/*
 * Hurl (https://hurl.dev)
 * Copyright (C) 2026 Orange
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *          http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
use std::collections::HashMap;
use std::str;
use std::str::FromStr;
use std::time::Instant;

use base64::Engine;
use base64::engine::general_purpose;
use chrono::Utc;
use curl::easy::{List, NetRc, SslOpt};
use curl::{Error, Version, easy};
use hurl_core::types::Count;

use super::call::Call;
use super::certificate::Certificate;
use super::cookie_store::{Cookie, CookieStore};
use super::curl_cmd::CurlCmd;
use super::debug;
use super::easy_ext;
use super::error::HttpError;
use super::header::{
    ACCEPT_ENCODING, AUTHORIZATION, CONTENT_TYPE, COOKIE, EXPECT, Header, HeaderVec, LOCATION,
    USER_AGENT,
};
use super::ip::IpAddr;
use super::options::{ClientOptions, Verbosity};
use super::param::Param;
use super::request::{
    CredentialForwarding, FollowLocation, IpResolve, Request, RequestedHttpVersion,
};
use super::request_cookie::RequestCookie;
use super::request_spec::{Body, FileParam, Method, MultipartParam, RequestSpec};
use super::response::{HttpVersion, Response};
use super::timings::Timings;
use super::url::Url;

use crate::runner::Output;
use crate::util::logger::Logger;
use crate::util::path::ContextDir;

/// Defines an HTTP client to execute HTTP requests.
///
/// Most of the methods are delegated to libcurl functions, while some
/// features are implemented "by hand" (like retry, redirection etc...)
#[derive(Debug)]
pub struct Client {
    /// The handle to libcurl binding
    handle: easy::Easy,
    /// HTTP version support
    http2: bool,
    http3: bool,
    /// Certificates cache to get SSL certificates on reused libcurl connections.
    certificates: HashMap<i64, Certificate>,
}

impl Client {
    /// Creates HTTP Hurl client.
    pub fn new() -> Client {
        let handle = easy::Easy::new();
        let version = Version::get();
        Client {
            handle,
            http2: version.feature_http2(),
            http3: version.feature_http3(),
            certificates: HashMap::new(),
        }
    }

    /// Executes an HTTP request `request_spec`, optionally follows redirection and returns a list of [`Call`].
    pub fn execute_with_redirect(
        &mut self,
        request_spec: &RequestSpec,
        options: &ClientOptions,
        logger: &mut Logger,
    ) -> Result<Vec<Call>, HttpError> {
        let mut calls = vec![];

        let original_url = &request_spec.url;
        let mut request_spec = request_spec.clone();
        let mut options = options.clone();

        // Unfortunately, follow-location feature from libcurl can not be used as libcurl returns a
        // single list of headers for the 2 responses and Hurl needs to keep every header of every
        // response.
        let mut redirect_count = 0;
        loop {
            let call = self.execute(&request_spec, &options, logger)?;
            // If we don't follow redirection, we can early exit here.
            if matches!(options.follow_location, FollowLocation::No) {
                calls.push(call);
                break;
            }
            let request_url = call.request.url.clone();
            let status = call.response.status;
            let redirect_url = self.follow_location(&request_url, &call.response)?;
            calls.push(call);
            if redirect_url.is_none() {
                break;
            }
            let redirect_url = redirect_url.unwrap();
            logger.debug("");
            logger.debug(&format!("=> Redirect to {redirect_url}"));
            logger.debug("");
            redirect_count += 1;
            if let Count::Finite(max_redirect) = options.max_redirect
                && redirect_count > max_redirect
            {
                return Err(HttpError::TooManyRedirect);
            };

            let redirect_method = redirect_method(status, &request_spec.method);
            let mut headers = request_spec.headers;

            // When following redirection, we filter `Authorization` and `Set-Cookie` headers if the
            // hostname changes unless the user explicitly trusts the redirected host with `--location-trusted`.
            // <https://curl.se/libcurl/c/CURLOPT_FOLLOWLOCATION.html>:
            //
            // > By default, libcurl only sends Authentication: or explicitly set Cookie: headers
            // > to the initial host given in the original URL, to avoid leaking username + password
            // > to other sites.
            if should_strip_credentials_on_redirect(
                original_url,
                &redirect_url,
                options.follow_location,
            ) {
                headers.retain(|h| !h.name_eq(AUTHORIZATION));
                headers.retain(|h| !h.name_eq(COOKIE));
                options.user = None;
            }

            // If the request method has changed due to redirection, the body is dropped from the
            // request, otherwise we keep it. We follow libcurl implementation <https://curl.se/libcurl/c/CURLOPT_FOLLOWLOCATION.html>:
            //
            // > When libcurl switches method to GET, it then uses that method without sending any
            // > request body. If it does not change the method, it sends the subsequent request the
            // > same way as the previous one; including the request body if one was provided.
            let (form, multipart, body, implicit_content_type) =
                if redirect_method != request_spec.method {
                    (vec![], vec![], Body::Binary(vec![]), None)
                } else {
                    (
                        request_spec.form,
                        request_spec.multipart,
                        request_spec.body,
                        request_spec.implicit_content_type,
                    )
                };
            request_spec = RequestSpec {
                method: redirect_method,
                url: redirect_url,
                headers,
                querystring: vec![],
                form,
                multipart,
                cookies: request_spec.cookies,
                body,
                implicit_content_type,
            };
        }
        Ok(calls)
    }

    /// Executes an HTTP request `request_spec`, without following redirection and returns a
    /// pair of [`Call`].
    pub fn execute(
        &mut self,
        request_spec: &RequestSpec,
        options: &ClientOptions,
        logger: &mut Logger,
    ) -> Result<Call, HttpError> {
        // The handle can be mutated in this function: to start from a clean state, we reset it
        // prior to everything.
        self.handle.reset();

        let (url, method) = self.configure(request_spec, options, logger)?;

        let start = Instant::now();
        let start_dt = Utc::now();
        let verbose = options.verbosity.is_some();
        let very_verbose = options.verbosity == Some(Verbosity::VeryVerbose);
        let mut request_headers = HeaderVec::new();
        let mut status_lines = None;
        let mut response_headers = vec![];
        let has_body_data = !request_spec.body.bytes().is_empty()
            || !request_spec.form.is_empty()
            || !request_spec.multipart.is_empty();

        // `request_body` are request body bytes computed by libcurl (the real bytes sent over the wire)
        // whereas`request_spec_body` are request body bytes provided by Hurl user. For instance, if user uses
        // a [FormParam] section, `request_body` is empty whereas libcurl sent a url-form encoded list
        // of key-value.
        let mut request_body = Vec::<u8>::new();
        let mut response_body = Vec::<u8>::new();

        {
            let mut transfer = self.handle.transfer();

            transfer.debug_function(|info_type, data| match info_type {
                // Return all request headers (not one by one)
                easy::InfoType::HeaderOut => {
                    let lines = split_lines(data);
                    // Extracts request headers from libcurl debug info.
                    // First line is method/path/version line, last line is empty
                    for line in &lines[1..lines.len() - 1] {
                        if let Some(header) = Header::parse(line) {
                            request_headers.push(header);
                        }
                    }

                    // Logs method, version and request headers now.
                    if verbose {
                        logger.debug_method_version_out(&lines[0]);
                        let headers = request_headers
                            .iter()
                            .map(|h| (h.name.as_str(), h.value.as_str()))
                            .collect::<Vec<_>>();
                        logger.debug_headers_out(&headers);
                    }

                    // If we don't send any data, we log an empty body here instead of relying on
                    // libcurl computing body in `easy::InfoType::DataOut` because libcurl doesn't
                    // call `easy::InfoType::DataOut` if there is no data to send.
                    if !has_body_data && very_verbose {
                        logger.debug_important("Request body:");
                        debug::log_body(&[], &request_headers, true, logger);
                    }
                }
                // We use this callback to get the real body bytes sent by libcurl and logs request
                // body chunks.
                easy::InfoType::DataOut => {
                    if very_verbose {
                        logger.debug_important("Request body:");
                        debug::log_body(data, &request_headers, true, logger);
                    }
                    // Constructs request body from libcurl debug info.
                    request_body.extend(data);
                }
                // Curl debug logs
                easy::InfoType::Text => {
                    let len = data.len();
                    if very_verbose && len > 0 {
                        let text = str::from_utf8(&data[..len - 1]);
                        if let Ok(text) = text {
                            logger.debug_curl(text);
                        }
                    }
                }
                _ => {}
            })?;
            transfer.header_function(|h| {
                if let Some(s) = decode_header(h) {
                    if s.starts_with("HTTP/") {
                        status_lines = Some(s);
                    } else {
                        response_headers.push(s);
                    }
                }
                true
            })?;

            transfer.write_function(|data| {
                response_body.extend(data);
                Ok(data.len())
            })?;

            if let Err(e) = transfer.perform() {
                let code = e.code() as i32; // due to windows build
                let description = match e.extra_description() {
                    None => e.description().to_string(),
                    Some(s) => s.to_string(),
                };
                return Err(HttpError::Libcurl { code, description });
            }
        }

        // We perform an additional check on the response size if maximum filesize is specified
        // because curl can fail to do this under certain circumstances.
        // See:
        // - <https://github.com/Orange-OpenSource/hurl/issues/3245>
        // - <https://curl.se/docs/manpage.html#--max-filesize>
        // > Note: before curl 8.4.0, when the file size is not known prior to download, for such files
        // > this option has no effect even if the file transfer ends up being larger than this given limit.
        if let Some(max_filesize) = options.max_filesize
            && response_body.len() as u64 > max_filesize
        {
            return Err(HttpError::AllowedResponseSizeExceeded(max_filesize));
        }

        let status = self.handle.response_code()?;
        let version = match &status_lines {
            Some(status_line) => self.parse_response_version(status_line)?,
            None => return Err(HttpError::CouldNotParseResponse),
        };
        let headers = self.parse_response_headers(&response_headers);
        let length = response_body.len();

        let certificate = self.cert_info(logger)?;
        let duration = start.elapsed();
        let stop_dt = start_dt + duration;
        let timings = Timings::new(&mut self.handle, start_dt, stop_dt);

        let url = Url::from_str(&url)?;
        let ip_addr = self.primary_ip()?;
        let request = Request::new(
            &method.to_string(),
            url.clone(),
            request_headers,
            request_body,
        );
        let response = Response::new(
            version,
            status,
            headers,
            response_body,
            duration,
            url,
            certificate,
            ip_addr,
        );

        if verbose {
            // FIXME: the cast to u64 seems not necessary.
            //  If we dont cast from u128 and try to format! or println!
            //  we have a segfault on Alpine Docker images and Rust 1.68.0, whereas it was
            //  ok with Rust >= 1.67.0.
            let duration = duration.as_millis() as u64;
            logger.debug_important(&format!(
                "Response: (received {length} bytes in {duration} ms)"
            ));
            logger.debug("");

            // FIXME: Explain why there may be multiple status line
            status_lines
                .iter()
                .filter(|s| s.starts_with("HTTP/"))
                .for_each(|s| logger.debug_status_version_in(s.trim()));

            let headers = response
                .headers
                .iter()
                .map(|h| (h.name.as_str(), h.value.as_str()))
                .collect::<Vec<_>>();
            logger.debug_headers_in(&headers);

            if very_verbose {
                logger.debug_important("Response body:");
                response.log_body(true, logger);
                logger.debug("");
                timings.log(logger);
            }
        }

        Ok(Call {
            request,
            response,
            timings,
        })
    }

    /// Configure libcurl handle to send a `request_spec`, using `options`.
    /// If configuration is successful, returns a tuple of the concrete requested URL and method.
    fn configure(
        &mut self,
        request_spec: &RequestSpec,
        options: &ClientOptions,
        logger: &mut Logger,
    ) -> Result<(String, Method), HttpError> {
        // Activates cookie engine.
        // See <https://curl.se/libcurl/c/CURLOPT_COOKIEFILE.html>
        // > It also enables the cookie engine, making libcurl parse and send cookies on subsequent
        // > requests with this handle.
        // > By passing the empty string ("") to this option, you enable the cookie
        // > engine without reading any initial cookies.
        if options.use_cookie_store {
            self.handle
                .cookie_file(options.cookie_input_file.clone().unwrap_or_default())?;
        }
        // FIXME: implements the else branch.
        // We want to set CURLOPT_COOKIEFILE to NULL in case `options.use_cookie_store` is `false`
        // because we want to support `--no-cookie-store` per request (for the moment the option is cli only).
        // If a handle has been configured to use cookie storage, it should be reset if we deactivate
        // cookie mid-file with a per-request

        // We check libcurl HTTP version support.
        let http_version = options.http_version;
        if (http_version == RequestedHttpVersion::Http2 && !self.http2)
            || (http_version == RequestedHttpVersion::Http3 && !self.http3)
        {
            return Err(HttpError::UnsupportedHttpVersion(http_version));
        }

        if !options.allow_reuse {
            logger.debug("Force refreshing connections because requested HTTP version change");
        }
        self.handle.fresh_connect(!options.allow_reuse)?;
        self.handle.forbid_reuse(!options.allow_reuse)?;
        self.handle.http_version(options.http_version.into())?;

        self.handle.ip_resolve(options.ip_resolve.into())?;

        // Activates the access of certificates info chain after a transfer has been executed.
        self.handle.certinfo(true)?;

        if !options.connects_to.is_empty() {
            let connects = to_list(&options.connects_to)?;
            self.handle.connect_to(connects)?;
        }
        if !options.resolves.is_empty() {
            let resolves = to_list(&options.resolves)?;
            self.handle.resolve(resolves)?;
        }
        self.handle.ssl_verify_host(!options.insecure)?;
        self.handle.ssl_verify_peer(!options.insecure)?;
        if let Some(cacert_file) = &options.cacert_file {
            self.handle.cainfo(cacert_file)?;
            self.handle.ssl_cert_type("PEM")?;
        }
        if let Some(client_cert_file) = &options.client_cert_file {
            match parse_cert_password(client_cert_file) {
                (cert, Some(password)) => {
                    self.handle.ssl_cert(cert)?;
                    self.handle.key_password(&password)?;
                }
                (cert, None) => {
                    self.handle.ssl_cert(cert)?;
                }
            }
            self.handle.ssl_cert_type("PEM")?;
        }
        if let Some(client_key_file) = &options.client_key_file {
            self.handle.ssl_key(client_key_file)?;
            self.handle.ssl_cert_type("PEM")?;
        }
        self.handle.path_as_is(options.path_as_is)?;
        if let Some(proxy) = &options.proxy {
            self.handle.proxy(proxy)?;
        }
        if let Some(no_proxy) = &options.no_proxy {
            self.handle.noproxy(no_proxy)?;
        }
        if let Some(unix_socket) = &options.unix_socket {
            self.handle.unix_socket(unix_socket)?;
        }
        if let Some(filename) = &options.netrc_file {
            easy_ext::netrc_file(&mut self.handle, filename)?;
            self.handle.netrc(if options.netrc_optional {
                NetRc::Optional
            } else {
                NetRc::Required
            })?;
        } else if options.netrc_optional {
            self.handle.netrc(NetRc::Optional)?;
        } else if options.netrc {
            self.handle.netrc(NetRc::Required)?;
        }
        self.handle.timeout(options.timeout)?;
        self.handle.connect_timeout(options.connect_timeout)?;
        if let Some(max_filesize) = options.max_filesize {
            self.handle.max_filesize(max_filesize)?;
        }
        if let Some(max_recv_speed) = options.max_recv_speed {
            self.handle.max_recv_speed(max_recv_speed.0)?;
        }
        if let Some(max_send_speed) = options.max_send_speed {
            self.handle.max_send_speed(max_send_speed.0)?;
        }
        if let Some(pinned_pub_key) = &options.pinned_pub_key {
            self.handle.pinned_public_key(pinned_pub_key)?;
        }
        if options.digest || options.ntlm || options.negotiate {
            let mut auth = easy::Auth::new();
            if options.digest {
                auth.digest(true);
            }
            if options.ntlm {
                auth.ntlm(true);
            }
            if options.negotiate {
                auth.gssnegotiate(true);
            }
            self.handle.http_auth(&auth)?;
        }

        self.set_ssl_options(options.ssl_no_revoke)?;

        let url = self.generate_url(&request_spec.url, &request_spec.querystring);
        self.handle.url(url.as_str())?;
        let method = &request_spec.method;
        self.set_method(method)?;
        self.set_cookies(&request_spec.cookies)?;
        self.set_form(&request_spec.form)?;
        self.set_multipart(&request_spec.multipart)?;
        let request_spec_body = &request_spec.body.bytes();
        self.set_body(request_spec_body)?;

        let mut headers = request_spec.headers.clone();
        headers.extend(&options.headers);
        self.set_headers(
            &headers,
            request_spec.implicit_content_type.as_deref(),
            options,
        )?;
        if let Some(aws_sigv4) = &options.aws_sigv4
            && let Err(e) = self.handle.aws_sigv4(aws_sigv4.as_str())
        {
            return match e.code() {
                curl_sys::CURLE_UNKNOWN_OPTION => Err(HttpError::LibcurlUnknownOption {
                    option: "aws-sigv4".to_string(),
                    minimum_version: "7.75.0".to_string(),
                }),
                _ => Err(e.into()),
            };
        }
        if *method == Method("HEAD".to_string()) {
            self.handle.nobody(true)?;
        }

        // We force libcurl verbose mode regardless of Hurl verbose option to be able to capture HTTP
        // request headers in libcurl `debug_function`. That's the only way to get access to the
        // outgoing headers. We call this at the end of the libcurl handle configuration to avoid
        // unwanted noisy logs from curl (see <https://github.com/Orange-OpenSource/hurl/issues/4406>)
        self.handle.verbose(true)?;

        Ok((url, method.clone()))
    }

    /// Generates URL.
    fn generate_url(&mut self, url: &Url, params: &[Param]) -> String {
        let url = url.raw();
        if params.is_empty() {
            url
        } else {
            let url = if url.ends_with('?') {
                url
            } else if url.contains('?') {
                format!("{url}&")
            } else {
                format!("{url}?")
            };
            let s = self.url_encode_params(params);
            format!("{url}{s}")
        }
    }

    /// Sets HTTP method.
    fn set_method(&mut self, method: &Method) -> Result<(), HttpError> {
        self.handle.custom_request(method.to_string().as_str())?;
        Ok(())
    }

    /// Sets HTTP headers.
    fn set_headers(
        &mut self,
        headers: &HeaderVec,
        implicit_content_type: Option<&str>,
        options: &ClientOptions,
    ) -> Result<(), HttpError> {
        let mut list = headers.to_curl_headers()?;

        // If request has no `Content-Type` header, we set it if the content type has been set
        // implicitly on this request.
        if !headers.contains_key(CONTENT_TYPE) {
            if let Some(s) = implicit_content_type {
                list.append(&format!("{CONTENT_TYPE}: {s}"))?;
            } else {
                // We remove default `Content-Type` headers added by curl because we want to
                // explicitly manage this header.
                // For instance, with --data option, curl will send a `Content-type: application/x-www-form-urlencoded`
                // header. From <https://curl.se/libcurl/c/CURLOPT_HTTPHEADER.html>, we can delete
                // the headers added by libcurl by adding a header with no content.
                list.append(&format!("{CONTENT_TYPE}:"))?;
            }
        }

        // Workaround for libcurl issue <https://github.com/curl/curl/issues/11664>:
        // When Hurl explicitly sets `Expect:` to remove the header, libcurl will generate
        // `SignedHeaders` that include `expect` even though the header is not present, causing
        // some APIs to reject the request.
        // Therefore, we only remove this header when not in aws_sigv4 mode.
        if !headers.contains_key(EXPECT) && options.aws_sigv4.is_none() {
            // We remove default Expect headers added by curl because we want to explicitly manage
            // this header.
            list.append(&format!("{EXPECT}:"))?;
        }

        if !headers.contains_key(USER_AGENT) {
            let user_agent = match options.user_agent {
                Some(ref u) => u.clone(),
                None => {
                    let pkg_version = env!("CARGO_PKG_VERSION");
                    format!("hurl/{pkg_version}")
                }
            };
            list.append(&format!("{USER_AGENT}: {user_agent}"))?;
        }

        if let Some(user) = &options.user {
            if options.aws_sigv4.is_some() || options.digest || options.ntlm || options.negotiate {
                // curl's aws_sigv4 support needs to know the username and password for the
                // request, as it uses those values to calculate the Authorization header for the
                // AWS V4 signature.
                //
                // --digest requires a username and password to be provided in order to complete the
                // authentication process. With curl, this would be `--digest -u username:password`
                //
                // --ntlm requires a username and password to be provided in order to complete the
                // authentication process. With curl, this would be `-u username:password`
                //
                // --negotiate requires a username and password, though they are not used.
                // From the curl man page:
                // > When using this option, you must also provide a fake `-u, --user` option to
                // > activate the authentication code properly. Sending a '-u :' is enough, as the
                // > username and password from the `-u, --user` option are not actually used.
                if let Some((username, password)) = user.split_once(':') {
                    self.handle.username(username)?;
                    self.handle.password(password)?;
                }
            } else {
                let user = user.as_bytes();
                let authorization = general_purpose::STANDARD.encode(user);
                if !headers.contains_key(AUTHORIZATION) {
                    list.append(&format!("{AUTHORIZATION}: Basic {authorization}"))?;
                }
            }
        }
        if options.compressed && !headers.contains_key(ACCEPT_ENCODING) {
            list.append(&format!("{ACCEPT_ENCODING}: gzip, deflate, br"))?;
        }

        self.handle.http_headers(list)?;
        Ok(())
    }

    /// Sets request cookies.
    fn set_cookies(&mut self, cookies: &[RequestCookie]) -> Result<(), HttpError> {
        let s = cookies
            .iter()
            .map(|c| c.to_string())
            .collect::<Vec<String>>()
            .join("; ");
        if !s.is_empty() {
            self.handle.cookie(s.as_str())?;
        }
        Ok(())
    }

    /// Sets form params.
    fn set_form(&mut self, params: &[Param]) -> Result<(), HttpError> {
        if !params.is_empty() {
            let s = self.url_encode_params(params);
            self.handle.post_fields_copy(s.as_bytes())?;
        }
        Ok(())
    }

    /// Sets multipart form data.
    fn set_multipart(&mut self, params: &[MultipartParam]) -> Result<(), HttpError> {
        if !params.is_empty() {
            let mut form = easy::Form::new();
            for param in params {
                match param {
                    MultipartParam::Param(Param { name, value }) => {
                        form.part(name).contents(value.as_bytes()).add()?;
                    }
                    MultipartParam::FileParam(FileParam {
                        name,
                        filename,
                        data,
                        content_type,
                    }) => form
                        .part(name)
                        .buffer(filename, data.clone())
                        .content_type(content_type)
                        .add()?,
                }
            }
            self.handle.httppost(form)?;
        }
        Ok(())
    }

    /// Sets request body.
    fn set_body(&mut self, data: &[u8]) -> Result<(), HttpError> {
        if !data.is_empty() {
            self.handle.post(true)?;
            self.handle.post_fields_copy(data)?;
        }
        Ok(())
    }

    /// Sets SSL options
    fn set_ssl_options(&mut self, no_revoke: bool) -> Result<(), HttpError> {
        let mut ssl_opt = SslOpt::new();
        ssl_opt.no_revoke(no_revoke);
        self.handle.ssl_options(&ssl_opt)?;
        Ok(())
    }

    /// URL encodes parameters.
    fn url_encode_params(&mut self, params: &[Param]) -> String {
        params
            .iter()
            .map(|p| {
                let value = self.handle.url_encode(p.value.as_bytes());
                format!("{}={}", p.name, value)
            })
            .collect::<Vec<String>>()
            .join("&")
    }

    /// Parses HTTP response version.
    fn parse_response_version(&mut self, line: &str) -> Result<HttpVersion, HttpError> {
        if line.starts_with("HTTP/1.0") {
            Ok(HttpVersion::Http10)
        } else if line.starts_with("HTTP/1.1") {
            Ok(HttpVersion::Http11)
        } else if line.starts_with("HTTP/2") {
            Ok(HttpVersion::Http2)
        } else if line.starts_with("HTTP/3") {
            Ok(HttpVersion::Http3)
        } else {
            Err(HttpError::CouldNotParseResponse)
        }
    }

    /// Parse headers from libcurl responses.
    fn parse_response_headers(&mut self, lines: &[String]) -> HeaderVec {
        let mut headers = HeaderVec::new();
        for line in lines {
            if let Some(header) = Header::parse(line) {
                headers.push(header);
            }
        }
        headers
    }

    /// Get the IP address of the last connection from libcurl
    fn primary_ip(&mut self) -> Result<IpAddr, HttpError> {
        match self.handle.primary_ip()? {
            Some(ip) => Ok(IpAddr::new(ip.to_string())),
            None => Err(HttpError::NoPrimaryIp),
        }
    }

    /// Retrieves an optional location to follow
    ///
    /// You need:
    /// 1. the option follow_location set to true
    /// 2. a 3xx response code
    /// 3. a header Location
    fn follow_location(
        &mut self,
        request_url: &Url,
        response: &Response,
    ) -> Result<Option<Url>, HttpError> {
        let response_code = response.status;
        if !(300..400).contains(&response_code) {
            return Ok(None);
        }
        let Some(location) = response.headers.get(LOCATION) else {
            return Ok(None);
        };
        let url = request_url.join(&location.value)?;
        Ok(Some(url))
    }

    /// Returns cookie store.
    pub fn cookie_store(&mut self, logger: &mut Logger) -> CookieStore {
        let mut cookie_store = CookieStore::new();

        let Ok(list) = self.handle.cookies() else {
            logger.warning("Cannot get cookies from libcurl");
            return cookie_store;
        };

        for cookie in list.iter() {
            let line = str::from_utf8(cookie).unwrap();
            if cookie_store.add_cookie(line).is_err() {
                logger.warning(&format!("Line <{line}> can not be parsed as cookie"));
            }
        }
        cookie_store
    }

    /// Adds a cookie to the cookie jar (experimental).
    pub fn add_cookie(&mut self, cookie: &Cookie, logger: &mut Logger) {
        logger.debug(&format!("Add to cookie store <{cookie}> (experimental)"));
        self.handle.cookie_list(&cookie.to_netscape()).unwrap();
    }

    /// Clears cookie storage (experimental).
    pub fn clear_cookie_storage(&mut self, logger: &mut Logger) {
        logger.debug("Clear cookie storage (experimental)");
        self.handle.cookie_list("ALL").unwrap();
    }

    /// Returns curl command-line for the HTTP `request_spec` run by this client.
    pub fn curl_command_line(
        &mut self,
        request_spec: &RequestSpec,
        context_dir: &ContextDir,
        output: Option<&Output>,
        options: &ClientOptions,
        logger: &mut Logger,
    ) -> CurlCmd {
        let cookies = self.cookie_store(logger);
        CurlCmd::new(request_spec, &cookies, context_dir, output, options)
    }

    /// Returns the SSL certificates information associated to this call.
    ///
    /// Certificate information are cached by libcurl handle connection id, in order to get
    /// SSL information even if libcurl connection is reused (see <https://github.com/Orange-OpenSource/hurl/issues/3031>).
    fn cert_info(&mut self, logger: &mut Logger) -> Result<Option<Certificate>, HttpError> {
        if let Some(cert_info) = easy_ext::cert_info(&self.handle)? {
            match Certificate::try_from(cert_info) {
                Ok(value) => {
                    // We try to get the connection id for the libcurl handle and cache the
                    // certificate. Getting a connection id can fail on older libcurl version, we
                    // don't cache the certificate in these cases.
                    if let Ok(conn_id) = easy_ext::conn_id(&self.handle) {
                        self.certificates.insert(conn_id, value.clone());
                    }
                    Ok(Some(value))
                }
                Err(message) => {
                    logger.warning(&format!("Can not parse certificate - {message}"));
                    Ok(None)
                }
            }
        } else {
            // We query the cache to see if we have a cached certificate for this connection;
            // As libcurl 8.2.0+ exposes the connection id through `CURLINFO_CONN_ID`, we don't
            // raise an error if we can't get a connection id (older version than 8.2.0), and return
            // a `None` certificate.
            match easy_ext::conn_id(&self.handle) {
                Ok(conn_id) => Ok(self.certificates.get(&conn_id).cloned()),
                Err(_) => Ok(None),
            }
        }
    }
}

/// Tests if credentials (`Authorization:`, `Cookie:` headers) should be filtered when there is a redirection
/// from the first `original_url` to `redirect_url`.
fn should_strip_credentials_on_redirect(
    original_url: &Url,
    redirect_url: &Url,
    follow_location: FollowLocation,
) -> bool {
    if matches!(
        follow_location,
        FollowLocation::Follow(CredentialForwarding::AllHosts)
    ) {
        return false;
    }
    // Different origin != strip credentials
    if original_url.scheme() != redirect_url.scheme() {
        return true;
    }
    if original_url.host() != redirect_url.host() {
        return true;
    }
    // Treat different ports as different origins
    original_url.port() != redirect_url.port()
}

/// Returns the method used for redirecting a request/response with `response_status`.
fn redirect_method(response_status: u32, original_method: &Method) -> Method {
    // This replicates curl's behavior
    match response_status {
        301..=303 => Method("GET".to_string()),
        // Could be only 307 and 308, but curl does this for all 3xx
        // codes not converted to GET above.
        _ => original_method.clone(),
    }
}

impl Header {
    /// Parses an HTTP header line received from the server
    /// It does not panic. Just returns `None` if it can not be parsed.
    pub fn parse(line: &str) -> Option<Header> {
        match line.find(':') {
            Some(index) => {
                let (name, value) = line.split_at(index);
                Some(Header::new(name.trim(), value[1..].trim()))
            }
            None => None,
        }
    }
}

impl HeaderVec {
    /// Converts this list of [`Header`] to a lib curl header list.
    fn to_curl_headers(&self) -> Result<List, HttpError> {
        let mut curl_headers = List::new();
        for header in self {
            if header.value.is_empty() {
                curl_headers.append(&format!("{};", header.name))?;
            } else {
                curl_headers.append(&format!("{}: {}", header.name, header.value))?;
            }
        }
        Ok(curl_headers)
    }
}

/// Splits an array of bytes into HTTP lines (\r\n separator).
fn split_lines(data: &[u8]) -> Vec<String> {
    let mut lines = vec![];
    let mut start = 0;
    let mut i = 0;
    if data.is_empty() {
        return lines;
    }
    while i < (data.len() - 1) {
        if data[i] == 13 && data[i + 1] == 10 {
            if let Ok(s) = str::from_utf8(&data[start..i]) {
                lines.push(s.to_string());
            }
            start = i + 2;
            i += 2;
        } else {
            i += 1;
        }
    }
    lines
}

/// Decodes optionally header value as text with UTF-8 or ISO-8859-1 encoding.
fn decode_header(data: &[u8]) -> Option<String> {
    match str::from_utf8(data) {
        Ok(s) => Some(s.to_string()),
        Err(_) => {
            // See the [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/#note-latin1-ascii).
            //
            // > The windows-1252 encoding has various labels, such as "latin1", "iso-8859-1", and "ascii",
            // > which have historically been confusing for developers. On the web, and in any software
            // > that seeks to be web-compatible by implementing this standard, these are synonyms: "latin1"
            // > and "ascii" are just labels for windows-1252, and any software following this standard will,
            // > for example, decode 0x80 as U+20AC (€) when asked for the "Latin1" or "ASCII" decoding of that byte.
            // So: in the web platform world, ISO-8859-1 is just an alias for Windows-1252.
            //
            // In the [encoding_rs crate doc](https://docs.rs/encoding_rs/latest/encoding_rs/#iso-8859-1)
            //
            // > ISO-8859-1 does not exist as a distinct encoding from windows-1252 in the Encoding Standard.
            // > Therefore, an encoding that maps the unsigned byte value to the same Unicode scalar value is
            // > not available via Encoding in this crate.
            encoding_rs::WINDOWS_1252
                .decode_without_bom_handling_and_without_replacement(data)
                .map(|s| s.to_string())
        }
    }
}

/// Converts a list of [`String`] to a libcurl's list of strings.
fn to_list(items: &[String]) -> Result<List, Error> {
    let mut list = List::new();
    for item in items {
        list.append(item)?;
    }
    Ok(list)
}

/// Parses a cert file name, with a potential user provided password, and returns a pair of
/// cert file name, password.
/// See <https://curl.se/docs/manpage.html#-E>
/// > In the <certificate> portion of the argument, you must escape the character ":" as "\:" so
/// > that it is not recognized as the password delimiter. Similarly, you must escape the character
/// > "\" as "\\" so that it is not recognized as an escape character.
fn parse_cert_password(cert_and_pass: &str) -> (String, Option<String>) {
    let mut iter = cert_and_pass.chars();
    let mut cert = String::new();
    let mut password = String::new();
    // The state of the parser:
    // - `true` if we're parsing the certificate portion of `cert_and_pass`
    // - `false` if we're parsing the password portion of `cert_and_pass`
    let mut parse_cert = true;
    while let Some(c) = iter.next() {
        if parse_cert {
            // We're parsing the certificate, do some escaping
            match c {
                '\\' => {
                    // We read the next escaped char, if we failed, we're at the end of this string,
                    // the read char is not an escaping \.
                    match iter.next() {
                        Some(c) => cert.push(c),
                        None => {
                            cert.push('\\');
                            break;
                        }
                    }
                }
                ':' if parse_cert => parse_cert = false,
                c => cert.push(c),
            }
        } else {
            // We have already found a cert/password separator, we don't need to escape anything now
            // we just update the password
            password.push(c);
        }
    }

    if parse_cert {
        (cert, None)
    } else {
        (cert, Some(password))
    }
}

impl From<RequestedHttpVersion> for easy::HttpVersion {
    fn from(value: RequestedHttpVersion) -> Self {
        match value {
            RequestedHttpVersion::Default => easy::HttpVersion::Any,
            RequestedHttpVersion::Http10 => easy::HttpVersion::V10,
            RequestedHttpVersion::Http11 => easy::HttpVersion::V11,
            RequestedHttpVersion::Http2 => easy::HttpVersion::V2,
            RequestedHttpVersion::Http3 => easy::HttpVersion::V3,
        }
    }
}

impl From<IpResolve> for easy::IpResolve {
    fn from(value: IpResolve) -> Self {
        match value {
            IpResolve::Default => easy::IpResolve::Any,
            IpResolve::IpV4 => easy::IpResolve::V4,
            IpResolve::IpV6 => easy::IpResolve::V6,
        }
    }
}

#[cfg(test)]
mod tests {
    use std::default::Default;
    use std::path::PathBuf;

    use super::*;
    use crate::util::logger::LoggerOptionsBuilder;
    use crate::util::term::{Stderr, WriteMode};

    #[test]
    fn test_parse_header() {
        assert_eq!(
            Header::parse("Foo: Bar\r\n").unwrap(),
            Header::new("Foo", "Bar")
        );
        assert_eq!(
            Header::parse("Location: http://localhost:8000/redirected\r\n").unwrap(),
            Header::new("Location", "http://localhost:8000/redirected")
        );
        assert!(Header::parse("Foo").is_none());
    }

    #[test]
    fn test_split_lines_header() {
        let data = b"GET /hello HTTP/1.1\r\nHost: localhost:8000\r\n\r\n";
        let lines = split_lines(data);
        assert_eq!(lines.len(), 3);
        assert_eq!(lines.first().unwrap().as_str(), "GET /hello HTTP/1.1");
        assert_eq!(lines.get(1).unwrap().as_str(), "Host: localhost:8000");
        assert_eq!(lines.get(2).unwrap().as_str(), "");
    }

    #[test]
    fn test_redirect_method() {
        // Status of the response to be redirected | method of the original request | method of the new request
        let data = [
            (301, "GET", "GET"),
            (301, "POST", "GET"),
            (301, "DELETE", "GET"),
            (302, "GET", "GET"),
            (302, "POST", "GET"),
            (302, "DELETE", "GET"),
            (303, "GET", "GET"),
            (303, "POST", "GET"),
            (303, "DELETE", "GET"),
            (304, "GET", "GET"),
            (304, "POST", "POST"),
            (304, "DELETE", "DELETE"),
            (308, "GET", "GET"),
            (308, "POST", "POST"),
            (308, "DELETE", "DELETE"),
        ];
        for (status, original, redirected) in data {
            assert_eq!(
                redirect_method(status, &Method(original.to_string())),
                Method(redirected.to_string())
            );
        }
    }

    #[test]
    fn test_should_strip_credentials_on_redirect() {
        let url1 = Url::from_str("http://example.com").unwrap();
        let url2 = Url::from_str("http://example.com:8080").unwrap();
        let url3 = Url::from_str("https://example.com").unwrap();
        let url4 = Url::from_str("http://other.com").unwrap();

        let follow_location = FollowLocation::Follow(CredentialForwarding::OnlyInitialHost);
        assert!(should_strip_credentials_on_redirect(
            &url1,
            &url2,
            follow_location
        ));
        assert!(should_strip_credentials_on_redirect(
            &url1,
            &url3,
            follow_location
        ));
        assert!(should_strip_credentials_on_redirect(
            &url1,
            &url4,
            follow_location
        ));
        assert!(should_strip_credentials_on_redirect(
            &url1,
            &url3,
            follow_location
        ));

        let follow_location = FollowLocation::Follow(CredentialForwarding::AllHosts);
        assert!(!should_strip_credentials_on_redirect(
            &url1,
            &url2,
            follow_location
        ));
        assert!(!should_strip_credentials_on_redirect(
            &url1,
            &url3,
            follow_location
        ));
        assert!(!should_strip_credentials_on_redirect(
            &url1,
            &url4,
            follow_location
        ));
        assert!(!should_strip_credentials_on_redirect(
            &url1,
            &url3,
            follow_location
        ));
    }

    #[test]
    fn command_line_args() {
        let mut client = Client::new();
        let request = RequestSpec {
            method: Method("GET".to_string()),
            url: Url::from_str("https://example.org").unwrap(),
            ..Default::default()
        };
        let context_dir = ContextDir::default();
        let file = Output::File(PathBuf::from("/tmp/foo.bin"));
        let output = Some(&file);
        let options = ClientOptions {
            aws_sigv4: Some("aws:amz:sts".to_string()),
            cacert_file: Some("/etc/cert.pem".to_string()),
            compressed: true,
            connects_to: vec!["example.com:443:host-47.example.com:443".to_string()],
            insecure: true,
            max_redirect: Count::Finite(10),
            path_as_is: true,
            proxy: Some("localhost:3128".to_string()),
            no_proxy: None,
            unix_socket: Some("/var/run/example.sock".to_string()),
            user: Some("user:password".to_string()),
            user_agent: Some("my-useragent".to_string()),
            verbosity: Some(Verbosity::VeryVerbose),
            ..Default::default()
        };

        let logger_options = LoggerOptionsBuilder::default().build();
        let stderr = Stderr::new(WriteMode::Immediate);
        let mut logger = Logger::new(&logger_options, stderr, &[]);

        let cmd = client.curl_command_line(&request, &context_dir, output, &options, &mut logger);
        assert_eq!(
            cmd.to_string(),
            "curl \
         --aws-sigv4 aws:amz:sts \
         --cacert /etc/cert.pem \
         --compressed \
         --connect-to example.com:443:host-47.example.com:443 \
         --insecure \
         --max-redirs 10 \
         --path-as-is \
         --proxy 'localhost:3128' \
         --unix-socket '/var/run/example.sock' \
         --user 'user:password' \
         --user-agent 'my-useragent' \
         --output /tmp/foo.bin \
         'https://example.org'"
        );
    }

    #[test]
    fn parse_cert_option() {
        assert_eq!(parse_cert_password("foobar"), ("foobar".to_string(), None));
        assert_eq!(
            parse_cert_password("foobar:toto"),
            ("foobar".to_string(), Some("toto".to_string()))
        );
        assert_eq!(
            parse_cert_password("foobar:toto:tata"),
            ("foobar".to_string(), Some("toto:tata".to_string()))
        );
        assert_eq!(
            parse_cert_password("foobar:"),
            ("foobar".to_string(), Some(String::new()))
        );
        assert_eq!(
            parse_cert_password("foobar\\"),
            ("foobar\\".to_string(), None)
        );
        assert_eq!(
            parse_cert_password("foo\\:bar\\:baz:toto:tata\\:tutu"),
            (
                "foo:bar:baz".to_string(),
                Some("toto:tata\\:tutu".to_string())
            )
        );
        assert_eq!(
            parse_cert_password("foo\\\\:toto\\:tata:tutu"),
            ("foo\\".to_string(), Some("toto\\:tata:tutu".to_string()))
        );
    }

    #[test]
    fn test_to_curl_headers() {
        let mut headers = HeaderVec::new();
        headers.push(Header::new("foo", "a"));
        headers.push(Header::new("bar", "b"));
        headers.push(Header::new("baz", ""));

        let list = headers.to_curl_headers().unwrap();
        assert_eq!(
            list.iter().collect::<Vec<_>>(),
            vec!["foo: a".as_bytes(), "bar: b".as_bytes(), "baz;".as_bytes()]
        );
    }
}
