import std;
import Crafter.Build;
using namespace Crafter;

namespace {
    int failures = 0;

    void Check(bool cond, std::string_view msg) {
        if (!cond) {
            std::println(std::cerr, "FAIL: {}", msg);
            ++failures;
        }
    }

    Configuration MakeBase() {
        Configuration cfg;
        cfg.path = "/tmp/variant-id-test";
        cfg.name = "vt";
        cfg.outputName = "vt";
        cfg.target = "x86_64-pc-linux-gnu";
        cfg.march = "native";
        cfg.mtune = "native";
        cfg.type = ConfigurationType::Executable;
        return cfg;
    }
}

// VariantId is the cache key for build outputs. Two Configurations that
// differ only in something that affects codegen must produce different
// VariantId / BuildDir / BinDir, otherwise their .o files collide.
int main() {
    {
        // Baseline against itself: VariantId is deterministic.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        Check(a.VariantId() == b.VariantId(), "identical configs have identical VariantId");
        Check(a.BuildDir() == b.BuildDir(), "identical configs have identical BuildDir");
    }
    {
        // type differs -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.type = ConfigurationType::LibraryStatic;
        Check(a.VariantId() != b.VariantId(), "type change perturbs VariantId");
    }
    {
        // debug differs -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.debug = true;
        Check(a.VariantId() != b.VariantId(), "debug change perturbs VariantId");
    }
    {
        // sysroot differs -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.sysroot = "/opt/sysroot";
        Check(a.VariantId() != b.VariantId(), "sysroot change perturbs VariantId");
    }
    {
        // defines differ -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.defines.push_back({"FOO", "1"});
        Check(a.VariantId() != b.VariantId(), "define added perturbs VariantId");
    }
    {
        // Same define name, different value -> VariantId differs.
        Configuration a = MakeBase();
        a.defines.push_back({"FOO", "1"});
        Configuration b = MakeBase();
        b.defines.push_back({"FOO", "2"});
        Check(a.VariantId() != b.VariantId(), "define value change perturbs VariantId");
    }
    {
        // compileFlags differ -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.compileFlags.push_back("-fno-omit-frame-pointer");
        Check(a.VariantId() != b.VariantId(), "compile flag added perturbs VariantId");
    }
    {
        // target differs -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.target = "aarch64-linux-gnu";
        Check(a.VariantId() != b.VariantId(), "target change perturbs VariantId");
    }
    {
        // march differs -> VariantId differs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.march = "x86-64-v3";
        Check(a.VariantId() != b.VariantId(), "march change perturbs VariantId");
    }
    {
        // PcmDir() differs between Executable (in BuildDir) and Library
        // (in BinDir) — Library PCMs land in the installable bin dir so
        // downstream consumers can find them.
        Configuration exe = MakeBase();
        Configuration lib = MakeBase();
        lib.type = ConfigurationType::LibraryStatic;
        Check(exe.PcmDir() == exe.BuildDir(), "Executable PcmDir == BuildDir");
        Check(lib.PcmDir() == lib.BinDir(), "Library PcmDir == BinDir");
    }
    {
        // VariantId is embedded in the path so distinct ids produce distinct dirs.
        Configuration a = MakeBase();
        Configuration b = MakeBase();
        b.debug = true;
        Check(a.BuildDir() != b.BuildDir(), "different VariantId yields different BuildDir");
        Check(a.BinDir() != b.BinDir(), "different VariantId yields different BinDir");
    }

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