use blockchain::common::binary_conversions::binary_to_string;
use blockchain::common::cli_prompts::prompt_hidden_nonempty;
use blockchain::common::network_startup::get_connections;
use blockchain::env;
use blockchain::json;
use blockchain::records::memory::response_channels::generate_uid;
use blockchain::standalone_tools::connections::handshake;
use blockchain::to_string_pretty;

fn decode_token_list(response: &[u8]) -> Option<String> {
    // An empty binary payload means the peer has no token index entries.
    if response.is_empty() {
        return Some("{\n  \"tokens\": []\n}".to_string());
    }

    // Each token-list row is 15 bytes token name and 64 bytes token hash text.
    if response.len() % 79 != 0 {
        return None;
    }

    let mut tokens = Vec::new();
    let mut offset = 0;
    while offset + 79 <= response.len() {
        // Convert fixed-width padded fields back into display strings.
        let token = binary_to_string(response[offset..offset + 15].to_vec())
            .trim()
            .to_string();
        let hash = binary_to_string(response[offset + 15..offset + 79].to_vec())
            .trim()
            .to_string();
        if !token.is_empty() && !hash.is_empty() {
            tokens.push(json!({
                "token": token,
                "hash": hash,
            }));
        }
        offset += 79;
    }

    let output = json!({
        "tokens": tokens,
    });
    to_string_pretty(&output).ok()
}

#[tokio::main]
async fn main() {
    // Command 31 asks a peer for the full token list.
    let hashmap_key = generate_uid();
    let rpc_command = 31;

    // This lookup takes no user arguments beyond the wallet key used for handshake auth.
    let args: Vec<String> = env::args().collect();
    if args.len() != 1 {
        println!("Usage: ./token_list");
        return;
    }

    let encryption_key = prompt_hidden_nonempty(
        "What is your wallet decryption key? ",
        "Wallet key cannot be empty. Please try again.",
    )
    .await;
    // Try each configured peer until one returns a parsable token list or text error.
    let connections = get_connections().await;
    let mut connected = false;

    for conn in connections {
        if connected {
            break;
        }

        let socket_address = conn.parse().expect("Failed to parse the socket address");
        let result = handshake::connect_and_handshake(
            socket_address,
            "".to_string(),
            rpc_command,
            handshake::HandshakeWallet::WalletKey(encryption_key.clone()),
            hashmap_key,
        )
        .await;

        match result {
            Ok(response) => {
                // Prefer binary token-list decoding; otherwise print a text error if one was returned.
                if let Some(output) = decode_token_list(&response) {
                    println!("{output}");
                    connected = true;
                } else {
                    let response_text = String::from_utf8_lossy(&response);
                    let trimmed = response_text.trim();
                    if !trimmed.is_empty() {
                        println!("{trimmed}");
                        connected = true;
                    } else {
                        connected = false;
                    }
                }
            }
            Err(_) => {
                connected = false;
            }
        }
    }

    if !connected {
        eprintln!("failed to connect");
    }
}