#include <catch2/catch_test_macros.hpp>
#include "../src/physics.h"
#include "../src/mission_planning.h"
#include "../src/simulation.h"
#include "../src/config_loader.h"
#include "../src/test_utilities.h"
#include <cmath>

TEST_CASE("Earth → Mars Hohmann Transfer - Basic", "[mission][hohmann][integration]") {
    const double TIME_STEP = 60.0;
    const double SECONDS_PER_DAY = 86400.0;

    SimulationState* sim = create_simulation(10, TIME_STEP);
    REQUIRE(load_system_config(sim, "tests/configs/earth_mars_simple.toml"));

    const int SUN_IDX = 0;
    const int EARTH_IDX = 1;
    const int MARS_IDX = 2;

    CelestialBody* earth = &sim->bodies[EARTH_IDX];
    CelestialBody* mars = &sim->bodies[MARS_IDX];
    CelestialBody* sun = &sim->bodies[SUN_IDX];

    double r_earth = vec3_distance(earth->position, sun->position);
    double r_mars = vec3_distance(mars->position, sun->position);
    TransferParameters params = calculate_hohmann_transfer(r_earth, r_mars, sun->mass);

    INFO("Transfer time: " << params.transfer_time / SECONDS_PER_DAY << " days");
    INFO("Required phase angle: " << params.phase_angle_deg << " degrees");
    INFO("Delta-v injection: " << params.delta_v_injection / 1000.0 << " km/s");

    wait_for_launch_window(sim, EARTH_IDX, MARS_IDX, params.phase_angle_deg, 1.0);

    double departure_time = sim->time;

    int probe_idx = spawn_spacecraft_on_transfer(sim, EARTH_IDX, &params);
    REQUIRE(probe_idx >= 0);

    CelestialBody* probe = &sim->bodies[probe_idx];

    REQUIRE(probe->parent_index == SUN_IDX);
    REQUIRE(vec3_distance(probe->position, earth->position) < 1e6);

    OrbitalMetrics initial_metrics = calculate_orbital_metrics(probe, sun);
    INFO("Initial orbital energy: " << initial_metrics.total_energy);

    double simulation_duration = params.transfer_time * 1.1;

    while (sim->time < departure_time + simulation_duration) {
        update_simulation(sim);
    }

    OrbitalMetrics final_metrics = calculate_orbital_metrics(probe, sun);
    INFO("Final orbital radius: " << final_metrics.orbital_radius / 1.496e11 << " AU");
    INFO("Final orbital energy: " << final_metrics.total_energy);

    double energy_drift = fabs(final_metrics.total_energy - initial_metrics.total_energy);
    if (initial_metrics.total_energy != 0.0) {
        energy_drift /= fabs(initial_metrics.total_energy);
    }
    INFO("Energy drift: " << (energy_drift * 100.0) << "%");

    REQUIRE(energy_drift < 0.05);

    destroy_simulation(sim);
}