mod auth;
mod bitcoin;
mod container;
mod lnd;
mod node;
mod package;
mod peers;
mod totp;

use crate::auth::AuthManager;
use crate::config::Config;
use crate::container::DevContainerOrchestrator;
use crate::port_allocator::PortAllocator;
use crate::session::{self, LoginRateLimiter, SessionStore};
use crate::state::StateManager;
use anyhow::{Context, Result};
use hyper::{Request, Response, StatusCode};
use serde::{Deserialize, Serialize};
use std::net::IpAddr;
use std::sync::{Arc, Mutex};
use tracing::{debug, error};

#[derive(Debug, Deserialize)]
struct RpcRequest {
    method: String,
    params: Option<serde_json::Value>,
}

#[derive(Debug, Serialize)]
struct RpcResponse {
    result: Option<serde_json::Value>,
    error: Option<RpcError>,
}

#[derive(Debug, Serialize)]
struct RpcError {
    code: i32,
    message: String,
    data: Option<serde_json::Value>,
}

/// Default dev password when no user is set up (matches mock-backend).
pub(crate) const DEV_DEFAULT_PASSWORD: &str = "password123";

/// Methods that do not require a valid session cookie.
const UNAUTHENTICATED_METHODS: &[&str] = &[
    "auth.login",
    "auth.login.totp",
    "auth.login.backup",
    "auth.isOnboardingComplete",
    "health",
];

pub struct RpcHandler {
    config: Config,
    auth_manager: AuthManager,
    orchestrator: Option<Arc<DevContainerOrchestrator>>,
    state_manager: Arc<StateManager>,
    port_allocator: Arc<Mutex<PortAllocator>>,
    pub session_store: SessionStore,
    login_rate_limiter: LoginRateLimiter,
}

impl RpcHandler {
    pub async fn new(
        config: Config,
        state_manager: Arc<StateManager>,
        session_store: SessionStore,
    ) -> Result<Self> {
        let auth_manager = AuthManager::new(config.data_dir.clone());
        let orchestrator = if config.dev_mode {
            Some(Arc::new(
                DevContainerOrchestrator::new(config.clone()).await?,
            ))
        } else {
            None
        };
        let port_allocator = Arc::new(Mutex::new(PortAllocator::new(&config.data_dir)?));

        Ok(Self {
            config,
            auth_manager,
            orchestrator,
            state_manager,
            port_allocator,
            session_store,
            login_rate_limiter: LoginRateLimiter::new(),
        })
    }

    pub async fn handle(
        &self,
        req: Request<hyper::Body>,
    ) -> Result<Response<hyper::Body>> {
        // Extract session cookie before consuming the request
        let (parts, body) = req.into_parts();
        let session_token = session::extract_session_cookie(&parts.headers);

        let body_bytes = hyper::body::to_bytes(body).await
            .context("Failed to read body")?;

        let rpc_req: RpcRequest = serde_json::from_slice(&body_bytes)
            .context("Invalid RPC request")?;

        debug!("RPC method: {}", rpc_req.method);

        // Enforce authentication for non-allowlisted methods
        let is_unauthenticated = UNAUTHENTICATED_METHODS.contains(&rpc_req.method.as_str());
        if !is_unauthenticated {
            let authenticated = match &session_token {
                Some(token) => self.session_store.validate(token).await,
                None => false,
            };
            if !authenticated {
                let rpc_resp = RpcResponse {
                    result: None,
                    error: Some(RpcError {
                        code: 401,
                        message: "Unauthorized".to_string(),
                        data: None,
                    }),
                };
                let resp_body = serde_json::to_vec(&rpc_resp)
                    .context("Failed to serialize response")?;
                return Ok(Response::builder()
                    .status(StatusCode::UNAUTHORIZED)
                    .header("Content-Type", "application/json")
                    .body(hyper::Body::from(resp_body))
                    .unwrap());
            }
        }

        // Rate limit login attempts
        if rpc_req.method == "auth.login" {
            let client_ip = extract_client_ip(&parts.headers);
            if !self.login_rate_limiter.check(client_ip).await {
                let rpc_resp = RpcResponse {
                    result: None,
                    error: Some(RpcError {
                        code: 429,
                        message: "Too many login attempts. Try again later.".to_string(),
                        data: None,
                    }),
                };
                let resp_body = serde_json::to_vec(&rpc_resp)
                    .context("Failed to serialize response")?;
                return Ok(Response::builder()
                    .status(StatusCode::TOO_MANY_REQUESTS)
                    .header("Content-Type", "application/json")
                    .header("Retry-After", "60")
                    .body(hyper::Body::from(resp_body))
                    .unwrap());
            }
        }

        // Extract params; clone for post-routing use (login 2FA check needs password)
        let params = rpc_req.params;
        let login_params: Option<serde_json::Value> = if rpc_req.method == "auth.login" {
            params.clone()
        } else {
            None
        };

        // Route to handler
        let result = match rpc_req.method.as_str() {
            "echo" => self.handle_echo(params).await,
            "server.echo" => self.handle_echo(params).await,
            "auth.login" => self.handle_auth_login(params).await,
            "auth.logout" => self.handle_auth_logout().await,
            "auth.changePassword" => self.handle_auth_change_password(params).await,
            "auth.onboardingComplete" => self.handle_auth_onboarding_complete().await,
            "auth.isOnboardingComplete" => self.handle_auth_is_onboarding_complete().await,
            "auth.resetOnboarding" => self.handle_auth_reset_onboarding().await,

            // Container orchestration (for Archipelago-managed containers)
            "container-install" => self.handle_container_install(params).await,
            "container-start" => self.handle_container_start(params).await,
            "container-stop" => self.handle_container_stop(params).await,
            "container-remove" => self.handle_container_remove(params).await,
            "container-list" => self.handle_container_list().await,
            "container-status" => self.handle_container_status(params).await,
            "container-logs" => self.handle_container_logs(params).await,
            "container-health" => self.handle_container_health(params).await,

            // Package management (for docker-compose apps)
            "package.install" => self.handle_package_install(params).await,
            "package.start" => self.handle_package_start(params).await,
            "package.stop" => self.handle_package_stop(params).await,
            "package.restart" => self.handle_package_restart(params).await,
            "package.uninstall" => self.handle_package_uninstall(params).await,

            // Bundled app management (for pre-loaded container images)
            "bundled-app-start" => self.handle_bundled_app_start(params).await,
            "bundled-app-stop" => self.handle_bundled_app_stop(params).await,

            // Node identity and P2P peers
            "node-add-peer" => self.handle_node_add_peer(params).await,
            "node-list-peers" => self.handle_node_list_peers().await,
            "node-remove-peer" => self.handle_node_remove_peer(params).await,
            "node-send-message" => self.handle_node_send_message(params).await,
            "node-check-peer" => self.handle_node_check_peer(params).await,
            "node-messages-received" => self.handle_node_messages_received().await,
            "node-nostr-discover" => self.handle_node_nostr_discover().await,
            "node.did" => self.handle_node_did().await,
            "node.signChallenge" => self.handle_node_sign_challenge(params).await,
            "node.createBackup" => self.handle_node_create_backup(params).await,
            "node.tor-address" => self.handle_node_tor_address().await,
            "node.nostr-publish" => self.handle_node_nostr_publish().await,
            "node.nostr-pubkey" => self.handle_node_nostr_pubkey().await,
            "node-nostr-verify-revoked" => self.handle_node_nostr_verify_revoked().await,

            // TOTP 2FA
            "auth.totp.setup.begin" => self.handle_totp_setup_begin(params).await,
            "auth.totp.setup.confirm" => self.handle_totp_setup_confirm(params).await,
            "auth.totp.disable" => self.handle_totp_disable(params).await,
            "auth.totp.status" => self.handle_totp_status().await,
            "auth.login.totp" => self.handle_login_totp(params, &session_token).await,
            "auth.login.backup" => self.handle_login_backup(params, &session_token).await,

            // Bitcoin & Lightning deep data
            "bitcoin.getinfo" => self.handle_bitcoin_getinfo().await,
            "lnd.getinfo" => self.handle_lnd_getinfo().await,

            _ => {
                Err(anyhow::anyhow!("Unknown method: {}", rpc_req.method))
            }
        };

        // Build response
        let rpc_resp = match result {
            Ok(data) => RpcResponse {
                result: Some(data),
                error: None,
            },
            Err(e) => {
                error!("RPC error: {}", e);
                RpcResponse {
                    result: None,
                    error: Some(RpcError {
                        code: -1,
                        message: e.to_string(),
                        data: None,
                    }),
                }
            }
        };

        let resp_body = serde_json::to_vec(&rpc_resp)
            .context("Failed to serialize response")?;

        let mut response = Response::builder()
            .status(StatusCode::OK)
            .header("Content-Type", "application/json")
            .body(hyper::Body::from(resp_body))
            .unwrap();

        // Track failed login attempts for rate limiting
        if rpc_req.method == "auth.login" && rpc_resp.error.is_some() {
            let client_ip = extract_client_ip(&parts.headers);
            self.login_rate_limiter.record_failure(client_ip).await;
        }

        // On successful login, check if 2FA is required
        if rpc_req.method == "auth.login" && rpc_resp.error.is_none() {
            let totp_enabled = self.auth_manager.is_totp_enabled().await.unwrap_or(false);
            if totp_enabled {
                // 2FA enabled: create a pending session with cached TOTP secret
                // We need the password to decrypt the TOTP secret for step 2
                let password = login_params
                    .as_ref()
                    .and_then(|p| p.get("password"))
                    .and_then(|v| v.as_str())
                    .unwrap_or("");
                if let Ok(Some(totp_data)) = self.auth_manager.get_totp_data().await {
                    if let Ok(secret) = crate::totp::decrypt_secret(&totp_data, password) {
                        let token = self.session_store.create_pending(secret).await;
                        response.headers_mut().insert(
                            "Set-Cookie",
                            format!("session={}; HttpOnly; SameSite=Strict; Path=/", token)
                                .parse()
                                .unwrap(),
                        );
                        // Override the response body to indicate TOTP is required
                        let totp_body = serde_json::json!({
                            "result": { "requires_totp": true },
                            "error": null
                        });
                        *response.body_mut() = hyper::Body::from(
                            serde_json::to_vec(&totp_body).unwrap_or_default(),
                        );
                    }
                }
            } else {
                // No 2FA: create a full session immediately
                let token = self.session_store.create().await;
                response.headers_mut().insert(
                    "Set-Cookie",
                    format!("session={}; HttpOnly; SameSite=Strict; Path=/", token)
                        .parse()
                        .unwrap(),
                );
            }
        }

        // On successful TOTP verification, the session is already upgraded to full
        // (handled inside handle_login_totp/handle_login_backup)

        // On logout, invalidate session and expire the cookie
        if rpc_req.method == "auth.logout" {
            if let Some(token) = &session_token {
                self.session_store.remove(token).await;
            }
            response.headers_mut().insert(
                "Set-Cookie",
                "session=; HttpOnly; SameSite=Strict; Path=/; Max-Age=0"
                    .parse()
                    .unwrap(),
            );
        }

        Ok(response)
    }

    async fn handle_echo(&self, params: Option<serde_json::Value>) -> Result<serde_json::Value> {
        if let Some(p) = params {
            if let Some(msg) = p.get("message").and_then(|v| v.as_str()) {
                return Ok(serde_json::json!({ "message": msg }));
            }
        }
        Ok(serde_json::json!({ "message": "Hello from Archipelago!" }))
    }
}

/// Extract the client IP from request headers (X-Real-IP or X-Forwarded-For).
fn extract_client_ip(headers: &hyper::HeaderMap) -> IpAddr {
    headers
        .get("x-real-ip")
        .or_else(|| headers.get("x-forwarded-for"))
        .and_then(|v| v.to_str().ok())
        .and_then(|s| s.split(',').next())
        .and_then(|s| s.trim().parse::<IpAddr>().ok())
        .unwrap_or(IpAddr::V4(std::net::Ipv4Addr::LOCALHOST))
}