extract.rs

//! Extractors for RustAPI
//!
//! Extractors automatically parse and validate data from incoming HTTP requests.
//! They implement the [`FromRequest`] or [`FromRequestParts`] traits and can be
//! used as handler function parameters.
//!
//! # Available Extractors
//!
//! | Extractor | Description | Consumes Body |
//! |-----------|-------------|---------------|
//! | [`Json<T>`] | Parse JSON request body | Yes |
//! | [`ValidatedJson<T>`] | Parse and validate JSON body | Yes |
//! | [`Query<T>`] | Parse query string parameters | No |
//! | [`Path<T>`] | Extract path parameters | No |
//! | [`State<T>`] | Access shared application state | No |
//! | [`Body`] | Raw request body bytes | Yes |
//! | [`Headers`] | Access all request headers | No |
//! | [`HeaderValue`] | Extract a specific header | No |
//! | [`Extension<T>`] | Access middleware-injected data | No |
//! | [`ClientIp`] | Extract client IP address | No |
//! | [`Cookies`] | Parse request cookies (requires `cookies` feature) | No |
//!
//! # Example
//!
//! ```rust,ignore
//! use rustapi_core::{Json, Query, Path, State};
//! use serde::{Deserialize, Serialize};
//!
//! #[derive(Deserialize)]
//! struct CreateUser {
//!     name: String,
//!     email: String,
//! }
//!
//! #[derive(Deserialize)]
//! struct Pagination {
//!     page: Option<u32>,
//!     limit: Option<u32>,
//! }
//!
//! // Multiple extractors can be combined
//! async fn create_user(
//!     State(db): State<DbPool>,
//!     Query(pagination): Query<Pagination>,
//!     Json(body): Json<CreateUser>,
//! ) -> impl IntoResponse {
//!     // Use db, pagination, and body...
//! }
//! ```
//!
//! # Extractor Order
//!
//! When using multiple extractors, body-consuming extractors (like `Json` or `Body`)
//! must come last since they consume the request body. Non-body extractors can be
//! in any order.

use crate::error::{ApiError, Result};
use crate::json;
use crate::request::Request;
use crate::response::IntoResponse;
use crate::stream::{StreamingBody, StreamingConfig};
use crate::validation::Validatable;
use bytes::Bytes;
use http::{header, StatusCode};
use rustapi_validate::v2::{AsyncValidate, ValidationContext};

use rustapi_openapi::schema::{RustApiSchema, SchemaCtx, SchemaRef};
use serde::de::DeserializeOwned;
use serde::Serialize;
use std::collections::BTreeMap;
use std::future::Future;
use std::ops::{Deref, DerefMut};
use std::str::FromStr;

/// Trait for extracting data from request parts (headers, path, query)
///
/// This is used for extractors that don't need the request body.
///
/// # Example: Implementing a custom extractor that requires a specific header
///
/// ```rust
/// use rustapi_core::FromRequestParts;
/// use rustapi_core::{Request, ApiError, Result};
/// use http::StatusCode;
///
/// struct ApiKey(String);
///
/// impl FromRequestParts for ApiKey {
///     fn from_request_parts(req: &Request) -> Result<Self> {
///         if let Some(key) = req.headers().get("x-api-key") {
///             if let Ok(key_str) = key.to_str() {
///                 return Ok(ApiKey(key_str.to_string()));
///             }
///         }
///         Err(ApiError::unauthorized("Missing or invalid API key"))
///     }
/// }
/// ```
pub trait FromRequestParts: Sized {
    /// Extract from request parts
    fn from_request_parts(req: &Request) -> Result<Self>;
}

/// Trait for extracting data from the full request (including body)
///
/// This is used for extractors that consume the request body.
///
/// # Example: Implementing a custom extractor that consumes the body
///
/// ```rust
/// use rustapi_core::FromRequest;
/// use rustapi_core::{Request, ApiError, Result};
/// use std::future::Future;
///
/// struct PlainText(String);
///
/// impl FromRequest for PlainText {
///     async fn from_request(req: &mut Request) -> Result<Self> {
///         // Ensure body is loaded
///         req.load_body().await?;
///         
///         // Consume the body
///         if let Some(bytes) = req.take_body() {
///             if let Ok(text) = String::from_utf8(bytes.to_vec()) {
///                 return Ok(PlainText(text));
///             }
///         }
///         
///         Err(ApiError::bad_request("Invalid plain text body"))
///     }
/// }
/// ```
pub trait FromRequest: Sized {
    /// Extract from the full request
    fn from_request(req: &mut Request) -> impl Future<Output = Result<Self>> + Send;
}

// Blanket impl: FromRequestParts -> FromRequest
impl<T: FromRequestParts> FromRequest for T {
    async fn from_request(req: &mut Request) -> Result<Self> {
        T::from_request_parts(req)
    }
}

/// JSON body extractor
///
/// Parses the request body as JSON and deserializes into type `T`.
/// Also works as a response type when T: Serialize.
///
/// # Example
///
/// ```rust,ignore
/// #[derive(Deserialize)]
/// struct CreateUser {
///     name: String,
///     email: String,
/// }
///
/// async fn create_user(Json(body): Json<CreateUser>) -> impl IntoResponse {
///     // body is already deserialized
/// }
/// ```
#[derive(Debug, Clone, Copy, Default)]
pub struct Json<T>(pub T);

impl<T: DeserializeOwned + Send> FromRequest for Json<T> {
    async fn from_request(req: &mut Request) -> Result<Self> {
        req.load_body().await?;
        let body = req
            .take_body()
            .ok_or_else(|| ApiError::internal("Body already consumed"))?;

        // Use simd-json accelerated parsing when available (2-4x faster)
        let value: T = json::from_slice(&body)?;
        Ok(Json(value))
    }
}

impl<T> Deref for Json<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for Json<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl<T> From<T> for Json<T> {
    fn from(value: T) -> Self {
        Json(value)
    }
}

/// Default pre-allocation size for JSON response buffers (256 bytes)
/// This covers most small to medium JSON responses without reallocation.
const JSON_RESPONSE_INITIAL_CAPACITY: usize = 256;

// IntoResponse for Json - allows using Json<T> as a return type
impl<T: Serialize> IntoResponse for Json<T> {
    fn into_response(self) -> crate::response::Response {
        // Use pre-allocated buffer to reduce allocations
        match json::to_vec_with_capacity(&self.0, JSON_RESPONSE_INITIAL_CAPACITY) {
            Ok(body) => http::Response::builder()
                .status(StatusCode::OK)
                .header(header::CONTENT_TYPE, "application/json")
                .body(crate::response::Body::from(body))
                .unwrap(),
            Err(err) => {
                ApiError::internal(format!("Failed to serialize response: {}", err)).into_response()
            }
        }
    }
}

/// Validated JSON body extractor
///
/// Parses the request body as JSON, deserializes into type `T`, and validates
/// using the `Validate` trait. Returns a 422 Unprocessable Entity error with
/// detailed field-level validation errors if validation fails.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_rs::prelude::*;
/// use validator::Validate;
///
/// #[derive(Deserialize, Validate)]
/// struct CreateUser {
///     #[validate(email)]
///     email: String,
///     #[validate(length(min = 8))]
///     password: String,
/// }
///
/// async fn register(ValidatedJson(body): ValidatedJson<CreateUser>) -> impl IntoResponse {
///     // body is already validated!
///     // If email is invalid or password too short, a 422 error is returned automatically
/// }
/// ```
#[derive(Debug, Clone, Copy, Default)]
pub struct ValidatedJson<T>(pub T);

impl<T> ValidatedJson<T> {
    /// Create a new ValidatedJson wrapper
    pub fn new(value: T) -> Self {
        Self(value)
    }

    /// Get the inner value
    pub fn into_inner(self) -> T {
        self.0
    }
}

impl<T: DeserializeOwned + Validatable + Send> FromRequest for ValidatedJson<T> {
    async fn from_request(req: &mut Request) -> Result<Self> {
        req.load_body().await?;
        // First, deserialize the JSON body using simd-json when available
        let body = req
            .take_body()
            .ok_or_else(|| ApiError::internal("Body already consumed"))?;

        let value: T = json::from_slice(&body)?;

        // Then, validate it using the unified Validatable trait
        value.do_validate()?;

        Ok(ValidatedJson(value))
    }
}

impl<T> Deref for ValidatedJson<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for ValidatedJson<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl<T> From<T> for ValidatedJson<T> {
    fn from(value: T) -> Self {
        ValidatedJson(value)
    }
}

impl<T: Serialize> IntoResponse for ValidatedJson<T> {
    fn into_response(self) -> crate::response::Response {
        Json(self.0).into_response()
    }
}

/// Async validated JSON body extractor
///
/// Parses the request body as JSON, deserializes into type `T`, and validates
/// using the `AsyncValidate` trait from `rustapi-validate`.
///
/// This extractor supports async validation rules, such as database uniqueness checks.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_rs::prelude::*;
/// use rustapi_validate::v2::prelude::*;
///
/// #[derive(Deserialize, Validate, AsyncValidate)]
/// struct CreateUser {
///     #[validate(email)]
///     email: String,
///     
///     #[validate(async_unique(table = "users", column = "email"))]
///     username: String,
/// }
///
/// async fn register(AsyncValidatedJson(body): AsyncValidatedJson<CreateUser>) -> impl IntoResponse {
///     // body is validated asynchronously (e.g. checked existing email in DB)
/// }
/// ```
#[derive(Debug, Clone, Copy, Default)]
pub struct AsyncValidatedJson<T>(pub T);

impl<T> AsyncValidatedJson<T> {
    /// Create a new AsyncValidatedJson wrapper
    pub fn new(value: T) -> Self {
        Self(value)
    }

    /// Get the inner value
    pub fn into_inner(self) -> T {
        self.0
    }
}

impl<T> Deref for AsyncValidatedJson<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for AsyncValidatedJson<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl<T> From<T> for AsyncValidatedJson<T> {
    fn from(value: T) -> Self {
        AsyncValidatedJson(value)
    }
}

impl<T: Serialize> IntoResponse for AsyncValidatedJson<T> {
    fn into_response(self) -> crate::response::Response {
        Json(self.0).into_response()
    }
}

impl<T: DeserializeOwned + AsyncValidate + Send + Sync> FromRequest for AsyncValidatedJson<T> {
    async fn from_request(req: &mut Request) -> Result<Self> {
        req.load_body().await?;

        let body = req
            .take_body()
            .ok_or_else(|| ApiError::internal("Body already consumed"))?;

        let value: T = json::from_slice(&body)?;

        // Create validation context from request
        // Check if validators are configured in App State
        let ctx = if let Some(ctx) = req.state().get::<ValidationContext>() {
            ctx.clone()
        } else {
            ValidationContext::default()
        };

        // Perform full validation (sync + async)
        if let Err(errors) = value.validate_full(&ctx).await {
            // Convert v2 ValidationErrors to ApiError
            let field_errors: Vec<crate::error::FieldError> = errors
                .fields
                .iter()
                .flat_map(|(field, errs)| {
                    let field_name = field.to_string();
                    errs.iter().map(move |e| crate::error::FieldError {
                        field: field_name.clone(),
                        code: e.code.to_string(),
                        message: e.message.clone(),
                    })
                })
                .collect();

            return Err(ApiError::validation(field_errors));
        }

        Ok(AsyncValidatedJson(value))
    }
}

/// Query string extractor
///
/// Parses the query string into type `T`.
///
/// # Example
///
/// ```rust,ignore
/// #[derive(Deserialize)]
/// struct Pagination {
///     page: Option<u32>,
///     limit: Option<u32>,
/// }
///
/// async fn list_users(Query(params): Query<Pagination>) -> impl IntoResponse {
///     // params.page, params.limit
/// }
/// ```
#[derive(Debug, Clone)]
pub struct Query<T>(pub T);

impl<T: DeserializeOwned> FromRequestParts for Query<T> {
    fn from_request_parts(req: &Request) -> Result<Self> {
        let query = req.query_string().unwrap_or("");
        let value: T = serde_urlencoded::from_str(query)
            .map_err(|e| ApiError::bad_request(format!("Invalid query string: {}", e)))?;
        Ok(Query(value))
    }
}

impl<T> Deref for Query<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Path parameter extractor
///
/// Extracts path parameters defined in the route pattern.
///
/// # Example
///
/// For route `/users/{id}`:
///
/// ```rust,ignore
/// async fn get_user(Path(id): Path<i64>) -> impl IntoResponse {
///     // id is extracted from path
/// }
/// ```
///
/// For multiple params `/users/{user_id}/posts/{post_id}`:
///
/// ```rust,ignore
/// async fn get_post(Path((user_id, post_id)): Path<(i64, i64)>) -> impl IntoResponse {
///     // Both params extracted
/// }
/// ```
#[derive(Debug, Clone)]
pub struct Path<T>(pub T);

impl<T: FromStr> FromRequestParts for Path<T>
where
    T::Err: std::fmt::Display,
{
    fn from_request_parts(req: &Request) -> Result<Self> {
        let params = req.path_params();

        // For single param, get the first one
        if let Some((_, value)) = params.iter().next() {
            let parsed = value
                .parse::<T>()
                .map_err(|e| ApiError::bad_request(format!("Invalid path parameter: {}", e)))?;
            return Ok(Path(parsed));
        }

        Err(ApiError::internal("Missing path parameter"))
    }
}

impl<T> Deref for Path<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Typed path extractor
///
/// Extracts path parameters and deserializes them into a struct implementing `Deserialize`.
/// This is similar to `Path<T>`, but supports complex structs that can be deserialized
/// from a map of parameter names to values (e.g. via `serde_json`).
///
/// # Example
///
/// ```rust,ignore
/// #[derive(Deserialize)]
/// struct UserParams {
///     id: u64,
///     category: String,
/// }
///
/// async fn get_user(Typed(params): Typed<UserParams>) -> impl IntoResponse {
///     // params.id, params.category
/// }
/// ```
#[derive(Debug, Clone)]
pub struct Typed<T>(pub T);

impl<T: DeserializeOwned + Send> FromRequestParts for Typed<T> {
    fn from_request_parts(req: &Request) -> Result<Self> {
        let params = req.path_params();
        let mut map = serde_json::Map::new();
        for (k, v) in params.iter() {
            map.insert(k.to_string(), serde_json::Value::String(v.to_string()));
        }
        let value = serde_json::Value::Object(map);
        let parsed: T = serde_json::from_value(value)
            .map_err(|e| ApiError::bad_request(format!("Invalid path parameters: {}", e)))?;
        Ok(Typed(parsed))
    }
}

impl<T> Deref for Typed<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// State extractor
///
/// Extracts shared application state.
///
/// # Example
///
/// ```rust,ignore
/// #[derive(Clone)]
/// struct AppState {
///     db: DbPool,
/// }
///
/// async fn handler(State(state): State<AppState>) -> impl IntoResponse {
///     // Use state.db
/// }
/// ```
#[derive(Debug, Clone)]
pub struct State<T>(pub T);

impl<T: Clone + Send + Sync + 'static> FromRequestParts for State<T> {
    fn from_request_parts(req: &Request) -> Result<Self> {
        req.state().get::<T>().cloned().map(State).ok_or_else(|| {
            ApiError::internal(format!(
                "State of type `{}` not found. Did you forget to call .state()?",
                std::any::type_name::<T>()
            ))
        })
    }
}

impl<T> Deref for State<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Raw body bytes extractor
#[derive(Debug, Clone)]
pub struct Body(pub Bytes);

impl FromRequest for Body {
    async fn from_request(req: &mut Request) -> Result<Self> {
        req.load_body().await?;
        let body = req
            .take_body()
            .ok_or_else(|| ApiError::internal("Body already consumed"))?;
        Ok(Body(body))
    }
}

impl Deref for Body {
    type Target = Bytes;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Streaming body extractor
pub struct BodyStream(pub StreamingBody);

impl FromRequest for BodyStream {
    async fn from_request(req: &mut Request) -> Result<Self> {
        let config = StreamingConfig::default();

        if let Some(stream) = req.take_stream() {
            Ok(BodyStream(StreamingBody::new(stream, config.max_body_size)))
        } else if let Some(bytes) = req.take_body() {
            // Handle buffered body as stream
            let stream = futures_util::stream::once(async move { Ok(bytes) });
            Ok(BodyStream(StreamingBody::from_stream(
                stream,
                config.max_body_size,
            )))
        } else {
            Err(ApiError::internal("Body already consumed"))
        }
    }
}

impl Deref for BodyStream {
    type Target = StreamingBody;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for BodyStream {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

// Forward stream implementation
impl futures_util::Stream for BodyStream {
    type Item = Result<Bytes, ApiError>;

    fn poll_next(
        mut self: std::pin::Pin<&mut Self>,
        cx: &mut std::task::Context<'_>,
    ) -> std::task::Poll<Option<Self::Item>> {
        std::pin::Pin::new(&mut self.0).poll_next(cx)
    }
}

/// Optional extractor wrapper
///
/// Makes any extractor optional - returns None instead of error on failure.
impl<T: FromRequestParts> FromRequestParts for Option<T> {
    fn from_request_parts(req: &Request) -> Result<Self> {
        Ok(T::from_request_parts(req).ok())
    }
}

/// Headers extractor
///
/// Provides access to all request headers as a typed map.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::extract::Headers;
///
/// async fn handler(headers: Headers) -> impl IntoResponse {
///     if let Some(content_type) = headers.get("content-type") {
///         format!("Content-Type: {:?}", content_type)
///     } else {
///         "No Content-Type header".to_string()
///     }
/// }
/// ```
#[derive(Debug, Clone)]
pub struct Headers(pub http::HeaderMap);

impl Headers {
    /// Get a header value by name
    pub fn get(&self, name: &str) -> Option<&http::HeaderValue> {
        self.0.get(name)
    }

    /// Check if a header exists
    pub fn contains(&self, name: &str) -> bool {
        self.0.contains_key(name)
    }

    /// Get the number of headers
    pub fn len(&self) -> usize {
        self.0.len()
    }

    /// Check if headers are empty
    pub fn is_empty(&self) -> bool {
        self.0.is_empty()
    }

    /// Iterate over all headers
    pub fn iter(&self) -> http::header::Iter<'_, http::HeaderValue> {
        self.0.iter()
    }
}

impl FromRequestParts for Headers {
    fn from_request_parts(req: &Request) -> Result<Self> {
        Ok(Headers(req.headers().clone()))
    }
}

impl OperationModifier for Headers {
    fn update_operation(_op: &mut Operation) {}
}

impl Deref for Headers {
    type Target = http::HeaderMap;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Single header value extractor
///
/// Extracts a specific header value by name. Returns an error if the header is missing.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::extract::HeaderValue;
///
/// async fn handler(
///     auth: HeaderValue<{ "authorization" }>,
/// ) -> impl IntoResponse {
///     format!("Auth header: {}", auth.0)
/// }
/// ```
///
/// Note: Due to Rust's const generics limitations, you may need to use the
/// `HeaderValueOf` type alias or extract headers manually using the `Headers` extractor.
#[derive(Debug, Clone)]
pub struct HeaderValue(pub String, pub &'static str);

impl HeaderValue {
    /// Create a new HeaderValue extractor for a specific header name
    pub fn new(name: &'static str, value: String) -> Self {
        Self(value, name)
    }

    /// Get the header value
    pub fn value(&self) -> &str {
        &self.0
    }

    /// Get the header name
    pub fn name(&self) -> &'static str {
        self.1
    }

    /// Extract a specific header from a request
    pub fn extract(req: &Request, name: &'static str) -> Result<Self> {
        req.headers()
            .get(name)
            .and_then(|v| v.to_str().ok())
            .map(|s| HeaderValue(s.to_string(), name))
            .ok_or_else(|| ApiError::bad_request(format!("Missing required header: {}", name)))
    }
}

impl Deref for HeaderValue {
    type Target = String;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

/// Extension extractor
///
/// Retrieves typed data from request extensions that was inserted by middleware.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::extract::Extension;
///
/// // Middleware inserts user data
/// #[derive(Clone)]
/// struct CurrentUser { id: i64 }
///
/// async fn handler(Extension(user): Extension<CurrentUser>) -> impl IntoResponse {
///     format!("User ID: {}", user.id)
/// }
/// ```
#[derive(Debug, Clone)]
pub struct Extension<T>(pub T);

impl<T: Clone + Send + Sync + 'static> FromRequestParts for Extension<T> {
    fn from_request_parts(req: &Request) -> Result<Self> {
        req.extensions()
            .get::<T>()
            .cloned()
            .map(Extension)
            .ok_or_else(|| {
                ApiError::internal(format!(
                    "Extension of type `{}` not found. Did middleware insert it?",
                    std::any::type_name::<T>()
                ))
            })
    }
}

impl<T> Deref for Extension<T> {
    type Target = T;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl<T> DerefMut for Extension<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

/// Client IP address extractor
///
/// Extracts the client IP address from the request. When `trust_proxy` is enabled,
/// it will use the `X-Forwarded-For` header if present.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::extract::ClientIp;
///
/// async fn handler(ClientIp(ip): ClientIp) -> impl IntoResponse {
///     format!("Your IP: {}", ip)
/// }
/// ```
#[derive(Debug, Clone)]
pub struct ClientIp(pub std::net::IpAddr);

impl ClientIp {
    /// Extract client IP, optionally trusting X-Forwarded-For header
    pub fn extract_with_config(req: &Request, trust_proxy: bool) -> Result<Self> {
        if trust_proxy {
            // Try X-Forwarded-For header first
            if let Some(forwarded) = req.headers().get("x-forwarded-for") {
                if let Ok(forwarded_str) = forwarded.to_str() {
                    // X-Forwarded-For can contain multiple IPs, take the first one
                    if let Some(first_ip) = forwarded_str.split(',').next() {
                        if let Ok(ip) = first_ip.trim().parse() {
                            return Ok(ClientIp(ip));
                        }
                    }
                }
            }
        }

        // Fall back to socket address from extensions (if set by server)
        if let Some(addr) = req.extensions().get::<std::net::SocketAddr>() {
            return Ok(ClientIp(addr.ip()));
        }

        // Default to localhost if no IP information available
        Ok(ClientIp(std::net::IpAddr::V4(std::net::Ipv4Addr::new(
            127, 0, 0, 1,
        ))))
    }
}

impl FromRequestParts for ClientIp {
    fn from_request_parts(req: &Request) -> Result<Self> {
        // By default, trust proxy headers
        Self::extract_with_config(req, true)
    }
}

/// Cookies extractor
///
/// Parses and provides access to request cookies from the Cookie header.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::extract::Cookies;
///
/// async fn handler(cookies: Cookies) -> impl IntoResponse {
///     if let Some(session) = cookies.get("session_id") {
///         format!("Session: {}", session.value())
///     } else {
///         "No session cookie".to_string()
///     }
/// }
/// ```
#[cfg(feature = "cookies")]
#[derive(Debug, Clone)]
pub struct Cookies(pub cookie::CookieJar);

#[cfg(feature = "cookies")]
impl Cookies {
    /// Get a cookie by name
    pub fn get(&self, name: &str) -> Option<&cookie::Cookie<'static>> {
        self.0.get(name)
    }

    /// Iterate over all cookies
    pub fn iter(&self) -> impl Iterator<Item = &cookie::Cookie<'static>> {
        self.0.iter()
    }

    /// Check if a cookie exists
    pub fn contains(&self, name: &str) -> bool {
        self.0.get(name).is_some()
    }
}

#[cfg(feature = "cookies")]
impl FromRequestParts for Cookies {
    fn from_request_parts(req: &Request) -> Result<Self> {
        let mut jar = cookie::CookieJar::new();

        if let Some(cookie_header) = req.headers().get(header::COOKIE) {
            if let Ok(cookie_str) = cookie_header.to_str() {
                // Parse each cookie from the header
                for cookie_part in cookie_str.split(';') {
                    let trimmed = cookie_part.trim();
                    if !trimmed.is_empty() {
                        if let Ok(cookie) = cookie::Cookie::parse(trimmed.to_string()) {
                            jar.add_original(cookie.into_owned());
                        }
                    }
                }
            }
        }

        Ok(Cookies(jar))
    }
}

#[cfg(feature = "cookies")]
impl Deref for Cookies {
    type Target = cookie::CookieJar;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

// Implement FromRequestParts for common primitive types (path params)
macro_rules! impl_from_request_parts_for_primitives {
    ($($ty:ty),*) => {
        $(
            impl FromRequestParts for $ty {
                fn from_request_parts(req: &Request) -> Result<Self> {
                    let Path(value) = Path::<$ty>::from_request_parts(req)?;
                    Ok(value)
                }
            }
        )*
    };
}

impl_from_request_parts_for_primitives!(
    i8, i16, i32, i64, i128, isize, u8, u16, u32, u64, u128, usize, f32, f64, bool, String
);

// OperationModifier implementations for extractors

use rustapi_openapi::{
    MediaType, Operation, OperationModifier, Parameter, RequestBody, ResponseModifier, ResponseSpec,
};

// ValidatedJson - Adds request body
impl<T: RustApiSchema> OperationModifier for ValidatedJson<T> {
    fn update_operation(op: &mut Operation) {
        let mut ctx = SchemaCtx::new();
        let schema_ref = T::schema(&mut ctx);

        let mut content = BTreeMap::new();
        content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(schema_ref),
                example: None,
            },
        );

        op.request_body = Some(RequestBody {
            description: None,
            required: Some(true),
            content,
        });

        // Add 422 Validation Error response
        let mut responses_content = BTreeMap::new();
        responses_content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(SchemaRef::Ref {
                    reference: "#/components/schemas/ValidationErrorSchema".to_string(),
                }),
                example: None,
            },
        );

        op.responses.insert(
            "422".to_string(),
            ResponseSpec {
                description: "Validation Error".to_string(),
                content: responses_content,
                headers: BTreeMap::new(),
            },
        );
    }

    fn register_components(spec: &mut rustapi_openapi::OpenApiSpec) {
        spec.register_in_place::<T>();
        spec.register_in_place::<rustapi_openapi::ValidationErrorSchema>();
        spec.register_in_place::<rustapi_openapi::ValidationErrorBodySchema>();
        spec.register_in_place::<rustapi_openapi::FieldErrorSchema>();
    }
}

// AsyncValidatedJson - Adds request body + 422 response (same as ValidatedJson)
impl<T: RustApiSchema> OperationModifier for AsyncValidatedJson<T> {
    fn update_operation(op: &mut Operation) {
        let mut ctx = SchemaCtx::new();
        let schema_ref = T::schema(&mut ctx);

        let mut content = BTreeMap::new();
        content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(schema_ref),
                example: None,
            },
        );

        op.request_body = Some(RequestBody {
            description: None,
            required: Some(true),
            content,
        });

        // Add 422 Validation Error response
        let mut responses_content = BTreeMap::new();
        responses_content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(SchemaRef::Ref {
                    reference: "#/components/schemas/ValidationErrorSchema".to_string(),
                }),
                example: None,
            },
        );

        op.responses.insert(
            "422".to_string(),
            ResponseSpec {
                description: "Validation Error".to_string(),
                content: responses_content,
                headers: BTreeMap::new(),
            },
        );
    }

    fn register_components(spec: &mut rustapi_openapi::OpenApiSpec) {
        spec.register_in_place::<T>();
        spec.register_in_place::<rustapi_openapi::ValidationErrorSchema>();
        spec.register_in_place::<rustapi_openapi::ValidationErrorBodySchema>();
        spec.register_in_place::<rustapi_openapi::FieldErrorSchema>();
    }
}

// Json - Adds request body (Same as ValidatedJson)
impl<T: RustApiSchema> OperationModifier for Json<T> {
    fn update_operation(op: &mut Operation) {
        let mut ctx = SchemaCtx::new();
        let schema_ref = T::schema(&mut ctx);

        let mut content = BTreeMap::new();
        content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(schema_ref),
                example: None,
            },
        );

        op.request_body = Some(RequestBody {
            description: None,
            required: Some(true),
            content,
        });
    }

    fn register_components(spec: &mut rustapi_openapi::OpenApiSpec) {
        spec.register_in_place::<T>();
    }
}

// Path - No op (handled by app routing)
impl<T> OperationModifier for Path<T> {
    fn update_operation(_op: &mut Operation) {}
}

// Typed - No op
impl<T> OperationModifier for Typed<T> {
    fn update_operation(_op: &mut Operation) {}
}

// Query - Extracts query params using field_schemas
impl<T: RustApiSchema> OperationModifier for Query<T> {
    fn update_operation(op: &mut Operation) {
        let mut ctx = SchemaCtx::new();
        if let Some(fields) = T::field_schemas(&mut ctx) {
            let new_params: Vec<Parameter> = fields
                .into_iter()
                .map(|(name, schema)| {
                    Parameter {
                        name,
                        location: "query".to_string(),
                        required: false, // Assume optional
                        deprecated: None,
                        description: None,
                        schema: Some(schema),
                    }
                })
                .collect();

            op.parameters.extend(new_params);
        }
    }

    fn register_components(spec: &mut rustapi_openapi::OpenApiSpec) {
        spec.register_in_place::<T>();
    }
}

// State - No op
impl<T> OperationModifier for State<T> {
    fn update_operation(_op: &mut Operation) {}
}

// Body - Generic binary body
impl OperationModifier for Body {
    fn update_operation(op: &mut Operation) {
        let mut content = BTreeMap::new();
        content.insert(
            "application/octet-stream".to_string(),
            MediaType {
                schema: Some(SchemaRef::Inline(
                    serde_json::json!({ "type": "string", "format": "binary" }),
                )),
                example: None,
            },
        );

        op.request_body = Some(RequestBody {
            description: None,
            required: Some(true),
            content,
        });
    }
}

// BodyStream - Generic binary stream
impl OperationModifier for BodyStream {
    fn update_operation(op: &mut Operation) {
        let mut content = BTreeMap::new();
        content.insert(
            "application/octet-stream".to_string(),
            MediaType {
                schema: Some(SchemaRef::Inline(
                    serde_json::json!({ "type": "string", "format": "binary" }),
                )),
                example: None,
            },
        );

        op.request_body = Some(RequestBody {
            description: None,
            required: Some(true),
            content,
        });
    }
}

// ResponseModifier implementations for extractors

// Json<T> - 200 OK with schema T
impl<T: RustApiSchema> ResponseModifier for Json<T> {
    fn update_response(op: &mut Operation) {
        let mut ctx = SchemaCtx::new();
        let schema_ref = T::schema(&mut ctx);

        let mut content = BTreeMap::new();
        content.insert(
            "application/json".to_string(),
            MediaType {
                schema: Some(schema_ref),
                example: None,
            },
        );

        op.responses.insert(
            "200".to_string(),
            ResponseSpec {
                description: "Successful response".to_string(),
                content,
                headers: BTreeMap::new(),
            },
        );
    }

    fn register_components(spec: &mut rustapi_openapi::OpenApiSpec) {
        spec.register_in_place::<T>();
    }
}

// RustApiSchema implementations

impl<T: RustApiSchema> RustApiSchema for Json<T> {
    fn schema(ctx: &mut SchemaCtx) -> SchemaRef {
        T::schema(ctx)
    }
}

impl<T: RustApiSchema> RustApiSchema for ValidatedJson<T> {
    fn schema(ctx: &mut SchemaCtx) -> SchemaRef {
        T::schema(ctx)
    }
}

impl<T: RustApiSchema> RustApiSchema for AsyncValidatedJson<T> {
    fn schema(ctx: &mut SchemaCtx) -> SchemaRef {
        T::schema(ctx)
    }
}

impl<T: RustApiSchema> RustApiSchema for Query<T> {
    fn schema(ctx: &mut SchemaCtx) -> SchemaRef {
        T::schema(ctx)
    }
    fn field_schemas(ctx: &mut SchemaCtx) -> Option<BTreeMap<String, SchemaRef>> {
        T::field_schemas(ctx)
    }
}

// ─── Pagination Extractors ──────────────────────────────────────────────────

/// Default page number (1-indexed)
const DEFAULT_PAGE: u64 = 1;
/// Default items per page
const DEFAULT_PER_PAGE: u64 = 20;
/// Maximum items per page (prevents abuse)
const MAX_PER_PAGE: u64 = 100;

/// Offset-based pagination extractor
///
/// Extracts pagination parameters from the query string.
/// Supports `?page=1&per_page=20` (defaults: page=1, per_page=20, max=100).
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::Paginate;
///
/// async fn list_users(paginate: Paginate) -> impl IntoResponse {
///     let offset = paginate.offset();
///     let limit = paginate.limit();
///     // SELECT * FROM users LIMIT $limit OFFSET $offset
/// }
/// ```
#[derive(Debug, Clone, Copy)]
pub struct Paginate {
    /// Current page (1-indexed)
    pub page: u64,
    /// Items per page (capped at MAX_PER_PAGE)
    pub per_page: u64,
}

impl Paginate {
    /// Create a new Paginate with given page and per_page
    pub fn new(page: u64, per_page: u64) -> Self {
        Self {
            page: page.max(1),
            per_page: per_page.clamp(1, MAX_PER_PAGE),
        }
    }

    /// Calculate the SQL OFFSET value
    pub fn offset(&self) -> u64 {
        (self.page - 1) * self.per_page
    }

    /// Get the LIMIT value (alias for per_page)
    pub fn limit(&self) -> u64 {
        self.per_page
    }

    /// Build a `Paginated<T>` response from this pagination and results
    pub fn paginate<T>(self, items: Vec<T>, total: u64) -> crate::hateoas::Paginated<T> {
        crate::hateoas::Paginated {
            items,
            page: self.page,
            per_page: self.per_page,
            total,
        }
    }
}

impl Default for Paginate {
    fn default() -> Self {
        Self {
            page: DEFAULT_PAGE,
            per_page: DEFAULT_PER_PAGE,
        }
    }
}

impl FromRequestParts for Paginate {
    fn from_request_parts(req: &Request) -> Result<Self> {
        let query = req.query_string().unwrap_or("");

        #[derive(serde::Deserialize)]
        struct PaginateQuery {
            page: Option<u64>,
            per_page: Option<u64>,
        }

        let params: PaginateQuery = serde_urlencoded::from_str(query).unwrap_or(PaginateQuery {
            page: None,
            per_page: None,
        });

        Ok(Paginate::new(
            params.page.unwrap_or(DEFAULT_PAGE),
            params.per_page.unwrap_or(DEFAULT_PER_PAGE),
        ))
    }
}

/// Cursor-based pagination extractor
///
/// Extracts cursor pagination parameters from the query string.
/// Supports `?cursor=abc123&limit=20` (defaults: cursor=None, limit=20, max=100).
///
/// Cursor-based pagination is preferred for large datasets or real-time data
/// where offset-based pagination would skip or duplicate items.
///
/// # Example
///
/// ```rust,ignore
/// use rustapi_core::CursorPaginate;
///
/// async fn list_events(cursor: CursorPaginate) -> impl IntoResponse {
///     let limit = cursor.limit();
///     if let Some(after) = cursor.after() {
///         // SELECT * FROM events WHERE id > $after ORDER BY id LIMIT $limit
///     } else {
///         // SELECT * FROM events ORDER BY id LIMIT $limit
///     }
/// }
/// ```
#[derive(Debug, Clone)]
pub struct CursorPaginate {
    /// Opaque cursor token (None = start from beginning)
    pub cursor: Option<String>,
    /// Items per page (capped at MAX_PER_PAGE)
    pub per_page: u64,
}

impl CursorPaginate {
    /// Create a new CursorPaginate
    pub fn new(cursor: Option<String>, per_page: u64) -> Self {
        Self {
            cursor,
            per_page: per_page.clamp(1, MAX_PER_PAGE),
        }
    }

    /// Get the cursor value (if any)
    pub fn after(&self) -> Option<&str> {
        self.cursor.as_deref()
    }

    /// Get the LIMIT value
    pub fn limit(&self) -> u64 {
        self.per_page
    }

    /// Check if this is the first page (no cursor)
    pub fn is_first_page(&self) -> bool {
        self.cursor.is_none()
    }
}

impl Default for CursorPaginate {
    fn default() -> Self {
        Self {
            cursor: None,
            per_page: DEFAULT_PER_PAGE,
        }
    }
}

impl FromRequestParts for CursorPaginate {
    fn from_request_parts(req: &Request) -> Result<Self> {
        let query = req.query_string().unwrap_or("");

        #[derive(serde::Deserialize)]
        struct CursorQuery {
            cursor: Option<String>,
            limit: Option<u64>,
        }

        let params: CursorQuery = serde_urlencoded::from_str(query).unwrap_or(CursorQuery {
            cursor: None,
            limit: None,
        });

        Ok(CursorPaginate::new(
            params.cursor,
            params.limit.unwrap_or(DEFAULT_PER_PAGE),
        ))
    }
}

#[cfg(test)]
mod tests {
    include!(concat!(
        env!("CARGO_MANIFEST_DIR"),
        "/tests/support/extract_lib.rs"
    ));
}