mvm_core_ui/MVMCoreUI/Templates/MoleculeStackTemplate.swift

//
//  MoleculeStackTemplate.swift
//  MVMCoreUI
//
//  Created by Scott Pfeil on 2/11/19.
//  Copyright © 2019 Verizon Wireless. All rights reserved.
//

import UIKit

public class MoleculeStackTemplate: ThreeLayerViewController {
    var modulesRequired: NSMutableArray?

    public override func shouldFinishProcessingLoad(_ loadObject: MVMCoreLoadObject, error: AutoreleasingUnsafeMutablePointer<MVMCoreErrorObject>) -> Bool {
        var shouldFinish = super.shouldFinishProcessingLoad(loadObject, error: error)
        if shouldFinish, let firstError = modulesNeeded().errors?.firstObject as? MVMCoreErrorObject {
            // Don't continue if there was an error loading needed modules.
            error.pointee = firstError
            shouldFinish = false
        }
        return shouldFinish
    }
    
    public override func spaceBetweenTopAndMiddle() -> CGFloat? {
        return 0
    }
    
    public override func viewForTop() -> UIView? {
        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.createMolecule(forJSON: moleculeJSON, delegateObject: delegateObject() as? MVMCoreUIDelegateObject, constrainIfNeeded: true) else {
            return nil
        }
        return molecule
    }
    
    public override func viewForMiddle() -> UIView? {
        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("moleculeStack") else {
            return nil
        }
        let stack = MoleculeStackView(frame: .zero)
        stack.useStackSpacingBeforeFirstItem = true
        stack.setWithJSON(moleculeJSON, delegateObject: delegateObject() as? MVMCoreUIDelegateObject, additionalData: nil)
        return stack
    }
    
    override public func viewForBottom() -> UIView? {
        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.createMolecule(forJSON: moleculeJSON, delegateObject: delegateObject() as? MVMCoreUIDelegateObject, constrainIfNeeded: true) else {
            return nil
        }
        return molecule
    }
    
    // MARK: - cache handling
    public override func pageTypesToListenFor() -> [Any]? {
        guard let pageType = self.pageType else {
            return super.pageTypesToListenFor()
        }
        return [pageType]
    }
    
    public override func modulesToListenFor() -> [Any]? {
        // Get all of the molecules that need modules.
        return modulesNeeded().modules as? [Any]
    }
    
    /// Gets the modules needed.
    func modulesNeeded() -> (modules: NSMutableArray?, errors: NSMutableArray?) {
        let modules: NSMutableArray = []
        let errors: NSMutableArray = []
        let delegate = delegateObject() as? MVMCoreUIDelegateObject
        MVMCoreUIMoleculeMappingObject.addRequiredModules(forJSON: loadObject?.pageJSON?.optionalDictionaryForKey("header"), delegateObject: delegate, moduleList: modules, errorList: errors)
        MVMCoreUIMoleculeMappingObject.addRequiredModules(forJSON: loadObject?.pageJSON?.optionalDictionaryForKey("footer"), delegateObject: delegate, moduleList: modules, errorList: errors)
        MVMCoreUIMoleculeMappingObject.addRequiredModules(forJSON: loadObject?.pageJSON?.optionalDictionaryForKey("moleculeStack"), delegateObject: delegate, moduleList: modules, errorList: errors)
        modulesRequired = modules
        return (modules.count > 0 ? modules : nil, errors.count > 0 ? errors : nil)
    }
}