//! Snapshot test for the WIT mirror.
//!
//! The SDK ships its own copy of `wit/world.wit` so the proc-macro
//! can embed it via `include_str!` at compile time. The hash MUST
//! match the platform's frozen v1.0 hash. If this test fails, the
//! mirror has drifted and the SDK cannot guarantee binary
//! compatibility with the platform.

#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]

use std::path::PathBuf;

use sha2::{Digest, Sha256};

/// Identical to FROZEN_WIT_SHA256 in
/// fai/platform :: crates/fai_runtime/tests/wit_freeze.rs.
/// Update both repos in lockstep, never one alone.
const PLATFORM_FROZEN_WIT_SHA256: &str =
    "6f4e2266a4264832a16fe5a3704622cd978b290b90f3300c3ed236d98b689b5f";

fn world_wit_path() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .parent()
        .expect("crates parent")
        .parent()
        .expect("workspace root")
        .join("wit")
        .join("world.wit")
}

#[test]
fn wit_mirror_matches_platform_frozen_hash() {
    let path = world_wit_path();
    let bytes = std::fs::read(&path).unwrap_or_else(|e| panic!("read {}: {e}", path.display()));

    let mut hasher = Sha256::new();
    hasher.update(&bytes);
    let actual = format!("{:x}", hasher.finalize());

    assert_eq!(
        actual, PLATFORM_FROZEN_WIT_SHA256,
        "\n\nwit/world.wit in this repo has drifted from the platform's\n\
         frozen v1.0 hash. The SDK MUST mirror the platform exactly\n\
         or modules built with this SDK will not be wire-compatible.\n\n\
         If the platform intentionally bumped to a new minor (e.g.\n\
         v1.1 with additive changes), update BOTH:\n\
           1. wit/world.wit here to match the platform copy\n\
           2. PLATFORM_FROZEN_WIT_SHA256 in this test\n\n\
         If the platform is still on the old hash, revert this WIT\n\
         change.\n\n\
         actual hash: {actual}\n"
    );
}