class TransactionCell: UITableViewCell {
}

class TransactionsHeaderView: UITableViewHeaderFooterView {
	static let reuseId = "CustomHeader"
}

class TransactionsViewController: UIViewController {

	let cellId = "cellID"
	let numSections: Int = 4
	
	lazy var tableView = UITableView()
	
	override func viewDidLoad() {
		super.viewDidLoad()
		
		commonInit()
	}
	
	private func commonInit() {
		
		//view.backgroundColor = .clear
		
		tableView.backgroundColor = .systemBackground
		tableView.rowHeight = 74
		tableView.sectionHeaderHeight = 50
		
		tableView.register(TransactionCell.self, forCellReuseIdentifier: cellId)
		tableView.register(TransactionsHeaderView.self, forHeaderFooterViewReuseIdentifier: TransactionsHeaderView.reuseId)
		
		tableView.delegate = self
		tableView.dataSource = self
		
		tableView.contentInsetAdjustmentBehavior = .never
		tableView.separatorInset = UIEdgeInsets(top: 0, left: 32, bottom: 0, right: 16)
		tableView.tableFooterView = UIView()
		
		view.addSubview(tableView)
		
		tableView.translatesAutoresizingMaskIntoConstraints = false
		
		let g = view.safeAreaLayoutGuide
		
		NSLayoutConstraint.activate([
			
			tableView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
			tableView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
			tableView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
			tableView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),
			
		])

	}
	
}

extension TransactionsViewController: UITableViewDelegate, UITableViewDataSource, UIScrollViewDelegate {
	
	func numberOfSections(in tableView: UITableView) -> Int {
		return numSections // self.sections.count
	}
	
	func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		
		return 4 //sections[section].transactions.count
	}
	
	func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		
		guard let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as? TransactionCell  else {
			fatalError("The dequeued cell is not an instance of HomeTableViewCell.")
		}
		return cell
	}
	
	func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
		print(#function, section)
		
		let header = tableView.dequeueReusableHeaderFooterView(withIdentifier: TransactionsHeaderView.reuseId) as! TransactionsHeaderView
		header.contentView.backgroundColor = .orange
		return header
	}
	
	func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
		print(#function, section)
		return 50
	}
	
}