// The command stream: what the adapter writes, the renderer process reads back the same.

#include <cstdio>
#include <cstring>

#include "t5de/protocol/commands.hpp"

using namespace t5de::protocol;

namespace {

int failures = 0;

void check(bool ok, const char* what)
{
    if (!ok) {
        std::printf("FAIL: %s\n", what);
        ++failures;
    }
}

} // namespace

int main()
{
    Writer writer;
    writer.add(Op::Clear, Clear{3, 0xff131313});
    const unsigned char pixels[] = {1, 2, 3, 4, 5, 6, 7, 8};
    std::memcpy(writer.add(Op::CreateTexture, CreateTexture{7, 2, 1, 6}, sizeof(pixels)), pixels, sizeof(pixels));
    std::byte* odd = writer.add(Op::UpdateBuffer, UpdateBuffer{9, 1, 3}, 3); // padded to 4
    std::memset(odd, 0xab, 3);
    writer.add(Op::EndFrame, EndFrame{});
    check(writer.size() % 4 == 0, "commands stay 4-byte aligned");

    Reader reader(writer.bytes());
    auto clear = reader.next();
    check(clear && clear->op() == Op::Clear && clear->body<Clear>()->color == 0xff131313, "clear");
    auto texture = reader.next();
    check(texture && texture->op() == Op::CreateTexture && texture->body<CreateTexture>()->id == 7, "texture");
    check(texture && texture->payload<CreateTexture>().size() == sizeof(pixels)
              && std::memcmp(texture->payload<CreateTexture>().data(), pixels, sizeof(pixels)) == 0,
          "texture pixels");
    auto update = reader.next();
    check(update && update->payload<UpdateBuffer>().size() == 4, "payload padded");
    auto end = reader.next();
    check(end && end->op() == Op::EndFrame, "end of frame");
    check(!reader.next(), "nothing after");

    // A truncated stream (a chunk cut short) yields only whole commands.
    Reader truncated(writer.bytes().first(writer.size() - 2));
    int count = 0;
    while (truncated.next()) {
        ++count;
    }
    check(count == 3, "truncated: whole commands only");

    if (failures == 0) {
        std::printf("ok\n");
    }
    return failures == 0 ? 0 : 1;
}