#include "catch.hpp"

#include <cmath>
#include <functional>
#include <string>
#include <vector>

#include <QVector2D>

#include "ConfigLoader.h"
#include "EntityId.h"
#include "Ship.h"
#include "ShipSystem.h"
#include "Tick.h"

static GameConfig loadConfig()
{
    return ConfigLoader::loadFromDirectory(DOTA_FACTORY_CONFIG_DIR);
}

// ---------------------------------------------------------------------------
// Combat ship
// ---------------------------------------------------------------------------

TEST_CASE("ShipSystem: interceptor spawn has weapon and threatResponse, no cargo or repair",
          "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    REQUIRE(ship != nullptr);
    REQUIRE(ship->weapon.has_value());
    REQUIRE(ship->threatResponse.has_value());
    REQUIRE_FALSE(ship->cargo.has_value());
    REQUIRE_FALSE(ship->repairTool.has_value());
    REQUIRE_FALSE(ship->repairBehavior.has_value());
    REQUIRE_FALSE(ship->scrapCollector.has_value());
}

TEST_CASE("ShipSystem: interceptor level 1 stats match config formulas", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    REQUIRE(ship != nullptr);
    // hp_formula = "40 + 5*x" at x=1 → 45
    REQUIRE(ship->maxHp == Approx(45.0f));
    REQUIRE(ship->hp    == Approx(45.0f));
    // damage_formula = "10 + 2*x" at x=1 → 12
    REQUIRE(ship->weapon->damage == Approx(12.0f));
    // attack_range_formula = "150"
    REQUIRE(ship->weapon->range == Approx(150.0f));
    // threatResponse.engagementRange mirrors weapon range
    REQUIRE(ship->threatResponse->engagementRange == Approx(150.0f));
    // cooldownTicks starts at 0
    REQUIRE(ship->weapon->cooldownTicks == Approx(0.0f));
}

TEST_CASE("ShipSystem: interceptor level 5 hp matches formula", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("interceptor", 5, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    // hp_formula = "40 + 5*x" at x=5 → 65
    REQUIRE(ship->maxHp == Approx(65.0f));
}

TEST_CASE("ShipSystem: interceptor level 0 speedPerTick matches formula / kTickRateHz", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("interceptor", 0, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    // speed_formula = "200 + 5*x" at x=0 → 200; speedPerTick = 200/30
    const float expected = 200.0f / static_cast<float>(kTickRateHz);
    REQUIRE(ship->speedPerTick == Approx(expected));
}

// ---------------------------------------------------------------------------
// Salvage ship
// ---------------------------------------------------------------------------

TEST_CASE("ShipSystem: salvage_ship spawn has cargo and scrapCollector, no weapon",
          "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("salvage_ship", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    REQUIRE(ship != nullptr);
    REQUIRE(ship->cargo.has_value());
    REQUIRE(ship->scrapCollector.has_value());
    REQUIRE_FALSE(ship->weapon.has_value());
    REQUIRE_FALSE(ship->repairTool.has_value());
}

TEST_CASE("ShipSystem: salvage_ship cargo capacity matches config", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("salvage_ship", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    // cargo_capacity = 10
    REQUIRE(ship->cargo->capacity == 10);
    REQUIRE(ship->cargo->current  == 0);
    REQUIRE(ship->scrapCollector->deliveryBay == kInvalidEntityId);
    REQUIRE_FALSE(ship->scrapCollector->scrapTarget.has_value());
}

// ---------------------------------------------------------------------------
// Repair ship
// ---------------------------------------------------------------------------

TEST_CASE("ShipSystem: repair_ship spawn has repairTool and repairBehavior, no weapon",
          "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("repair_ship", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    REQUIRE(ship != nullptr);
    REQUIRE(ship->repairTool.has_value());
    REQUIRE(ship->repairBehavior.has_value());
    REQUIRE_FALSE(ship->weapon.has_value());
    REQUIRE_FALSE(ship->cargo.has_value());
}

TEST_CASE("ShipSystem: repair_ship level 1 repair stats match config formulas", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("repair_ship", 1, QVector2D(0.0f, 0.0f));
    const Ship* ship = ss.findShip(id);

    // repair_rate_formula = "5 + x" at x=1 → 6
    REQUIRE(ship->repairTool->ratePerTick == Approx(6.0f));
    // repair_range_formula = "80"
    REQUIRE(ship->repairTool->range == Approx(80.0f));
}

// ---------------------------------------------------------------------------
// Entity ids and removal
// ---------------------------------------------------------------------------

TEST_CASE("ShipSystem: spawned ships receive strictly increasing entity ids", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id1 = ss.spawn("interceptor",  1, QVector2D(0.0f, 0.0f));
    const EntityId id2 = ss.spawn("salvage_ship", 1, QVector2D(1.0f, 0.0f));

    REQUIRE(id2 > id1);
}

TEST_CASE("ShipSystem: despawn removes the ship", "[ship]")
{
    const GameConfig cfg = loadConfig();
    EntityId nextId = 1;
    ShipSystem ss(cfg, [&nextId]() { return nextId++; });

    const EntityId id = ss.spawn("interceptor", 1, QVector2D(0.0f, 0.0f));
    REQUIRE(ss.findShip(id) != nullptr);

    ss.despawn(id);
    REQUIRE(ss.findShip(id) == nullptr);
}