// Standalone tests for the deferred FX-park queue's re-entrancy rule — no
// REAPER, no test framework.
//
// The property under test: a mode switch leaves its per-FX offline work here, so
// a second switch arriving before the first drained must leave every track in the
// state the SECOND switch specifies — never the first's, never both replayed.

#include "../src/shell/view/view_fx_park.h"

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

using namespace reasampler;

static int g_fail = 0;
#define CHECK(cond) do { if(!(cond)) { \
    std::printf("FAIL line %d: %s\n", __LINE__, #cond); ++g_fail; } } while(0)

// -- helpers -----------------------------------------------------------------

// The ops applyMode hands a restore: one per FX captured in the track's snapshot.
static std::vector<FxOfflineOp> ops(const std::string& fxGuid, bool offline) {
    return {FxOfflineOp{"{TRACK}", FxKeying::Identity, fxGuid, 0, offline}};
}

static const FxParkIntent* intentFor(const FxParkQueue& q, const std::string& guid) {
    for (const FxParkIntent& i : q.pending())
        if (i.guid == guid) return &i;
    return nullptr;
}

// -- tests -------------------------------------------------------------------

static void testParkEnqueuesOneIntentCarryingNoOps() {
    FxParkQueue q;
    q.park("{A}");

    CHECK(q.pending().size() == 1);
    const FxParkIntent* held = intentFor(q, "{A}");
    CHECK(held != nullptr);
    CHECK(held && held->park);
    CHECK(held && held->restoreOps.empty());
}

static void testRestoreOnAnUndrainedParkCancelsRatherThanStacks() {
    // The park never ran, so the track's FX still hold their captured state —
    // exactly what the restore would write. Replaying both would unload every
    // plugin only to reload it.
    FxParkQueue q;
    q.park("{A}");
    q.restore("{A}", ops("{FX}", false));

    CHECK(q.empty());
}

static void testParkOnAnUndrainedRestoreCancelsRatherThanStacks() {
    // The mirror case: the restore never ran, so the FX are still parked offline,
    // which is where the new park wants them.
    FxParkQueue q;
    q.restore("{A}", ops("{FX}", false));
    q.park("{A}");

    CHECK(q.empty());
}

static void testRepeatedParkStaysOneIntent() {
    FxParkQueue q;
    q.park("{A}");
    q.park("{A}");
    q.park("{A}");

    CHECK(q.pending().size() == 1);
    CHECK(intentFor(q, "{A}") && intentFor(q, "{A}")->park);
}

static void testLaterRestoreReplacesTheEarlierOnesOps() {
    FxParkQueue q;
    q.restore("{A}", ops("{OLD}", false));
    q.restore("{A}", ops("{NEW}", true));

    CHECK(q.pending().size() == 1);
    const FxParkIntent* held = intentFor(q, "{A}");
    CHECK(held && !held->park);
    CHECK(held && held->restoreOps.size() == 1);
    CHECK(held && held->restoreOps.front().fxGuid == "{NEW}");
    CHECK(held && held->restoreOps.front().offline);
}

static void testOneTracksCancelLeavesEveryOtherTrackAlone() {
    FxParkQueue q;
    q.park("{A}");
    q.park("{B}");
    q.park("{C}");
    q.restore("{B}", ops("{FX}", false));  // cancels B only

    CHECK(q.pending().size() == 2);
    CHECK(intentFor(q, "{A}") != nullptr);
    CHECK(intentFor(q, "{B}") == nullptr);
    CHECK(intentFor(q, "{C}") != nullptr);
    // Order survives the middle erase: the drain applies in enqueue order.
    CHECK(q.pending()[0].guid == "{A}");
    CHECK(q.pending()[1].guid == "{C}");
}

static void testCancelledTrackCanBeQueuedAgain() {
    // Two rapid switches then a third: the third is the one that must land.
    FxParkQueue q;
    q.park("{A}");
    q.restore("{A}", ops("{FX}", false));
    q.park("{A}");

    CHECK(q.pending().size() == 1);
    CHECK(intentFor(q, "{A}") && intentFor(q, "{A}")->park);
}

static void testClearDropsEverythingPending() {
    FxParkQueue q;
    q.park("{A}");
    q.restore("{B}", ops("{FX}", true));
    q.clear();

    CHECK(q.empty());
    CHECK(q.pending().empty());
}

int main() {
    testParkEnqueuesOneIntentCarryingNoOps();
    testRestoreOnAnUndrainedParkCancelsRatherThanStacks();
    testParkOnAnUndrainedRestoreCancelsRatherThanStacks();
    testRepeatedParkStaysOneIntent();
    testLaterRestoreReplacesTheEarlierOnesOps();
    testOneTracksCancelLeavesEveryOtherTrackAlone();
    testCancelledTrackCanBeQueuedAgain();
    testClearDropsEverythingPending();

    if (g_fail == 0) std::printf("All tests passed.\n");
    return g_fail ? 1 : 0;
}