#include "physics.h"
#include "simulation.h"
#include "config_loader.h"
#include "renderer.h"
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>

// Configuration defaults - edit to change default run mode
//#define DEFAULT_CONFIG_FILE "configs/test_simple.toml"
#define DEFAULT_CONFIG_FILE "tests/configs/solar_system.toml"

struct ProgramArgs {
    const char* config_file;
};

void parse_command_line_args(int argc, char** argv, ProgramArgs* args) {
    args->config_file = DEFAULT_CONFIG_FILE;

    for (int i = 1; i < argc; i++) {
        if (argv[i][0] != '-') {
            args->config_file = argv[i];
        }
    }
}

void print_startup_info(const ProgramArgs* args) {
    printf("=== Orbital Mechanics Simulation ===\n");
    printf("Loading configuration: %s\n", args->config_file);
}

void run_gui_simulation(SimulationState* sim) {
    init_renderer(1600, 900, "Orbital Mechanics Simulation");

    RenderState render_state;
    setup_camera(&render_state);

    // Find root body (body with parent_index == -1)
    int root_body_index = -1;
    for (int i = 0; i < sim->body_count; i++) {
        if (sim->bodies[i].parent_index == -1) {
            root_body_index = i;
            break;
        }
    }

    // Initialize UI state
    render_state.selected_body_index = root_body_index >= 0 ? root_body_index : -1;
    render_state.previous_selected_body = -1;  // Previous selected body index
    render_state.body_list_scroll = 0;     // Initial scroll position
    render_state.body_list_active = root_body_index >= 0 ? root_body_index : -1;  // Sync with selected body
    render_state.camera_follow_body = root_body_index >= 0; // Follow root body if found
    render_state.camera_offset = (Vector3){ 0, 50, 100 }; // Default offset
    render_state.was_following_body = false;

    bool paused = false;
    double speed_multiplier = 1.0;
    int physics_steps_per_frame = 100;

    printf("\nSimulation started!\n");
    printf("Controls:\n");
    printf("  Arrow keys: Rotate and zoom camera\n");
    printf("  Space: Pause/Resume\n");
    printf("  +/-: Speed up/slow down simulation\n");
    printf("  Select body from list to follow it\n");
    printf("  ESC: Quit\n\n");

    while (!WindowShouldClose()) {
        if (IsKeyPressed(KEY_SPACE)) {
            paused = !paused;
            printf("Simulation %s\n", paused ? "paused" : "resumed");
        }

        if (IsKeyPressed(KEY_EQUAL) || IsKeyPressed(KEY_KP_ADD)) {
            speed_multiplier *= 2.0;
            printf("Speed multiplier: %.1fx\n", speed_multiplier);
        }

        if (IsKeyPressed(KEY_MINUS) || IsKeyPressed(KEY_KP_SUBTRACT)) {
            speed_multiplier /= 2.0;
            if (speed_multiplier < 0.125) speed_multiplier = 0.125;
            printf("Speed multiplier: %.1fx\n", speed_multiplier);
        }

        if (!paused) {
            int steps = (int)(physics_steps_per_frame * speed_multiplier);
            for (int i = 0; i < steps; i++) {
                update_simulation(sim);
            }
        }

        update_camera(&render_state, sim);

        render_simulation(sim, &render_state);
    }

    close_renderer();
    printf("\nSimulation ended. Final time: %.2f days\n", sim->time / 86400.0);
}

int main(int argc, char** argv) {
    ProgramArgs args;
    parse_command_line_args(argc, argv, &args);
    print_startup_info(&args);

    // Create simulation with time step of 60 seconds
    const int MAX_BODIES = 100;
    const double TIME_STEP = 60.0;  // 60 seconds per step
    SimulationState* sim = create_simulation(MAX_BODIES, TIME_STEP);

    // Load system configuration
    if (!load_system_config(sim, args.config_file)) {
        printf("Failed to load configuration file\n");
        destroy_simulation(sim);
        return 1;
    }

    run_gui_simulation(sim);

    destroy_simulation(sim);
    return 0;
}