//
//  ScriptPolicyViewController.swift
//  SBrowser
//
//  Created by James Magahern on 7/24/20.
//

import UIKit

protocol ScriptPolicyViewControllerDelegate {
    func didChangeScriptPolicy()
}

class ScriptPolicyControlListCell: UICollectionViewListCell
{
    let policyControl = ScriptPolicyControl()
    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(policyControl)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        let policyControlWidth = CGFloat(100.0)
        policyControl.frame = CGRect(x: bounds.maxX - policyControlWidth, y: 0, width: policyControlWidth, height: bounds.height)
        bringSubviewToFront(policyControl)
        
        contentView.frame = CGRect(origin: contentView.frame.origin, size: CGSize(width: bounds.width - policyControl.frame.width, height: contentView.frame.height))
    }
}

class ScriptPolicyViewController: UIViewController, UICollectionViewDelegate
{
    var collectionView: UICollectionView?
    var delegate: ScriptPolicyViewControllerDelegate? = nil
    var dataSource: UICollectionViewDiffableDataSource<Int, String>?
    
    private var didChangeScriptPolicy = false
    
    convenience init(policyManager: ResourcePolicyManager, blockedScripts: Set<String>) {
        self.init(nibName: nil, bundle: nil)
        
        let listConfig = UICollectionLayoutListConfiguration(appearance: .grouped)
        let listLayout = UICollectionViewCompositionalLayout.list(using: listConfig)
        let collectionView = UICollectionView(frame: .zero, collectionViewLayout: listLayout)
        
        let registry = UICollectionView.CellRegistration<ScriptPolicyControlListCell, String> { (listCell, indexPath, item) in
            var config = listCell.defaultContentConfiguration()
            config.text = item
            
            listCell.contentConfiguration = config
            
            if policyManager.allowedOriginsForScriptResources().contains(item) {
                listCell.policyControl.policyStatus = .allowed
            } else {
                listCell.policyControl.policyStatus = .blocked
            }
            
            listCell.policyControl.addAction(UIAction(handler: { _ in
                if listCell.policyControl.policyStatus == .allowed {
                    policyManager.allowOriginToLoadScriptResources(item)
                } else {
                    policyManager.disallowOriginToLoadScriptResources(item)
                }
                
                self.didChangeScriptPolicy = true
            }), for: .valueChanged)
        }
        
        let dataSource = UICollectionViewDiffableDataSource<Int, String>(collectionView: collectionView) { (collectionView, indexPath, item) -> UICollectionViewCell? in
            collectionView.dequeueConfiguredReusableCell(using: registry, for: indexPath, item: item)
        }
        
        collectionView.dataSource = dataSource
        collectionView.delegate = self
        
        var snapshot = dataSource.snapshot()
        snapshot.appendSections([ 0 ])
        snapshot.appendItems(Array(blockedScripts))
        dataSource.apply(snapshot)
        
        self.dataSource = dataSource
        self.collectionView = collectionView
        
        title = "Script Origin Policy"
        navigationItem.rightBarButtonItem = UIBarButtonItem(systemItem: .done, primaryAction: UIAction(handler: { action in
            if self.didChangeScriptPolicy {
                self.delegate?.didChangeScriptPolicy()
            }
            
            self.dismiss(animated: true, completion: nil)
        }), menu: nil)
    }
    
    override func loadView() {
        self.view = collectionView
    }
    
    // MARK: UICollectionViewDelegate
    
    func collectionView(_ collectionView: UICollectionView, shouldHighlightItemAt indexPath: IndexPath) -> Bool {
        false
    }
    
    func collectionView(_ collectionView: UICollectionView, shouldSelectItemAt indexPath: IndexPath) -> Bool {
        false
    }
}