import Foundation
import UIKit
import Display
import AsyncDisplayKit
import ComponentFlow
import SwiftSignalKit
import ViewControllerComponent
import ComponentDisplayAdapters
import TelegramPresentationData
import AccountContext
import TelegramCore
import MultilineTextComponent
import EmojiStatusComponent
import TelegramStringFormatting
import CheckNode
import SegmentedControlNode

final class SegmentControlComponent: Component {
    struct Item: Equatable {
        var id: AnyHashable
        var title: String
    }
    
    let theme: PresentationTheme
    let items: [Item]
    let selectedId: AnyHashable?
    let action: (AnyHashable) -> Void
    
    init(
        theme: PresentationTheme,
        items: [Item],
        selectedId: AnyHashable?,
        action: @escaping (AnyHashable) -> Void
    ) {
        self.theme = theme
        self.items = items
        self.selectedId = selectedId
        self.action = action
    }
    
    static func ==(lhs: SegmentControlComponent, rhs: SegmentControlComponent) -> Bool {
        if lhs.theme !== rhs.theme {
            return false
        }
        if lhs.items != rhs.items {
            return false
        }
        if lhs.selectedId != rhs.selectedId {
            return false
        }
        return true
    }
    
    class SegmentedControlView: UISegmentedControl {
        var foregroundColor: UIColor? {
            didSet {
                self.resetChrome()
            }
        }
        
        override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
            super.touchesBegan(touches, with: event)
            self.resetChrome()
        }
        
        override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
            super.touchesEnded(touches, with: event)
            self.resetChrome()
        }
        
        func resetChrome() {
            for case let view as UIImageView in self.subviews {
                view.isHidden = true
            }
            if let selectorView = self.subviews.last, let loupe = selectorView.subviews.first, let innerLoupe = loupe.subviews.first {
                for view in innerLoupe.subviews {
                    if type(of: view) == UIView.self {
                        view.backgroundColor = self.foregroundColor
                    }
                }
            }
        }
                
        override func layoutSubviews() {
            super.layoutSubviews()
            
            self.resetChrome()
        }
    }
    
    class View: UIView {
        private let title = ComponentView<Empty>()
        
        private var component: SegmentControlComponent?
        
        private var nativeSegmentedView: SegmentedControlView?
        private var legacySegmentedNode: SegmentedControlNode?
        
        override init(frame: CGRect) {
            super.init(frame: frame)
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        func update(component: SegmentControlComponent, availableSize: CGSize, state: EmptyComponentState, environment: Environment<Empty>, transition: ComponentTransition) -> CGSize {
            let themeUpdated = self.component?.theme !== component.theme
            
            self.component = component
            
            var controlSize = CGSize()
            if #available(iOS 26.0, *) {
                let segmentedView: SegmentedControlView
                if let current = self.nativeSegmentedView {
                    segmentedView = current
                } else {
                    let mappedActions: [UIAction] = component.items.map { item -> UIAction in
                        return UIAction(title: item.title, handler: { [weak self] _ in
                            guard let self, let component = self.component else {
                                return
                            }
                            component.action(item.id)
                        })
                    }
                    segmentedView = SegmentedControlView(frame: .zero, actions: mappedActions)
                    segmentedView.selectedSegmentIndex = component.items.firstIndex(where: { $0.id == component.selectedId }) ?? 0
                    self.nativeSegmentedView = segmentedView
                    self.addSubview(segmentedView)
                }
                
                if themeUpdated {
                    let backgroundColor = component.theme.overallDarkAppearance ? component.theme.list.itemBlocksBackgroundColor : component.theme.rootController.navigationBar.segmentedBackgroundColor
                    segmentedView.setTitleTextAttributes([
                        .font: UIFont.boldSystemFont(ofSize: 15.0),
                        .foregroundColor: component.theme.rootController.navigationBar.segmentedTextColor
                    ], for: .normal)
                    segmentedView.foregroundColor = component.theme.rootController.navigationBar.segmentedForegroundColor
                    segmentedView.backgroundColor = backgroundColor
                }
                
                controlSize = segmentedView.sizeThatFits(availableSize)
                controlSize.width = min(availableSize.width - 32.0, max(300.0, controlSize.width))
                controlSize.height = 36.0
                segmentedView.frame = CGRect(origin: .zero, size: controlSize)
            } else {
                let segmentedNode: SegmentedControlNode
                if let current = self.legacySegmentedNode {
                    segmentedNode = current
                    
                    if themeUpdated {
                        let backgroundColor = component.theme.overallDarkAppearance ? component.theme.list.itemBlocksBackgroundColor : component.theme.rootController.navigationBar.segmentedBackgroundColor
                        let controlTheme = SegmentedControlTheme(backgroundColor: backgroundColor, foregroundColor: component.theme.rootController.navigationBar.segmentedForegroundColor, shadowColor: .clear, textColor: component.theme.rootController.navigationBar.segmentedTextColor, dividerColor: component.theme.rootController.navigationBar.segmentedDividerColor)
                        segmentedNode.updateTheme(controlTheme)
                    }
                } else {
                    let mappedItems: [SegmentedControlItem] = component.items.map { item -> SegmentedControlItem in
                        return SegmentedControlItem(title: item.title)
                    }
                    let backgroundColor = component.theme.overallDarkAppearance ? component.theme.list.itemBlocksBackgroundColor : component.theme.rootController.navigationBar.segmentedBackgroundColor
                    let controlTheme = SegmentedControlTheme(backgroundColor: backgroundColor, foregroundColor: component.theme.rootController.navigationBar.segmentedForegroundColor, shadowColor: .clear, textColor: component.theme.rootController.navigationBar.segmentedTextColor, dividerColor: component.theme.rootController.navigationBar.segmentedDividerColor)
                    segmentedNode = SegmentedControlNode(theme: controlTheme, items: mappedItems, selectedIndex: component.items.firstIndex(where: { $0.id == component.selectedId }) ?? 0, cornerRadius: 18.0)
                    self.legacySegmentedNode = segmentedNode
                    self.addSubnode(segmentedNode)
                    
                    segmentedNode.selectedIndexChanged = { [weak self] index in
                        guard let self, let component = self.component else {
                            return
                        }
                        component.action(component.items[index].id)
                    }
                }
                
                controlSize = segmentedNode.updateLayout(SegmentedControlLayout.sizeToFit(maximumWidth: availableSize.width, minimumWidth: min(availableSize.width, 300.0), height: 36.0), transition: transition.containedViewLayoutTransition)
                transition.containedViewLayoutTransition.updateFrame(node: segmentedNode, frame: CGRect(origin: CGPoint(x: 0.0, y: 0.0), size: controlSize))
            }
            
            return controlSize
        }
    }
    
    func makeView() -> View {
        return View(frame: CGRect())
    }
    
    func update(view: View, availableSize: CGSize, state: EmptyComponentState, environment: Environment<Empty>, transition: ComponentTransition) -> CGSize {
        return view.update(component: self, availableSize: availableSize, state: state, environment: environment, transition: transition)
    }
}