vector_core/

blossom.rs

use nostr_sdk::{NostrSigner, Url, Event, EventBuilder, Timestamp, JsonUtil};
use nostr_sdk::hashes::{sha256::Hash as Sha256Hash, Hash};
use nostr_blossom::prelude::*;
use reqwest::header::{HeaderMap, HeaderValue, AUTHORIZATION, CONTENT_LENGTH, CONTENT_TYPE};
use reqwest::{Body, StatusCode};
use std::str::FromStr;
use std::sync::{Arc, Mutex};
use std::sync::atomic::{AtomicBool, Ordering};
use tokio::sync::mpsc;
use futures_util::Stream;
use std::pin::Pin;
use std::task::{Context, Poll};

/// Progress callback function type
pub type ProgressCallback = std::sync::Arc<dyn Fn(Option<u8>, Option<u64>) -> Result<(), String> + Send + Sync>;

/// Custom upload stream that tracks progress
struct ProgressTrackingStream {
    bytes_sent: Arc<Mutex<u64>>,
    inner: mpsc::Receiver<Result<Vec<u8>, std::io::Error>>,
}

impl ProgressTrackingStream {
    fn new(data: Arc<Vec<u8>>, bytes_sent: Arc<Mutex<u64>>) -> Self {
        let (tx, rx) = mpsc::channel(8); // Buffer size of 8 chunks

        // Spawn a background task to feed the stream
        tokio::spawn(async move {
            let chunk_size = 64 * 1024; // 64 KB chunks - only unavoidable copy
            let mut position = 0;

            while position < data.len() {
                let end = std::cmp::min(position + chunk_size, data.len());
                let chunk = data[position..end].to_vec();

                // Send chunk through channel
                if tx.send(Ok(chunk)).await.is_err() {
                    break; // Receiver was dropped
                }

                position = end;
            }
        });

        Self {
            bytes_sent,
            inner: rx,
        }
    }
}

impl Stream for ProgressTrackingStream {
    type Item = Result<Vec<u8>, std::io::Error>;

    fn poll_next(
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<Option<Self::Item>> {
        match self.inner.poll_recv(cx) {
            Poll::Ready(Some(result)) => {
                // Update the bytes sent counter
                if let Ok(chunk) = &result {
                    let mut bytes_sent = self.bytes_sent.lock().unwrap();
                    *bytes_sent += chunk.len() as u64;
                }
                Poll::Ready(Some(result))
            }
            Poll::Ready(None) => Poll::Ready(None),
            Poll::Pending => Poll::Pending,
        }
    }
}

/// Builds the Blossom authorization header
async fn build_auth_header<T>(
    signer: &T,
    hash: Sha256Hash,
) -> Result<HeaderValue, String>
where
    T: NostrSigner,
{
    // Create Blossom authorization
    let expiration = Timestamp::now() + std::time::Duration::from_secs(300);
    let auth = BlossomAuthorization::new(
        "Blossom upload authorization".to_string(),
        expiration,
        BlossomAuthorizationVerb::Upload,
        BlossomAuthorizationScope::BlobSha256Hashes(vec![hash]),
    );

    // Sign the authorization event
    let auth_event: Event = EventBuilder::blossom_auth(auth)
        .sign(signer)
        .await
        .map_err(|e| format!("Failed to sign auth event: {}", e))?;

    // Encode as base64
    let encoded_auth = base64_simd::STANDARD.encode_to_string(auth_event.as_json());
    let value = format!("Nostr {}", encoded_auth);

    HeaderValue::try_from(value)
        .map_err(|e| format!("Failed to create header value: {}", e))
}

/// Upload to a single Blossom server with progress callbacks.
/// `retry_count` defaults to 0; `retry_spacing` defaults to 1s.
pub async fn upload_blob_with_progress<T>(
    signer: T,
    server_url: &Url,
    file_data: Arc<Vec<u8>>,
    mime_type: Option<&str>,
    progress_callback: ProgressCallback,
    retry_count: Option<u32>,
    retry_spacing: Option<std::time::Duration>,
    cancel_flag: Option<Arc<AtomicBool>>,
) -> Result<String, String>
where
    T: NostrSigner + Clone,
{
    let retry_count = retry_count.unwrap_or(0);
    let retry_spacing = retry_spacing.unwrap_or(std::time::Duration::from_secs(1));

    let mut last_error = None;

    for attempt in 0..=retry_count {
        if attempt > 0 {
            tokio::time::sleep(retry_spacing).await;
        }

        if let Some(ref flag) = cancel_flag {
            if flag.load(Ordering::Relaxed) {
                return Err("Upload cancelled".to_string());
            }
        }

        match upload_attempt(
            signer.clone(),
            server_url,
            file_data.clone(),
            mime_type,
            &progress_callback,
            cancel_flag.clone(),
        ).await {
            Ok(url) => return Ok(url),
            Err(e) => {
                if e == "Upload cancelled" {
                    return Err(e);
                }
                crate::log_warn!(
                    "[Blossom] Attempt {}/{} to {} failed: {}",
                    attempt + 1, retry_count + 1, server_url, e,
                );
                // Deterministic rejections (413/415 etc.) — outer failover handles them.
                let status = parse_status_from_error(&e);
                let permanent = crate::blossom_capabilities::is_mime_rejection(status, &e)
                    || crate::blossom_capabilities::is_size_rejection(status);
                if permanent {
                    return Err(e);
                }
                // On large uploads, mid-stream drops are almost always a
                // size policy; don't burn retries. Below 8MB, treat as a
                // genuine transient blip and retry.
                let looks_like_mid_stream_drop = (
                    e.contains("Upload request failed")
                    || e.contains("error sending request")
                    || e.contains("connection reset")
                    || e.contains("connection closed")
                    || e.contains("connection refused")
                    || e.contains("body write")
                    || e.contains("IncompleteMessage")
                    || e.contains("broken pipe")
                ) && file_data.len() > 8 * 1024 * 1024;
                if looks_like_mid_stream_drop {
                    crate::log_warn!(
                        "[Blossom] {} dropped the connection mid-upload of {} bytes, treating as permanent",
                        server_url, file_data.len(),
                    );
                    return Err(e);
                }
                last_error = Some(e);
            }
        }
    }

    // All attempts failed, return the last error
    Err(last_error.unwrap_or_else(|| "No upload attempts were made".to_string()))
}

/// Internal function that performs a single upload attempt with progress tracking
async fn upload_attempt<T>(
    signer: T,
    server_url: &Url,
    file_data: Arc<Vec<u8>>,
    mime_type: Option<&str>,
    progress_callback: &ProgressCallback,
    cancel_flag: Option<Arc<AtomicBool>>,
) -> Result<String, String>
where
    T: NostrSigner,
{
    let upload_url = server_url.join("upload")
        .map_err(|e| format!("Invalid server URL: {}", e))?;

    let total_size = file_data.len() as u64;
    let hash = Sha256Hash::hash(&*file_data);

    progress_callback(Some(0), Some(0)).map_err(|e| e)?;

    // One auth event covers both HEAD preflight and PUT.
    let auth_header = build_auth_header(&signer, hash).await?;

    // Redirects disabled: a 3xx mid-PUT would re-issue as GET and drop the body.
    let client = crate::net::build_http_client_with_options(
        std::time::Duration::from_secs(300),
        false,
    )?;

    // BUD-06 preflight (best-effort; non-supporting servers 404/405).
    {
        let mut head_headers = HeaderMap::new();
        head_headers.insert(AUTHORIZATION, auth_header.clone());
        head_headers.insert(
            "X-Content-Length",
            HeaderValue::from_str(&total_size.to_string())
                .map_err(|e| format!("Invalid X-Content-Length: {}", e))?,
        );
        // BUD-06 requires lowercase hex. SIMD encode of the 32-byte digest (sha256::Hash displays
        // in forward byte order, matching to_byte_array — see the parity test).
        head_headers.insert(
            "X-SHA-256",
            HeaderValue::from_str(&crate::simd::hex::bytes_to_hex_32(&hash.to_byte_array()))
                .map_err(|e| format!("Invalid X-SHA-256: {}", e))?,
        );
        if let Some(ct) = mime_type {
            head_headers.insert(
                "X-Content-Type",
                HeaderValue::from_str(ct).map_err(|e| format!("Invalid X-Content-Type: {}", e))?,
            );
        }
        match tokio::time::timeout(
            std::time::Duration::from_secs(5),
            client.head(upload_url.clone()).headers(head_headers).send(),
        ).await {
            Ok(Ok(resp)) => {
                let status = resp.status();
                // BUD-02: X-Reason is display-only. Body IS fed to the classifier
                // to catch non-compliant servers that 400 instead of 415.
                let x_reason = resp.headers().get("X-Reason")
                    .and_then(|v| v.to_str().ok())
                    .map(|s| s.to_string());
                let body = resp.text().await.unwrap_or_default();
                let diag = if !body.is_empty() {
                    if let Some(r) = &x_reason {
                        format!("{} (X-Reason: {})", body, r)
                    } else {
                        body
                    }
                } else if let Some(r) = x_reason {
                    r
                } else {
                    format!("rejected at preflight ({})", status)
                };
                let is_413 = status == StatusCode::PAYLOAD_TOO_LARGE;
                let is_415 = status == StatusCode::UNSUPPORTED_MEDIA_TYPE;
                let mime_hinted = status.is_client_error() && !is_413 && {
                    crate::blossom_capabilities::is_mime_rejection(Some(status.as_u16()), &diag)
                };
                if is_413 || is_415 || mime_hinted {
                    crate::log_warn!(
                        "[Blossom Preflight] {} REJECTED {} ({} bytes, {}): {}",
                        server_url, status, total_size,
                        mime_type.unwrap_or("(no mime)"), diag,
                    );
                    return Err(format!(
                        "Upload failed with status {}: {}",
                        status, diag,
                    ));
                }
                crate::log_debug!(
                    "[Blossom Preflight] {} → {} ({} bytes); proceeding to PUT",
                    server_url, status, total_size,
                );
            }
            Ok(Err(e)) => {
                crate::log_debug!("[Blossom Preflight] {} HEAD failed: {}, falling through to PUT", server_url, e);
            }
            Err(_) => {
                crate::log_debug!("[Blossom Preflight] {} HEAD timed out (5s), falling through to PUT", server_url);
            }
        }
    }

    let bytes_sent = Arc::new(Mutex::new(0u64));
    let tracking_stream = ProgressTrackingStream::new(file_data, Arc::clone(&bytes_sent));
    let body = Body::wrap_stream(tracking_stream);

    let mut headers = HeaderMap::new();
    headers.insert(AUTHORIZATION, auth_header);
    if let Some(ct) = mime_type {
        headers.insert(
            CONTENT_TYPE,
            HeaderValue::from_str(ct).map_err(|e| format!("Invalid content type: {}", e))?
        );
    }
    // `Body::wrap_stream` is unknown-length so reqwest would default to
    // chunked encoding and omit Content-Length — some servers (e.g.
    // blossom.data.haus) then 411.
    headers.insert(CONTENT_LENGTH, HeaderValue::from(total_size));

    let mut request_future = Box::pin(client
        .put(upload_url.clone())
        .headers(headers)
        .body(body)
        .send());

    let mut last_percentage = 0;
    let mut poll_interval = tokio::time::interval(tokio::time::Duration::from_millis(100));

    let response = loop {
        tokio::select! {
            response = &mut request_future => {
                break response.map_err(|e| format!("Upload request failed: {}", e))?;
            },
            _ = poll_interval.tick() => {
                if let Some(ref flag) = cancel_flag {
                    if flag.load(Ordering::Relaxed) {
                        return Err("Upload cancelled".to_string());
                    }
                }

                let current_bytes = *bytes_sent.lock().unwrap();
                let percentage = if total_size > 0 {
                    ((current_bytes as f64 / total_size as f64) * 100.0) as u8
                } else {
                    0
                };

                if percentage != last_percentage {
                    if let Err(e) = progress_callback(Some(percentage), Some(current_bytes)) {
                        return Err(e);
                    }
                    last_percentage = percentage;
                }
            }
        }
    };

    let final_bytes = *bytes_sent.lock().unwrap();
    if final_bytes == total_size && last_percentage < 100 {
        progress_callback(Some(100), Some(total_size)).map_err(|e| e)?;
    }

    // BUD-02: accept any 2xx (200 OK or 201 Created).
    let status = response.status();
    if status.is_success() {
        let descriptor: BlobDescriptor = response.json().await
            .map_err(|e| format!("Failed to parse response: {}", e))?;
        Ok(descriptor.url.to_string())
    } else {
        // BUD-02: X-Reason is display-only; body feeds the classifier.
        let x_reason = response.headers().get("X-Reason")
            .and_then(|v| v.to_str().ok())
            .map(|s| s.to_string());
        let error_text = response.text().await.unwrap_or_else(|_| "Unknown error".to_string());
        let display = match (error_text.is_empty(), x_reason) {
            (false, Some(r)) => format!("{} (X-Reason: {})", error_text, r),
            (false, None)    => error_text,
            (true, Some(r))  => r,
            (true, None)     => "Unknown error".to_string(),
        };
        crate::log_warn!("[Blossom Error] Upload failed with status {}: {}", status, display);
        Err(format!("Upload failed with status {}: {}", status, display))
    }
}

/// Simple upload without progress tracking
pub async fn upload_blob<T>(
    signer: T,
    server_url: &Url,
    file_data: Arc<Vec<u8>>,
    mime_type: Option<&str>,
) -> Result<String, String>
where
    T: NostrSigner,
{
    let upload_url = server_url.join("upload")
        .map_err(|e| format!("Invalid server URL: {}", e))?;

    let hash = Sha256Hash::hash(&*file_data);
    let total_size = file_data.len() as u64;

    let auth_header = build_auth_header(&signer, hash).await?;

    let mut headers = HeaderMap::new();
    headers.insert(AUTHORIZATION, auth_header);
    if let Some(ct) = mime_type {
        headers.insert(
            CONTENT_TYPE,
            HeaderValue::from_str(ct).map_err(|e| format!("Invalid content type: {}", e))?
        );
    }
    headers.insert(CONTENT_LENGTH, HeaderValue::from(total_size));

    // Redirects disabled so a 3xx mid-PUT doesn't re-issue as GET.
    let client = crate::net::build_http_client_with_options(
        std::time::Duration::from_secs(300),
        false,
    )?;

    let body_data: Vec<u8> = Arc::try_unwrap(file_data)
        .unwrap_or_else(|arc| (*arc).clone());
    let response = client
        .put(upload_url)
        .headers(headers)
        .body(body_data)
        .send()
        .await
        .map_err(|e| format!("Upload request failed: {}", e))?;

    // BUD-02: accept any 2xx (200 OK or 201 Created).
    let status = response.status();
    if status.is_success() {
        let descriptor: BlobDescriptor = response.json().await
            .map_err(|e| format!("Failed to parse response: {}", e))?;
        Ok(descriptor.url.to_string())
    } else {
        let error_text = response.text().await.unwrap_or_else(|_| "Unknown error".to_string());
        Err(format!("Upload failed with status {}: {}", status, error_text))
    }
}

/// Upload to multiple Blossom servers with failover, in input order.
///
/// **Does NOT participate in the capability cache.** Used by the
/// marketplace (plaintext mini-app uploads); for high-volume callers
/// prefer `upload_blob_with_progress_and_failover` so they benefit
/// from cache-aware routing.
pub async fn upload_blob_with_failover<T>(
    signer: T,
    server_urls: Vec<String>,
    file_data: Arc<Vec<u8>>,
    mime_type: Option<&str>,
) -> Result<String, String>
where
    T: NostrSigner + Clone,
{
    let mut last_error = String::from("No servers available");

    for (index, server_url_str) in server_urls.iter().enumerate() {
        let server_url = match Url::parse(server_url_str) {
            Ok(url) => url,
            Err(e) => {
                crate::log_warn!("[Blossom Error] Invalid server URL '{}': {}", server_url_str, e);
                last_error = format!("Invalid server URL: {}", e);
                continue;
            }
        };

        crate::log_info!("[Blossom] Attempting upload to server {} of {}: {}",
            index + 1, server_urls.len(), server_url_str);

        match upload_blob(signer.clone(), &server_url, file_data.clone(), mime_type).await {
            Ok(url) => {
                crate::log_info!("[Blossom] Upload successful to: {}", server_url_str);
                return Ok(url);
            }
            Err(e) => {
                crate::log_warn!("[Blossom Error] Upload failed to {}: {}", server_url_str, e);
                last_error = e;
            }
        }
    }

    Err(format!("All Blossom servers failed. Last error: {}", last_error))
}

/// Upload with progress + failover, cache-aware routing, and capability learning.
pub async fn upload_blob_with_progress_and_failover<T>(
    signer: T,
    server_urls: Vec<String>,
    file_data: Arc<Vec<u8>>,
    mime_type: Option<&str>,
    is_encrypted: bool,
    progress_callback: ProgressCallback,
    retry_count: Option<u32>,
    retry_spacing: Option<std::time::Duration>,
    cancel_flag: Option<Arc<AtomicBool>>,
) -> Result<String, String>
where
    T: NostrSigner + Clone,
{
    let mut last_error = String::from("No servers available");

    // Known-good first, unknown second, MIME-rejected last. Stable within
    // tier so the user's BUD-03 trust order wins ties.
    let size_bytes = file_data.len() as u64;
    let mime_for_routing = mime_type.unwrap_or("application/octet-stream");
    let ranked = crate::blossom_capabilities::rank_servers(server_urls, mime_for_routing, is_encrypted, size_bytes);
    // Pin capability writes to the account that started the upload.
    let upload_session = crate::state::SessionGuard::capture();

    for (index, server_url_str) in ranked.iter().enumerate() {
        if let Some(ref flag) = cancel_flag {
            if flag.load(Ordering::Relaxed) {
                return Err("Upload cancelled".to_string());
            }
        }

        let server_url = match Url::parse(server_url_str) {
            Ok(url) => url,
            Err(e) => {
                crate::log_warn!("[Blossom Error] Invalid server URL '{}': {}", server_url_str, e);
                last_error = format!("Invalid server URL: {}", e);
                continue;
            }
        };

        crate::log_info!("[Blossom] Attempting upload to server {} of {}: {}",
            index + 1, ranked.len(), server_url_str);

        match upload_blob_with_progress(
            signer.clone(),
            &server_url,
            file_data.clone(),
            mime_type,
            progress_callback.clone(),
            retry_count,
            retry_spacing,
            cancel_flag.clone(),
        ).await {
            Ok(url) => {
                crate::log_info!("[Blossom] Upload successful to: {}", server_url_str);
                if let Err(err) = crate::blossom_capabilities::record_accepted(
                    server_url_str, mime_for_routing, is_encrypted, size_bytes, upload_session,
                ) {
                    crate::log_warn!("[Blossom Cap] record_accepted failed: {}", err);
                }
                return Ok(url);
            }
            Err(e) => {
                if e == "Upload cancelled" {
                    return Err(e);
                }
                crate::log_warn!("[Blossom Error] Upload failed to {}: {}", server_url_str, e);
                let status = parse_status_from_error(&e);
                if crate::blossom_capabilities::is_mime_rejection(status, &e) {
                    if let Err(err) = crate::blossom_capabilities::record_rejected_mime(
                        server_url_str, mime_for_routing, is_encrypted, upload_session,
                    ) {
                        crate::log_warn!("[Blossom Cap] record_rejected_mime failed: {}", err);
                    }
                } else if crate::blossom_capabilities::is_size_rejection(status) {
                    if let Err(err) = crate::blossom_capabilities::record_rejected_size(
                        server_url_str, mime_for_routing, is_encrypted, size_bytes, upload_session,
                    ) {
                        crate::log_warn!("[Blossom Cap] record_rejected_size failed: {}", err);
                    }
                }
                // Mid-stream drops aren't cached (too ambiguous); only
                // an explicit 413 sets min_rejected_size.
                last_error = e;
                let _ = progress_callback(Some(0), Some(0));
            }
        }
    }

    Err(format!("All Blossom servers failed. Last error: {}", last_error))
}

// ============================================================================
// Blossom DELETE — paired with NIP-17 message deletion
// ============================================================================

/// Build a BUD-01 DELETE authorization header (kind-24242, verb=delete).
async fn build_delete_auth_header<T>(
    signer: &T,
    hash: Sha256Hash,
) -> Result<HeaderValue, String>
where
    T: NostrSigner,
{
    let expiration = Timestamp::now() + std::time::Duration::from_secs(300);
    let auth = BlossomAuthorization::new(
        "Blossom delete authorization".to_string(),
        expiration,
        BlossomAuthorizationVerb::Delete,
        BlossomAuthorizationScope::BlobSha256Hashes(vec![hash]),
    );

    let auth_event: Event = EventBuilder::blossom_auth(auth)
        .sign(signer)
        .await
        .map_err(|e| format!("Failed to sign auth event: {}", e))?;

    let encoded_auth = base64_simd::STANDARD.encode_to_string(auth_event.as_json());
    let value = format!("Nostr {}", encoded_auth);

    HeaderValue::try_from(value)
        .map_err(|e| format!("Failed to create header value: {}", e))
}

/// Delete a blob from a Blossom server. 2xx and 404 both count as
/// success (idempotent: "blob is gone" is the goal). 401/403/5xx and
/// network errors propagate.
pub async fn delete_blob<T>(
    signer: T,
    server_url: &Url,
    hash: Sha256Hash,
) -> Result<(), String>
where
    T: NostrSigner + Clone,
{
    let auth_header = build_delete_auth_header(&signer, hash).await?;

    let mut url = server_url.clone();
    // BUD-01 DELETE endpoint: `<origin>/<hash>`.
    url.set_path(&format!("/{}", hash));

    let mut headers = HeaderMap::new();
    headers.insert(AUTHORIZATION, auth_header);

    let client = crate::net::build_http_client(std::time::Duration::from_secs(30))?;

    let response = client
        .delete(url)
        .headers(headers)
        .send()
        .await
        .map_err(|e| format!("Blossom DELETE request failed: {}", e))?;

    let status = response.status();
    if status.is_success() || status == StatusCode::NOT_FOUND {
        Ok(())
    } else {
        let body = response.text().await.unwrap_or_else(|_| "<no body>".into());
        Err(format!("Blossom DELETE returned {}: {}", status, body))
    }
}

/// Parse a Blossom blob URL into (origin, hash) and DELETE that blob.
/// Awaitable single-URL variant of `delete_blobs_best_effort` — caller
/// drives sequencing + per-URL UI feedback.
pub async fn delete_blob_by_url<T>(signer: T, url_str: &str) -> Result<(), String>
where
    T: NostrSigner + Clone,
{
    let parsed = Url::parse(url_str)
        .map_err(|e| format!("Invalid Blossom URL: {}", e))?;
    let last_segment = parsed
        .path_segments()
        .and_then(|segs| segs.rev().find(|s| !s.is_empty()))
        .ok_or_else(|| "Blossom URL has no path segment".to_string())?;
    let hash_str = last_segment.split('.').next().unwrap_or("");
    let hash = Sha256Hash::from_str(hash_str)
        .map_err(|e| format!("Path is not a SHA-256 hash: {}", e))?;

    let mut origin = parsed.clone();
    origin.set_path("/");
    origin.set_query(None);
    origin.set_fragment(None);

    crate::log_info!("[Blossom] DELETE {} from {}", hash, origin);
    // Hard ceiling — a black-holed server must not hang the caller's
    // UI (e.g. the pack creator's "Deleting…" overlay) indefinitely.
    // 15s is generous for a healthy server and short enough that a
    // misbehaving one fails over to the next blob in a batch quickly.
    let timeout = std::time::Duration::from_secs(15);
    match tokio::time::timeout(timeout, delete_blob(signer, &origin, hash)).await {
        Ok(Ok(())) => {
            crate::log_info!("[Blossom] DELETE successful: {} from {}", hash, origin);
            Ok(())
        }
        Ok(Err(e)) => {
            crate::log_warn!("[Blossom] DELETE failed: {} from {}: {}", hash, origin, e);
            Err(e)
        }
        Err(_) => {
            let msg = format!("DELETE timed out after {}s", timeout.as_secs());
            crate::log_warn!("[Blossom] {} ({} from {})", msg, hash, origin);
            Err(msg)
        }
    }
}

/// Fire-and-forget DELETE for each parseable blob URL. Pairs with
/// `delete_own_dm` so removing a NIP-17 file message also removes
/// the ciphertext from the server it was uploaded to.
pub fn delete_blobs_best_effort<T>(signer: T, urls: Vec<String>)
where
    T: NostrSigner + Clone + Send + Sync + 'static,
{
    for url_str in urls {
        let url = match Url::parse(&url_str) {
            Ok(u) => u,
            Err(_) => continue,
        };

        // Last non-empty path segment (trailing-slash URLs leave an empty tail).
        let last_segment = match url.path_segments()
            .and_then(|segs| segs.rev().find(|s| !s.is_empty()))
        {
            Some(s) => s,
            None => continue,
        };
        // Strip an optional `.ext` suffix some servers append.
        let hash_str = last_segment.split('.').next().unwrap_or("");
        let hash = match Sha256Hash::from_str(hash_str) {
            Ok(h) => h,
            Err(_) => continue,
        };

        let mut origin = url.clone();
        origin.set_path("/");
        origin.set_query(None);
        origin.set_fragment(None);

        let signer = signer.clone();
        tokio::spawn(async move {
            if let Err(e) = delete_blob(signer, &origin, hash).await {
                crate::log_warn!("[Blossom delete] {} from {}: {}", hash, origin, e);
            }
        });
    }
}

/// Probe `(server, application/octet-stream, encrypted=true)` with a
/// 32-byte random blob to learn whether the server accepts the binary
/// uploads Vector produces for chat attachments. Single-shot per
/// (server,mime,encrypted). Successful probes are cleaned up via DELETE.
pub async fn probe_servers_for_octet_stream<T>(
    signer: T,
    server_urls: Vec<String>,
    session: crate::state::SessionGuard,
) -> Result<usize, String>
where
    T: NostrSigner + Clone,
{
    use rand::RngCore;
    if !session.is_valid() { return Ok(0); }
    if server_urls.is_empty() { return Ok(0); }

    const PROBE_MIME: &str = "application/octet-stream";
    let mut payload = vec![0u8; 32];
    rand::thread_rng().fill_bytes(&mut payload[..]);
    let payload = Arc::new(payload);
    let payload_size = payload.len() as u64;

    let mut probed = 0usize;
    for server_url_str in &server_urls {
        if !session.is_valid() { return Ok(probed); }
        if crate::blossom_capabilities::has_fresh_capability_for(server_url_str, PROBE_MIME, true) {
            continue;
        }
        let parsed = match Url::parse(server_url_str) {
            Ok(u) => u,
            Err(_) => continue,
        };
        // 4s per-server budget bounds worst-case probe pass.
        let no_op_progress: ProgressCallback = Arc::new(|_, _| Ok(()));
        match tokio::time::timeout(
            std::time::Duration::from_secs(4),
            upload_blob_with_progress(
                signer.clone(),
                &parsed,
                payload.clone(),
                Some(PROBE_MIME),
                no_op_progress,
                Some(0),
                None,
                None,
            ),
        ).await {
            Ok(Ok(url)) => {
                // Race-guard: server may have been disabled/removed
                // between spawn and now (purge_server already cleared).
                if !crate::blossom_servers::is_enabled_server(server_url_str) {
                    if let Some(hash) = extract_hash_from_blossom_url(&url) {
                        let _ = delete_blob(signer.clone(), &parsed, hash).await;
                    }
                    continue;
                }
                if let Err(e) = crate::blossom_capabilities::record_accepted(
                    server_url_str, PROBE_MIME, true, payload_size, session,
                ) {
                    crate::log_warn!("[Blossom Probe] record_accepted failed: {}", e);
                }
                if let Some(hash) = extract_hash_from_blossom_url(&url) {
                    let _ = delete_blob(signer.clone(), &parsed, hash).await;
                }
                probed += 1;
                crate::log_info!("[Blossom Probe] {} accepts octet-stream", server_url_str);
            }
            Ok(Err(e)) => {
                let status = parse_status_from_error(&e);
                if crate::blossom_capabilities::is_mime_rejection(status, &e) {
                    if !crate::blossom_servers::is_enabled_server(server_url_str) {
                        continue;
                    }
                    if let Err(err) = crate::blossom_capabilities::record_rejected_mime(
                        server_url_str, PROBE_MIME, true, session,
                    ) {
                        crate::log_warn!("[Blossom Probe] record_rejected_mime failed: {}", err);
                    }
                    probed += 1;
                    crate::log_info!("[Blossom Probe] {} rejects octet-stream: {}", server_url_str, e);
                } else {
                    // Transient — leave reputation unchanged so we re-probe later.
                    crate::log_debug!("[Blossom Probe] {} transient error (not cached): {}", server_url_str, e);
                }
            }
            Err(_) => {
                crate::log_debug!("[Blossom Probe] {} timed out, not cached", server_url_str);
            }
        }
    }
    Ok(probed)
}

/// Parse the sha256 out of `<origin>/<sha256>[.<ext>][/]`. Skips an
/// empty trailing segment when the URL came back with a trailing slash.
fn extract_hash_from_blossom_url(url: &str) -> Option<Sha256Hash> {
    let parsed = Url::parse(url).ok()?;
    let last = parsed.path_segments()?.rev().find(|s| !s.is_empty())?;
    let stem = last.split('.').next()?;
    Sha256Hash::from_str(stem).ok()
}

/// Extract the HTTP status from an error string. Anchored to the
/// `"with status NNN"` shape produced by `upload_blob_with_progress`
/// so unrelated `status` substrings don't false-match.
fn parse_status_from_error(msg: &str) -> Option<u16> {
    let key = "with status ";
    let i = msg.find(key)?;
    let tail = &msg[i + key.len()..];
    let digits: String = tail.chars().take_while(|c| c.is_ascii_digit()).collect();
    digits.parse::<u16>().ok()
}

#[cfg(test)]
mod parse_status_tests {
    use super::parse_status_from_error;

    #[test]
    fn extracts_status_code() {
        assert_eq!(parse_status_from_error("Upload failed with status 500 Internal Server Error: x"), Some(500));
        assert_eq!(parse_status_from_error("Upload failed with status 413 Payload Too Large"), Some(413));
        assert_eq!(parse_status_from_error("Upload failed with status 415"), Some(415));
    }

    #[test]
    fn returns_none_when_absent() {
        assert_eq!(parse_status_from_error("network error: timeout"), None);
    }
}

#[cfg(test)]
mod hash_extract_tests {
    use super::extract_hash_from_blossom_url;

    const HASH_HEX: &str = "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08";

    #[test]
    fn plain_url() {
        let url = format!("https://srv.example/{}", HASH_HEX);
        assert!(extract_hash_from_blossom_url(&url).is_some());
    }

    #[test]
    fn with_extension() {
        let url = format!("https://srv.example/{}.jpg", HASH_HEX);
        assert!(extract_hash_from_blossom_url(&url).is_some());
    }

    #[test]
    fn trailing_slash_still_resolves() {
        // Some servers append a trailing slash to the descriptor URL.
        let url = format!("https://srv.example/{}/", HASH_HEX);
        assert!(extract_hash_from_blossom_url(&url).is_some());
    }

    #[test]
    fn malformed_returns_none() {
        assert!(extract_hash_from_blossom_url("https://srv.example/").is_none());
        assert!(extract_hash_from_blossom_url("not a url").is_none());
        assert!(extract_hash_from_blossom_url("https://srv.example/notahash").is_none());
    }

    #[test]
    fn x_sha256_simd_hex_matches_lowerhex() {
        use nostr_sdk::hashes::{sha256::Hash as Sha256Hash, Hash};
        // The X-SHA-256 header swapped format!("{:x}") for the SIMD encoder; they MUST agree
        // byte-for-byte (sha256::Hash displays in forward order — a reversed-display hash type would
        // silently corrupt the upload header).
        let hash = Sha256Hash::hash(b"vector blossom x-sha-256 parity check");
        assert_eq!(
            crate::simd::hex::bytes_to_hex_32(&hash.to_byte_array()),
            format!("{:x}", hash),
        );
    }
}