%% main.m — closed-loop entry point
%
%  Scenario: a 100% → 80% SG demand step.  Compare the plant's intrinsic
%  feedback response (ctrl_null) against the stabilizing operation-mode
%  controller (ctrl_operation) holding T_avg at the nominal setpoint.
%
%  Controller signature (thesis naming):
%     u = ctrl_<mode>(t, x, plant, ref)
%  where x is the continuous state vector and u is the external rod reactivity.

clear; clc; close all;
addpath('controllers');

%% ===== Plant =====
plant = pke_params();

%% ===== Scenario =====

% SG heat removal: step down to 80% at t = 30s, hold.
Q_sg = @(t) plant.P0 * (1.0 - 0.2 * (t >= 30));

% Reference for the operation-mode controller.
ref        = struct();
ref.T_avg  = plant.T_c0;    % hold T_avg at steady-state value

% Simulation window.
tspan = [0, 600];

%% ===== Baseline: unforced feedback response =====
fprintf('\n----- Run 1: ctrl_null (plant feedback only) -----\n');
[t1, X1, U1] = pke_solver(plant, Q_sg, @ctrl_null, [], tspan);

%% ===== Closed loop: operation mode =====
fprintf('\n----- Run 2: ctrl_operation (P on T_avg) -----\n');
[t2, X2, U2] = pke_solver(plant, Q_sg, @ctrl_operation, ref, tspan);

%% ===== Plots =====
plot_pke_results(t1, X1, U1, plant, Q_sg, 'ctrl_null (baseline)');
plot_pke_results(t2, X2, U2, plant, Q_sg, 'ctrl_operation (P on T_avg)');

%% ===== Quick comparison figure =====
CtoF = @(T) T*9/5 + 32;
figure('Position', [100 50 1000 450], 'Name', 'T_avg comparison');
plot(t1, CtoF(X1(:,9)), 'b-',  'LineWidth', 1.5); hold on;
plot(t2, CtoF(X2(:,9)), 'r-',  'LineWidth', 1.5);
yline(CtoF(plant.T_c0), 'k--', 'LineWidth', 1.0);
xlabel('Time [s]'); ylabel('T_{avg} [F]');
legend('ctrl\_null', 'ctrl\_operation', 'setpoint', 'Location', 'best');
title('T_{avg} tracking: baseline vs stabilizing controller');
grid on;