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

import UIKit

public class MoleculeStackTemplate: ThreeLayerViewController {
    
    public override func shouldFinishProcessingLoad(_ loadObject: MVMCoreLoadObject, error: AutoreleasingUnsafeMutablePointer<MVMCoreErrorObject>) -> Bool {
        var shouldFinish = super.shouldFinishProcessingLoad(loadObject, error: error)
        if shouldFinish, let firstError = modulesNeeded().errors?.first {
            // 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()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
            return nil
        }
        return molecule
    }
    
    public override func viewForMiddle() -> UIView? {
        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("moleculeStack") else {
            return nil
        }
        return MoleculeStackView(withJSON: moleculeJSON, delegateObject: delegateObject(), additionalData: nil)
    }
    
    override public func viewForBottom() -> UIView? {
        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) 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
    }
    
    // MARK: - Module Molecule Handling
    func addModule(for moduleMolecule: [AnyHashable: Any]?, modules: inout [String], errors: inout [MVMCoreErrorObject]) {
        var error: MVMCoreErrorObject?
        if let moleculeName = MVMCoreUIMoleculeMappingObject.getMoleculeName(forModuleMolecule: moduleMolecule, moduleMap: loadObject?.modulesJSON, error: &error) {
            modules.append(moleculeName)
            if let errorObject = error {
                MVMCoreLoggingHandler.shared()?.addError(toLog: errorObject)
                errors.append(errorObject)
            }
        }
    }
    
    func modulesNeeded() -> (modules: [String]?, errors: [MVMCoreErrorObject]?) {
        var modules: [String] = []
        var errors: [MVMCoreErrorObject] = []
        addModule(for: loadObject?.pageJSON?.optionalDictionaryForKey("header"), modules: &modules, errors: &errors)
        addModule(for: loadObject?.pageJSON?.optionalDictionaryForKey("footer"), modules: &modules, errors: &errors)
        if let molecules = loadObject?.pageJSON?.optionalArrayForChainOfKeysOrIndexes(["moleculeStack","molecules"]) as? [[AnyHashable: Any]] {
            for molecule in molecules {
                addModule(for: molecule, modules: &modules, errors: &errors)
            }
        }
        return (modules.count > 0 ? modules : nil, errors.count > 0 ? errors : nil)
    }
}