use std::{net::SocketAddr, sync::Arc};

use crate::{
    ApiAuthenticator, ApiError, ApiResult, AuthenticateMiddleware, Client, ClientBuilder,
    DnsResolver, Initialiser, IntoUrl, LogConfig, LogMiddleware, Method, Middleware,
    RequestBuilder, RequestTraceIdMiddleware, ReqwestDnsResolver, ReqwestUrlRewriter, Url, UrlOps,
    UrlRewriter,
};

/// This struct is used to build an instance of ApiCore
pub struct ApiBuilder {
    /// Reqwest ClientBuilder
    client: ClientBuilder,
    /// Base url for target api
    base_url: Url,
    /// The holder of UrlRewriter
    rewriter: Option<ReqwestUrlRewriter>,
    /// The holder of DnsResolver
    resolver: Option<ReqwestDnsResolver>,
    /// The holder of ApiAuthenticator
    authenticator: Option<Arc<dyn ApiAuthenticator>>,
    /// The holder of LogConfig
    logger: Option<Arc<LogConfig>>,
    /// The initialisers for Reqwest
    initialisers: Vec<Arc<dyn Initialiser>>,
    /// The middlewares for Reqwest
    middlewares: Vec<Arc<dyn Middleware>>,
}

impl ApiBuilder {
    /// Create an instance of ApiBuilder
    /// - base_url: base url for target api
    pub fn new(base_url: impl IntoUrl + std::fmt::Debug) -> ApiResult<Self> {
        Ok(Self {
            client: ClientBuilder::default(),
            base_url: base_url.into_url().map_err(ApiError::InvalidUrl)?,
            rewriter: None,
            resolver: None,
            authenticator: None,
            logger: None,
            initialisers: vec![],
            middlewares: vec![],
        })
    }

    /// Set the ClientBuilder to create Client instance of Reqwest
    /// - client: Reqwest ClientBuilder
    pub fn with_client(self, client: ClientBuilder) -> Self {
        Self { client, ..self }
    }

    /// Set the UrlRewriter
    /// - resolver: UrlRewriter
    pub fn with_rewriter<T>(self, rewriter: T) -> Self
    where
        T: UrlRewriter,
    {
        Self {
            rewriter: Some(ReqwestUrlRewriter::new(rewriter)),
            ..self
        }
    }

    /// Set the DnsResolver
    /// - resolver: DnsResolver
    pub fn with_resolver<T>(self, resolver: T) -> Self
    where
        T: DnsResolver,
    {
        Self {
            resolver: Some(ReqwestDnsResolver::new(resolver)),
            ..self
        }
    }

    /// Set the ApiAuthenticator
    /// - authenticator: ApiAuthenticator
    pub fn with_authenticator<T>(self, authenticator: T) -> Self
    where
        T: ApiAuthenticator,
    {
        Self {
            authenticator: Some(Arc::new(authenticator)),
            ..self
        }
    }

    /// Set the LogConfig
    /// - logger: LogConfig
    pub fn with_logger<T>(self, logger: T) -> Self
    where
        T: Into<LogConfig>,
    {
        Self {
            logger: Some(Arc::new(logger.into())),
            ..self
        }
    }

    /// Add initialiser
    /// - initialiser: Reqwest Initialiser
    pub fn with_initialiser<T>(self, initialiser: T) -> Self
    where
        T: Initialiser,
    {
        let mut s = self;
        s.initialisers.push(Arc::new(initialiser));
        s
    }

    /// Add middleware
    /// - middleware: Reqwest Middleware
    pub fn with_middleware<T>(self, middleware: T) -> Self
    where
        T: Middleware,
    {
        let mut s = self;
        s.middlewares.push(Arc::new(middleware));
        s
    }

    /// Build an instance of ApiCore
    pub fn build(self) -> ApiCore {
        let client = match self.resolver.clone() {
            Some(r) => self.client.dns_resolver(Arc::new(r)),
            None => self.client,
        };
        let mut client = reqwest_middleware::ClientBuilder::new(client.build().unwrap());

        // Apply middleware in correct order
        client = client.with(RequestTraceIdMiddleware);
        // client = client.with(RewriteHostMiddleware);
        for middleware in self.middlewares {
            client = client.with_arc(middleware);
        }
        if self.authenticator.is_some() {
            client = client.with(AuthenticateMiddleware);
        }
        client = client.with(LogMiddleware);

        // Apply initialisers
        if let Some(logger) = self.logger {
            client = client.with_arc_init(logger);
        }
        for initialiser in self.initialisers {
            client = client.with_arc_init(initialiser);
        }

        ApiCore {
            client: client.build(),
            base_url: self.base_url,
            rewriter: self.rewriter,
            resolver: self.resolver,
            authenticator: self.authenticator,
        }
    }
}

/// This struct is used to create HTTP request
pub struct ApiCore {
    /// Reqwest Client
    client: Client,
    /// Base url for target api
    base_url: Url,
    /// The holder of ReqwestUrlRewriter
    rewriter: Option<ReqwestUrlRewriter>,
    /// The holder of ReqwestDnsResolver
    resolver: Option<ReqwestDnsResolver>,
    /// The holder of ApiAuthenticator
    authenticator: Option<Arc<dyn ApiAuthenticator>>,
}

impl std::fmt::Debug for ApiCore {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let mut d = f.debug_struct("ApiCore");
        let mut d = d
            .field("client", &self.client)
            .field("base_url", &self.base_url);
        if let Some(r) = self.rewriter.as_ref() {
            d = d.field("rewriter", &r.type_name());
        }
        if let Some(r) = self.resolver.as_ref() {
            d = d.field("resolver", &r.type_name());
        }
        if let Some(s) = self.authenticator.as_ref() {
            d = d.field("authenticator", &s.type_name());
        }
        d.finish()
    }
}

impl ApiCore {
    /// Create a new ApiCore with a different base_url
    pub fn rebase(&self, base_url: impl IntoUrl) -> ApiResult<Self> {
        let base_url = base_url.into_url().map_err(ApiError::InvalidUrl)?;
        Ok(Self {
            client: self.client.clone(),
            base_url,
            rewriter: self.rewriter.clone(),
            resolver: self.resolver.clone(),
            authenticator: self.authenticator.clone(),
        })
    }

    /// Set the UrlRewriter
    /// - resolver: UrlRewriter
    pub fn with_rewriter<T>(&self, rewriter: T) -> Self
    where
        T: UrlRewriter,
    {
        Self {
            client: self.client.clone(),
            base_url: self.base_url.clone(),
            rewriter: Some(ReqwestUrlRewriter::new(rewriter)),
            resolver: self.resolver.clone(),
            authenticator: self.authenticator.clone(),
        }
    }

    /// Set the DnsResolver
    /// - resolver: DnsResolver
    pub fn with_resolver<T>(&self, resolver: T) -> Self
    where
        T: DnsResolver,
    {
        Self {
            client: self.client.clone(),
            base_url: self.base_url.clone(),
            rewriter: self.rewriter.clone(),
            resolver: Some(ReqwestDnsResolver::new(resolver)),
            authenticator: self.authenticator.clone(),
        }
    }

    /// Set rewriter to use endpoint
    /// - endpoint: SocketAddr
    pub fn with_endpoint<T>(&self, endpoint: T) -> Self
    where
        T: Into<SocketAddr>,
    {
        self.with_rewriter(endpoint.into())
    }

    /// Build base_url
    async fn build_base_url(&self) -> Result<Url, ApiError> {
        let mut base_url = self.base_url.clone();
        if let Some(router) = self.rewriter.as_ref() {
            base_url = router.rewrite(base_url).await?;
        }
        if let Some(resolver) = self.resolver.as_ref() {
            base_url = resolver.rewrite(base_url).await?;
        }
        Ok(base_url)
    }

    /// Build a new request url
    /// - path: relative path to base_url
    ///
    /// Return error when failed to retrieve valid endpoint from ApiRouter
    pub async fn build_url(&self, path: impl AsRef<str>) -> ApiResult<Url> {
        let base = self.build_base_url().await?;
        Ok(base.merge_path(path.as_ref()))
    }

    /// Build a new HTTP request
    /// - method: HTTP method
    /// - path: relative path to base_url
    pub async fn build_request(
        &self,
        method: Method,
        path: impl AsRef<str>,
    ) -> ApiResult<RequestBuilder> {
        let url = self.build_url(path.as_ref()).await?;
        let req = self.client.request(method, url);

        match self.authenticator.clone() {
            Some(authenticator) => Ok(req.with_extension(authenticator)),
            None => Ok(req),
        }
    }
}