// Trade-raid encounter generation -- the strategic turn's dominant RNG consumer.
//
// The original runs this from inside encounter detection, over the server's player vector,
// rolling up to three chances per player. Two of the three roll on every turn measured; the
// third is behind a subsystem that was not present. The important property, and the reason
// this is modelled at all while the rest of encounter detection is not, is that NO BACK EDGE
// contains any of the three roll sites: the cost is one word per player per firing site, as a
// bound rather than as an observation.
//
// The probabilities are simulation constants that come from the game data. Their in-image
// defaults are used when no tuning table is loaded; either way all three are strictly inside
// (0, 1), so the chance helper takes neither of its early-outs and every roll is exactly one
// word. That is why the WORD COUNT is independent of the probabilities and the RAID DECISIONS
// are not.
#pragma once

#include "game/sim/rng.h"

namespace sots::app {

// The chance helper's contract, transcribed: p <= 0 is false with NO draw, p >= 1 is true with
// NO draw, otherwise exactly one draw and the test is `p > r` -- equality is a failure. A NaN
// probability falls through both early-outs and draws.
bool Chance(sots::sim::IRandom& rng, float p);

struct TradeRaidOdds {
    // In-image defaults. A loaded tuning table overrides them; the word cost does not move.
    float player = 0.2f;
    float npc = 0.05f;
    float refugee = 0.05f;
};

struct TradeRaidGates {
    // The NPC-raid roll is behind a single server-level test that does not depend on the
    // player, so it is all-or-nothing for the whole turn. Measured open on 8 of 8 turns
    // across two saves; it is not on the wire, so this is a HYPOTHESIS with a stated default.
    bool npcRaids = true;
    // The refugee-raid roll needs a subsystem manager that was absent on every measured turn.
    bool refugeeRaids = false;
};

struct TradeRaidResult {
    int players = 0;        // entries of the player vector the loop visited
    int words = 0;          // generator words consumed
    int playerRaidHits = 0; // rolls that SUCCEEDED -- each one may cost a further word we do
    int npcRaidHits = 0;    //   not model (the target-selection draw), so a non-zero total
    int refugeeRaidHits = 0;//   here is the signal that the ledger is about to fall short
};

// Roll the raid chances for `players` players, in the original's order: player raid, then NPC
// raid, then refugee raid, per player, before moving to the next player.
TradeRaidResult RollTradeRaids(sots::sim::IRandom& rng, int players, const TradeRaidOdds& odds,
                               const TradeRaidGates& gates);

}  // namespace sots::app