bun_runtime 0.1.0

// @trace REQ-ENG-007 [entity:HttpClientBridge]
// @trace REQ-PERF-001 [entity:HttpResponse] @trace REQ-PERF-003 [entity:BufferManager]
//! Synchronous HTTP client bridge using bun_http::AsyncHTTP::init_sync + send_sync().
//!
//! Provides a simple synchronous HTTP request function that can be called
//! from anywhere in bao_runtime without needing SpiderMonkey context.

use bun_core::MutableString;
use bun_http::header_builder::HeaderBuilder;
use bun_http::{AsyncHTTP, FetchRedirect, Method};
use bun_url::URL;
use bytes::Bytes;
use compact_str::CompactString;
use smallvec::SmallVec;

/// Simplified HTTP response type extracted from picohttp::Response.
/// Owns all data (no borrowed lifetime) so it can be stored and used freely.
///
/// Zero-copy / zero-alloc optimizations:
/// - `status_text`: CompactString inlines short strings like "OK" (no heap alloc)
/// - `headers`: SmallVec stacks ≤8 header pairs (typical case), spills to heap only for many headers
/// - `body`: Bytes enables zero-copy slicing and avoids clone() on large responses
pub struct HttpResponse {
    /// HTTP status code (e.g. 200, 404, 500).
    pub status_code: u32,
    /// Status text (e.g. "OK", "Not Found"). CompactString: inline for ≤24 bytes.
    pub status_text: CompactString,
    /// Response headers as (name, value) pairs. SmallVec: stack for ≤8 pairs.
    pub headers: SmallVec<[(CompactString, CompactString); 8]>,
    /// Response body. Bytes: zero-copy slicing, cheap clone (Arc ref count).
    pub body: Bytes,
}

/// Perform a synchronous HTTP request via bun_http::AsyncHTTP::send_sync().
///
/// This function:
/// 1. Parses the URL via bun_url::URL::parse
/// 2. Builds request headers via HeaderBuilder
/// 3. Initializes AsyncHTTP via init_sync()
/// 4. Executes the request via send_sync() (blocking)
/// 5. Extracts the response into an owned HttpResponse
pub fn http_request(
    method: Method,
    url: &str,
    headers: &[(String, String)],
    body: Option<&[u8]>,
) -> ::std::result::Result<HttpResponse, String> {
    // Parse URL from bytes
    let url_bytes = url.as_bytes();
    let parsed_url = URL::parse(url_bytes);

    // Build header entries via HeaderBuilder: count -> allocate -> append
    let mut hb = HeaderBuilder::default();
    for (name, value) in headers {
        hb.count(name.as_bytes(), value.as_bytes());
    }
    if let ::std::result::Result::Err(e) = hb.allocate() {
        return ::std::result::Result::Err(format!("Header allocation failed: {:?}", e));
    }
    for (name, value) in headers {
        hb.append(name.as_bytes(), value.as_bytes());
    }

    let entry_list = hb.entries;
    let headers_buf: &[u8] = unsafe {
        if let Some(ptr) = hb.content.ptr {
            ::std::slice::from_raw_parts(ptr.as_ptr(), hb.content.len)
        } else {
            &[]
        }
    };

    // Allocate response buffer — send_sync writes the response body here
    let response_buffer = Box::into_raw(Box::new(MutableString::default()));

    let body_slice: &[u8] = body.unwrap_or_default();

    let mut async_http = AsyncHTTP::init_sync(
        method,
        parsed_url,
        entry_list,
        headers_buf,
        response_buffer,
        body_slice,
        None, // http_proxy
        None, // hostname
        FetchRedirect::Follow,
    );

    let result = async_http.send_sync().map_err(|e| format!("{:?}", e))?;

    // Read body from response_buffer via zero-copy take (avoids clone of potentially MB-sized buffer)
    let body_vec = unsafe { std::mem::take(&mut (*response_buffer).list) };

    // Reclaim response buffer
    unsafe {
        drop(Box::from_raw(response_buffer));
    }

    // Extract fields from picohttp::Response into owned HttpResponse
    let status_code = result.status_code;
    let status_text = CompactString::new(::std::str::from_utf8(result.status).unwrap_or(""));

    let headers: SmallVec<[(CompactString, CompactString); 8]> = result
        .headers
        .list
        .iter()
        .map(|h| {
            let name = CompactString::new(::std::str::from_utf8(h.name()).unwrap_or(""));
            let value = CompactString::new(::std::str::from_utf8(h.value()).unwrap_or(""));
            (name, value)
        })
        .collect();

    ::std::result::Result::Ok(HttpResponse {
        status_code,
        status_text,
        headers,
        body: Bytes::from(body_vec),
    })
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_method_roundtrip() {
        assert_eq!(Method::GET.as_str(), "GET");
        assert_eq!(Method::POST.as_str(), "POST");
        assert_eq!(Method::PUT.as_str(), "PUT");
        assert_eq!(Method::DELETE.as_str(), "DELETE");
        assert_eq!(Method::PATCH.as_str(), "PATCH");
        assert_eq!(Method::HEAD.as_str(), "HEAD");
    }

    #[test]
    fn test_http_response_construction() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![("Content-Type".into(), "text/html".into())],
            body: Bytes::from_static(b"hello"),
        };
        assert_eq!(resp.status_code, 200);
        assert_eq!(resp.status_text, "OK");
        assert_eq!(resp.headers.len(), 1);
        assert_eq!(&resp.body[..], b"hello");
    }

    // ─── HttpResponse extended tests ──────────────────────────────
    // @trace REQ-ENG-007 [req:REQ-ENG-007] [level:unit]

    #[test]
    fn test_http_response_empty_body() {
        let resp = HttpResponse {
            status_code: 204,
            status_text: CompactString::new("No Content"),
            headers: SmallVec::new(),
            body: Bytes::new(),
        };
        assert_eq!(resp.status_code, 204);
        assert!(resp.body.is_empty());
        assert!(resp.headers.is_empty());
    }

    #[test]
    fn test_http_response_multiple_headers() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![
                ("content-type".into(), "application/json".into()),
                ("x-request-id".into(), "abc-123".into()),
                ("cache-control".into(), "no-cache".into()),
            ],
            body: Bytes::from_static(b"{}"),
        };
        assert_eq!(resp.headers.len(), 3);
        assert_eq!(resp.headers[0].0, "content-type");
        assert_eq!(resp.headers[1].1, "abc-123");
    }

    #[test]
    fn test_http_response_error_status() {
        let resp = HttpResponse {
            status_code: 500,
            status_text: CompactString::new("Internal Server Error"),
            headers: SmallVec::new(),
            body: Bytes::from_static(b"error"),
        };
        assert_eq!(resp.status_code, 500);
        assert_eq!(resp.status_text, "Internal Server Error");
    }

    #[test]
    fn test_http_response_redirect_status() {
        let resp = HttpResponse {
            status_code: 301,
            status_text: CompactString::new("Moved Permanently"),
            headers: smallvec::smallvec![("location".into(), "https://example.com".into())],
            body: Bytes::new(),
        };
        assert_eq!(resp.status_code, 301);
        assert_eq!(resp.headers[0].0, "location");
    }

    #[test]
    fn test_method_all_variants() {
        assert_eq!(Method::GET.as_str(), "GET");
        assert_eq!(Method::POST.as_str(), "POST");
        assert_eq!(Method::PUT.as_str(), "PUT");
        assert_eq!(Method::DELETE.as_str(), "DELETE");
        assert_eq!(Method::PATCH.as_str(), "PATCH");
        assert_eq!(Method::HEAD.as_str(), "HEAD");
        assert_eq!(Method::OPTIONS.as_str(), "OPTIONS");
    }

    #[test]
    fn test_method_connect_trace() {
        assert_eq!(Method::CONNECT.as_str(), "CONNECT");
        assert_eq!(Method::TRACE.as_str(), "TRACE");
    }

    // ─── http_client extended edge case tests ────────────────
    // @trace REQ-ENG-007 [req:REQ-ENG-007] [level:unit]

    #[test]
    fn test_http_response_status_codes_range() {
        for code in [
            200, 201, 204, 301, 302, 304, 400, 401, 403, 404, 500, 502, 503,
        ] {
            let resp = HttpResponse {
                status_code: code,
                status_text: CompactString::new(""),
                headers: SmallVec::new(),
                body: Bytes::new(),
            };
            assert_eq!(resp.status_code, code);
        }
    }

    #[test]
    fn test_http_response_body_binary() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: SmallVec::new(),
            body: Bytes::from(vec![0x89, 0x50, 0x4E, 0x47]),
        };
        assert_eq!(&resp.body[..4], &[0x89, 0x50, 0x4E, 0x47]);
    }

    #[test]
    fn test_http_response_header_value_with_semicolon() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![(
                "content-type".into(),
                "text/html; charset=utf-8".into()
            )],
            body: Bytes::new(),
        };
        assert!(resp.headers[0].1.contains("charset=utf-8"));
    }

    #[test]
    fn test_http_response_large_body() {
        let large_body: Vec<u8> = (0..10_000).map(|i| (i % 256) as u8).collect();
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: SmallVec::new(),
            body: Bytes::from(large_body.clone()),
        };
        assert_eq!(resp.body.len(), 10_000);
        assert_eq!(resp.body[0], 0);
        assert_eq!(resp.body[255], 255);
    }

    #[test]
    fn test_http_response_header_order_preserved() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![
                ("x-first".into(), "1".into()),
                ("x-second".into(), "2".into()),
                ("x-third".into(), "3".into()),
            ],
            body: Bytes::new(),
        };
        assert_eq!(resp.headers[0].0, "x-first");
        assert_eq!(resp.headers[1].0, "x-second");
        assert_eq!(resp.headers[2].0, "x-third");
    }

    #[test]
    fn test_http_response_status_4xx() {
        for code in [400, 401, 403, 404, 405, 408, 429] {
            let resp = HttpResponse {
                status_code: code,
                status_text: CompactString::new(""),
                headers: SmallVec::new(),
                body: Bytes::new(),
            };
            assert!(resp.status_code >= 400 && resp.status_code < 500);
        }
    }

    #[test]
    fn test_http_response_status_5xx() {
        for code in [500, 502, 503, 504] {
            let resp = HttpResponse {
                status_code: code,
                status_text: CompactString::new(""),
                headers: SmallVec::new(),
                body: Bytes::new(),
            };
            assert!(resp.status_code >= 500 && resp.status_code < 600);
        }
    }

    #[test]
    fn test_method_debug_format() {
        let _ = format!("{:?}", Method::GET);
        let _ = format!("{:?}", Method::POST);
    }

    #[test]
    fn test_http_response_unicode_body() {
        let unicode_body = "你好世界".as_bytes().to_vec();
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![(
                "content-type".into(),
                "text/plain; charset=utf-8".into()
            )],
            body: Bytes::from(unicode_body.clone()),
        };
        assert_eq!(&resp.body[..], &unicode_body[..]);
    }

    #[test]
    fn test_http_response_empty_status_text() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new(""),
            headers: SmallVec::new(),
            body: Bytes::new(),
        };
        assert!(resp.status_text.is_empty());
    }

    #[test]
    fn test_http_response_header_duplicate_names() {
        let resp = HttpResponse {
            status_code: 200,
            status_text: CompactString::new("OK"),
            headers: smallvec::smallvec![
                ("set-cookie".into(), "a=1".into()),
                ("set-cookie".into(), "b=2".into()),
            ],
            body: Bytes::new(),
        };
        assert_eq!(resp.headers.len(), 2);
        assert_eq!(resp.headers[0].0, "set-cookie");
        assert_eq!(resp.headers[1].0, "set-cookie");
        assert_ne!(resp.headers[0].1, resp.headers[1].1);
    }

    // ── Zero-copy / zero-alloc optimization tests ──────────────────
    // @trace REQ-PURE-002 [req:REQ-PURE-002] [level:unit]

    /// CompactString inlines short status texts like "OK" — no heap allocation.
    #[test]
    fn test_short_status_text_no_heap_alloc() {
        let short = CompactString::new("OK");
        assert_eq!(short.len(), 2);
        assert_eq!(&*short, "OK");
        // CompactString inlines strings up to 24 bytes on 64-bit platforms
        let longer = CompactString::new("Internal Server Error");
        assert_eq!(&*longer, "Internal Server Error");
    }

    /// SmallVec stacks ≤8 header pairs — no heap allocation for typical responses.
    #[test]
    fn test_small_headers_stack_allocated() {
        let headers: SmallVec<[(CompactString, CompactString); 8]> = smallvec::smallvec![
            ("content-type".into(), "text/html".into()),
            ("content-length".into(), "42".into()),
            ("server".into(), "bao".into()),
        ];
        assert_eq!(headers.len(), 3);
        // ≤8 items: stored on the stack (no heap allocation)
        assert!(headers.len() <= 8);
    }

    /// Bytes::from(Vec) is zero-copy — the Vec's buffer is moved into Bytes without cloning.
    #[test]
    fn test_body_take_no_clone() {
        let original = vec![0xDE, 0xAD, 0xBE, 0xEF];
        let ptr = original.as_ptr();
        let b = Bytes::from(original);
        // Bytes::from(Vec) reuses the same allocation — pointer is identical
        assert_eq!(
            b.as_ptr(),
            ptr,
            "Bytes::from(Vec) must reuse the same allocation (zero-copy)"
        );
        assert_eq!(&b[..], &[0xDE, 0xAD, 0xBE, 0xEF]);
    }
}