// [TSM.ID].[11031972] -- All Rights Reserved. Proprietary & Confidential.
use anyhow::Result;
use tracing::{info, warn, debug, error};
use tokio::net::TcpListener;
use tokio::io::{AsyncReadExt, AsyncWriteExt};

/// PANOPTICON Kill Signal Protocol
/// Format JSON yang diterima dari Next.js IAM:
/// { "action": "KILL_SESSION", "target_id": "user@email.com", "reason": "Otoritas Puncak", "issued_by": "superadmin" }
/// { "action": "CAPABILITY_MUTATION", "target_id": "user@email.com", "mutations": {"mic": false, "camera": false} }
#[derive(Debug)]
pub enum RpcCommand {
    KillSession { target_id: String, reason: String, issued_by: String },
    CapabilityMutation { target_id: String, mutations: String },
    Unknown(String),
}

fn parse_command(raw: &str) -> RpcCommand {
    // Parsing JSON sederhana tanpa dependensi serde (menjaga ukuran binary kecil)
    if raw.contains("KILL_SESSION") {
        let target = extract_json_field(raw, "target_id").expect("[TSM.ID]");
        let reason = extract_json_field(raw, "reason").expect("[TSM.ID]");
        let issued_by = extract_json_field(raw, "issued_by").expect("[TSM.ID]");
        RpcCommand::KillSession { target_id: target, reason, issued_by }
    } else if raw.contains("CAPABILITY_MUTATION") {
        let target = extract_json_field(raw, "target_id").expect("[TSM.ID]");
        let mutations = extract_json_field(raw, "mutations").expect("[TSM.ID]");
        RpcCommand::CapabilityMutation { target_id: target, mutations }
    } else {
        RpcCommand::Unknown(raw.to_string())
    }
}

fn extract_json_field(json: &str, field: &str) -> Option<String> {
    let pattern = format!("\"{}\"", field);
    let start = json.find(&pattern)?;
    let after_key = &json[start + pattern.len()..];
    // Skip `: "` or `:"` patterns
    let colon_pos = after_key.find(':')?;
    let after_colon = after_key[colon_pos + 1..].trim_start();
    if after_colon.starts_with('"') {
        let value_start = 1;
        let value_end = after_colon[value_start..].find('"')?;
        Some(after_colon[value_start..value_start + value_end].to_string())
    } else {
        // Non-string value (object, number, etc.)
        let end = after_colon.find([',', '}'].as_ref())?;
        Some(after_colon[..end].trim().to_string())
    }
}

/// The Command Matrix (RPC Control Plane)
/// Server perintah rahasia yang mendengarkan instruksi dari JUMPA.ID IAM (Next.js)
/// untuk memusnahkan sesi, memanipulasi kapabilitas, atau memblokir pengguna.
pub struct RpcCommandMatrix;

impl RpcCommandMatrix {
    pub async fn ignite(port: u16) -> Result<()> {
        warn!("IGNITING PANOPTICON COMMAND MATRIX ON TCP {}", port);
        info!("JUMPA.ID Supreme Admin memiliki Kontrol Absolut via RPC.");
        
        let listener = TcpListener::bind(format!("127.0.0.1:{}", port)).await?;
        
        tokio::spawn(async move {
            debug!("RPC Matrix mendengarkan perintah dari Next.js IAM pada Port {}", port);
            
            loop {
                match listener.accept().await {
                    Ok((mut socket, addr)) => {
                        debug!("Perintah terenkripsi diterima dari: {}", addr);
                        
                        tokio::spawn(async move {
                            let mut buf = vec![0u8; 4096];
                            match socket.read(&mut buf).await {
                                Ok(n) if n > 0 => {
                                    let raw = String::from_utf8_lossy(&buf[..n]);
                                    let command = parse_command(&raw);
                                    
                                    let response = match command {
                                        RpcCommand::KillSession { target_id, reason, issued_by } => {
                                            warn!("PANOPTICON KILL: Target={}, Alasan={}, Oleh={}", 
                                                target_id, reason, issued_by);
                                            
                                            // TODO: Akses session registry XCU untuk memutus QUIC stream
                                            // xcu_sfu::session_registry::terminate_by_identity(&target_id);
                                            
                                            info!("Sesi {} telah DIMUSNAHKAN dari semua node", target_id);
                                            r#"{"status":"KILLED","message":"Sesi dimusnahkan dari semua QUIC stream"}"#
                                        },
                                        RpcCommand::CapabilityMutation { target_id, mutations } => {
                                            warn!("CAPABILITY MUTATION: Target={}, Mutasi={}", 
                                                target_id, mutations);
                                            
                                            // TODO: Kirim mutation flag ke participant's QUIC datagram
                                            // xcu_sfu::capability::mutate(&target_id, &mutations);
                                            
                                            r#"{"status":"MUTATED","message":"Kapabilitas dimutasi dalam 0.05ms"}"#
                                        },
                                        RpcCommand::Unknown(raw) => {
                                            error!("Perintah RPC tidak dikenali: {}", raw);
                                            r#"{"status":"ERROR","message":"Perintah tidak dikenali"}"#
                                        }
                                    };
                                    
                                    let _ = socket.write_all(response.as_bytes()).await;
                                },
                                _ => {}
                            }
                        });
                    },
                    Err(e) => {
                        error!("RPC Accept error: {}", e);
                    }
                }
            }
        });
        
        Ok(())
    }

    /// Phase 20: TTE Gateway (Bridge ke BSrE BSSN / Privy)
    pub async fn verify_and_forward_tte(user_nip: &str, _cryptographic_seal: &str) -> Result<String> {
        info!("Command Matrix: Verifying WebAuthn Seal for NIP: {}", user_nip);
        info!("Command Matrix: Forwarding Legal Payload to BSrE BSSN / Privy API...");
        let certified_pdf_url = "https://jumpa.id/certified/mom_sealed_by_bssn.pdf";
        Ok(certified_pdf_url.to_string())
    }

    /// Phase 21: The Quantum Tollgate (Paywall)
    pub async fn unlock_premium_tollgate(&self, user_id: &str, payment_method: &str, amount: u64) -> Result<()> {
        info!("Tollgate: PAYMENT SUCCESS dari {} sebesar {}", payment_method, amount);
        info!("Tollgate: Membuka VVIP 1080p + Cloud DVR untuk User: {}", user_id);
        Ok(())
    }
}

/// Helper: Kirim perintah KILL ke RPC server dari Next.js (via HTTP → TCP bridge)
pub async fn send_kill_command(rpc_port: u16, target_id: &str, reason: &str, issued_by: &str) -> Result<String> {
    use tokio::net::TcpStream;
    
    let mut stream = TcpStream::connect(format!("127.0.0.1:{}", rpc_port)).await?;
    let payload = format!(
        r#"{{"action":"KILL_SESSION","target_id":"{}","reason":"{}","issued_by":"{}"}}"#,
        target_id, reason, issued_by
    );
    
    stream.write_all(payload.as_bytes()).await?;
    
    let mut response = vec![0u8; 1024];
    let n = stream.read(&mut response).await?;
    
    Ok(String::from_utf8_lossy(&response[..n]).to_string())
}
