import std;
import Crafter.Build;
namespace fs = std::filesystem;
using namespace Crafter;

extern "C" int setenv(const char* name, const char* value, int overwrite);

// Covers the browser-wasm variant plumbing that does NOT require a wasm
// toolchain run: EnableWasiRelaxedSimdVariant's registration, the
// variants.json manifest EnableWasiBrowserRuntime emits, and the VariantId
// perturbation that keeps each variant's objects in their own build dir. The
// actual multi-.wasm production is exercised by a real wasm build (manual /
// integration), not here — same boundary the WasiBrowserRuntime test draws.
namespace {
    int failures = 0;
    void Check(bool cond, std::string_view msg) {
        if (!cond) { std::println(std::cerr, "FAIL: {}", msg); ++failures; }
    }
}

int main() {
    // ── EnableWasiRelaxedSimdVariant: registration + idempotency ──────────
    {
        Configuration cfg;
        cfg.target = "wasm32-wasip1";
        EnableWasiRelaxedSimdVariant(cfg);
        Check(cfg.wasmVariants.size() == 1, "one variant registered");
        if (!cfg.wasmVariants.empty()) {
            const WasmVariant& v = cfg.wasmVariants.front();
            Check(v.label == "relaxed-simd", "label is relaxed-simd");
            Check(v.flags.size() == 1 && v.flags.front() == "-mrelaxed-simd", "flag is -mrelaxed-simd");
            Check(v.probes.size() == 1 && v.probes.front() == "relaxed-simd", "probe is relaxed-simd");
        }
        EnableWasiRelaxedSimdVariant(cfg);
        Check(cfg.wasmVariants.size() == 1, "second call is idempotent");
    }

    // ── wasmVariantFlags perturbs VariantId / BuildDir / BinDir ──────────
    // Configuration owns move-only members (unique_ptr<Module>), so build the
    // two cases independently rather than copying.
    {
        auto make = [] {
            Configuration c;
            c.path = "/tmp/wasm-variant-id-test";
            c.name = "wv"; c.outputName = "wv";
            c.target = "wasm32-wasip1";
            c.type = ConfigurationType::Executable;
            return c;
        };
        Configuration a = make();
        Configuration b = make();
        b.wasmVariantFlags = {"-mrelaxed-simd"};
        Check(a.VariantId() != b.VariantId(), "wasmVariantFlags perturbs VariantId");
        Check(a.BuildDir() != b.BuildDir(), "wasmVariantFlags perturbs BuildDir");
        Check(a.BinDir() != b.BinDir(), "wasmVariantFlags perturbs BinDir");
    }

    // ── variants.json manifest contents ──────────────────────────────────
    {
        fs::path repoWasi = fs::current_path() / "wasi-runtime";
        fs::path systemHome = "/usr/local/share/crafter-build";
        if (fs::exists(repoWasi / "runtime.js")) {
            setenv("CRAFTER_BUILD_HOME", fs::current_path().c_str(), 1);
        } else if (fs::exists(systemHome / "wasi-runtime" / "runtime.js")) {
            setenv("CRAFTER_BUILD_HOME", systemHome.c_str(), 1);
        } else {
            std::println(std::cerr, "wasi-runtime assets not found; skipping manifest check");
            return failures ? 1 : 77;
        }

        Configuration cfg;
        cfg.path = fs::temp_directory_path() / "crafter-build-wasm-variants-test";
        cfg.name = "wvhelper";
        cfg.outputName = "wvhelper";
        cfg.target = "wasm32-wasip1";
        cfg.type = ConfigurationType::Executable;

        std::error_code ec;
        fs::remove_all(cfg.path, ec);
        fs::create_directories(cfg.path);

        EnableWasiRelaxedSimdVariant(cfg);
        EnableWasiBrowserRuntime(cfg);

        const fs::path* variants = nullptr;
        for (const fs::path& f : cfg.files) {
            if (f.filename() == "variants.json") variants = &f;
        }
        Check(variants != nullptr, "variants.json registered");
        if (variants) {
            std::ifstream vin(*variants);
            std::string j{std::istreambuf_iterator<char>(vin), std::istreambuf_iterator<char>()};
            // relaxed-simd entry, with its labelled url + probe.
            Check(j.find("\"label\":\"relaxed-simd\"") != std::string::npos, "manifest has relaxed-simd label");
            Check(j.find("\"wvhelper.relaxed-simd.wasm\"") != std::string::npos, "manifest has labelled url");
            Check(j.find("\"relaxed-simd\"") != std::string::npos, "manifest has relaxed-simd probe");
            // baseline fallback entry.
            Check(j.find("\"wvhelper.wasm\"") != std::string::npos, "manifest has baseline url");
            // The relaxed-simd variant must precede the baseline so the runtime
            // prefers it when probes pass.
            auto relaxedPos = j.find("relaxed-simd");
            auto baselinePos = j.find("\"wvhelper.wasm\"");
            Check(relaxedPos != std::string::npos && baselinePos != std::string::npos && relaxedPos < baselinePos,
                  "relaxed-simd entry precedes baseline");
        }

        fs::remove_all(cfg.path, ec);
    }

    if (failures > 0) {
        std::println(std::cerr, "{} assertions failed", failures);
        return 1;
    }
    return 0;
}