//
//  ComposeContentToolbarView.swift
//  
//
//  Created by MainasuK on 22/10/18.
//

import os.log
import SwiftUI
import MastodonAsset
import MastodonLocalization
import MastodonSDK

protocol ComposeContentToolbarViewDelegate: AnyObject {
    func composeContentToolbarView(_ viewModel: ComposeContentToolbarView.ViewModel, toolbarItemDidPressed action: ComposeContentToolbarView.ViewModel.Action)
    func composeContentToolbarView(_ viewModel: ComposeContentToolbarView.ViewModel, attachmentMenuDidPressed action: ComposeContentToolbarView.ViewModel.AttachmentAction)
}

struct ComposeContentToolbarView: View {
    
    let logger = Logger(subsystem: "ComposeContentToolbarView", category: "View")
    
    static var toolbarHeight: CGFloat { 48 }
    
    @ObservedObject var viewModel: ViewModel
    
    var body: some View {
        HStack(spacing: .zero) {
            ForEach(ComposeContentToolbarView.ViewModel.Action.allCases, id: \.self) { action in
                switch action {
                case .attachment:
                    Menu {
                        ForEach(ComposeContentToolbarView.ViewModel.AttachmentAction.allCases, id: \.self) { attachmentAction in
                            Button {
                                logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public), \(attachmentAction.title)")
                                viewModel.delegate?.composeContentToolbarView(viewModel, attachmentMenuDidPressed: attachmentAction)
                            } label: {
                                Label {
                                    Text(attachmentAction.title)
                                } icon: {
                                    Image(uiImage: attachmentAction.image)
                                }
                            }
                        }
                    } label: {
                        label(for: action)
                            .opacity(viewModel.isAttachmentButtonEnabled ? 1.0 : 0.5)
                    }
                    .disabled(!viewModel.isAttachmentButtonEnabled)
                    .frame(width: 48, height: 48)
                case .visibility:
                    Menu {
                        Picker(selection: $viewModel.visibility) {
                            ForEach(viewModel.allVisibilities, id: \.self) { visibility in
                                Label {
                                    Text(visibility.title)
                                } icon: {
                                    Image(uiImage: visibility.image)
                                }
                            }
                        } label: {
                            Text(viewModel.visibility.title)
                        }
                    } label: {
                        label(for: viewModel.visibility.image)
                            .accessibilityLabel(L10n.Scene.Compose.Keyboard.selectVisibilityEntry(viewModel.visibility.title))
                    }
                    .frame(width: 48, height: 48)
                case .poll:
                    Button {
                        logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): \(String(describing: action))")
                        viewModel.delegate?.composeContentToolbarView(viewModel, toolbarItemDidPressed: action)
                    } label: {
                        label(for: action)
                            .opacity(viewModel.isPollButtonEnabled ? 1.0 : 0.5)
                    }
                    .disabled(!viewModel.isPollButtonEnabled)
                    .frame(width: 48, height: 48)
                default:
                    Button {
                        logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): \(String(describing: action))")
                        viewModel.delegate?.composeContentToolbarView(viewModel, toolbarItemDidPressed: action)
                    } label: {
                        label(for: action)
                    }
                    .frame(width: 48, height: 48)
                }
            }
            Spacer()
            let count: Int = {
                if viewModel.isContentWarningActive {
                    return viewModel.contentWeightedLength + viewModel.contentWarningWeightedLength
                } else {
                    return viewModel.contentWeightedLength
                }
            }()
            let remains = viewModel.maxTextInputLimit - count
            let isOverflow = remains < 0
            Text("\(remains)")
                .foregroundColor(Color(isOverflow ? UIColor.systemRed : UIColor.secondaryLabel))
                .font(.system(size: isOverflow ? 18 : 16, weight: isOverflow ? .medium : .regular))
                .accessibilityLabel(L10n.A11y.Plural.Count.charactersLeft(remains))
        }
        .padding(.leading, 4)       // 4 + 12 = 16
        .padding(.trailing, 16)
        .frame(height: ComposeContentToolbarView.toolbarHeight)
        .background(Color(viewModel.backgroundColor))
        .accessibilityElement(children: .contain)
        .accessibilityLabel(L10n.Scene.Compose.Accessibility.postOptions)
    }
    
}

extension ComposeContentToolbarView {
    func label(for action: ComposeContentToolbarView.ViewModel.Action) -> some View {
        Image(uiImage: viewModel.image(for: action))
            .foregroundColor(Color(Asset.Scene.Compose.buttonTint.color))
            .frame(width: 24, height: 24, alignment: .center)
            .accessibilityLabel(viewModel.label(for: action))
    }
    
    func label(for image: UIImage) -> some View {
        Image(uiImage: image)
            .foregroundColor(Color(Asset.Scene.Compose.buttonTint.color))
            .frame(width: 24, height: 24, alignment: .center)
    }
}

extension Mastodon.Entity.Status.Visibility {
    fileprivate var title: String {
        switch self {
        case .public:               return L10n.Scene.Compose.Visibility.public
        case .unlisted:             return L10n.Scene.Compose.Visibility.unlisted
        case .private:              return L10n.Scene.Compose.Visibility.private
        case .direct:               return L10n.Scene.Compose.Visibility.direct
        case ._other(let value):    return value
        }
    }
    
    fileprivate var image: UIImage {
        switch self {
        case .public:       return Asset.Scene.Compose.earth.image.withRenderingMode(.alwaysTemplate)
        case .unlisted:     return Asset.Scene.Compose.people.image.withRenderingMode(.alwaysTemplate)
        case .private:      return Asset.Scene.Compose.peopleAdd.image.withRenderingMode(.alwaysTemplate)
        case .direct:       return Asset.Scene.Compose.mention.image.withRenderingMode(.alwaysTemplate)
        case ._other:       return Asset.Scene.Compose.more.image.withRenderingMode(.alwaysTemplate)
        }
    }
}