package classes.holonControlUnit;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import com.google.gson.Gson;

import classes.holonControlUnit.OptimizationManager.OptimizationScheme;
import classes.holonControlUnit.messages.MergeMsg;
import classes.holonControlUnit.messages.Message;
import classes.holonControlUnit.messages.OrderMsg;
import classes.holonControlUnit.messages.StateMsg;

public class TargetStateAssembler {
	
	private HolonControlUnit hcu;
	private float desiredPowerUsage = 100f;
	private OrderMsg order;
	private HashMap<String, OrderMsg> ordersForSubholon;
	
	public TargetStateAssembler(HolonControlUnit hcu) {
		this.order = null;
		this.hcu = hcu;
		this.ordersForSubholon = new HashMap<String, OrderMsg>();
	}
	
	public void assembleTargetState(int timeStep) {
		if(this.order == null || this.order.getTimeStep() != timeStep-1) {
			this.desiredPowerUsage =  0f;
		} else {
			this.desiredPowerUsage = this.order.getDesiredPowerUsage();
		}
		this.ordersForSubholon.clear();
		System.out.println(this.hcu.getHolon().getUniqueID()+" opt scheme: "+this.hcu.getOptimizer().getOptimizationScheme());

		//balance the sub holons
		switch(this.hcu.getOptimizer().getOptimizationScheme()) {
			case COMFORT:
				assembleTargetStateComfort(timeStep);
				break;
			case MIN_COST:
				break;
			case ENERGY_CONSUMPTION:
				break;
			case STABILITY:
				assembleTargetStateStability(timeStep);
				break;
			case RECOVERY:
				assembleTargetStateRecovery(timeStep);
				break;
			default:
				System.err.println("Unknown optimization scheme in "+this.hcu.getHolon().getUniqueID());
		}
		this.hcu.getHierarchyController().propagateMergeReqToParent(timeStep-1);
		//send order to subholons
		Gson gson = this.hcu.getCommunicator().getGson();
		for(String s : this.ordersForSubholon.keySet()) {
			if(this.hcu.getHierarchyController().getSubHolons().contains(s))
				this.hcu.getCommunicator().sendMsg(s, Message.Type.ORDER, gson.toJson(this.ordersForSubholon.get(s)));
		}
	}
	
	private void assembleTargetStateComfort(int timeStep) {
		//overall power usage inside this holarchy
		float powerUsage = this.hcu.getStateEstimator().getPowerUsage();
		ArrayList<Float> predictedPowerUsage = this.hcu.getStateEstimator().getPredictedPowerUsage();
		if(predictedPowerUsage.size() < 1) {
			//no more iterations inside simulator
			return;
		}

		//check if this holon can run independent from parent without risking stability
		if(this.hcu.matchPowerRange(powerUsage, 0f, predictedPowerUsage, this.hcu.getOptimizer().getCurrentPowerThreshold()) 
				&& this.hcu.getHolon().getParent().canRunIndependent(this.hcu.getHolon()) && this.hcu.getHolon().getLayer() > 1) {
			System.out.println(this.hcu.getHolon().getUniqueID()+" can run independent");
			this.hcu.getHierarchyController().splitSuperHolon(timeStep);
			this.desiredPowerUsage = 0f;
		}

		//powerUsage already matches desired value, everything as before
		if(this.hcu.matchPowerRange(powerUsage, this.desiredPowerUsage, predictedPowerUsage, this.hcu.getOptimizer().getCurrentPowerThreshold())) {
			System.out.println(this.hcu.getHolon().getUniqueID()+" power usage as desired "+powerUsage);
			HashMap<String, StateMsg> childStates = this.hcu.getStateEstimator().getChildStates();
			for(String s : childStates.keySet()) {
				OrderMsg o = new OrderMsg(childStates.get(s).getPredictedPowerUsage().get(0), null, OptimizationScheme.STABILITY, timeStep);
				this.ordersForSubholon.put(s, o);
			}
			return;
		}
		System.out.println(this.hcu.getHolon().getUniqueID()+" power usage "+powerUsage+" not as desired "+this.desiredPowerUsage);
		float requiredPower = this.desiredPowerUsage - powerUsage;
		
		//find flexibility which matches required power
		float savedWithFlexibilities = gothroughFlexibilities(timeStep, requiredPower, predictedPowerUsage);
		if(savedWithFlexibilities == requiredPower) {
			return;
		}
		requiredPower -= savedWithFlexibilities;
		
		//go through merge requests from last iteration
		float savedByMerging = gothroughMergeReq(timeStep, requiredPower, predictedPowerUsage, OptimizationScheme.COMFORT);
		if(savedByMerging == requiredPower) {
			return;
		}
		requiredPower -= savedByMerging;
		
		//look out for another superholon
		findNewSuperHolon(timeStep, powerUsage, predictedPowerUsage);
		
		//tell all holons to use a little more/less energy
		orderSubholonsRequiredPower(timeStep, powerUsage, requiredPower, OptimizationScheme.COMFORT);
	}
	
	private void assembleTargetStateStability(int timeStep) {
		//overall power usage inside this holarchy
		float powerUsage = this.hcu.getStateEstimator().getPowerUsage();
		ArrayList<Float> predictedPowerUsage = this.hcu.getStateEstimator().getPredictedPowerUsage();
		if(predictedPowerUsage.size() < 1) {
			//no more iterations inside simulator
			return;
		}

		//powerUsage already matches desired value, everything as before
		if(this.hcu.matchPowerRange(powerUsage, this.desiredPowerUsage, predictedPowerUsage, this.hcu.getOptimizer().getCurrentPowerThreshold())) {
			System.out.println(this.hcu.getHolon().getUniqueID()+" power usage as desired "+powerUsage);
			HashMap<String, StateMsg> childStates = this.hcu.getStateEstimator().getChildStates();
			for(String s : childStates.keySet()) {
				OrderMsg o = new OrderMsg(childStates.get(s).getPredictedPowerUsage().get(0), null, OptimizationScheme.STABILITY, timeStep);
				this.ordersForSubholon.put(s, o);
			}
			return;
		}
		System.out.println(this.hcu.getHolon().getUniqueID()+" power usage "+powerUsage+" not as desired "+this.desiredPowerUsage);
		float requiredPower = this.desiredPowerUsage - powerUsage;
		
		//find flexibility which matches required power
		float savedWithFlexibilities = gothroughFlexibilities(timeStep, requiredPower, predictedPowerUsage);
		if(savedWithFlexibilities == requiredPower) {
			return;
		}
		requiredPower -= savedWithFlexibilities;
		
		//go through merge requests from last iteration
		float savedByMerging = gothroughMergeReq(timeStep, requiredPower, predictedPowerUsage, OptimizationScheme.STABILITY);
		if(savedByMerging == requiredPower) {
			return;
		}
		requiredPower -= savedByMerging;
		
		//look out for another superholon
		findNewSuperHolon(timeStep, powerUsage, predictedPowerUsage);
		
		//tell all holons to use a little more/less energy
		orderSubholonsRequiredPower(timeStep, powerUsage, requiredPower, OptimizationScheme.STABILITY);
	}
	
	private void assembleTargetStateRecovery(int timeStep) {
		//overall power usage inside this holarchy
		float powerUsage = this.hcu.getStateEstimator().getPowerUsage();
		ArrayList<Float> predictedPowerUsage = this.hcu.getStateEstimator().getPredictedPowerUsage();
		if(predictedPowerUsage.size() < 1) {
			//no more iterations inside simulator
			return;
		}

		//powerUsage already matches desired value, everything as before
		if(this.hcu.matchPowerRange(powerUsage, this.desiredPowerUsage, predictedPowerUsage, this.hcu.getOptimizer().getCurrentPowerThreshold())) {
			System.out.println(this.hcu.getHolon().getUniqueID()+" power usage as desired "+powerUsage);
			HashMap<String, StateMsg> childStates = this.hcu.getStateEstimator().getChildStates();
			for(String s : childStates.keySet()) {
				OrderMsg o = new OrderMsg(childStates.get(s).getPredictedPowerUsage().get(0), null, OptimizationScheme.STABILITY, timeStep);
				this.ordersForSubholon.put(s, o);
			}
			return;
		}
		System.out.println(this.hcu.getHolon().getUniqueID()+" power usage "+powerUsage+" not as desired "+this.desiredPowerUsage);
		float requiredPower = this.desiredPowerUsage - powerUsage;
		
		//find flexibility which matches required power
		float savedWithFlexibilities = gothroughFlexibilities(timeStep, requiredPower, predictedPowerUsage);
		if(savedWithFlexibilities == requiredPower) {
			return;
		}
		requiredPower -= savedWithFlexibilities;

		//go through merge requests from last iteration
		float savedByMerging = gothroughMergeReq(timeStep, requiredPower, predictedPowerUsage, OptimizationScheme.RECOVERY);
		if(savedByMerging == requiredPower) {
			return;
		}
		requiredPower -= savedByMerging;
		
		float p = this.hcu.getHolon().isPhysical ? this.hcu.getHolon().getHolonObject().getEnergyAtTimeStepFlex(timeStep) : 0f;
		requiredPower = this.desiredPowerUsage - p;
		
		//split dysfunctional parts
		HashMap<String, StateMsg> childStates = this.hcu.getStateEstimator().getChildStates();
		List<List<String>> childPerm = getAllPermutations(List.copyOf(childStates.keySet()));
		HashMap<Float, List<String>> potChild = new HashMap<Float, List<String>>();
		for(List<String> l : childPerm) {
			//check how much power this subset of child would consume
			float pu = p;
			for(String s : l) {
				if(Math.abs(pu) > Math.abs(requiredPower))
					break;
				pu += childStates.get(s).getPowerUsage();
			}
			if(Math.abs(pu) <= Math.abs(requiredPower)) {
				if(potChild.containsKey(pu) && potChild.get(pu).size() >= l.size())
					continue;
				potChild.put(pu, l);
			}
		}
		//find subset of children with most fitting powerUsage
		float max = 0f;
		for(float f : potChild.keySet()) {
			if(Math.abs(f) > Math.abs(max)) {
				max = f;
			}
		}
		//split all other subholons
		List<String> list = new ArrayList<String>();
		if(potChild.containsKey(max)) {
			list = potChild.get(max);
		}
		List<String> subs = List.copyOf(this.hcu.getHierarchyController().getSubHolons());
		for(String s : subs) {
			if(!list.contains(s)) {
				this.hcu.getHierarchyController().splitSubHolon(s, timeStep);
			}
		}
		requiredPower -= max;
		if(requiredPower == 0) {
			return;
		}

		//Split from superholon?
		if(Math.abs(requiredPower) > Math.abs(p) && this.hcu.getHolon().getLayer() > 1) {
			this.hcu.getHierarchyController().splitSuperHolon(timeStep);
			return;
		}
		
		//look out for another superholon
		findNewSuperHolon(timeStep, powerUsage, predictedPowerUsage);
		
		//tell all holons to use a little more/less energy
		orderSubholonsRequiredPower(timeStep, powerUsage, requiredPower, OptimizationScheme.RECOVERY);
	}
	
	private float gothroughFlexibilities(int timeStep, float requiredPower, ArrayList<Float> predictedPowerUsage) {
		return this.hcu.getFlexMan().applyFlexibilities(requiredPower, predictedPowerUsage, timeStep);
	}

	/**
	 * go through all previously received merge requests from other holons
	 * if there is a fitting one merge
	 * @param timeStep
	 * @param requiredPower
	 * @return saved power
	 */
	private float gothroughMergeReq(int timeStep, float requiredPower, ArrayList<Float> predictedPowerUsage, 
			OptimizationScheme optScheme) {
		List<MergeMsg> requests = this.hcu.getHierarchyController().getMergeRequestsForTimeStep(timeStep-1);
		if(requests == null)
			return 0f;
		//store holon which would help decrease |requiredPower|
		ArrayList<MergeMsg> poten = new ArrayList<MergeMsg>();
		//find a perfect match or holon which would help decrease |requiredPower|
		for(MergeMsg req : requests) {
			float r = req.getPredictedPowerUsage().get(0); //since merge req is from timeStep-1
			String requester = req.getRequester();
			float newThroughput = req.getNetThroughput() + this.hcu.getStateEstimator().getNetThroughput();
			
			if(!this.hcu.getHierarchyController().canMerge(requester, newThroughput)) {
				//cannot merge with the requester
				continue;
			}
			
			if(this.hcu.matchPowerRange(r, requiredPower, predictedPowerUsage, this.hcu.getOptimizer().getCurrentPowerThreshold())) {
				//perfect match
				this.hcu.getHierarchyController().sendMergeAck(timeStep, req);
				OrderMsg o = new OrderMsg(r, null, optScheme, timeStep);
				this.ordersForSubholon.put(requester, o);
				requests.remove(req);
				return r;
			} else if( ((r < 0 && requiredPower < 0) || (r > 0 && requiredPower > 0))
					&& this.hcu.decreasesPowerUsage(requiredPower, r, req.getPredictedPowerUsage())) {
				//accepting this request would help this holon
				poten.add(req);
			}
		}
		//go through all poten candidates and find most suiting subset
		//all candidates have either power < 0 or > 0
		if(poten.size() < 1)
			return 0f;
		List<List<MergeMsg>> potPermut = getAllPermutations(poten);
		HashMap<Float, List<MergeMsg>> potSavings = new HashMap<Float, List<MergeMsg>>();
		for(List<MergeMsg> l : potPermut) {
			//check how much power this subset of merges would save
			float saving = 0f;
			Float[] savings = new Float[predictedPowerUsage.size()];
			for(int i=0; i<savings.length; i++)
				savings[i] = 0f;
			for(MergeMsg m : l) {
				if(!this.hcu.decreasesPowerUsage(requiredPower, saving, List.of(savings)))
					break;
				saving += m.getPredictedPowerUsage().get(0); //since merge req is from timeStep-1
				for(int i=0; i<savings.length; i++) {
					savings[i] = savings[i] + m.getPredictedPowerUsage().get(i);
				}
			}
			if(this.hcu.decreasesPowerUsage(requiredPower, saving, List.of(savings))) {
				if(potSavings.containsKey(saving) && potSavings.get(saving).size() >= l.size())
					continue;
				potSavings.put(saving, l);
			}
		}
		if(potSavings.size() < 1) {
			return 0f;
		}
		float max = 0f;
		for(float f : potSavings.keySet()) {
			if(Math.abs(f) > Math.abs(max)) {
				max = f;
			}
		}
		//merge with all holons that are part of the subset with the max saving
		if(potSavings.containsKey(max)) {
			for(MergeMsg req : potSavings.get(max)) {
				float r = req.getPower();
				String requester = req.getRequester();
				this.hcu.getHierarchyController().sendMergeAck(timeStep, req);
				OrderMsg o = new OrderMsg(r, null, optScheme, timeStep);
				this.ordersForSubholon.put(requester, o);
			}
			requests.removeAll(potSavings.get(max));
		}
		return max;
	}
	
	private void findNewSuperHolon(int timeStep, float powerUsage, ArrayList<Float> predictedPowerUsage) {
		for(String physicalNeighbor : this.hcu.getHierarchyController().getPhysicalNeighborsFromOtherHolarchy()) {
			this.hcu.getHierarchyController().sendMergeReq(powerUsage, predictedPowerUsage, timeStep, physicalNeighbor);
		}
	}
	
	
	/**
	 * compute a new target value for all subholons
	 * "fairness": all subholons get same target value
	 * @param timeStep
	 * @param powerUsage
	 * @param requiredPower
	 * @param optScheme
	 */
	private void orderSubholonsRequiredPower(int timeStep, float powerUsage, float requiredPower, OptimizationScheme optScheme) {
		float p = this.hcu.getHolon().isPhysical ? this.hcu.getHolon().getHolonObject().getEnergyAtTimeStep(timeStep) : 0f;
		requiredPower = this.desiredPowerUsage - p;
		HashMap<String, StateMsg> childStates = this.hcu.getStateEstimator().getChildStates();
		float opt = requiredPower/(childStates.size() != 0 ? childStates.size() : 1);
		for(String s : this.hcu.getHierarchyController().getSubHolons()) {
			//order for subholon
			if(this.ordersForSubholon.containsKey(s))
				continue;
			OrderMsg o = new OrderMsg(opt, null, optScheme, timeStep);
			this.ordersForSubholon.put(s, o);
		}
	}
	
	private <T> List<List<T>> getAllPermutations(List<T> set){
		List<List<T>> out = new ArrayList<List<T>>();
		
		for(int i=0; i<set.size(); i++) {
			for(int j=i; j<set.size(); j++) {
				List<T> l = new ArrayList<T>();
				l.addAll(set.subList(i, j+1));
				out.add(l);
			}
		}
		
		return out;
	}
	
	public float getDesiredPowerUsage() {
		return this.desiredPowerUsage;
	}

	public void setOrder(OrderMsg order, String sender) {
		if(sender.equals(this.hcu.getHierarchyController().getSuperHolon())) {
			this.order = order;
		}
	}
	
}