Swiftgram/submodules/PeerInfoUI/Sources/PeerAllowedReactionListController.swift

import Foundation
import UIKit
import Display
import AsyncDisplayKit
import SwiftSignalKit
import Postbox
import TelegramCore
import TelegramPresentationData
import TelegramUIPreferences
import ItemListUI
import PresentationDataUtils
import AccountContext
import PresentationDataUtils

private final class PeerAllowedReactionListControllerArguments {
    let context: AccountContext
    let toggleAll: () -> Void
    let toggleItem: (String) -> Void
    
    init(
        context: AccountContext,
        toggleAll: @escaping () -> Void,
        toggleItem: @escaping (String) -> Void
    ) {
        self.context = context
        self.toggleAll = toggleAll
        self.toggleItem = toggleItem
    }
}

private enum PeerAllowedReactionListControllerSection: Int32 {
    case all
    case items
}

private enum PeerAllowedReactionListControllerEntry: ItemListNodeEntry {
    enum StableId: Hashable {
        case allowAll
        case allowAllInfo
        case itemsHeader
        case item(String)
    }
    
    case allowAll(text: String, isEnabled: Bool)
    case allowAllInfo(String)
    
    case itemsHeader(String)
    case item(index: Int, value: String, file: TelegramMediaFile?, text: String, isEnabled: Bool)
    
    var section: ItemListSectionId {
        switch self {
        case .allowAll, .allowAllInfo:
            return PeerAllowedReactionListControllerSection.all.rawValue
        case .itemsHeader, .item:
            return PeerAllowedReactionListControllerSection.items.rawValue
        }
    }
    
    var stableId: StableId {
        switch self {
        case .allowAll:
            return .allowAll
        case .allowAllInfo:
            return .allowAllInfo
        case .itemsHeader:
            return .itemsHeader
        case let .item(_, value, _, _, _):
            return .item(value)
        }
    }
    
    var sortId: Int {
        switch self {
        case .allowAll:
            return 0
        case .allowAllInfo:
            return 1
        case .itemsHeader:
            return 2
        case let .item(index, _, _, _, _):
            return 100 + index
        }
    }
    
    static func ==(lhs: PeerAllowedReactionListControllerEntry, rhs: PeerAllowedReactionListControllerEntry) -> Bool {
        switch lhs {
        case let .allowAll(text, isEnabled):
            if case .allowAll(text, isEnabled) = rhs {
                return true
            } else {
                return false
            }
        case let .allowAllInfo(text):
            if case .allowAllInfo(text) = rhs {
                return true
            } else {
                return false
            }
        case let .itemsHeader(text):
            if case .itemsHeader(text) = rhs {
                return true
            } else {
                return false
            }
        case let .item(index, value, file, text, isEnabled):
            if case .item(index, value, file, text, isEnabled) = rhs {
                return true
            } else {
                return false
            }
        }
    }
    
    static func <(lhs: PeerAllowedReactionListControllerEntry, rhs: PeerAllowedReactionListControllerEntry) -> Bool {
        return lhs.sortId < rhs.sortId
    }
    
    func item(presentationData: ItemListPresentationData, arguments: Any) -> ListViewItem {
        let arguments = arguments as! PeerAllowedReactionListControllerArguments
        switch self {
        case let .allowAll(text, isEnabled):
            return ItemListSwitchItem(presentationData: presentationData, title: text, value: isEnabled, sectionId: self.section, style: .blocks, updated: { _ in
                arguments.toggleAll()
            })
        case let .allowAllInfo(text):
            return ItemListTextItem(presentationData: presentationData, text: .plain(text), sectionId: self.section)
        case let .itemsHeader(text):
            return ItemListSectionHeaderItem(presentationData: presentationData, text: text, sectionId: self.section)
        case let .item(_, value, file, text, isEnabled):
            return ItemListReactionItem(
                context: arguments.context,
                presentationData: presentationData,
                file: file,
                title: text,
                value: isEnabled,
                sectionId: self.section,
                style: .blocks,
                updated: { _ in
                    arguments.toggleItem(value)
                }
            )
        }
    }
}

private struct PeerAllowedReactionListControllerState: Equatable {
    var updatedAllowedReactions: Set<String>? = nil
}

private func peerAllowedReactionListControllerEntries(
    presentationData: PresentationData,
    availableReactions: AvailableReactions?,
    cachedData: CachedPeerData?,
    state: PeerAllowedReactionListControllerState
) -> [PeerAllowedReactionListControllerEntry] {
    var entries: [PeerAllowedReactionListControllerEntry] = []
    
    if let availableReactions = availableReactions, let allowedReactions = state.updatedAllowedReactions {
        entries.append(.allowAll(text: "Allow Reactions", isEnabled: !allowedReactions.isEmpty))
        entries.append(.allowAllInfo("Allow subscribers to reacts to channel posts."))
        
        entries.append(.itemsHeader("AVAILABLE REACTIONS"))
        var index = 0
        for availableReaction in availableReactions.reactions {
            entries.append(.item(index: index, value: availableReaction.value, file: availableReaction.staticIcon, text: availableReaction.title, isEnabled: allowedReactions.contains(availableReaction.value)))
            index += 1
        }
    }
    
    return entries
}

public func peerAllowedReactionListController(
    context: AccountContext,
    updatedPresentationData: (initial: PresentationData, signal: Signal<PresentationData, NoError>)? = nil,
    peerId: PeerId
) -> ViewController {
    let statePromise = ValuePromise(PeerAllowedReactionListControllerState(), ignoreRepeated: true)
    let stateValue = Atomic(value: PeerAllowedReactionListControllerState())
    let updateState: ((PeerAllowedReactionListControllerState) -> PeerAllowedReactionListControllerState) -> Void = { f in
        statePromise.set(stateValue.modify { f($0) })
    }
    
    var dismissImpl: (() -> Void)?
    let _ = dismissImpl
    
    let actionsDisposable = DisposableSet()
    actionsDisposable.add((context.account.postbox.transaction { transaction -> Set<String>? in
        let cachedData = transaction.getPeerCachedData(peerId: peerId)
        if let cachedData = cachedData as? CachedChannelData {
            return cachedData.allowedReactions.flatMap(Set.init)
        } else if let cachedData = cachedData as? CachedGroupData {
            return cachedData.allowedReactions.flatMap(Set.init)
        } else {
            return nil
        }
    }
    |> deliverOnMainQueue).start(next: { allowedReactions in
        updateState { state in
            var state = state
            state.updatedAllowedReactions = allowedReactions
            return state
        }
    }))
    
    let arguments = PeerAllowedReactionListControllerArguments(
        context: context,
        toggleAll: {
            let _ = (context.engine.stickers.availableReactions()
            |> take(1)
            |> deliverOnMainQueue).start(next: { availableReactions in
                guard let availableReactions = availableReactions else {
                    return
                }
                updateState { state in
                    var state = state
                    if var updatedAllowedReactions = state.updatedAllowedReactions {
                        if updatedAllowedReactions.isEmpty {
                            for availableReaction in availableReactions.reactions {
                                updatedAllowedReactions.insert(availableReaction.value)
                            }
                        } else {
                            updatedAllowedReactions.removeAll()
                        }
                        state.updatedAllowedReactions = updatedAllowedReactions
                    }
                    return state
                }
            })
        },
        toggleItem: { reaction in
            updateState { state in
                var state = state
                if var updatedAllowedReactions = state.updatedAllowedReactions {
                    if updatedAllowedReactions.contains(reaction) {
                        updatedAllowedReactions.remove(reaction)
                    } else {
                        updatedAllowedReactions.insert(reaction)
                    }
                    state.updatedAllowedReactions = updatedAllowedReactions
                }
                return state
            }
        }
    )
    
    let peerView = context.account.viewTracker.peerView(peerId)
    |> deliverOnMainQueue
    
    let presentationData = updatedPresentationData?.signal ?? context.sharedContext.presentationData
    let signal = combineLatest(queue: .mainQueue(),
        presentationData,
        statePromise.get(),
        context.engine.stickers.availableReactions(),
        peerView
    )
    |> deliverOnMainQueue
    |> map { presentationData, state, availableReactions, peerView -> (ItemListControllerState, (ItemListNodeState, Any)) in
        //TODO:localize
        let title: String = "Reactions"
        
        let entries = peerAllowedReactionListControllerEntries(
            presentationData: presentationData,
            availableReactions: availableReactions,
            cachedData: peerView.cachedData,
            state: state
        )
        
        let controllerState = ItemListControllerState(
            presentationData: ItemListPresentationData(presentationData),
            title: .text(title),
            leftNavigationButton: nil,
            rightNavigationButton: nil,
            backNavigationButton: ItemListBackButton(title: presentationData.strings.Common_Back),
            animateChanges: false
        )
        let listState = ItemListNodeState(
            presentationData: ItemListPresentationData(presentationData),
            entries: entries,
            style: .blocks,
            animateChanges: true
        )
        
        return (controllerState, (listState, arguments))
    }
    |> afterDisposed {
        actionsDisposable.dispose()
    }
    
    let controller = ItemListController(context: context, state: signal)
    controller.willDisappear = { _ in
        let _ = (context.account.postbox.transaction { transaction -> Set<String>? in
            let cachedData = transaction.getPeerCachedData(peerId: peerId)
            if let cachedData = cachedData as? CachedChannelData {
                return cachedData.allowedReactions.flatMap(Set.init)
            } else if let cachedData = cachedData as? CachedGroupData {
                return cachedData.allowedReactions.flatMap(Set.init)
            } else {
                return nil
            }
        }
        |> deliverOnMainQueue).start(next: { initialAllowedReactions in
            let updatedAllowedReactions = stateValue.with({ $0 }).updatedAllowedReactions
            if let updatedAllowedReactions = updatedAllowedReactions, initialAllowedReactions != updatedAllowedReactions {
                let _ = context.engine.peers.updatePeerAllowedReactions(peerId: peerId, allowedReactions: Array(updatedAllowedReactions)).start()
            }
        })
    }
    dismissImpl = { [weak controller] in
        guard let controller = controller else {
            return
        }
        controller.dismiss()
    }
    
    return controller
}