import Foundation
import UIKit
import Display
import SwiftSignalKit
import Postbox
import TelegramCore
import TelegramPresentationData
import TelegramUIPreferences
import ItemListUI
import OverlayStatusController
import AccountContext
import AlertUI
import ItemListPeerItem

private final class ChannelBlacklistControllerArguments {
    let account: Account
    
    let setPeerIdWithRevealedOptions: (PeerId?, PeerId?) -> Void
    let addPeer: () -> Void
    let removePeer: (PeerId) -> Void
    let openPeer: (RenderedChannelParticipant) -> Void
    
    init(account: Account, setPeerIdWithRevealedOptions: @escaping (PeerId?, PeerId?) -> Void, addPeer: @escaping  () -> Void, removePeer: @escaping (PeerId) -> Void, openPeer: @escaping (RenderedChannelParticipant) -> Void) {
        self.account = account
        self.addPeer = addPeer
        self.setPeerIdWithRevealedOptions = setPeerIdWithRevealedOptions
        self.removePeer = removePeer
        self.openPeer = openPeer
    }
}

private enum ChannelBlacklistSection: Int32 {
    case add
    case banned
}

private enum ChannelBlacklistEntryStableId: Hashable {
    case index(Int)
    case peer(PeerId)
}

private enum ChannelBlacklistEntry: ItemListNodeEntry {
    case add(PresentationTheme, String)
    case addInfo(PresentationTheme, String)
    case bannedHeader(PresentationTheme, String)
    case peerItem(PresentationTheme, PresentationStrings, PresentationDateTimeFormat, PresentationPersonNameOrder, Int32, RenderedChannelParticipant, ItemListPeerItemEditing, Bool)
    
    var section: ItemListSectionId {
        switch self {
            case .add, .addInfo:
                return ChannelBlacklistSection.add.rawValue
            case .bannedHeader:
                return ChannelBlacklistSection.banned.rawValue
            case .peerItem:
                return ChannelBlacklistSection.banned.rawValue
        }
    }
    
    var stableId: ChannelBlacklistEntryStableId {
        switch self {
            case .add:
                return .index(0)
            case .addInfo:
                return .index(1)
            case .bannedHeader:
                return .index(2)
            case let .peerItem(_, _, _, _, _, participant, _, _):
                return .peer(participant.peer.id)
        }
    }
    
    static func ==(lhs: ChannelBlacklistEntry, rhs: ChannelBlacklistEntry) -> Bool {
        switch lhs {
            case let .add(lhsTheme, lhsText):
                if case let .add(rhsTheme, rhsText) = rhs, lhsTheme === rhsTheme, lhsText == rhsText {
                    return true
                } else {
                    return false
                }
            case let .addInfo(lhsTheme, lhsText):
                if case let .addInfo(rhsTheme, rhsText) = rhs, lhsTheme === rhsTheme, lhsText == rhsText {
                    return true
                } else {
                    return false
                }
            case let .bannedHeader(lhsTheme, lhsText):
                if case let .bannedHeader(rhsTheme, rhsText) = rhs, lhsTheme === rhsTheme, lhsText == rhsText {
                    return true
                } else {
                    return false
                }
            case let .peerItem(lhsTheme, lhsStrings, lhsDateTimeFormat, lhsNameOrder, lhsIndex, lhsParticipant, lhsEditing, lhsEnabled):
                if case let .peerItem(rhsTheme, rhsStrings, rhsDateTimeFormat, rhsNameOrder, rhsIndex, rhsParticipant, rhsEditing, rhsEnabled) = rhs {
                    if lhsTheme !== rhsTheme {
                        return false
                    }
                    if lhsStrings !== rhsStrings {
                        return false
                    }
                    if lhsDateTimeFormat != rhsDateTimeFormat {
                        return false
                    }
                    if lhsNameOrder != rhsNameOrder {
                        return false
                    }
                    if lhsIndex != rhsIndex {
                        return false
                    }
                    if lhsParticipant != rhsParticipant {
                        return false
                    }
                    if lhsEditing != rhsEditing {
                        return false
                    }
                    if lhsEnabled != rhsEnabled {
                        return false
                    }
                    return true
                } else {
                    return false
                }
        }
    }
    
    static func <(lhs: ChannelBlacklistEntry, rhs: ChannelBlacklistEntry) -> Bool {
        switch lhs {
            case let .peerItem(_, _, _, _, index, _, _, _):
                switch rhs {
                    case let .peerItem(_, _, _, _, rhsIndex, _, _, _):
                        return index < rhsIndex
                    default:
                        return false
                }
            default:
                if case let .index(lhsIndex) = lhs.stableId {
                    if case let .index(rhsIndex) = rhs.stableId {
                        return lhsIndex < rhsIndex
                    } else {
                        return true
                    }
                } else {
                    assertionFailure()
                    return false
                }
        }
    }
    
    func item(_ arguments: ChannelBlacklistControllerArguments) -> ListViewItem {
        switch self {
            case let .add(theme, text):
                return ItemListActionItem(theme: theme, title: text, kind: .generic, alignment: .natural, sectionId: self.section, style: .blocks, action: {
                    arguments.addPeer()
                })
            case let .addInfo(theme, text):
                return ItemListTextItem(theme: theme, text: .plain(text), sectionId: self.section)
            case let .bannedHeader(theme, text):
                return ItemListSectionHeaderItem(theme: theme, text: text, sectionId: self.section)
            case let .peerItem(theme, strings, dateTimeFormat, nameDisplayOrder, _, participant, editing, enabled):
                var text: ItemListPeerItemText = .none
                switch participant.participant {
                    case let .member(_, _, _, banInfo, _):
                        if let banInfo = banInfo, let peer = participant.peers[banInfo.restrictedBy] {
                            text = .text(strings.Channel_Management_RemovedBy(peer.displayTitle).0)
                        }
                    default:
                        break
                }
                return ItemListPeerItem(theme: theme, strings: strings, dateTimeFormat: dateTimeFormat, nameDisplayOrder: nameDisplayOrder, account: arguments.account, peer: participant.peer, presence: nil, text: text, label: .none, editing: editing, switchValue: nil, enabled: enabled, selectable: true, sectionId: self.section, action: {
                    arguments.openPeer(participant)
                }, setPeerIdWithRevealedOptions: { previousId, id in
                    arguments.setPeerIdWithRevealedOptions(previousId, id)
                }, removePeer: { peerId in
                    arguments.removePeer(peerId)
                })
        }
    }
}

private struct ChannelBlacklistControllerState: Equatable {
    let referenceTimestamp: Int32
    let editing: Bool
    let peerIdWithRevealedOptions: PeerId?
    let removingPeerId: PeerId?
    let searchingMembers: Bool

    init(referenceTimestamp: Int32) {
        self.referenceTimestamp = referenceTimestamp
        self.editing = false
        self.peerIdWithRevealedOptions = nil
        self.removingPeerId = nil
        self.searchingMembers = false
    }
    
    init(referenceTimestamp: Int32, editing: Bool, peerIdWithRevealedOptions: PeerId?, removingPeerId: PeerId?, searchingMembers: Bool) {
        self.referenceTimestamp = referenceTimestamp
        self.editing = editing
        self.peerIdWithRevealedOptions = peerIdWithRevealedOptions
        self.removingPeerId = removingPeerId
        self.searchingMembers = searchingMembers
    }
    
    static func ==(lhs: ChannelBlacklistControllerState, rhs: ChannelBlacklistControllerState) -> Bool {
        if lhs.referenceTimestamp != rhs.referenceTimestamp {
            return false
        }
        if lhs.editing != rhs.editing {
            return false
        }
        if lhs.peerIdWithRevealedOptions != rhs.peerIdWithRevealedOptions {
            return false
        }
        if lhs.removingPeerId != rhs.removingPeerId {
            return false
        }
        if lhs.searchingMembers != rhs.searchingMembers {
            return false
        }
        
        return true
    }
    
    func withUpdatedSearchingMembers(_ searchingMembers: Bool) -> ChannelBlacklistControllerState {
        return ChannelBlacklistControllerState(referenceTimestamp: self.referenceTimestamp, editing: self.editing, peerIdWithRevealedOptions: self.peerIdWithRevealedOptions, removingPeerId: self.removingPeerId, searchingMembers: searchingMembers)
    }
    
    func withUpdatedEditing(_ editing: Bool) -> ChannelBlacklistControllerState {
        return ChannelBlacklistControllerState(referenceTimestamp: self.referenceTimestamp, editing: editing, peerIdWithRevealedOptions: self.peerIdWithRevealedOptions, removingPeerId: self.removingPeerId, searchingMembers: self.searchingMembers)
    }
    
    
    func withUpdatedPeerIdWithRevealedOptions(_ peerIdWithRevealedOptions: PeerId?) -> ChannelBlacklistControllerState {
        return ChannelBlacklistControllerState(referenceTimestamp: self.referenceTimestamp, editing: self.editing, peerIdWithRevealedOptions: peerIdWithRevealedOptions, removingPeerId: self.removingPeerId, searchingMembers: self.searchingMembers)
    }
    
    func withUpdatedRemovingPeerId(_ removingPeerId: PeerId?) -> ChannelBlacklistControllerState {
        return ChannelBlacklistControllerState(referenceTimestamp: self.referenceTimestamp, editing: self.editing, peerIdWithRevealedOptions: self.peerIdWithRevealedOptions, removingPeerId: removingPeerId, searchingMembers: self.searchingMembers)
    }
}

private func channelBlacklistControllerEntries(presentationData: PresentationData, view: PeerView, state: ChannelBlacklistControllerState, participants: [RenderedChannelParticipant]?) -> [ChannelBlacklistEntry] {
    var entries: [ChannelBlacklistEntry] = []
    
    if let channel = view.peers[view.peerId] as? TelegramChannel, let participants = participants {
        entries.append(.add(presentationData.theme, presentationData.strings.GroupRemoved_Remove))
        
        let isGroup: Bool
        if case .group = channel.info {
            isGroup = true
        } else {
            isGroup = false
        }
        entries.append(.addInfo(presentationData.theme, isGroup ? presentationData.strings.GroupRemoved_RemoveInfo : presentationData.strings.ChannelRemoved_RemoveInfo))
        
        var index: Int32 = 0
        if !participants.isEmpty {
            entries.append(.bannedHeader(presentationData.theme, presentationData.strings.GroupRemoved_UsersSectionTitle))
        }
        for participant in participants {
            entries.append(.peerItem(presentationData.theme, presentationData.strings, presentationData.dateTimeFormat, presentationData.nameDisplayOrder, index, participant, ItemListPeerItemEditing(editable: true, editing: state.editing, revealed: participant.peer.id == state.peerIdWithRevealedOptions), state.removingPeerId != participant.peer.id))
            index += 1
        }
    }
    
    return entries
}

public func channelBlacklistController(context: AccountContext, peerId: PeerId) -> ViewController {
    let statePromise = ValuePromise(ChannelBlacklistControllerState(referenceTimestamp: Int32(Date().timeIntervalSince1970)), ignoreRepeated: true)
    let stateValue = Atomic(value: ChannelBlacklistControllerState(referenceTimestamp: Int32(Date().timeIntervalSince1970)))
    let updateState: ((ChannelBlacklistControllerState) -> ChannelBlacklistControllerState) -> Void = { f in
        statePromise.set(stateValue.modify { f($0) })
    }
    
    var presentControllerImpl: ((ViewController, Any?) -> Void)?
    var pushControllerImpl: ((ViewController) -> Void)?

    let actionsDisposable = DisposableSet()
    
    let updateBannedDisposable = MetaDisposable()
    actionsDisposable.add(updateBannedDisposable)
    
    let removePeerDisposable = MetaDisposable()
    actionsDisposable.add(removePeerDisposable)
    
    let peerView = Promise<PeerView>()
    peerView.set(context.account.viewTracker.peerView(peerId))
    let blacklistPromise = Promise<[RenderedChannelParticipant]?>(nil)
    
    let arguments = ChannelBlacklistControllerArguments(account: context.account, setPeerIdWithRevealedOptions: { peerId, fromPeerId in
        updateState { state in
            if (peerId == nil && fromPeerId == state.peerIdWithRevealedOptions) || (peerId != nil && fromPeerId == nil) {
                return state.withUpdatedPeerIdWithRevealedOptions(peerId)
            } else {
                return state
            }
        }
    }, addPeer: {
        var dismissController: (() -> Void)?
        let controller = ChannelMembersSearchController(context: context, peerId: peerId, mode: .ban, openPeer: { peer, participant in
            if let participant = participant {
                let presentationData = context.sharedContext.currentPresentationData.with { $0 }
                switch participant.participant {
                    case .creator:
                        return
                    case let .member(_, _, adminInfo, _, _):
                        if let adminInfo = adminInfo, adminInfo.promotedBy != context.account.peerId {
                            presentControllerImpl?(textAlertController(context: context, title: nil, text: presentationData.strings.Channel_Members_AddBannedErrorAdmin, actions: [TextAlertAction(type: .defaultAction, title: presentationData.strings.Common_OK, action: {})]), nil)
                            return
                        }
                }
            }
            let _ = (context.account.postbox.loadedPeerWithId(peerId)
            |> deliverOnMainQueue).start(next: { channel in
                guard let _ = channel as? TelegramChannel else {
                    return
                }
                
                let presentationData = context.sharedContext.currentPresentationData.with { $0 }
                let progress = OverlayStatusController(theme: presentationData.theme, strings: presentationData.strings, type: .loading(cancelled: nil))
                presentControllerImpl?(progress, nil)
                removePeerDisposable.set((context.peerChannelMemberCategoriesContextsManager.updateMemberBannedRights(account: context.account, peerId: peerId, memberId: peer.id, bannedRights: TelegramChatBannedRights(flags: [.banReadMessages], untilDate: Int32.max))
                    |> deliverOnMainQueue).start(error: { [weak progress] _ in
                        progress?.dismiss()
                        dismissController?()
                    }, completed: { [weak progress] in 
                        progress?.dismiss()
                        dismissController?()
                    }))
            })
        })
        dismissController = { [weak controller] in
            controller?.dismiss()
        }
        presentControllerImpl?(controller, ViewControllerPresentationArguments(presentationAnimation: .modalSheet))
    }, removePeer: { memberId in
        updateState {
            return $0.withUpdatedRemovingPeerId(memberId)
        }
        
        removePeerDisposable.set((context.peerChannelMemberCategoriesContextsManager.updateMemberBannedRights(account: context.account, peerId: peerId, memberId: memberId, bannedRights: nil)  |> deliverOnMainQueue).start(error: { _ in
            updateState {
                return $0.withUpdatedRemovingPeerId(nil)
            }
        }, completed: {
            updateState {
                return $0.withUpdatedRemovingPeerId(nil)
            }
        }))
    }, openPeer: { participant in
        let _ = (peerView.get()
        |> take(1)
        |> deliverOnMainQueue).start(next: { peerView in
            guard let channel = peerView.peers[peerId] as? TelegramChannel else {
                return
            }
            let presentationData = context.sharedContext.currentPresentationData.with { $0 }
            let actionSheet = ActionSheetController(presentationTheme: presentationData.theme)
            var items: [ActionSheetItem] = []
            if !participant.peer.displayTitle.isEmpty {
                items.append(ActionSheetTextItem(title: participant.peer.displayTitle))
            }
            items.append(ActionSheetButtonItem(title: presentationData.strings.GroupRemoved_ViewUserInfo, action: { [weak actionSheet] in
                actionSheet?.dismissAnimated()
                if let infoController = context.sharedContext.makePeerInfoController(context: context, peer: participant.peer, mode: .generic) {
                    pushControllerImpl?(infoController)
                }
            }))
            if case .group = channel.info, channel.hasPermission(.inviteMembers) {
                items.append(ActionSheetButtonItem(title: presentationData.strings.GroupRemoved_AddToGroup, action: { [weak actionSheet] in
                    actionSheet?.dismissAnimated()
                    let memberId = participant.peer.id
                    updateState {
                        return $0.withUpdatedRemovingPeerId(memberId)
                    }
                    let signal = context.peerChannelMemberCategoriesContextsManager.updateMemberBannedRights(account: context.account, peerId: peerId, memberId: memberId, bannedRights: nil)
                    |> ignoreValues
                    |> then(
                        context.peerChannelMemberCategoriesContextsManager.addMember(account: context.account, peerId: peerId, memberId: memberId)
                        |> map { _ -> Void in
                            return Void()
                        }
                        |> `catch` { _ -> Signal<Void, NoError> in
                            return .complete()
                        }
                        |> ignoreValues
                    )
                    removePeerDisposable.set((signal |> deliverOnMainQueue).start(error: { _ in
                        updateState {
                            return $0.withUpdatedRemovingPeerId(nil)
                        }
                    }, completed: {
                        updateState {
                            return $0.withUpdatedRemovingPeerId(nil)
                        }
                    }))
                }))
            }
            items.append(ActionSheetButtonItem(title: presentationData.strings.GroupRemoved_DeleteUser, color: .destructive, font: .default, enabled: true, action: { [weak actionSheet] in
                actionSheet?.dismissAnimated()
                let memberId = participant.peer.id
                updateState {
                    return $0.withUpdatedRemovingPeerId(memberId)
                }
                
                removePeerDisposable.set((context.peerChannelMemberCategoriesContextsManager.updateMemberBannedRights(account: context.account, peerId: peerId, memberId: memberId, bannedRights: nil)  |> deliverOnMainQueue).start(error: { _ in
                    updateState {
                        return $0.withUpdatedRemovingPeerId(nil)
                    }
                }, completed: {
                    updateState {
                        return $0.withUpdatedRemovingPeerId(nil)
                    }
                }))
            }))
            actionSheet.setItemGroups([ActionSheetItemGroup(items: items), ActionSheetItemGroup(items: [
                ActionSheetButtonItem(title: presentationData.strings.Common_Cancel, color: .accent, action: { [weak actionSheet] in
                    actionSheet?.dismissAnimated()
                })
            ])])
            presentControllerImpl?(actionSheet, nil)
        })
    })
    
    let (listDisposable, loadMoreControl) = context.peerChannelMemberCategoriesContextsManager.banned(postbox: context.account.postbox, network: context.account.network, accountPeerId: context.account.peerId, peerId: peerId, updated: { listState in
        if case .loading(true) = listState.loadingState, listState.list.isEmpty {
            blacklistPromise.set(.single(nil))
        } else {
            blacklistPromise.set(.single(listState.list))
        }
    })
    actionsDisposable.add(listDisposable)
    
    let previousParticipantsValue = Atomic<[RenderedChannelParticipant]?>(value: nil)
    
    let signal = combineLatest(queue: .mainQueue(), context.sharedContext.presentationData, statePromise.get(), peerView.get(), blacklistPromise.get())
    |> deliverOnMainQueue
    |> map { presentationData, state, view, participants -> (ItemListControllerState, (ItemListNodeState<ChannelBlacklistEntry>, ChannelBlacklistEntry.ItemGenerationArguments)) in
        var rightNavigationButton: ItemListNavigationButton?
        var secondaryRightNavigationButton: ItemListNavigationButton?
        if let participants = participants, !participants.isEmpty {
            if state.editing {
                rightNavigationButton = ItemListNavigationButton(content: .text(presentationData.strings.Common_Done), style: .bold, enabled: true, action: {
                    updateState { state in
                        return state.withUpdatedEditing(false)
                    }
                })
            } else {
                rightNavigationButton = ItemListNavigationButton(content: .text(presentationData.strings.Common_Edit), style: .regular, enabled: true, action: {
                    updateState { state in
                        return state.withUpdatedEditing(true)
                    }
                })
            }
            
            if !state.editing {
                if rightNavigationButton == nil {
                    rightNavigationButton = ItemListNavigationButton(content: .icon(.search), style: .regular, enabled: true, action: {
                        updateState { state in
                            return state.withUpdatedSearchingMembers(true)
                        }
                    })
                } else {
                    secondaryRightNavigationButton = ItemListNavigationButton(content: .icon(.search), style: .regular, enabled: true, action: {
                        updateState { state in
                            return state.withUpdatedSearchingMembers(true)
                        }
                    })
                }
            }
        }
        
        var emptyStateItem: ItemListControllerEmptyStateItem?
        if participants == nil {
            emptyStateItem = ItemListLoadingIndicatorEmptyStateItem(theme: presentationData.theme)
        }
        
        let previous = previousParticipantsValue.swap(participants)
        
        var searchItem: ItemListControllerSearch?
        if state.searchingMembers {
            searchItem = ChannelMembersSearchItem(context: context, peerId: peerId, searchContext: nil, searchMode: .searchKicked, cancel: {
                updateState { state in
                    return state.withUpdatedSearchingMembers(false)
                }
            }, openPeer: { _, rendered in
                if let rendered = rendered, case .member = rendered.participant {
                    arguments.openPeer(rendered)
                }
            }, pushController: { c in
                pushControllerImpl?(c)
            })
        }
        
        let controllerState = ItemListControllerState(theme: presentationData.theme, title: .text(presentationData.strings.GroupRemoved_Title), leftNavigationButton: nil, rightNavigationButton: rightNavigationButton, secondaryRightNavigationButton: secondaryRightNavigationButton, backNavigationButton: ItemListBackButton(title: presentationData.strings.Common_Back), animateChanges: true)
        let listState = ItemListNodeState(entries: channelBlacklistControllerEntries(presentationData: presentationData, view: view, state: state, participants: participants), style: .blocks, emptyStateItem: emptyStateItem, searchItem: searchItem, animateChanges: previous != nil && participants != nil && previous!.count >= participants!.count)
        
        return (controllerState, (listState, arguments))
    }
    |> afterDisposed {
        actionsDisposable.dispose()
    }
    
    let controller = ItemListController(context: context, state: signal)
    presentControllerImpl = { [weak controller] c, p in
        if let controller = controller {
            controller.present(c, in: .window(.root), with: p)
            controller.view.endEditing(true)
        }
    }
    
    pushControllerImpl = { [weak controller] c in
        if let controller = controller {
            (controller.navigationController as? NavigationController)?.pushViewController(c)
        }
    }
    controller.visibleBottomContentOffsetChanged = { offset in
        if case let .known(value) = offset, value < 40.0 {
            context.peerChannelMemberCategoriesContextsManager.loadMore(peerId: peerId, control: loadMoreControl)
        }
    }
    return controller
}