var utils = require('util_etc');
var energyUtils = {

	// get energy from a container (if available) otherwise just mine for it at 
	// an energy source
    gatherEnergy : function(creep) {
		let storage;
		if(creep.room.memory.containers > 0){
			storage = creep.pos.findClosestByRange(FIND_STRUCTURES, {
				filter: (structure) => {
					return (structure.structureType == STRUCTURE_CONTAINER) &&
						structure.store.getUsedCapacity(RESOURCE_ENERGY) > 0;
				}
			});
		}
		else{
			if(typeof creep.memory.assignedSource === 'undefined') energyUtils.sourceDelegate(creep);
			let source = Game.getObjectById(creep.memory.assignedSource);
			if(creep.harvest(source) == ERR_NOT_IN_RANGE) {
				creep.moveTo(source);
			}
			return;
		}

		if(storage == null) return;

        if(creep.withdraw(storage, RESOURCE_ENERGY) == ERR_NOT_IN_RANGE) {
            creep.moveTo(storage);
        }
    },

	//assign a creep to source in the room the creep is in
	sourceDelegate : function(creep){
		const room = creep.room;

		const sources = creep.room.find(FIND_SOURCES);

		let minSource = sources[0].id;
		let minSourceCount = 0;

		if(typeof room.memory[sources[0].id] !== 'undefined') 
			minSourceCount = room.memory[sources[0].id].length;

		for(const source of sources){
			if(typeof room.memory[source.id] === 'undefined')
				room.memory[source.id] = [];

			room.memory[source.id].forEach(function(assignedCreep, index){
				if(!Game.creeps[assignedCreep]){
					room.memory[source.id].splice(index, 1); 
				}
			});

			if(room.memory[source.id].length < minSourceCount 
				&& room.memory[source.id].length < utils.calculateSourceSpace(source)){

				minSource = source.id;
				minSourceCount = room.memory[source.id].length;
			}
		}
	
		room.memory[minSource].push(creep.name);
		creep.memory.assignedSource = minSource;

	},

	// put energy into storage, first if possible into a spawner / extension
	// otherwise put it into a container
    depositEnergy : function(creep) {
        var target = creep.pos.findClosestByRange(FIND_STRUCTURES, {
            filter: (structure) => {
                return (structure.structureType == STRUCTURE_SPAWN ||
				structure.structureType == STRUCTURE_EXTENSION) &&
                    structure.store.getFreeCapacity(RESOURCE_ENERGY) > 0;
            }
        });
        if(target == null){
            target = creep.pos.findClosestByRange(FIND_STRUCTURES, {
                filter: (structure) => {
                    return (structure.structureType == STRUCTURE_CONTAINER) &&
                        structure.store.getFreeCapacity(RESOURCE_ENERGY) > 0;
                }
            });
        }
        if(target != null) {
            if(creep.transfer(target, RESOURCE_ENERGY) == ERR_NOT_IN_RANGE) {
                creep.moveTo(target, {visualizePathStyle: {stroke: '#ffffff'}});
            }
			return true;
        }

		// if no storage anywhere, then just build something
		// in order to speed up early game, since no storage
		if(creep.room.memory.containers == 0){
			target = creep.pos.findClosestByRange(FIND_CONSTRUCTION_SITES);
			if(target != null){
				if(creep.build(target) == ERR_NOT_IN_RANGE){
					creep.moveTo(target);
				}
				return true;
			}
		}
        return false;
    }
}

module.exports = energyUtils;