//! Milestone 0 — Blaze transport reachability observation.
//!
//! PURE LOGGING, NO NEW DETOURS. This module does not hook anything itself. It is
//! called from the three Winsock detours the hook ALREADY installs — getaddrinfo
//! (`hooks.rs`), connect/WSAConnect (`connect_hook.rs`) and ConnectEx
//! (`connectex_hook.rs`) — and, when armed, emits a single grep-friendly
//! `TRANSPORT_WATCH:` line per resolution/connect so we can answer one question:
//!
//!   Does the FIFA 23 client attempt ANY Blaze-flavored transport activity across a
//!   full menu+FUT session, or none at all?
//!
//! Everything here is READ-ONLY: we parse the hostname / sockaddr the game passed
//! only to describe it in the log. We never change a resolution result or a
//! connection target — that redirect logic lives in the detours themselves and is
//! untouched. The env kill switch `OPENFUT_TRANSPORT_WATCH=1` gates all output;
//! disarmed (default) this module is inert (each entry point returns immediately).
//!
//! Future-reference note (beyond-beginner, deliberately NOT done here): a
//! types-first design would model a `ConnectTarget` enum (Inet{ip,port} / NonInet /
//! Short) and a `TransportEvent` and route them through the `tracing` crate with
//! structured fields, instead of hand-formatting strings into a flat log file. That
//! buys machine-parseable logs and log levels. For a one-shot observation gate,
//! flat `write_log` lines that `grep` cleanly are the lower-ceremony choice.

use core::sync::atomic::{AtomicBool, Ordering};

/// Armed once at DLL load from `OPENFUT_TRANSPORT_WATCH`. `AtomicBool` (not a plain
/// `static mut bool`) because the detours that read it run on arbitrary game threads;
/// an atomic gives race-free reads with no `unsafe`. `Relaxed` is enough — this is a
/// standalone flag with no ordering relationship to other memory.
static ARMED: AtomicBool = AtomicBool::new(false);

/// Read the env var once, at DLL load, and log the arm state. Called from `DllMain`
/// (`install_hooks`). Reading the env in-process (rather than as a command prefix) is
/// what makes the switch actually propagate through the umu/Proton launch — the same
/// gotcha the probe switches hit; it works because the launch script `export`s it.
pub fn arm_from_env() {
    let on = std::env::var("OPENFUT_TRANSPORT_WATCH")
        .map(|v| v == "1")
        .unwrap_or(false);
    ARMED.store(on, Ordering::Relaxed);
    crate::write_log(&format!(
        "TRANSPORT_WATCH: {} (env OPENFUT_TRANSPORT_WATCH)\n",
        if on { "ARMED" } else { "disarmed" }
    ));
}

fn armed() -> bool {
    ARMED.load(Ordering::Relaxed)
}

/// True if `host` looks like EA/Blaze infrastructure. Broad on purpose: this is a log
/// classifier that makes a hit visually pop (`<-- BLAZE/EA-FLAVORED`), NOT a routing
/// decision. The actual redirect decision stays in `hooks::is_ea_host`, which is
/// deliberately narrower and unchanged.
fn is_blaze_flavored(host: &str) -> bool {
    let h = host.to_ascii_lowercase();
    [
        "redirector",
        "gosredirector",
        "blaze",
        "gosca",
        "easfc",
        "utas",
        "fut",
        "ea.com",
        "easports",
    ]
    .iter()
    .any(|k| h.contains(k))
}

/// Log one getaddrinfo hostname. Self-gates on the arm flag, so the call site can be
/// unconditional. The existing `openfut_hook: getaddrinfo(...)` line stays; this adds
/// the tagged, classified line so `grep TRANSPORT_WATCH` sees the full resolution set
/// and a Blaze host stands out.
pub fn note_getaddrinfo(host: &str) {
    if !armed() {
        return;
    }
    let tag = if is_blaze_flavored(host) {
        "  <-- BLAZE/EA-FLAVORED"
    } else {
        ""
    };
    crate::write_log(&format!("TRANSPORT_WATCH: getaddrinfo host=\"{host}\"{tag}\n"));
}

const AF_INET: u16 = 2; // IPv4
const AF_INET6: u16 = 23; // IPv6 (Windows value; Linux uses 10 — we're in Wine/Win ABI)

/// Minimal view of a `sockaddr_in`; the first `u16` is the address family for ANY
/// sockaddr, so reading this layout is safe enough to classify the family even when
/// the real struct is a `sockaddr_un` or larger — we only trust the rest once we've
/// confirmed `sin_family == AF_INET`.
#[repr(C)]
struct SockaddrIn {
    sin_family: u16,
    sin_port: u16,
    sin_addr: u32,
    sin_zero: [u8; 8],
}

/// Minimal view of a `sockaddr_in6` (Win32 layout). `sin6_port` is network byte order;
/// `sin6_addr` is the 16 raw address bytes in network order. We ignore flowinfo/scope.
#[repr(C)]
struct SockaddrIn6 {
    sin6_family: u16,
    sin6_port: u16,
    sin6_flowinfo: u32,
    sin6_addr: [u8; 16],
    sin6_scope_id: u32,
}

/// Is `port` a known/suspected Blaze port? SHAPE — public general knowledge; the exact
/// port for FIFA23's Blaze version is UNKNOWN. 42127 main, 10041/10744 redirector
/// variants, 3659 classic redirector.
fn is_blaze_port(port: u16) -> bool {
    matches!(port, 42127 | 10744 | 3659 | 10041)
}

/// Log one outbound connect attempt. `api` names the call path (`connect` /
/// `WSAConnect` / `ConnectEx`) so we can tell which Winsock entry the client used.
///
/// SAFETY: `name` must point to at least `namelen` readable bytes — it's the sockaddr
/// the game just handed to a Winsock connect API, so that always holds at the call
/// sites. We read it read-only and never write through it. `s` is the socket handle,
/// used only to query `SO_TYPE` (TCP=1 / UDP=2) so a real Blaze TCP dial is
/// distinguishable from UDP game/voice traffic.
pub unsafe fn note_connect(api: &str, name: *const u8, namelen: i32, s: usize) {
    if !armed() {
        return;
    }
    if name.is_null() || namelen < 8 {
        crate::write_log(&format!(
            "TRANSPORT_WATCH: {api} (no/short sockaddr, namelen={namelen})\n"
        ));
        return;
    }
    // SAFE: name is non-null and >= 8 bytes (checked above); the first u16 is the
    // address family for ANY sockaddr, so reading it is valid regardless of the real
    // struct type. We only trust family-specific fields after matching the family.
    let family = *(name as *const u16);

    // SAFE: getsockopt is a read-only Winsock query on a valid socket handle; a bad
    // handle just leaves ty=-1, which we log verbatim. TCP=1 / UDP=2.
    let sock_type = {
        use windows_sys::Win32::Networking::WinSock::{getsockopt, SOL_SOCKET, SO_TYPE};
        let mut ty: i32 = -1;
        let mut len: i32 = 4;
        getsockopt(
            s,
            SOL_SOCKET as i32,
            SO_TYPE,
            &mut ty as *mut i32 as *mut u8,
            &mut len,
        );
        ty
    };

    match family {
        AF_INET => {
            // SAFE: family is AF_INET and namelen >= 8 == sizeof(sockaddr_in) fields we read.
            let sa = &*(name as *const SockaddrIn);
            // sin_addr holds the address in NETWORK byte order; on little-endian x86,
            // to_le_bytes reproduces those 4 bytes in memory order, which IS the dotted
            // quad. So b[0].b[1].b[2].b[3] is correct. (The legacy connect_hook log line
            // prints these reversed — a cosmetic bug there; this M0 line is the correct
            // one to trust.)
            let b = sa.sin_addr.to_le_bytes();
            let port = u16::from_be(sa.sin_port);
            let is_loopback = b[0] == 127;
            let is_lsx = matches!(port, 3216 | 3217); // known-good LSX channel; not Blaze
            let mut tag = String::new();
            if is_blaze_port(port) {
                tag.push_str("  <-- BLAZE-PORT");
            }
            // A loopback connect on anything other than LSX is the situation-(a) signal.
            if is_loopback && !is_lsx {
                tag.push_str("  <-- LOOPBACK non-LSX");
            }
            crate::write_log(&format!(
                "TRANSPORT_WATCH: {api} target={}.{}.{}.{}:{port} sock_type={sock_type}{tag}\n",
                b[0], b[1], b[2], b[3]
            ));
        }
        AF_INET6 => {
            if namelen < 28 {
                crate::write_log(&format!(
                    "TRANSPORT_WATCH: {api} family=INET6 (short sockaddr, namelen={namelen})\n"
                ));
                return;
            }
            // SAFE: family is AF_INET6 and namelen >= 28 == sizeof(sockaddr_in6).
            let sa = &*(name as *const SockaddrIn6);
            let a = sa.sin6_addr; // 16 bytes, network order
            let port = u16::from_be(sa.sin6_port);
            // Format as 8 colon-separated hex groups (not compressed — clarity over
            // brevity for a log meant to be grepped).
            let hex = (0..8)
                .map(|i| format!("{:02x}{:02x}", a[i * 2], a[i * 2 + 1]))
                .collect::<Vec<_>>()
                .join(":");
            // ::1 = loopback: first 15 bytes zero, last byte 1.
            let is_loopback = a[..15].iter().all(|&x| x == 0) && a[15] == 1;
            let mut tag = String::new();
            if is_blaze_port(port) {
                tag.push_str("  <-- BLAZE-PORT");
            }
            if is_loopback {
                tag.push_str("  <-- IPv6 LOOPBACK (::1)");
            }
            crate::write_log(&format!(
                "TRANSPORT_WATCH: {api} target=[{hex}]:{port} sock_type={sock_type} (IPv6){tag}\n"
            ));
        }
        other => {
            // AF_UNIX=1 or anything else — where a named-pipe/unix-socket-style local
            // Blaze transport would surface.
            crate::write_log(&format!(
                "TRANSPORT_WATCH: {api} family={other} (non-INET — possible AF_UNIX/pipe-like)\n"
            ));
        }
    }
}