sots-engine/tests/app/test_treaty.cpp

// The treaty-turn stamp, pinned as a rule rather than as a table of observations.
//
// The corpus agrees with this rule on ten of eleven saves -- two games, species 0/2/4/5,
// turns 2 through 23 -- reproducing every entry, every `other` id, every entry's ORDER and
// every stamped value. (The eleventh is a turn-1 save on which no turn has been processed,
// so its ledger is empty; it is the input of the reference pair and the rule predicts what
// it becomes.) That comparison lives against the owner's saves. What is pinned HERE is what
// the corpus cannot separate:
//
//   * the relation codes. Every save's treaties are either alliances or non-aggression
//     pacts, so the cease-fire arm has never been exercised and an implementation that
//     swapped 1 and 3 would look right on ten of the eleven if it also swapped the fields.
//   * the bit is the player's INDEX FIELD, not its vector position. Every save in the corpus
//     has the two equal.
//   * the alliance mask is consulted with no alliance-id guard, unlike the shared-vision
//     mask -- in the corpus no player holds an alliance mask without an alliance id.
//   * a fresh entry's three "last in force" fields start at -1, not 0. A save cannot show
//     this for a field that was then stamped; it shows only for the two that were not.
//   * the entry is appended at the END and found by first match, so re-running the step is
//     idempotent rather than appending duplicates.
#include <cstdio>

#include "app/treaty.h"
#include "mars/stream/shapes.h"

static int failures = 0;
#define CHECK_EQ(a, b)                                                          \
    do {                                                                        \
        const long long va = (long long)(a), vb = (long long)(b);               \
        if (va != vb) {                                                         \
            std::printf("FAIL %s:%d  %s == %s  (%lld != %lld)\n", __FILE__,     \
                        __LINE__, #a, #b, va, vb);                              \
            ++failures;                                                         \
        }                                                                       \
    } while (0)

using mars::stream::shapes::PlayerEntry;
using sots::app::Relation;
using sots::app::RelationTo;
using sots::app::StampTreatyTurns;

static std::vector<PlayerEntry> MakePlayers(std::size_t n) {
    std::vector<PlayerEntry> v(n);
    for (std::size_t i = 0; i < n; ++i) {
        v[i].playerID = static_cast<std::int32_t>(16 * (i + 1));
        v[i].player.plyrIdx = static_cast<std::int32_t>(i);
    }
    return v;
}

int main() {
    // 1. The relation codes, and their precedence. Alliance beats NAP beats cease-fire, and
    // a player is allied to itself whatever the masks say.
    {
        std::vector<PlayerEntry> p = MakePlayers(3);
        p[0].player.alliances.al = 1 << 1;
        p[0].player.alliances.na = (1 << 1) | (1 << 2);
        p[0].player.alliances.cf = (1 << 1) | (1 << 2);
        CHECK_EQ((int)RelationTo(p[0].player, p[1].player), (int)Relation::Allied);
        CHECK_EQ((int)RelationTo(p[0].player, p[2].player), (int)Relation::NonAggression);
        CHECK_EQ((int)RelationTo(p[0].player, p[0].player), (int)Relation::Allied);
        CHECK_EQ((int)RelationTo(p[1].player, p[0].player), (int)Relation::War);  // not symmetric

        p[0].player.alliances.na = 0;
        CHECK_EQ((int)RelationTo(p[0].player, p[2].player), (int)Relation::CeaseFire);
        p[0].player.alliances.cf = 0;
        CHECK_EQ((int)RelationTo(p[0].player, p[2].player), (int)Relation::War);
    }

    // 2. The bit is the INDEX FIELD. Give the vector's second element index 5 and the mask
    // bit that reaches it is bit 5, not bit 1.
    {
        std::vector<PlayerEntry> p = MakePlayers(2);
        p[1].player.plyrIdx = 5;
        p[0].player.alliances.na = 1 << 5;
        CHECK_EQ((int)RelationTo(p[0].player, p[1].player), (int)Relation::NonAggression);
        p[0].player.alliances.na = 1 << 1;
        CHECK_EQ((int)RelationTo(p[0].player, p[1].player), (int)Relation::War);
    }

    // 3. No alliance-id guard: an alliance mask with no alliance id still means allied.
    {
        std::vector<PlayerEntry> p = MakePlayers(2);
        p[0].player.alliances.alid = -1;
        p[0].player.alliances.al = 1 << 1;
        CHECK_EQ((int)RelationTo(p[0].player, p[1].player), (int)Relation::Allied);
    }

    // 4. A created entry: the right field stamped, the other two at -1, every counter 0,
    // and `other` the OTHER PLAYER'S ID -- not its index.
    {
        std::vector<PlayerEntry> p = MakePlayers(2);
        p[0].player.alliances.na = 1 << 1;
        p[1].player.alliances.na = 1 << 0;
        const sots::app::TreatyStampResult r = StampTreatyTurns(p, 7);
        CHECK_EQ(r.pairsStamped, 2);
        CHECK_EQ(r.entriesCreated, 2);
        CHECK_EQ(r.fieldsWritten, 2);
        CHECK_EQ(p[0].player.dipstats.size(), 1u);
        const auto& e = p[0].player.dipstats[0];
        CHECK_EQ(e.other, 32);
        CHECK_EQ(e.lastnap, 7);
        CHECK_EQ(e.lastally, -1);
        CHECK_EQ(e.lastcf, -1);
        CHECK_EQ(e.lastnapbty, 0);
        CHECK_EQ(e.bknnap, 0);
        CHECK_EQ(e.btynap, 0);
        CHECK_EQ(e.deadhome, 0);
        CHECK_EQ(p[1].player.dipstats[0].other, 16);
    }

    // 5. Re-running does not duplicate: the entry is found by first match on `other` and the
    // stamp is overwritten in place.
    {
        std::vector<PlayerEntry> p = MakePlayers(2);
        p[0].player.alliances.na = 1 << 1;
        (void)StampTreatyTurns(p, 7);
        const sots::app::TreatyStampResult r = StampTreatyTurns(p, 8);
        CHECK_EQ(p[0].player.dipstats.size(), 1u);
        CHECK_EQ(p[0].player.dipstats[0].lastnap, 8);
        CHECK_EQ(r.entriesCreated, 0);
        CHECK_EQ(r.fieldsWritten, 1);
        // Stamping the same turn twice writes nothing new.
        const sots::app::TreatyStampResult again = StampTreatyTurns(p, 8);
        CHECK_EQ(again.fieldsWritten, 0);
        CHECK_EQ(again.pairsStamped, 1);  // the pair still holds a treaty; it just did not move
    }

    // 6. Entries are appended in the order pairs are first stamped, which is player-vector
    // order -- and a later turn that adds a new treaty appends after the existing ones.
    {
        std::vector<PlayerEntry> p = MakePlayers(4);
        p[0].player.alliances.na = (1 << 2) | (1 << 3);
        (void)StampTreatyTurns(p, 4);
        CHECK_EQ(p[0].player.dipstats.size(), 2u);
        CHECK_EQ(p[0].player.dipstats[0].other, 48);   // index 2
        CHECK_EQ(p[0].player.dipstats[1].other, 64);   // index 3
        p[0].player.alliances.al = 1 << 1;
        (void)StampTreatyTurns(p, 5);
        CHECK_EQ(p[0].player.dipstats.size(), 3u);
        CHECK_EQ(p[0].player.dipstats[2].other, 32);   // appended at the END, not sorted in
        CHECK_EQ(p[0].player.dipstats[2].lastally, 5);
        CHECK_EQ(p[0].player.dipstats[2].lastnap, -1);
        CHECK_EQ(p[0].player.dipstats[0].lastnap, 5);  // and the older ones were re-stamped
    }

    // 7. War with everyone writes nothing at all -- the ledger of a player with no treaty
    // stays empty, which is what both real empires in the reference save look like.
    {
        std::vector<PlayerEntry> p = MakePlayers(4);
        const sots::app::TreatyStampResult r = StampTreatyTurns(p, 9);
        CHECK_EQ(r.pairsStamped, 0);
        CHECK_EQ(r.leafWrites, 0);
        for (const auto& e : p) CHECK_EQ(e.player.dipstats.size(), 0u);
    }

    std::printf("app_test_treaty: %d failure(s)\n", failures);
    return failures ? 1 : 0;
}