sots-engine/tests/game_sim/test_economy.cpp

#include "game/sim/economy.h"
#include "game/sim/numeric.h"

#include "check.h"

using namespace sots::sim;

// The two interest rates are WIDENED FLOAT literals in the image, so a round treasury earns
// one less than the exact decimal would give. Every expectation below that moved by exactly 1
// was hand-computed from the exact decimal and is corrected here (G3).
static void test_interest() {
    CHECK_EQ(SavingsInterest(1000, true), 9);      // 1000 x (double)0.01f = 9.99999977 -> 9
    CHECK_EQ(SavingsInterest(199, true), 1);       // 1.99 truncates
    CHECK_EQ(SavingsInterest(1000, false), 0);     // no systems, no interest
    CHECK_EQ(SavingsInterest(-500, true), 0);
    CHECK_EQ(SavingsInterest(0, true), 0);

    CHECK_EQ(DebtInterest(-1000), 150);
    CHECK_EQ(DebtInterest(-7), 1);                 // 1.05 truncates
    CHECK_EQ(DebtInterest(5), 0);
    CHECK_EQ(DebtInterest(0), 0);

    CHECK_EQ(MaintenanceCost(100, 2.0), 50);
    CHECK_EQ(MaintenanceCost(100, 1.9), 100);      // divisor truncates to 1
    CHECK_EQ(MaintenanceCost(100, 0.5), 100);      // divisor 0 guarded

    CHECK_EQ(SaturatingAdd(1900000000, 500000000), 2000000000);
    CHECK_EQ(SaturatingAdd(-1900000000, -500000000), -2000000000);
    CHECK_EQ(SaturatingAdd(5, -7), -2);
}

static void test_research_points() {
    // 50000 / 50 = 1000; x1.15 = 1150; x0.5 = 575; x0.85 = 488.75 -> 488
    CHECK_EQ(ResearchPointsFromMoney(50000, 1, 1, 0, 0, 1, 1, 1), 488);
    // (ResMod + shrm + TRM) = 2 -> 977.5 -> 977
    CHECK_EQ(ResearchPointsFromMoney(50000, 1, 1, 0.5, 0.5, 1, 1, 1), 977);
    // difficulty 0.5 -> 244.375 -> 244
    CHECK_EQ(ResearchPointsFromMoney(50000, 0.5, 1, 0, 0, 1, 1, 1), 244);
    // tech x2, server x0.5, scale x1 -> unchanged 488
    CHECK_EQ(ResearchPointsFromMoney(50000, 1, 1, 0, 0, 2, 0.5, 1), 488);
    CHECK_EQ(ResearchPointsFromMoney(0, 1, 1, 0, 0, 1, 1, 1), 0);
    // 100 money -> 0.9775 -> 0
    CHECK_EQ(ResearchPointsFromMoney(100, 1, 1, 0, 0, 1, 1, 1), 0);
}

static void test_expenses() {
    std::vector<ExpenseSlider> s = {{100, 300, 0.5f}, {50, 60, 0.1f}};
    // s1: request ftol(0.5 x 1000) - 100 = 400, room 200 -> 200
    // s2: request 100 - 50 = 50, room 10 -> 10;  minimums 150 + takes 210 = 360
    CHECK_EQ(ExpenseTotal(s, 1000), 360);
    // avail 200: s1 request 0, s2 request -30 -> 0; only the minimums
    CHECK_EQ(ExpenseTotal(s, 200), 150);
    // avail below the minimums: total is capped at avail
    CHECK_EQ(ExpenseTotal(s, 100), 100);
    CHECK_EQ(ExpenseTotal({}, 1000), 0);

    // max 0 = unlimited
    CHECK_EQ(ExpenseTotal({{0, 0, 0.25f}}, 1000), 250);
    // a negative minimum counts as 0
    CHECK_EQ(ExpenseTotal({{-50, 100, 0.1f}}, 1000), 100);
    // min above max: the entry contributes its minimum, its (negative) take is absorbed
    CHECK_EQ(ExpenseTotal({{100, 50, 1.0f}}, 1000), 100);
    // takes are capped by what is left after the minimums
    CHECK_EQ(ExpenseTotal({{100, 0, 1.0f}, {200, 0, 1.0f}}, 1000), 1000);
    // the product is taken in single precision: 0.7f x 1000 = 699.99998 -> 699
    CHECK_EQ(ExpenseTotal({{0, 0, 0.7f}}, 1000), 699);
    // ... and the income itself is rounded to a float first
    CHECK_EQ(ExpenseTotal({{0, 0, 1.0f}}, 16777217), 16777216);
}

static BudgetInputs base_inputs() {
    BudgetInputs in;
    in.savings = 10000;
    in.ownsSystems = true;
    in.systemIncome = {5000, 3000, -200};
    in.tradeIncome = 1000;
    in.maintenance = 2000;
    in.maintenanceDivisor = 1.0;
    in.constructionDemand = 500;
    in.researchRate = 0.5;
    in.hasResearchTarget = true;
    return in;
}

static void test_budget_hand_case() {
    Budget b = ComputeBudget(base_inputs(), false);
    CHECK_EQ(b.savingsInterest, 99);
    CHECK_EQ(b.debtInterest, 0);
    CHECK_EQ(b.systemIncomePositive, 8000);
    CHECK_EQ(b.systemIncomeNegative, 200);
    CHECK_EQ(b.maintenance, 2000);
    CHECK_EQ(b.expenses, 0);
    // 8000 + 1000 + 100 - 200 - 2000 = 6900
    CHECK_EQ(b.available, 6899);
    CHECK_EQ(b.construction, 500);
    // (6900 - 500) x 0.5 = 3200
    CHECK_EQ(b.researchMoney, 3199);
    // 3200/50 = 64; x1.15 = 73.6; x0.5 = 36.8; x0.85 = 31.28 -> 31
    CHECK_EQ(b.researchPoints, 31);
    CHECK_EQ(b.totalResearchPoints, 31);
    CHECK(b.hasResearchAllocation);
    CHECK_EQ(b.researchMoneyKept, 3199);
    CHECK_EQ(b.bonusIncome, 0);
    CHECK_EQ(b.savingsGiven, 0);
    // 6900 - 500 - 3200
    CHECK_EQ(b.net, 3200);
}

// A player with no research target still reports its research money and points -- the UI
// shows them -- but never spends the money: the "kept" line and the research allocation are
// written in the same branch. (Verified against the live game, docs/B1.md.)
static void test_budget_without_research_target() {
    BudgetInputs in = base_inputs();
    in.hasResearchTarget = false;
    Budget b = ComputeBudget(in, false);
    CHECK_EQ(b.researchMoney, 3199);
    CHECK_EQ(b.researchPoints, 31);
    CHECK_EQ(b.totalResearchPoints, 31);
    CHECK(!b.hasResearchAllocation);
    CHECK_EQ(b.researchMoneyKept, 0);
    // The research money stays in the treasury: 6900 - 500 construction.
    CHECK_EQ(b.net, 6399);
}

static void test_budget_projected() {
    Budget b = ComputeBudget(base_inputs(), true);
    CHECK_EQ(b.researchMoney, 0);
    CHECK_EQ(b.researchPoints, 0);
    CHECK_EQ(b.net, 6399);
}

static void test_budget_debt() {
    BudgetInputs in = base_inputs();
    in.savings = -1000;
    Budget b = ComputeBudget(in, false);
    CHECK_EQ(b.savingsInterest, 0);
    CHECK_EQ(b.debtInterest, 150);
    // 8000 + 1000 - 200 - 2000 - 150 = 6650
    CHECK_EQ(b.available, 6650);
    CHECK_EQ(b.construction, 500);
    // (6650 - 500) x 0.5 = 3075
    CHECK_EQ(b.researchMoney, 3075);
    CHECK_EQ(b.net, 6650 - 500 - 3075);
}

static void test_budget_aid_and_bonus() {
    BudgetInputs in = base_inputs();
    in.aidResearchPercent = 50;
    in.aidSavings = 100;
    in.tra = 4;
    in.trp = 5;
    Budget b = ComputeBudget(in, false);
    CHECK_EQ(b.researchMoney, 3199);
    CHECK_EQ(b.researchMoneyGiven, 1599);
    CHECK_EQ(b.researchMoneyKept, 1600);
    // 31 + 4 + 5 = 40; given 20; kept 20
    CHECK_EQ(b.researchPointsGiven, 20);
    CHECK_EQ(b.totalResearchPoints, 20);
    CHECK_EQ(b.savingsGiven, 100);
    // 6900 - 500 - 1600 - 1600 - 100
    CHECK_EQ(b.net, 3100);

    in.aidResearchPercent = 250;   // clamps to 100
    in.aidSavings = 0;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.researchMoneyGiven, 3199);
    CHECK_EQ(b.totalResearchPoints, 0);

    in = base_inputs();
    in.techIncomeMult = 1.1;
    b = ComputeBudget(in, false);
    // full net before the bonus = 3200 -> ftol(0.1 x 3200) = 320
    CHECK_EQ(b.bonusIncome, 320);
    CHECK_EQ(b.net, 3520);

    // the bonus reads the net *after* research aid was deducted
    in.aidResearchPercent = 50;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.bonusIncome, 320);            // 1600 kept + 1600 given: net unchanged
    in.aidResearchPercent = 0;

    // a multiplier below 1 never takes money away
    in.techIncomeMult = 0.5;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.bonusIncome, 0);
    CHECK_EQ(b.net, 3200);

    // no bonus on a negative net
    in.techIncomeMult = 1.1;
    in.maintenance = 20000;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.available, 0);
    CHECK_EQ(b.bonusIncome, 0);
    CHECK_EQ(b.net, -11101);

    // savings aid is capped by the projected treasury, not by the turn net
    in = base_inputs();
    in.savings = -5000;                      // debt interest 750
    in.aidSavings = 100;
    b = ComputeBudget(in, false);
    // available 8000+1000-200-2000-750 = 6050; construction 500; research 2775; net 2775
    CHECK_EQ(b.researchMoney, 2775);
    CHECK_EQ(b.savingsGiven, 0);             // -5000 + 2775 < 0: nothing to give
    CHECK_EQ(b.net, 2775);

    in.savings = -2000;                      // debt interest 300
    in.aidSavings = 5000;
    b = ComputeBudget(in, false);
    // available 6500; construction 500; research 3000; net 3000; projected 1000
    CHECK_EQ(b.savingsGiven, 1000);
    CHECK_EQ(b.net, 2000);

    in.savings = 10000;
    in.techIncomeMult = 1.1;                 // bonus 320 counts toward the projection
    in.aidSavings = 20000;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.bonusIncome, 320);
    CHECK_EQ(b.savingsGiven, 13520);         // 10000 + 3200 + 320: the whole projected treasury
    CHECK_EQ(b.net, -10000);                 // ... so the treasury ends the turn at 0

    in.aidSavings = -5;                      // negative aid gives nothing
    b = ComputeBudget(in, false);
    CHECK_EQ(b.savingsGiven, 0);
}

static void test_budget_edges() {
    BudgetInputs in = base_inputs();
    in.isAI = true;
    Budget b = ComputeBudget(in, false);
    CHECK_EQ(b.construction, 0);            // AI path spends construction elsewhere
    CHECK_EQ(b.researchMoney, 3449);        // 6900 x 0.5

    in = base_inputs();
    in.systemIncome = {};
    in.tradeIncome = 0;
    in.maintenance = 5000;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.available, 0);               // floored at zero
    CHECK_EQ(b.construction, 0);
    CHECK_EQ(b.researchMoney, 0);
    CHECK_EQ(b.net, 99 - 5000);            // interest minus maintenance

    in = base_inputs();
    in.constructionDemand = 100000;
    b = ComputeBudget(in, false);
    CHECK_EQ(b.construction, 6899);         // capped at available
    CHECK_EQ(b.researchMoney, 0);

    in = base_inputs();
    in.expenses = {{1000, 2000, 0.5f}};
    b = ComputeBudget(in, false);
    // pre-expense avail 6900: request 3450 - 1000 = 2450, room 1000 -> 2000 total
    CHECK_EQ(b.expenses, 2000);
    CHECK_EQ(b.available, 4899);
}

static void test_trade() {
    TuningTable t;
    t.TRADE_ROUTE_REQ_CIVPOPULATION = 1e6;
    t.TRADE_ROUTE_REQ_IMPPOPULATION = 1e6;
    CHECK_EQ(TradeRoutesSupported(2.5e6, 1e6, t), 4);   // ceil(2.5) + 1
    CHECK_EQ(TradeRoutesSupported(0, 0, t), 1);          // minimum one
    CHECK_EQ(TradeRoutesSupported(1, 0, t), 1);
    TuningTable zero;
    CHECK_EQ(TradeRoutesSupported(5e6, 5e6, zero), 1);   // zero requirement guarded

    t.TRADE_ROUTE_STARTUP_TURNS = 3;
    t.TRADE_ROUTE_STARTUP_INCOME = 7;
    t.TRADE_ROUTE_MIN_INCOME = 100;
    t.TRADE_ROUTE_MAX_FREIGHTERS = 5;
    t.TRADE_ROUTE_INCOME_PERFREIGHTER_CRQ = 30;
    t.TRADE_ROUTE_INCOME_PERFREIGHTER_CR = 20;
    t.TRADE_ROUTE_INCOME_PERFREIGHTER_DE = 10;
    t.STATION_BONUS_TRADE_INCOME = 0.1;
    t.ADDICTION_TRADE_MOD = 0.5;
    t.TRADE_ROUTE_OWNERS_SHARE = 0.6;

    TradeRouteState r;
    r.ageTurns = 3;
    r.freighters[0] = 2;   // CRQ: 2 x 30 = 60, cap left 3
    r.freighters[1] = 4;   // CR: min(4,3) = 3 x 20 = 60, cap left 0
    r.freighters[2] = 3;   // DE: nothing left
    CHECK_EQ(TradeRouteGrossIncome(r, t), 220);
    r.tradeStationsAtSystem = 2;
    CHECK_EQ(TradeRouteGrossIncome(r, t), 264);          // x 1.2
    r.partnerAddicted = true;
    CHECK_EQ(TradeRouteGrossIncome(r, t), 132);          // x 0.5
    CHECK_EQ(TradeRouteIncome(r, true, 1.0, t), 79);     // 132 x 0.6 = 79.2
    CHECK_EQ(TradeRouteIncome(r, false, 1.0, t), 52);    // 132 x 0.4 = 52.8
    CHECK_EQ(TradeRouteIncome(r, true, 2.0, t), 158);    // AI trade multiplier
    r.ageTurns = 2;
    CHECK_EQ(TradeRouteGrossIncome(r, t), 7);            // startup income is flat

    TradeRouteState empty;
    empty.ageTurns = 10;
    CHECK_EQ(TradeRouteGrossIncome(empty, t), 100);      // MIN_INCOME with no freighters
    t.TRADE_ROUTE_OWNERS_SHARE = 1.5;                     // clamps to 1
    CHECK_EQ(TradeRouteIncome(empty, true, 1.0, t), 100);
    CHECK_EQ(TradeRouteIncome(empty, false, 1.0, t), 0);
}

static void test_bankruptcy() {
    TuningTable t;
    t.BANKRUPTCY_PROTECTION_LIMIT_FACTOR = 3.3;
    t.BANKRUPTCY_ELIMINATION_TURNS = 5;
    // max income 1000: elimination at 1000 / -0.15 = -6666.67 -> -6666; protection -3300
    BankruptcyLimits l = ComputeBankruptcyLimits(1000, t);
    CHECK_EQ(l.eliminationFloor, -6666);
    CHECK_EQ(l.protectionLimit, -3300);
    CHECK_EQ(BankruptcyLevel(-6667, l), 2);
    CHECK_EQ(BankruptcyLevel(-6666, l), 1);
    CHECK_EQ(BankruptcyLevel(-3301, l), 1);
    CHECK_EQ(BankruptcyLevel(-3300, l), 0);
    CHECK_EQ(BankruptcyLevel(0, l), 0);

    l = ComputeBankruptcyLimits(100, t);
    CHECK_EQ(l.eliminationFloor, -666);
    CHECK_EQ(l.protectionLimit, -330);

    // a factor beyond the interest break-even is pinned to the elimination floor
    TuningTable big = t;
    big.BANKRUPTCY_PROTECTION_LIMIT_FACTOR = 10.0;
    l = ComputeBankruptcyLimits(1000, big);
    CHECK_EQ(l.eliminationFloor, -6666);
    CHECK_EQ(l.protectionLimit, -6666);

    // huge income: the floor saturates at the treasury limit
    l = ComputeBankruptcyLimits(400000000, t);
    CHECK_EQ(l.eliminationFloor, -2000000000);
    CHECK_EQ(l.protectionLimit, -1320000000);

    // LANE N: the divisor is the widened float literal, not the decimal -0.15. The two
    // disagree for every maxIncome divisible by 3, and maxIncome = 3 is where it first
    // bites: 3 / -0.15 is -20 exactly in decimal but -19.99999920... with the image's
    // constant, and the conversion TRUNCATES.
    CHECK_EQ(ComputeBankruptcyLimits(3, t).eliminationFloor, -19);
    CHECK_EQ(ComputeBankruptcyLimits(6, t).eliminationFloor, -39);
    CHECK_EQ(ComputeBankruptcyLimits(9, t).eliminationFloor, -59);
    // ... and above ~3,000,000 maximum income they differ on essentially every value.
    CHECK_EQ(ComputeBankruptcyLimits(238592, t).eliminationFloor, -1590613);
    CHECK_EQ(ComputeBankruptcyLimits(3000001, t).eliminationFloor, -20000005);

    BankruptcyLimits none = ComputeBankruptcyLimits(0, t);
    CHECK_EQ(none.eliminationFloor, 0);
    CHECK_EQ(none.protectionLimit, 0);
    CHECK_EQ(BankruptcyLevel(-1, none), 2);     // no income at all: any debt is terminal

    // Stamping happens on the transition; actions run on the previous state.
    BankruptcyState s;
    CHECK_EQ(s.startTurn, -1);
    BankruptcyDecision d = BankruptcyStep(s, 1, 10, t);
    CHECK(!d.costCutting);                      // first turn at level 1: not yet
    CHECK(!d.eliminate);
    CHECK_EQ(s.warningLevel, 1);
    CHECK_EQ(s.startTurn, 10);
    d = BankruptcyStep(s, 1, 11, t);
    CHECK(d.costCutting);                       // second turn: cost cutting
    CHECK_EQ(s.startTurn, 10);                  // no restamp while the level holds
    d = BankruptcyStep(s, 2, 12, t);            // 1 -> 2 restamps the clock at 12
    CHECK(d.costCutting);
    CHECK(!d.eliminate);
    CHECK_EQ(s.startTurn, 12);
    d = BankruptcyStep(s, 2, 16, t);
    CHECK(!d.eliminate);                        // 4 turns < 5
    d = BankruptcyStep(s, 2, 17, t);
    CHECK(d.eliminate);                         // 5 turns -> eliminated
    d = BankruptcyStep(s, 0, 18, t);            // recovering on the turn after the clock
    CHECK(!d.costCutting);
    CHECK(d.eliminate);                         // ... still acts on the old level-2 state
    CHECK_EQ(s.warningLevel, 0);
    CHECK_EQ(s.startTurn, -1);

    // 2 -> 1 -> 2 restarts the clock each time
    BankruptcyState r;
    BankruptcyStep(r, 2, 20, t);
    CHECK_EQ(r.startTurn, 20);
    d = BankruptcyStep(r, 1, 22, t);
    CHECK(d.costCutting);
    CHECK_EQ(r.startTurn, 22);
    d = BankruptcyStep(r, 2, 25, t);
    CHECK(!d.eliminate);                        // old level was 1
    CHECK_EQ(r.startTurn, 25);
    d = BankruptcyStep(r, 2, 29, t);
    CHECK(!d.eliminate);
    d = BankruptcyStep(r, 2, 30, t);
    CHECK(d.eliminate);

    // even with a zero-turn limit, elimination happens the turn after level 2 is reached
    TuningTable instant = t;
    instant.BANKRUPTCY_ELIMINATION_TURNS = 0;
    BankruptcyState q;
    d = BankruptcyStep(q, 2, 5, instant);
    CHECK(!d.eliminate);
    d = BankruptcyStep(q, 2, 6, instant);
    CHECK(d.eliminate);
}

int main() {
    test_interest();
    test_research_points();
    test_expenses();
    test_budget_hand_case();
    test_budget_without_research_target();
    test_budget_projected();
    test_budget_debt();
    test_budget_aid_and_bonus();
    test_budget_edges();
    test_trade();
    test_bankruptcy();
    return simtest::finish("test_economy");
}