import UIKit
import BetterSegmentedControl

// MARK: - SearchViewController -

final class SearchViewController: BBViewController, CollectionSource, UITextFieldDelegate {

    // MARK: - Types definitions

    private enum Filter {
        case all, movies, tvShows

        static let filters: [Filter] = [.all, .movies, .tvShows]
        static var names: [String] { return filters.map { $0.title.uppercased() } }

        var title: String {
            switch self {
            case .all: return R.string.localizable.filterAll()
            case .movies: return R.string.localizable.filterMovies()
            case .tvShows: return R.string.localizable.filterTvShows()
            }
        }
    }

    // MARK: - Properties

    private var query = ""
    private var filter: Filter = .all
    private var products: [BlockbusterProduct] = []
    private var filteredProducts: [BlockbusterProduct] {
        switch filter {
        case .all: return products
        case .movies: return products.filter { $0 is BlockbusterMovie }
        case .tvShows: return products.filter { $0 is BlockbusterSeries }
        }
    }

    private let collectionView = UICollectionView.instantinate
    private let textField = UITextField()
    private let crossButton = UIButton()
    private let segmentedControl = BetterSegmentedControl(frame: .zero, titles: Filter.names)
    private let iconImageView = UIImageView()
    private let separator = UIView()
    private var headerTopConstraint: NSLayoutConstraint?

    // MARK: - Static

    static func instantinate(query: String) -> SearchViewController {
        let controller = SearchViewController()
        controller.query = query
        return controller
    }

    // MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
        setup()
        underConstruction()
    }

    // MARK: - Search

    func updateQuery(_ query: String, shouldPerformNetworking: Bool = true) {
        self.query = query
        textField.text = query
        if shouldPerformNetworking { search(self.query) }
    }

    func search(_ query: String) {

    }

    @objc func filterChanged(_ filterControl: BetterSegmentedControl) {
        filter = Filter.filters[Int(filterControl.index)]
        collectionView.reloadData()
    }

    @objc func clearSearch() {
        textField.text = ""
    }

    private func updateUiOnFocus(_ isFocused: Bool) {
        let color = GUI.tintColor(isFocused: isFocused)
        separator.backgroundColor = color
        iconImageView.tintColor = color
    }

    // MARK: - UICollectionViewDataSource

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return filteredProducts.count
    }

    func collectionView(_ collectionView: UICollectionView,
                        cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(cellClass: ProductCVCell.self, for: indexPath)
        cell.configure(with: filteredProducts[indexPath.row])
        return cell
    }

    // MARK: - UIScrollViewDelegate

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        headerTopConstraint?.constant = -scrollView.yOffset
    }

    // MARK: - UITextFieldDelegate

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        view.endEditing(true)
        return false
    }

    func textFieldDidBeginEditing(_ textField: UITextField) {
        updateUiOnFocus(true)
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        updateUiOnFocus(false)
    }

    // MARK: - Configuration

    // swiftlint:disable function_body_length

    private func setup() {
        adjust {
            $0.title = GUI.title
            $0.view.backgroundColor = UIColor.bb_bg
        }

        collectionView.addTo(view).adjust {
            $0.pinSV()
            $0.backgroundColor = .clear
            $0.alwaysBounceVertical = true
            $0.contentInset = UIEdgeInsets(top: GUI.headerHeight, left: 0, bottom: GUI.padding, right: 0)
            $0.registerNib(for: ProductCVCell.self)
            $0.dataSource = self
            $0.delegate = self
        }

        let header = UIView().addTo(view).adjust {
            $0.pinL(view, GUI.headerMargin).pinR(view, -GUI.headerMargin).pinH(GUI.headerHeight)
            headerTopConstraint = $0.pinnedT(view)
        }

        textField.addTo(header).adjust {
            $0.pinT(header, GUI.textFieldY).pinL(header, GUI.textViewPadding).pinR(header, -GUI.textViewPadding)
            $0.font = UIFont.font(.bold, size: 17)
            $0.textColor = .white
            $0.attributedPlaceholder = R.string.localizable.searchTypeToStartMessage().attr.rgb(.white)
            $0.delegate = self
            $0.text = query
        }

        iconImageView.addTo(header).adjust {
            $0.pinL(header, GUI.padding).pinCY(textField, -2)
            $0.image = R.image.ic_search()?.withRenderingMode(.alwaysTemplate)
            $0.contentMode = .scaleAspectFit
            $0.tintColor = GUI.tintColor(isFocused: false)
        }

        UIButton(type: .custom).addTo(header).adjust {
            $0.pinR(header, -GUI.padding).pinCY(textField, -2)
            $0.setImage(R.image.close_search(), for: .normal)
            $0.addTarget(self, action: #selector(clearSearch), for: .touchUpInside)
        }

        separator.addTo(header).adjust {
            $0.pinUnder(textField, GUI.padding).pinL(header, GUI.padding).pinR(header, -GUI.padding).pinH(1)
            $0.backgroundColor = GUI.tintColor(isFocused: false)
        }

        segmentedControl.addTo(header).adjust {
            $0.pinUnder(separator, GUI.padding).pinL(header, GUI.padding).pinR(header, -GUI.padding).pinH(44)
            $0.addTarget(self, action: #selector(filterChanged(_:)), for: .valueChanged)
            $0.options = [.titleBorderWidth(1),
                          .titleBorderColor(.lightGray),
                          .cornerRadius(2),
                          .titleFont(UIFont.font(.bold, size: 17)),
                          .selectedTitleFont(UIFont.font(.bold, size: 17)),
                          .titleColor(.darkGray)]
        }
    }

    // swiftlint:enable function_body_length

    // MARK: - GUI

    private struct GUI {
        static let headerHeight: CGFloat = isPad ? 150 : 100
        static let headerMargin: CGFloat = isPad ? 200 : 0
        static let textFieldY: CGFloat = isPad ? 48 : 24
        static let padding: CGFloat = 16
        static let searchIconSide: CGFloat = 30
        static let textViewMargin: CGFloat = 8
        static let textViewPadding = padding + searchIconSide + textViewMargin

        static let title = R.string.localizable.generalSearch().uppercased()

        static func tintColor(isFocused: Bool) -> UIColor { return isFocused ? .bb_yellow : .white }
    }
}