//! Link the vendored static libvpx (UCRT MinGW ABI) + generate FFI bindings
//! from the vendored vpx headers via bindgen (libclang). RustDesk does the same
//! (its vpx.rs include!s an OUT_DIR/vpx_ffi.rs). We vendor a UCRT-ABI libvpx.a
//! so there is no vcpkg/MSYS2 or runtime DLL dependency.
use std::path::PathBuf;

fn main() {
    let manifest = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
    let tp = manifest.join("..").join("third_party").join("ucrt64");
    let lib = tp.join("lib");
    let inc = tp.join("include");

    println!("cargo:rustc-link-search=native={}", lib.display());
    println!("cargo:rustc-link-lib=static=vpx");
    println!("cargo:rustc-link-lib=pthread");
    println!("cargo:rerun-if-changed=wrapper.h");
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed={}", lib.join("libvpx.a").display());

    // bindgen needs libclang; point at the installed LLVM if the env is unset.
    if std::env::var("LIBCLANG_PATH").is_err() {
        for p in ["C:/Program Files/LLVM/bin", "C:/Program Files (x86)/LLVM/bin"] {
            if PathBuf::from(p).join("libclang.dll").exists() {
                std::env::set_var("LIBCLANG_PATH", p);
                break;
            }
        }
    }

    // Based on RustDesk's proven bindgen config (libs/scrap/build.rs): a single
    // `^[vV].*` allowlist for types/vars/functions, rustified enums.
    //
    // vpx_codec_enc_cfg and vpx_codec_dec_cfg are forward-declared (by pointer)
    // in vpx_codec.h's iface struct BEFORE vpx_encoder.h/vpx_decoder.h define
    // them. libclang 22 then reports them to bindgen as incomplete, so bindgen
    // emits them as opaque `_address: u8` blobs with no fields — making g_w /
    // rc_target_bitrate / threads unsettable. (bindgen version, trust_clang_
    // mangling, rustified_enum, and a by-value use all failed to change this.)
    // So we blocklist both here and hand-write their exact #[repr(C)] layouts
    // in src/lib.rs (ffi module) from the vendored headers. Everything else
    // (vpx_image, cx_pkt, ctx, enums, functions) still comes from bindgen.
    let regex = "^[vV].*";
    let bindings = bindgen::Builder::default()
        .header("wrapper.h")
        .clang_arg(format!("-I{}", inc.display()))
        .allowlist_type(regex)
        .allowlist_var(regex)
        .allowlist_function(regex)
        .rustified_enum(regex)
        .blocklist_type("vpx_codec_enc_cfg")
        .blocklist_type("vpx_codec_enc_cfg_t")
        .blocklist_type("vpx_codec_dec_cfg")
        .blocklist_type("vpx_codec_dec_cfg_t")
        .trust_clang_mangling(false)
        .layout_tests(false)
        .generate_comments(false)
        .generate()
        .expect("bindgen libvpx");
    bindings
        .write_to_file(PathBuf::from(std::env::var("OUT_DIR").unwrap()).join("vpx_ffi.rs"))
        .expect("write vpx_ffi.rs");
}