ("Cookie", "rama-ua-test=1"),
                    ("Sec-Fetch-Dest", "document"),
                    ("Sec-Fetch-Mode", "navigate"),
                    ("Sec-Fetch-Site", "cross-site"),
                    ("Sec-Fetch-User", "?1"),
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
                original_http_header_order: Some(vec![
                    "x-show-price",
                    "x-show-price-currency",
                    "accept-language",
                    "cookie",
                ]),
                original_headers: vec![
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("accept-language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("cookie", "session=on; foo=bar"),
                    ("x-requested-with", "XMLHttpRequest"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("www.google.com")),
                    Protocol::HTTPS_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTPS,
                requested_client_hints: None,
                expected: vec![
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("x-requested-with", "XMLHttpRequest"),
                    ("Cookie", "session=on; foo=bar"),
                    ("Sec-Fetch-Dest", "document"),
                    ("Sec-Fetch-Mode", "navigate"),
                    ("Sec-Fetch-Site", "none"),
                    ("Sec-Fetch-User", "?1"),
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
            },
            TestCase {
                description: "secure example request with referer",
                base_http_headers: vec![
                    ("Host", "www.google.com"),
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Referer", "https://www.google.com/"),
                    ("Sec-Fetch-Site", "cross-site"),
                ],
                original_http_header_order: None,
                original_headers: vec![("referer", "https://maps.google.com/")],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("www.google.com")),
                    Protocol::HTTPS_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTPS,
                requested_client_hints: None,
                expected: vec![
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Referer", "https://maps.google.com/"),
                    ("Sec-Fetch-Site", "same-site"),
                ],
            },
            TestCase {
                description: "realistic browser example over tls with requested client hints",
                base_http_headers: vec![
                    ("Host", "www.google.com"),
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "en-US,en;q=0.9"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Referer", "https://www.google.com/"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-rama-custom-header-marker", "1"),
                    ("Cookie", "rama-ua-test=1"),
                    ("Sec-Fetch-Dest", "document"),
                    ("Sec-Fetch-Mode", "navigate"),
                    ("Sec-Fetch-Site", "cross-site"),
                    ("Sec-Fetch-User", "?1"),
                    ("Sec-CH-Downlink", "100"),
                    ("Sec-CH-Ect", "4g"),
                    ("Sec-CH-RTT", "100"),
                    ("Sec-CH-UA-Arch", "arm"),
                    ("Sec-CH-UA-Bitness", "64"),
                    ("Sec-CH-UA-Full-Version", "120.0.0.0"),
                    ("Sec-CH-UA-Full-Version-List", "Chrome 120.0.0.0"),
                    ("Sec-CH-UA-Mobile", "?0"),
                    ("Sec-CH-UA-Platform", "macOS"),
                    ("Sec-CH-UA-Platform-Version", "10.15.7"),
                    ("Sec-CH-UA-Model", "LimitedEdition"),
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
                original_http_header_order: Some(vec![
                    "x-show-price",
                    "x-show-price-currency",
                    "accept-language",
                    "cookie",
                ]),
                original_headers: vec![
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("accept-language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("cookie", "session=on; foo=bar"),
                    ("x-requested-with", "XMLHttpRequest"),
                    ("sec-ch-ua-model", "Macintosh"),
                    ("sec-ch-prefers-contrast", "xx"),
                ],
                preserve_ua_header: false,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("www.google.com")),
                    Protocol::HTTPS_DEFAULT_PORT,
                ),
                protocol: Protocol::HTTPS,
                requested_client_hints: Some(vec![
                    "Downlink",
                    "Ect",
                    "RTT",
                    "Sec-CH-UA-Arch",
                    "Sec-CH-UA-Bitness",
                    // requested but not available
                    "Sec-CH-Prefers-Reduced-Transparency",
                ]),
                expected: vec![
                    (
                        "User-Agent",
                        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
                    ),
                    (
                        "Accept",
                        "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
                    ),
                    ("Accept-Language", "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7"),
                    ("Accept-Encoding", "gzip, deflate, br"),
                    ("Connection", "keep-alive"),
                    ("Upgrade-Insecure-Requests", "1"),
                    ("x-show-price", "true"),
                    ("x-show-price-currency", "USD"),
                    ("x-requested-with", "XMLHttpRequest"),
                    ("Cookie", "session=on; foo=bar"),
                    ("Sec-Fetch-Dest", "document"),
                    ("Sec-Fetch-Mode", "navigate"),
                    ("Sec-Fetch-Site", "none"),
                    ("Sec-Fetch-User", "?1"),
                    ("Sec-CH-Downlink", "100"),
                    ("Sec-CH-Ect", "4g"),
                    ("Sec-CH-RTT", "100"),
                    ("Sec-CH-UA-Arch", "arm"),
                    ("Sec-CH-UA-Bitness", "64"),
                    ("Sec-CH-UA-Mobile", "?0"), // not requested, but low entropy
                    ("Sec-CH-UA-Platform", "macOS"), // not requested, but low entropy
                    ("Sec-CH-UA-Model", "LimitedEdition"),
                    // sec-ch-prefers-contrast was requested, but UA profile doesn't contain it :)
                    ("DNT", "1"),
                    ("Sec-GPC", "1"),
                    ("Priority", "u=0, i"),
                ],
            },
        ];

        for test_case in test_cases {
            let base_http_headers =
                HeaderMap::from_iter(test_case.base_http_headers.into_iter().map(
                    |(name, value)| {
                        (
                            HeaderName::from_str(name).unwrap(),
                            HeaderValue::from_static(value),
                        )
                    },
                ));
            let original_http_header_order = test_case.original_http_header_order.map(|headers| {
                InputHeaderOrder(
                    headers
                        .into_iter()
                        .map(|header| HeaderName::from_str(header).unwrap())
                        .collect(),
                )
            });
            let original_headers = HeaderMap::from_iter(
                test_case.original_headers.into_iter().map(|(name, value)| {
                    (
                        HeaderName::from_static(name),
                        HeaderValue::from_static(value),
                    )
                }),
            );
            let preserve_ua_header = test_case.preserve_ua_header;
            let requested_client_hints = test_case.requested_client_hints.map(|hints| {
                hints
                    .into_iter()
                    .map(|hint| ClientHint::from_str(hint).unwrap())
                    .collect::<Vec<_>>()
            });

            let output_headers = merge_http_headers(
                &base_http_headers,
                original_http_header_order,
                original_headers,
                preserve_ua_header,
                Some(Cow::Borrowed(&test_case.request_authority)),
                Some(Cow::Borrowed(&test_case.protocol)),
                None,
                requested_client_hints.as_deref(),
            );

            let output_str = output_headers
                .into_ordered_iter()
                .map(|(name, value)| format!("{}: {}\r\n", name, value.to_str().unwrap()))
                .join("");

            let expected_str = test_case
                .expected
                .iter()
                .map(|(name, value)| format!("{name}: {value}\r\n"))
                .join("");

            assert_eq!(
                output_str, expected_str,
                "test case '{}' failed",
                test_case.description
            );
        }
    }

    #[tokio::test]
    async fn test_get_base_h2_headers() {
        let ua = UserAgent::new(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
        );

        let ua_profile = UserAgentProfile {
            ua_kind: ua.ua_kind().unwrap(),
            ua_version: ua.ua_version(),
            platform: ua.platform(),
            http: Arc::new(HttpProfile {
                h1: Http1Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::default(),
                        fetch: None,
                        xhr: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http1Settings::default(),
                },
                h2: Http2Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate"),
                        )]),
                        fetch: None,
                        xhr: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http2Settings::default(),
                },
            }),
            #[cfg(feature = "tls")]
            tls: Arc::new(crate::profile::TlsProfile {
                client_hello: rama_tls::client::ClientHello::new(
                    rama_tls::ProtocolVersion::TLSv1_3,
                    Vec::new(),
                    Vec::new(),
                    Vec::new(),
                ),
                ws_client_config_overwrites: None,
            }),
            runtime: None,
        };

        let ua_service = (
            UserAgentEmulateLayer::new(ua_profile),
            UserAgentEmulateHttpRequestModifierLayer::default(),
        )
            .into_layer(service_fn(async |req: Request| {
                Ok::<_, Infallible>(
                    req.headers()
                        .get(ETAG)
                        .map(|header| header.to_str().unwrap().to_owned())
                        .unwrap_or_default(),
                )
            }));

        let req = Request::builder()
            .method(Method::GET)
            .body(Body::empty())
            .unwrap();
        let res = ua_service.serve(req).await.unwrap();
        assert_eq!(res, "");

        let req = Request::builder()
            .method(Method::GET)
            .version(Version::HTTP_2)
            .body(Body::empty())
            .unwrap();
        let res = ua_service.serve(req).await.unwrap();
        assert_eq!(res, "navigate");
    }

    #[tokio::test]
    async fn test_get_base_http_headers_profile_with_only_navigate_headers() {
        let ua = UserAgent::new(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
        );
        let ua_profile = UserAgentProfile {
            ua_kind: ua.ua_kind().unwrap(),
            ua_version: ua.ua_version(),
            platform: ua.platform(),
            http: Arc::new(HttpProfile {
                h1: Http1Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate"),
                        )]),
                        xhr: None,
                        fetch: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http1Settings::default(),
                },
                h2: Http2Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::default(),
                        fetch: None,
                        xhr: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http2Settings::default(),
                },
            }),
            #[cfg(feature = "tls")]
            tls: Arc::new(crate::profile::TlsProfile {
                client_hello: rama_tls::client::ClientHello::new(
                    rama_tls::ProtocolVersion::TLSv1_3,
                    Vec::new(),
                    Vec::new(),
                    Vec::new(),
                ),
                ws_client_config_overwrites: None,
            }),
            runtime: None,
        };

        let ua_service = (
            UserAgentEmulateLayer::new(ua_profile),
            UserAgentEmulateHttpRequestModifierLayer::default(),
        )
            .into_layer(service_fn(async |req: Request| {
                Ok::<_, Infallible>(
                    req.headers()
                        .get(ETAG)
                        .map(|header| header.to_str().unwrap().to_owned())
                        .unwrap_or_default(),
                )
            }));

        let req = Request::builder()
            .method(Method::DELETE)
            .body(Body::empty())
            .unwrap();
        let res = ua_service.serve(req).await.unwrap();
        assert_eq!(res, "navigate");
    }

    #[tokio::test]
    async fn test_get_base_http_headers_profile_without_fetch_headers() {
        let ua = UserAgent::new(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
        );
        let ua_profile = UserAgentProfile {
            ua_kind: ua.ua_kind().unwrap(),
            ua_version: ua.ua_version(),
            platform: ua.platform(),
            http: Arc::new(HttpProfile {
                h1: Http1Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate"),
                        )]),
                        xhr: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("xhr"),
                        )])),
                        fetch: None,
                        form: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("form"),
                        )])),
                        ws: None,
                    },
                    settings: Http1Settings::default(),
                },
                h2: Http2Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::default(),
                        fetch: None,
                        xhr: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http2Settings::default(),
                },
            }),
            #[cfg(feature = "tls")]
            tls: Arc::new(crate::profile::TlsProfile {
                client_hello: rama_tls::client::ClientHello::new(
                    rama_tls::ProtocolVersion::TLSv1_3,
                    Vec::new(),
                    Vec::new(),
                    Vec::new(),
                ),
                ws_client_config_overwrites: None,
            }),
            runtime: None,
        };

        let ua_service = (
            UserAgentEmulateLayer::new(ua_profile),
            UserAgentEmulateHttpRequestModifierLayer::default(),
        )
            .into_layer(service_fn(async |req: Request| {
                Ok::<_, Infallible>(
                    req.headers()
                        .get(ETAG)
                        .map(|header| header.to_str().unwrap().to_owned())
                        .unwrap_or_default(),
                )
            }));

        let req = Request::builder()
            .method(Method::DELETE)
            .body(Body::empty())
            .unwrap();
        let res = ua_service.serve(req).await.unwrap();
        assert_eq!(res, "xhr");
    }

    #[tokio::test]
    async fn test_get_base_http_headers_profile_without_xhr_headers() {
        let ua = UserAgent::new(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
        );
        let ua_profile = UserAgentProfile {
            ua_kind: ua.ua_kind().unwrap(),
            ua_version: ua.ua_version(),
            platform: ua.platform(),
            http: Arc::new(HttpProfile {
                h1: Http1Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate"),
                        )]),
                        fetch: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("fetch"),
                        )])),
                        xhr: None,
                        form: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("form"),
                        )])),
                        ws: None,
                    },
                    settings: Http1Settings::default(),
                },
                h2: Http2Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::default(),
                        fetch: None,
                        xhr: None,
                        form: None,
                        ws: None,
                    },
                    settings: Http2Settings::default(),
                },
            }),
            #[cfg(feature = "tls")]
            tls: Arc::new(crate::profile::TlsProfile {
                client_hello: rama_tls::client::ClientHello::new(
                    rama_tls::ProtocolVersion::TLSv1_3,
                    Vec::new(),
                    Vec::new(),
                    Vec::new(),
                ),
                ws_client_config_overwrites: None,
            }),
            runtime: None,
        };

        let ua_service = (
            UserAgentEmulateLayer::new(ua_profile),
            UserAgentEmulateHttpRequestModifierLayer::default(),
        )
            .into_layer(service_fn(async |req: Request| {
                Ok::<_, Infallible>(
                    req.headers()
                        .get(ETAG)
                        .map(|header| header.to_str().unwrap().to_owned())
                        .unwrap_or_default(),
                )
            }));

        let req = Request::builder()
            .method(Method::DELETE)
            .header(
                HeaderName::from_static("x-requested-with"),
                "XmlHttpRequest",
            )
            .body(Body::empty())
            .unwrap();
        let res = ua_service.serve(req).await.unwrap();
        assert_eq!(res, "fetch");
    }

    #[tokio::test]
    async fn test_get_base_http_headers() {
        let ua = UserAgent::new(
            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
        );
        let ua_profile = UserAgentProfile {
            ua_kind: ua.ua_kind().unwrap(),
            ua_version: ua.ua_version(),
            platform: ua.platform(),
            http: Arc::new(HttpProfile {
                h1: Http1Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate"),
                        )]),
                        fetch: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("fetch"),
                        )])),
                        xhr: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("xhr"),
                        )])),
                        form: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("form"),
                        )])),
                        ws: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("ws"),
                        )])),
                    },
                    settings: Http1Settings::default(),
                },
                h2: Http2Profile {
                    headers: HttpHeadersProfile {
                        navigate: HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("navigate2"),
                        )]),
                        fetch: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("fetch2"),
                        )])),
                        xhr: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("xhr2"),
                        )])),
                        form: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("form2"),
                        )])),
                        ws: Some(HeaderMap::from_iter([(
                            ETAG,
                            HeaderValue::from_static("ws2"),
                        )])),
                    },
                    settings: Http2Settings::default(),
                },
            }),
            #[cfg(feature = "tls")]
            tls: Arc::new(crate::profile::TlsProfile {
                client_hello: rama_tls::client::ClientHello::new(
                    rama_tls::ProtocolVersion::TLSv1_3,
                    Vec::new(),
                    Vec::new(),
                    Vec::new(),
                ),
                ws_client_config_overwrites: None,
            }),
            runtime: None,
        };

        let ua_service = (
            UserAgentEmulateLayer::new(ua_profile),
            UserAgentEmulateHttpRequestModifierLayer::default(),
        )
            .into_layer(service_fn(async |req: Request| {
                Ok::<_, Infallible>(
                    req.headers()
                        .get(ETAG)
                        .map(|header| header.to_str().unwrap().to_owned())
                        .unwrap_or_default(),
                )
            }));

        struct TestCase {
            description: &'static str,
            version: Option<Version>,
            method: Option<Method>,
            headers: Option<HeaderMap>,
            extensions: Option<Extensions>,
            expected: &'static str,
        }

        let test_cases = [
            TestCase {
                description: "GET request",
                version: None,
                method: None,
                headers: None,
                extensions: None,
                expected: "navigate",
            },
            TestCase {
                description: "GET request with XRW header",
                version: None,
                method: None,
                headers: Some(
                    [(
                        HeaderName::from_static("x-requested-with"),
                        HeaderValue::from_static("XmlHttpRequest"),
                    )]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "xhr",
            },
            TestCase {
                description: "GET request with RequestInitiator hint Navigate",
                version: None,
                method: None,
                headers: None,
                extensions: Some({
                    let extensions = Extensions::default();
                    extensions.insert(RequestInitiator::Navigate);
                    extensions
                }),
                expected: "navigate",
            },
            TestCase {
                description: "GET request with RequestInitiator hint Form",
                version: None,
                method: None,
                headers: None,
                extensions: Some({
                    let extensions = Extensions::default();
                    extensions.insert(RequestInitiator::Form);
                    extensions
                }),
                expected: "form",
            },
            TestCase {
                description: "explicit GET request",
                version: None,
                method: Some(Method::GET),
                headers: None,
                extensions: None,
                expected: "navigate",
            },
            TestCase {
                description: "HTTP/1.1 WebSocket upgrade request",
                version: None,
                method: Some(Method::GET),
                headers: Some(
                    [(SEC_WEBSOCKET_VERSION, HeaderValue::from_static("13"))]
                        .into_iter()
                        .collect(),
                ),
                extensions: None,
                expected: "ws",
            },
            TestCase {
                description: "H2 WebSocket upgrade request",
                version: Some(Version::HTTP_2),
                method: Some(Method::CONNECT),
                headers: Some(
                    [(SEC_WEBSOCKET_VERSION, HeaderValue::from_static("13"))]
                        .into_iter()
                        .collect(),
                ),
                extensions: None,
                expected: "ws2",
            },
            TestCase {
                description: "explicit POST request",
                version: None,
                method: Some(Method::POST),
                headers: None,
                extensions: None,
                expected: "fetch",
            },
            TestCase {
                description: "explicit POST request with XRW header",
                version: None,
                method: Some(Method::POST),
                headers: Some(
                    [(
                        HeaderName::from_static("x-requested-with"),
                        HeaderValue::from_static("XmlHttpRequest"),
                    )]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "xhr",
            },
            TestCase {
                description: "explicit POST request with multipart/form-data and XRW header",
                version: None,
                method: Some(Method::POST),
                headers: Some(
                    [
                        (
                            CONTENT_TYPE,
                            HeaderValue::from_static(
                                "multipart/form-data; boundary=ExampleBoundaryString",
                            ),
                        ),
                        (
                            HeaderName::from_static("x-requested-with"),
                            HeaderValue::from_static("XmlHttpRequest"),
                        ),
                    ]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "xhr",
            },
            TestCase {
                description: "explicit POST request with application/x-www-form-urlencoded and XRW header",
                version: None,
                method: Some(Method::POST),
                headers: Some(
                    [
                        (
                            CONTENT_TYPE,
                            HeaderValue::from_static("application/x-www-form-urlencoded"),
                        ),
                        (
                            HeaderName::from_static("x-requested-with"),
                            HeaderValue::from_static("XmlHttpRequest"),
                        ),
                    ]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "xhr",
            },
            TestCase {
                description: "explicit POST request with multipart/form-data",
                version: None,
                method: Some(Method::POST),
                headers: Some(
                    [(
                        CONTENT_TYPE,
                        HeaderValue::from_static(
                            "multipart/form-data; boundary=ExampleBoundaryString",
                        ),
                    )]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "form",
            },
            TestCase {
                description: "explicit POST request with application/x-www-form-urlencoded",
                version: None,
                method: Some(Method::POST),
                headers: Some(
                    [(
                        CONTENT_TYPE,
                        HeaderValue::from_static("application/x-www-form-urlencoded"),
                    )]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "form",
            },
            TestCase {
                description: "explicit DELETE request with XRW header",
                version: None,
                method: Some(Method::DELETE),
                headers: Some(
                    [(
                        HeaderName::from_static("x-requested-with"),
                        HeaderValue::from_static("XmlHttpRequest"),
                    )]
                    .into_iter()
                    .collect(),
                ),
                extensions: None,
                expected: "xhr",
            },
            TestCase {
                description: "explicit DELETE request",
                version: None,
                method: Some(Method::DELETE),
                headers: None,
                extensions: None,
                expected: "fetch",
            },
            TestCase {
                description: "explicit DELETE request with RequestInitiator hint",
                version: None,
                method: Some(Method::DELETE),
                headers: None,
                extensions: Some({
                    let extensions = Extensions::default();
                    extensions.insert(RequestInitiator::Xhr);
                    extensions
                }),
                expected: "xhr",
            },
        ];

        for test_case in test_cases {
            let mut req = Request::builder()
                .version(test_case.version.unwrap_or(Version::HTTP_11))
                .method(test_case.method.unwrap_or(Method::GET))
                .body(Body::empty())
                .unwrap();
            if let Some(headers) = test_case.headers {
                req.headers_mut().extend(headers);
            }
            if let Some(extensions) = test_case.extensions {
                req.extensions().extend(&extensions);
            }

            let res = ua_service.serve(req).await.unwrap();
            assert_eq!(res, test_case.expected, "{}", test_case.description);
        }
    }

    #[test]
    fn test_compute_sec_fetch_site_value() {
        #[derive(Debug)]
        struct TestCase {
            referer: Option<&'static str>,
            method: Option<Method>,
            protocol: Protocol,
            request_authority: HostWithOptPort,
            expected_value: &'static str,
        }

        let test_cases = [
            TestCase {
                referer: None,
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "none",
            },
            TestCase {
                referer: Some("http://example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "same-origin",
            },
            TestCase {
                referer: Some("http://example.com:8080/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "same-site",
            },
            TestCase {
                referer: Some("https://example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "cross-site",
            },
            TestCase {
                referer: Some("http://example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTPS,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "cross-site",
            },
            TestCase {
                referer: Some("http://example.be/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "cross-site",
            },
            TestCase {
                referer: Some("http://sub.example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::example_domain_http(),
                expected_value: "same-site",
            },
            TestCase {
                referer: Some("http://example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("sub.example.com")),
                    Protocol::HTTP_DEFAULT_PORT,
                ),
                expected_value: "same-site",
            },
            TestCase {
                referer: Some("http://a.example.com/foo?q=1"),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("b.example.com")),
                    Protocol::HTTP_DEFAULT_PORT,
                ),
                expected_value: "same-site",
            },
            TestCase {
                referer: Some("......."),
                method: None,
                protocol: Protocol::HTTP,
                request_authority: HostWithOptPort::new_with_port(
                    Host::Name(Domain::from_static("b.example.com")),
                    Protocol::HTTP_DEFAULT_PORT,
                ),
                expected_value: "cross-site",
            },
        ];

        for test_case in test_cases {
            let original_header_referer_value = test_case.referer.map(HeaderValue::from_static);
            let computed_value = compute_sec_fetch_site_value(
                original_header_referer_value.as_ref(),
                test_case.method.as_ref(),
                Some(&test_case.protocol),
                Some(&test_case.request_authority),
            );
            assert_eq!(
                computed_value.to_str().unwrap(),
                test_case.expected_value,
                "test_case: {test_case:?}",
            );
        }
    }
}