sots-engine/tests/app/test_command_replay.cpp

// Replaying a recorded command stream against a save.
//
// Every check here runs on a save built in this file, so the test always runs and no .sav enters
// the repo. What it pins:
//
//   1. THE COUNT IS CHARGED FOR EVERY COMMAND, whether or not we can apply it. That is the
//      point of the whole module: the modification counter is a property of the turn's command
//      stream, not of our ability to model what the commands did, and it is the one leaf of the
//      save that a save alone can never supply.
//   2. A COMMAND WE CANNOT APPLY IS COUNTED AND DECLINED, WITH A NAMED REASON -- never applied
//      with a guessed payload, and never dropped.
//   3. AN INCOMPLETE ELEMENT IS NOT A ZERO ELEMENT. A route whose hops the instrument could not
//      read must leave the fleet alone.
//   4. THE COUNT-ONLY CONTROL. With writing suppressed the state is untouched and the count is
//      unchanged. That is what separates "our handlers happen to agree with the oracle" from
//      "our handlers wrote to the right place", which an outcome cannot tell apart when the
//      command re-issues a value the save already holds -- and on the reference turn EVERY
//      modelled handler does exactly that.
#include <cstdio>
#include <string>

#include "app/command_replay.h"
#include "game/ai/command_capture.h"

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

using mars::stream::shapes::SaveGame;

namespace {

// Two players and one system, which is all any command below names.
SaveGame Board() {
    SaveGame g;
    g.sim.modCount = 100;
    mars::stream::shapes::PlayerEntry a, b;
    a.playerID = 16;
    a.player.resRate = 0.25f;
    b.playerID = 32;
    b.player.resRate = 0.25f;
    g.sim.players = {a, b};
    mars::stream::shapes::SysEntry s;
    s.sysID = 288;
    s.sys.rts.srsc = 1.0f;
    g.sim.systems = {s};
    return g;
}

sots::ai::Capture Parse(const char* text) {
    sots::ai::Capture c;
    sots::ai::CaptureDiagnostics d;
    if (!sots::ai::ParseCapture(text, c, d)) {
        for (const auto& e : d.errors) std::printf("  parse error: %s\n", e.c_str());
        ++failures;
    }
    return c;
}

// The reference turn's shape: four submitting blocks, one with orders, four empty slots.
const char* kStream = R"(tcb 1
block 0 16
gate 0 rate 0.25
block 1 32
gate 1 rate 0.8
list 1 3 1
elem 1 3 0 i2 i18 i288 i0
list 1 5 1
elem 1 5 0 i288 ? ? ? ? ? ? ?
list 1 8 1
elem 1 8 0 i34 v1
list 1 10 1
elem 1 10 0 i288 i34 v1
list 1 14 2
elem 1 14 0 i34 i0 b1
elem 1 14 1 i34 i1 b1
list 1 23 1
elem 1 23 0 i288 ?
block 2 0
block 3 0
)";

void TestTheStreamIsCountedInFull() {
    SaveGame g = Board();
    const sots::ai::Capture c = Parse(kStream);
    sots::app::ReplayOptions opt;
    const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);

    // Two rate gates + build + rates + list 8 + list 10 + two list-14 = 8. List 23 is in the
    // free half and costs nothing, which is the half no save has ever exercised.
    CHECK(r.bumps == 8);
    CHECK(r.bumpsExact);
    CHECK(r.commands == 9);          // the eight paying ones plus the free list-23 element
    CHECK(r.blocks == 4);
    CHECK(r.submittingBlocks == 2);
    // Every command has a disposition and the four sum to the total.
    CHECK(r.applied + r.transcribed + r.declined + r.incomplete == r.commands);
    // Nothing may be silently dropped: every logged command carries a `what`, and every command
    // we did not apply carries a reason.
    for (const auto& e : r.log) {
        CHECK(!e.what.empty());
        if (e.disposition != sots::app::ReplayDisposition::Applied) CHECK(!e.reason.empty());
    }
}

void TestDeclinedCommandsChangeNothing() {
    SaveGame g = Board();
    const sots::ai::Capture c = Parse(kStream);
    sots::app::ReplayOptions opt;
    sots::app::ReplayTurnCommands(g, c, opt);
    // The build order names design 18 and system 288; the fleet commands name fleet 34, which
    // this board does not contain. None of it may have leaked into the save.
    CHECK(g.sim.fleets.empty());
    CHECK(g.sim.systems.size() == 1);
    CHECK(g.sim.systems[0].sys.rts.srsc == 1.0f);   // the rates frame is unread, so untouched
    CHECK(g.sim.systems[0].sys.rts.srt == 0.0f);
    // The one thing that IS modelled did run: the AI's rate reached its player and only its
    // player.
    CHECK(g.sim.players[1].player.resRate == 0.8f);
    CHECK(g.sim.players[0].player.resRate == 0.25f);
}

void TestCountOnlyIsTheControl() {
    const sots::ai::Capture c = Parse(kStream);
    SaveGame wrote = Board(), counted = Board();
    sots::app::ReplayOptions on, off;
    off.countOnly = true;
    const sots::app::ReplayReport a = sots::app::ReplayTurnCommands(wrote, c, on);
    const sots::app::ReplayReport b = sots::app::ReplayTurnCommands(counted, c, off);
    CHECK(a.bumps == b.bumps);          // suppressing the writes may not change the count
    CHECK(b.leafWrites == 0);
    CHECK(a.leafWrites == 1);           // the AI's rate, 0.25 -> 0.8
    CHECK(counted.sim.players[1].player.resRate == 0.25f);
    CHECK(wrote.sim.players[1].player.resRate == 0.8f);
}

void TestAnEmptyBlockStillCostsOne() {
    SaveGame g = Board();
    const sots::ai::Capture c = Parse("tcb 1\nblock 0 16\ngate 0 rate 0.25\n");
    sots::app::ReplayOptions opt;
    const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
    // The send-buffer build sets the rate gate unconditionally, so a player who ordered nothing
    // at all still costs one -- and on the reference turn four of the ten bumps are exactly this.
    CHECK(r.bumps == 1);
    CHECK(r.commands == 1);
    CHECK(r.leafWrites == 0);  // 0.25 was already the value
}

void TestAGateWithNoApplierMakesTheCountInexact() {
    SaveGame g = Board();
    const sots::ai::Capture c = Parse("tcb 1\nblock 0 16\ngate 0 civilian\n");
    sots::app::ReplayOptions opt;
    const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
    CHECK(!r.bumpsExact);
    CHECK(r.bumps == 0);  // a lower bound, and the report says so rather than guessing
    CHECK(!r.warnings.empty());
}

void TestTheTargetGateIsATranscription() {
    const char* stream = "tcb 1\nblock 0 32\ngate 0 target 144 name IND_Waldo\n";
    // Without the flag the command is counted and declined: the wire carries an id, the save
    // carries a name, and the map between them is unread.
    {
        SaveGame g = Board();
        const sots::ai::Capture c = Parse(stream);
        sots::app::ReplayOptions opt;
        const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
        CHECK(r.bumps == 1);
        CHECK(r.declined == 1 && r.transcribed == 0);
        CHECK(g.sim.players[1].player.resTNm.empty());
    }
    // With it, the leaf is written -- and reported in its own column, because writing a value an
    // instrument observed is not the same as computing one.
    {
        SaveGame g = Board();
        const sots::ai::Capture c = Parse(stream);
        sots::app::ReplayOptions opt;
        opt.useRecordedNames = true;
        const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
        CHECK(r.bumps == 1);
        CHECK(r.transcribed == 1 && r.applied == 0);
        CHECK(g.sim.players[1].player.resTNm == "IND_Waldo");
    }
    // A capture with no recorded name declines even when the flag is given.
    {
        SaveGame g = Board();
        const sots::ai::Capture c = Parse("tcb 1\nblock 0 32\ngate 0 target 144\n");
        sots::app::ReplayOptions opt;
        opt.useRecordedNames = true;
        const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
        CHECK(r.declined == 1 && r.transcribed == 0);
        CHECK(g.sim.players[1].player.resTNm.empty());
    }
}

void TestCommandsAreAppliedInTheOriginalsOrder() {
    SaveGame g = Board();
    const sots::ai::Capture c = Parse(kStream);
    sots::app::ReplayOptions opt;
    const sots::app::ReplayReport r = sots::app::ReplayTurnCommands(g, c, opt);
    // The log is in schedule order, and the schedule is not list order: list 5 and list 23 come
    // before the gates, and the gates come before list 3, list 10, list 14 and list 8. A port
    // that applied lists 1..27 in order would produce a log whose step numbers were sorted by
    // list number instead.
    int prev = -1;
    for (const auto& e : r.log) {
        CHECK(e.step >= prev);
        prev = e.step;
    }
    CHECK(r.log.front().what.rfind("list 5", 0) == 0);
    CHECK(r.log.back().what.rfind("list 8", 0) == 0);
    // A player id reaches every logged command, so a multi-player turn can be attributed.
    for (const auto& e : r.log) CHECK(e.playerId == 16 || e.playerId == 32);
}

}  // namespace

int main() {
    TestTheStreamIsCountedInFull();
    TestDeclinedCommandsChangeNothing();
    TestCountOnlyIsTheControl();
    TestAnEmptyBlockStillCostsOne();
    TestAGateWithNoApplierMakesTheCountInexact();
    TestTheTargetGateIsATranscription();
    TestCommandsAreAppliedInTheOriginalsOrder();
    std::printf("app_test_command_replay: %s\n", failures ? "FAILURES" : "ok");
    return failures ? 1 : 0;
}