use crate::auth::{OAuthClient, UserSession, refresh_access_token_internal};
use crate::config::Config;
use crate::gsd::service::GSDService;
use crate::repository::RedisRepository;
use crate::util::set_and_log_session;
use axum::extract::{Request, State};
use axum::http::{HeaderValue, StatusCode};
use axum::middleware::Next;
use axum::response::{IntoResponse, Response};
use axum_extra::extract::CookieJar;
use log::{error, info, warn};
use std::sync::Arc;

#[derive(Clone)]
pub struct AppState {
    pub config: Config,
    pub repository: RedisRepository,
    pub gsd_service: GSDService,
    pub oauth_client: OAuthClient,
    pub frontend_url: String,
}

/// Middleware to validate session and refresh tokens if needed
pub async fn session_auth_middleware(
    jar: CookieJar,
    State(state): State<Arc<AppState>>,
    mut request: Request,
    next: Next,
) -> Response {
    // 1. Extract session ID from cookie
    let session_id = match jar.get("session_id") {
        Some(cookie) => cookie.value().to_string(),
        None => {
            warn!("No session cookie found");
            return (StatusCode::UNAUTHORIZED, "No session cookie").into_response();
        }
    };

    // 2. Find session in Redis
    let session_key = format!("user_session:{}", session_id);
    let session_json = match state.repository.get(&session_key).await {
        Ok(Some(json)) => json,
        Ok(None) => {
            warn!("Session not found in Redis: {}", session_id);
            return (StatusCode::UNAUTHORIZED, "Session expired or invalid").into_response();
        }
        Err(e) => {
            error!("Redis error while fetching session: {:?}", e);
            return (StatusCode::INTERNAL_SERVER_ERROR, "Internal error").into_response();
        }
    };

    // 3. Parse session data
    let mut user_session: UserSession = match serde_json::from_str(&session_json) {
        Ok(session) => session,
        Err(e) => {
            error!("Failed to parse session JSON: {:?}", e);
            return (StatusCode::INTERNAL_SERVER_ERROR, "Invalid session data").into_response();
        }
    };

    // 4. Check if access token is expired
    let now = chrono::Utc::now().timestamp();
    if user_session.expires_at <= now {
        info!(
            "Access token expired for session {}, attempting refresh",
            session_id
        );

        // 5. Refresh the access token using refresh token
        match refresh_access_token_internal(
            &state.oauth_client,
            &state.repository,
            &session_id,
            &mut user_session,
        )
        .await
        {
            Ok(new_access_token) => {
                info!(
                    "Successfully refreshed access token for session {}",
                    session_id
                );
                user_session.access_token = new_access_token;
            }
            Err(e) => {
                error!("Failed to refresh access token: {}", e);
                // Clean up invalid session
                let _ = state.repository.delete(&session_key).await;
                return (
                    StatusCode::UNAUTHORIZED,
                    "Session expired, please login again",
                )
                    .into_response();
            }
        }
    } else {
        info!(
            "Access token still valid for session {} (expires in {} seconds)",
            session_id,
            user_session.expires_at - now
        );
    }

    // 6. Attach validated access token to request for downstream handlers
    match HeaderValue::from_str(format!("Bearer {}", &user_session.access_token).as_str()) {
        Ok(header_value) => {
            request.headers_mut().insert("authorization", header_value);
        }
        Err(e) => {
            error!("Failed to create authorization header: {:?}", e);
            return (StatusCode::INTERNAL_SERVER_ERROR, "Internal error").into_response();
        }
    }

    // 7. Pass the request to the next handler
    next.run(request).await
}

pub async fn gsd_decorate_header(
    State(state): State<Arc<AppState>>,
    mut request: Request,
    next: Next,
) -> Response {
    let state_cloned = state.clone();

    let session = state_cloned.repository.get_session().await;
    match session {
        Ok(session) => {
            let session_value;

            if session.is_none() {
                match state_cloned.gsd_service.get_session().await {
                    Ok(session) => {
                        session_value = session.clone();
                        set_and_log_session(&state_cloned, session.clone()).await;
                    }
                    Err(error) => {
                        error!("Error getting session: {:?}", error);
                        return StatusCode::UNAUTHORIZED.into_response();
                    }
                }
            } else {
                session_value = session.unwrap();
            }

            request.headers_mut().insert(
                "sessionId",
                HeaderValue::from_str(session_value.as_str()).unwrap(),
            );
        }
        Err(error) => {
            error!(
                "Redis error occured during fetching current session id. Error: {}",
                error
            );
            return StatusCode::INTERNAL_SERVER_ERROR.into_response();
        }
    }

    request.headers_mut().insert(
        "appkey",
        HeaderValue::from_str(state_cloned.config.gsd_app_key.as_str()).unwrap(),
    );

    next.run(request).await

}