// Synth WASM ABI descriptor and Worker-response correlation tests
// (synth-nodes.md §7.2 / VAL-COMP-013..017).
//
// These tests cover the versioned synth artefact ABI surface exposed from
// the generated interpreter WASM bundle:
//
//   VAL-COMP-015: The synth artefact ABI is versioned and rejects
//                 incompatible consumers.
//   VAL-COMP-016: Native and generated-WASM compilation produce
//                 equivalent normalised artefacts for the synth corpus.
//
// The Worker-response atomicity (VAL-COMP-013/014) is covered by the
// root Mocha integration tests. The "fresh root assets load the current
// interpreter ABI" assertion (VAL-COMP-017) is exercised by the root
// rebuild + agent-browser validator.

#define CATCH_CONFIG_MAIN
#include "../catch.hpp"

#include "src/signal_engine/signal_engine.h"
#include "src/signal_engine/synth_graph.h"
#include "src/signal_engine/synth_registry.h"

#include <cstdio>
#include <cstring>
#include <string>
#include <vector>

using namespace sig;

namespace {

struct SynthHarness {
    SignalEngine engine;

    SynthHarness() { engine.init_defaults(); }

    EvalResult eval(const std::string& code)
    {
        return eval_cold(code.c_str(), static_cast<uint32_t>(code.size()), engine);
    }

    bool eval_ok(const std::string& code)
    {
        EvalResult r = eval(code);
        INFO("code: " << code);
        if (r.kind == EvalResult::Error && r.diagnostic_count > 0) {
            for (uint8_t i = 0; i < r.diagnostic_count; i++) {
                INFO("diagnostic[" << i << "]: "
                     << (r.diagnostics[i].message ? r.diagnostics[i].message : ""));
            }
        }
        return r.kind != EvalResult::Error;
    }

    bool eval_fails(const std::string& code)
    {
        EvalResult r = eval(code);
        return r.kind == EvalResult::Error;
    }
};

std::string snapshot_synth_artifacts(const SynthHarness& h)
{
    const char* json = synth_artifacts_json(h.engine);
    return json ? std::string(json) : std::string();
}

} // namespace

// ============================================================================
// VAL-COMP-015: Synth artefact ABI is versioned
// ============================================================================

TEST_CASE("synth: artefact ABI exposes a version marker",
          "[synth][val-comp-015]") {
    SynthHarness h;

    // The published artefact JSON must carry an `abi` field naming the
    // version the engine's synth-graph module advertises. Consumers read
    // this before touching the payload.
    //
    // NOTE: the wasm wrapper wraps the body with an `abi` field. Native
    // callers reach the same surface through synth_artifacts_supports_abi()
    // which returns true for the engine's declared version and false for
    // incompatible consumers.
    REQUIRE(SYNTH_ARTIFACT_ABI_VERSION > 0);

    SECTION("supports current abi") {
        REQUIRE(synth_artifacts_supports_abi(SYNTH_ARTIFACT_ABI_VERSION));
    }

    SECTION("rejects incompatible abi") {
        // A future consumer built against abi=99 must be rejected explicitly
        // rather than silently misreading the layout.
        REQUIRE_FALSE(synth_artifacts_supports_abi(SYNTH_ARTIFACT_ABI_VERSION + 1));
        REQUIRE_FALSE(synth_artifacts_supports_abi(99));
        REQUIRE_FALSE(synth_artifacts_supports_abi(0));
    }
}

TEST_CASE("synth: wasm abi wrapper marks the snapshot with abi version",
          "[synth][val-comp-015]") {
    // Mirrors the wrapper that useq_synth_artifacts() applies in the WASM
    // bundle. The C helper wraps the raw synth_artifacts_json body with an
    // `abi` marker so a consumer can reject incompatible bundles up front.
    SynthHarness h;
    REQUIRE(h.eval_ok("(synth \"osc/sine\" :name \"lead\" :freq 440)"));

    char buf[SYNTH_ARTIFACT_JSON_CAP + 64];
    bool ok = synth_artifacts_render_abi_wrapper(
        h.engine, SYNTH_ARTIFACT_ABI_VERSION, buf, sizeof(buf));
    REQUIRE(ok);

    std::string wrapped(buf);
    REQUIRE(wrapped.find("\"abi\":") != std::string::npos);
    REQUIRE(wrapped.find(std::to_string(SYNTH_ARTIFACT_ABI_VERSION))
            != std::string::npos);

    // An incompatible consumer-version must be rejected by the helper up
    // front (the wrapper still renders a minimal error object so the wire
    // shape stays valid JSON).
    bool rejected = synth_artifacts_render_abi_wrapper(
        h.engine, SYNTH_ARTIFACT_ABI_VERSION + 7, buf, sizeof(buf));
    REQUIRE_FALSE(rejected);
}

TEST_CASE("synth: maximum accepted shipped graph fits artifact capacity",
          "[synth][capacity][serialization]") {
    SynthHarness h;
    for (uint16_t i = 0; i < SYNTH_MAX_NODES; i++) {
        char id[32];
        std::snprintf(id, sizeof(id), "node-%026u", (unsigned)i);
        std::string code = "(synth \"osc/sine\" :name \"";
        code += id;
        code += "\" :freq 440 :amp 0.25)";
        INFO("declaration " << i);
        REQUIRE(h.eval_ok(code));
    }
    REQUIRE(h.engine.synth_graph.declaration_count() == SYNTH_MAX_NODES);
    REQUIRE(h.engine.synth_graph.control_count() == SYNTH_MAX_NODES * 2);

    char body[SYNTH_ARTIFACT_JSON_CAP];
    REQUIRE(synth_graph_render_json(
        h.engine.synth_graph, body, sizeof(body)));
    REQUIRE(std::string(body).find("\"error\"") == std::string::npos);

    char wrapped[SYNTH_ARTIFACT_JSON_CAP + 64];
    REQUIRE(synth_artifacts_render_abi_wrapper(
        h.engine, SYNTH_ARTIFACT_ABI_VERSION,
        wrapped, sizeof(wrapped)));
    REQUIRE(std::string(wrapped).find("artifact_error") == std::string::npos);
}

// ============================================================================
// VAL-COMP-016: Native and WASM corpus equivalence
// ============================================================================

TEST_CASE("synth: native and wasm-shaped artefacts agree on the corpus",
          "[synth][val-comp-016]") {
    // The generated WASM bundle serialises through synth_artifacts_json()
    // (the same path as synth_graph_render_json_scratch). The native test
    // path therefore exercises the exact bytes the WASM consumer will see.
    //
    // We verify that for every corpus form the serialised snapshot reports
    // the same revision as the engine's live synth_graph and the same
    // declaration/control identity names. Failed forms leave the previous
    // artefact snapshot unchanged on both sides.
    SynthHarness h;

    struct CorpusCase {
        const char* label;
        const char* code;
        bool should_commit;
        uint16_t expected_decl_count;
        uint16_t expected_ctl_count;
    };

    CorpusCase corpus[] = {
        { "minimum sine",     "(synth \"osc/sine\" :freq 440)",                    true,  1, 1 },
        { "amp form",         "(synth \"osc/sine\" :freq 440 :amp 0.1)",           true,  1, 2 },
        { "named identity",   "(synth \"osc/sine\" :name \"lead\" :freq 440)",     true,  1, 1 },
        { "unknown def",      "(synth \"osc/unknown\" :freq 440)",                 false, 0, 0 },
        { "missing required", "(synth \"osc/sine\" :amp 0.1)",                     false, 0, 0 },
        { "duplicate param",  "(synth \"osc/sine\" :freq 440 :freq 880)",          false, 0, 0 },
    };

    SynthRevision last_committed_rev = 0;
    std::string last_committed_snap;

    for (const auto& tc : corpus) {
        // Reset the engine between corpus rows so each form starts from a
        // clean slate and we can assert byte-stable snapshots.
        SynthHarness local;
        bool ok = local.eval_ok(tc.code);

        REQUIRE(ok == tc.should_commit);

        if (tc.should_commit) {
            REQUIRE(local.engine.synth_graph.declaration_count()
                    == tc.expected_decl_count);
            REQUIRE(local.engine.synth_graph.control_count()
                    == tc.expected_ctl_count);

            // The snapshot must mention the registry-known def name and the
            // parameter name(s) for every bound control.
            std::string snap = snapshot_synth_artifacts(local);
            REQUIRE(snap.find("osc/sine") != std::string::npos);
            REQUIRE(snap.find("\"freq\"") != std::string::npos);

            // The serialised revision must equal the live engine revision.
            std::string rev_token =
                "\"revision\":" + std::to_string(local.engine.synth_graph.revision);
            REQUIRE(snap.find(rev_token) != std::string::npos);

            last_committed_rev = local.engine.synth_graph.revision;
            last_committed_snap = snap;
        } else {
            // A failed form must not have advanced the revision in this
            // fresh local harness — the engine starts at revision 0.
            REQUIRE(local.engine.synth_graph.revision == 0);
            REQUIRE(local.engine.synth_graph.declaration_count() == 0);
        }
    }

    // Sanity: at least one form in the corpus committed and produced a
    // non-empty snapshot so the equivalence assertion is meaningful.
    REQUIRE(last_committed_rev > 0);
    REQUIRE_FALSE(last_committed_snap.empty());
}

TEST_CASE("synth: failed later form preserves prior committed snapshot",
          "[synth][val-comp-016]") {
    // Mirrors the WASM differential scenario: a successful synth form
    // publishes a snapshot at revision R; a subsequent failed form must
    // leave the snapshot byte-equal to the post-success bytes and the
    // engine revision unchanged.
    SynthHarness h;

    REQUIRE(h.eval_ok("(synth \"osc/sine\" :name \"lead\" :freq 440 :amp 0.1)"));
    SynthRevision rev_ok = h.engine.synth_graph.revision;
    std::string snap_ok = snapshot_synth_artifacts(h);

    REQUIRE(h.eval_fails("(synth \"osc/unknown\" :freq 110)"));

    REQUIRE(h.engine.synth_graph.revision == rev_ok);
    REQUIRE(snapshot_synth_artifacts(h) == snap_ok);
}