preserve-tombs.cpp

#include "Debug.h"
#include "PluginManager.h"

#include "modules/Units.h"
#include "modules/Buildings.h"
#include "modules/Persistence.h"
#include "modules/EventManager.h"
#include "modules/World.h"

#include "df/world.h"
#include "df/unit.h"
#include "df/building.h"
#include "df/building_civzonest.h"

using namespace DFHack;
using namespace df::enums;

DFHACK_PLUGIN("preserve-tombs");
DFHACK_PLUGIN_IS_ENABLED(is_enabled);

REQUIRE_GLOBAL(world);

static const std::string CONFIG_KEY = std::string(plugin_name) + "/config";
static PersistentDataItem config;

static int32_t cycle_timestamp;
static constexpr int32_t CYCLE_TICKS = 107;

enum ConfigValues {
    CONFIG_IS_ENABLED = 0,
};

static std::unordered_map<int32_t, int32_t> tomb_assignments;

namespace DFHack {
    DBG_DECLARE(preservetombs, control, DebugCategory::LINFO);
    DBG_DECLARE(preservetombs, cycle, DebugCategory::LINFO);
    DBG_DECLARE(preservetombs, event, DebugCategory::LINFO);
}

static bool assign_to_tomb(df::unit * unit, int32_t building_id);
static void update_tomb_assignments(color_ostream& out);
void onUnitDeath(color_ostream& out, void* ptr);
static command_result do_command(color_ostream& out, std::vector<std::string>& params);

DFhackCExport command_result plugin_init(color_ostream &out, std::vector <PluginCommand> &commands) {
    commands.push_back(PluginCommand(
        plugin_name,
        "Preserve tomb assignments when assigned units die.",
        do_command));
    return CR_OK;
}

static command_result do_command(color_ostream& out, std::vector<std::string>& params) {
    if (!Core::getInstance().isMapLoaded() || !World::isFortressMode()) {
        out.printerr("Cannot use %s without a loaded fort.\n", plugin_name);
        return CR_FAILURE;
    }
    if (params.size() == 0 || params[0] == "status") {
        out.print("%s is currently %s\n", plugin_name, is_enabled ? "enabled" : "disabled");
        if (is_enabled) {
            out.print("tracked tomb assignments:\n");
            std::for_each(tomb_assignments.begin(), tomb_assignments.end(), [&out](const auto& p){
                auto& [unit_id, building_id] = p;
                auto* unit = df::unit::find(unit_id);
                std::string name = unit ? DF2CONSOLE(Units::getReadableName(unit)) : "UNKNOWN UNIT" ;
                out.print("%s (id %d) -> building %d\n", name.c_str(), unit_id, building_id);
            });
        }
        return CR_OK;
    }
    if (params[0] == "now") {
        if (!is_enabled) {
            out.printerr("Cannot update %s when not enabled", plugin_name);
            return CR_FAILURE;
        }
        update_tomb_assignments(out);
        out.print("Updated tomb assignments\n");
        return CR_OK;
    }
    return CR_WRONG_USAGE;
}

// event listener
EventManager::EventHandler assign_tomb_handler(plugin_self, onUnitDeath, 0);

static void do_enable(color_ostream &out) {
    EventManager::registerListener(EventManager::EventType::UNIT_DEATH, assign_tomb_handler);
    update_tomb_assignments(out);
}

static void do_disable() {
    tomb_assignments.clear();
    EventManager::unregisterAll(plugin_self);
}

DFhackCExport command_result plugin_enable(color_ostream &out, bool enable) {
    if (!Core::getInstance().isMapLoaded() || !World::isFortressMode()) {
        out.printerr("Cannot enable %s without a loaded fort.\n", plugin_name);
        return CR_FAILURE;
    }

    if (enable != is_enabled) {
        is_enabled = enable;
        DEBUG(control,out).print("%s from the API; persisting\n",
                                is_enabled ? "enabled" : "disabled");
        config.set_bool(CONFIG_IS_ENABLED, is_enabled);
        if (enable)
            do_enable(out);
        else
            do_disable();
    } else {
        DEBUG(control,out).print("%s from the API, but already %s; no action\n",
                                is_enabled ? "enabled" : "disabled",
                                is_enabled ? "enabled" : "disabled");
    }
    return CR_OK;
}

DFhackCExport command_result plugin_shutdown (color_ostream &out) {
    DEBUG(control,out).print("shutting down %s\n", plugin_name);

    // PluginManager handles unregistering our handler from EventManager,
    // so we don't have to do that here
    return CR_OK;
}

DFhackCExport command_result plugin_load_site_data (color_ostream &out) {
    cycle_timestamp = 0;
    config = World::GetPersistentSiteData(CONFIG_KEY);

    if (!config.isValid()) {
        DEBUG(control,out).print("no config found in this save; initializing\n");
        config = World::AddPersistentSiteData(CONFIG_KEY);
        config.set_bool(CONFIG_IS_ENABLED, is_enabled);
    }

    is_enabled = config.get_bool(CONFIG_IS_ENABLED);
    DEBUG(control,out).print("loading persisted enabled state: %s\n",
                            is_enabled ? "true" : "false");
    if (is_enabled)
        do_enable(out);

    return CR_OK;
}

DFhackCExport command_result plugin_onstatechange(color_ostream &out, state_change_event event) {
    if (event == DFHack::SC_WORLD_UNLOADED && is_enabled) {
        DEBUG(control,out).print("world unloaded; disabling %s\n",
                                plugin_name);
        is_enabled = false;
        do_disable();
    }
    return CR_OK;
}

DFhackCExport command_result plugin_onupdate(color_ostream &out) {
    if (world->frame_counter - cycle_timestamp >= CYCLE_TICKS)
        update_tomb_assignments(out);
    return CR_OK;
}

// On unit death - check if we assigned them a tomb
//
//
void onUnitDeath(color_ostream& out, void* ptr) {
    // input is void* that contains the unit id
    int32_t unit_id = reinterpret_cast<std::intptr_t>(ptr);

    // check if unit was assigned a tomb in life
    auto it = tomb_assignments.find(unit_id);
    if (it == tomb_assignments.end()) return;

    // assign that unit to their previously assigned tomb in life
    auto unit = df::unit::find(unit_id);
    int32_t building_id = it->second;
    if (!assign_to_tomb(unit, building_id)) {
        if (unit) {
            WARN(event, out).print("%s died - but failed to assign them back to their tomb %d\n",
                DF2CONSOLE(Units::getReadableName(unit)).c_str(), building_id);
        } else {
            WARN(event, out).print("Unit %d died - but failed to assign them back to their tomb %d\n", unit_id, building_id);
        }
        return;
    }

    // success, print status update and remove assignment from our memo-list
    INFO(event, out).print("%s died - assigning them back to their tomb\n",
        DF2CONSOLE(Units::getReadableName(unit)).c_str());
    tomb_assignments.erase(it);
}

// Update tomb assignments
//
//
static void update_tomb_assignments(color_ostream &out) {
    cycle_timestamp = world->frame_counter;
    // check tomb civzones for assigned units
    for (auto* tomb : world->buildings.other.ZONE_TOMB) {
        if (!tomb || !tomb->flags.bits.exists) continue;
        if (tomb->assigned_unit_id == -1) continue;
        auto unit = Buildings::getOwner(tomb);
        if (!unit || Units::isDead(unit)) continue; // we only care about living units

        auto it = tomb_assignments.find(tomb->assigned_unit_id);

        if (it == tomb_assignments.end()) {
            tomb_assignments.emplace(tomb->assigned_unit_id, tomb->id);
            DEBUG(cycle, out).print("%s new tomb assignment, unit %d to tomb %d\n",
                                    plugin_name, tomb->assigned_unit_id, tomb->id);
        } else if (it->second != tomb->id) {
            DEBUG(cycle, out).print("%s tomb assignment to %d changed, (old: %d, new: %d)\n",
                                    plugin_name, tomb->assigned_unit_id, it->second, tomb->id);
            it->second = tomb->id;
        }
    }

    // now check our civzones for unassignment / deleted zone
    std::erase_if(tomb_assignments,[&](const auto& p){
        auto &[unit_id, building_id] = p;

        auto bld = df::building::find(building_id);
        if (!bld) {
            DEBUG(cycle, out).print("%s tomb missing: %d - removing\n", plugin_name, building_id);
            return true;
        }

        auto tomb = virtual_cast<df::building_civzonest>(bld);
        if (!tomb || !tomb->flags.bits.exists) {
            DEBUG(cycle, out).print("%s tomb missing: %d - removing\n", plugin_name, building_id);
            return true;
        }
        if (tomb->assigned_unit_id != unit_id) {
            DEBUG(cycle, out).print("%s unit %d unassigned from tomb %d - removing\n", plugin_name, unit_id, building_id);
            return true;
        }

        return false;
    });
}

// ASSIGN UNIT TO TOMB
//
//
static bool assign_to_tomb(df::unit * unit, int32_t building_id) {
    if (!unit || !Units::isDead(unit)) return false;

    auto bld = df::building::find(building_id);
    if (!bld) return false;

    auto tomb = virtual_cast<df::building_civzonest>(bld);
    if (!tomb || tomb->assigned_unit_id != -1) return false;

    Buildings::setOwner(tomb, unit);
    return true;
}