import Foundation
import Display
import SwiftSignalKit
import Postbox
import TelegramCore

import LegacyComponents

private struct CreateGroupArguments {
    let account: Account
    
    let updateEditingName: (ItemListAvatarAndNameInfoItemName) -> Void
    let done: () -> Void
    let changeProfilePhoto: () -> Void
}

private enum CreateGroupSection: Int32 {
    case info
    case members
}

private enum CreateGroupEntryTag: ItemListItemTag {
    case info
    
    func isEqual(to other: ItemListItemTag) -> Bool {
        if let other = other as? CreateGroupEntryTag {
            switch self {
                case .info:
                    if case .info = other {
                        return true
                    } else {
                        return false
                    }
            }
        } else {
            return false
        }
    }
}

private enum CreateGroupEntry: ItemListNodeEntry {
    case groupInfo(PresentationTheme, PresentationStrings, PresentationDateTimeFormat, Peer?, ItemListAvatarAndNameInfoItemState, ItemListAvatarAndNameInfoItemUpdatingAvatar?)
    case setProfilePhoto(PresentationTheme, String)
    
    case member(Int32, PresentationTheme, PresentationStrings, PresentationDateTimeFormat, PresentationPersonNameOrder, Peer, PeerPresence?)
    
    var section: ItemListSectionId {
        switch self {
            case .groupInfo, .setProfilePhoto:
                return CreateGroupSection.info.rawValue
            case .member:
                return CreateGroupSection.members.rawValue
        }
    }
    
    var stableId: Int32 {
        switch self {
            case .groupInfo:
                return 0
            case .setProfilePhoto:
                return 1
            case let .member(index, _, _, _, _, _, _):
                return 2 + index
        }
    }
    
    static func ==(lhs: CreateGroupEntry, rhs: CreateGroupEntry) -> Bool {
        switch lhs {
            case let .groupInfo(lhsTheme, lhsStrings, lhsDateTimeFormat, lhsPeer, lhsEditingState, lhsAvatar):
                if case let .groupInfo(rhsTheme, rhsStrings, rhsDateTimeFormat, rhsPeer, rhsEditingState, rhsAvatar) = rhs {
                    if lhsTheme !== rhsTheme {
                        return false
                    }
                    if lhsStrings !== rhsStrings {
                        return false
                    }
                    if lhsDateTimeFormat != rhsDateTimeFormat {
                        return false
                    }
                    if let lhsPeer = lhsPeer, let rhsPeer = rhsPeer {
                        if !lhsPeer.isEqual(rhsPeer) {
                            return false
                        }
                    } else if (lhsPeer != nil) != (rhsPeer != nil) {
                        return false
                    }
                    if lhsEditingState != rhsEditingState {
                        return false
                    }
                    if lhsAvatar != rhsAvatar {
                        return false
                    }
                    return true
                } else {
                    return false
                }
            case let .setProfilePhoto(lhsTheme, lhsText):
                if case let .setProfilePhoto(rhsTheme, rhsText) = rhs, lhsTheme === rhsTheme, lhsText == rhsText {
                    return true
                } else {
                    return false
                }
            case let .member(lhsIndex, lhsTheme, lhsStrings, lhsDateTimeFormat, lhsNameDisplayOrder, lhsPeer, lhsPresence):
                if case let .member(rhsIndex, rhsTheme, rhsStrings, rhsDateTimeFormat, rhsNameDisplayOrder, rhsPeer, rhsPresence) = rhs {
                    if lhsIndex != rhsIndex {
                        return false
                    }
                    if lhsTheme !== rhsTheme {
                        return false
                    }
                    if lhsStrings !== rhsStrings {
                        return false
                    }
                    if lhsDateTimeFormat != rhsDateTimeFormat {
                        return false
                    }
                    if lhsNameDisplayOrder != rhsNameDisplayOrder {
                        return false
                    }
                    if !lhsPeer.isEqual(rhsPeer) {
                        return false
                    }
                    if let lhsPresence = lhsPresence, let rhsPresence = rhsPresence {
                        if !lhsPresence.isEqual(to: rhsPresence) {
                            return false
                        }
                    } else if (lhsPresence != nil) != (rhsPresence != nil) {
                        return false
                    }
                    return true
                } else {
                    return false
                }
        }
    }
    
    static func <(lhs: CreateGroupEntry, rhs: CreateGroupEntry) -> Bool {
        return lhs.stableId < rhs.stableId
    }
    
    func item(_ arguments: CreateGroupArguments) -> ListViewItem {
        switch self {
            case let .groupInfo(theme, strings, dateTimeFormat, peer, state, avatar):
                return ItemListAvatarAndNameInfoItem(account: arguments.account, theme: theme, strings: strings, dateTimeFormat: dateTimeFormat, mode: .generic, peer: peer, presence: nil, cachedData: nil, state: state, sectionId: ItemListSectionId(self.section), style: .blocks(withTopInset: false), editingNameUpdated: { editingName in
                    arguments.updateEditingName(editingName)
                }, avatarTapped: {
                }, updatingImage: avatar, tag: CreateGroupEntryTag.info)
            case let .setProfilePhoto(theme, text):
                return ItemListActionItem(theme: theme, title: text, kind: .generic, alignment: .natural, sectionId: ItemListSectionId(self.section), style: .blocks, action: {
                    arguments.changeProfilePhoto()
                })
            case let .member(_, theme, strings, dateTimeFormat, nameDisplayOrder, peer, presence):
                return ItemListPeerItem(theme: theme, strings: strings, dateTimeFormat: dateTimeFormat, nameDisplayOrder: nameDisplayOrder, account: arguments.account, peer: peer, presence: presence, text: .presence, label: .none, editing: ItemListPeerItemEditing(editable: false, editing: false, revealed: false), switchValue: nil, enabled: true, sectionId: self.section, action: nil, setPeerIdWithRevealedOptions: { _, _ in }, removePeer: { _ in })
        }
    }
}

private struct CreateGroupState: Equatable {
    var creating: Bool
    var editingName: ItemListAvatarAndNameInfoItemName
    var avatar: ItemListAvatarAndNameInfoItemUpdatingAvatar?
    
    static func ==(lhs: CreateGroupState, rhs: CreateGroupState) -> Bool {
        if lhs.creating != rhs.creating {
            return false
        }
        if lhs.editingName != rhs.editingName {
            return false
        }
        if lhs.avatar != rhs.avatar {
            return false
        }
        
        return true
    }
}

private func createGroupEntries(presentationData: PresentationData, state: CreateGroupState, peerIds: [PeerId], view: MultiplePeersView) -> [CreateGroupEntry] {
    var entries: [CreateGroupEntry] = []
    
    let groupInfoState = ItemListAvatarAndNameInfoItemState(editingName: state.editingName, updatingName: nil)
    
    let peer = TelegramGroup(id: PeerId(namespace: -1, id: 0), title: state.editingName.composedTitle, photo: [], participantCount: 0, role: .creator, membership: .Member, flags: [], defaultBannedRights: nil, migrationReference: nil, creationDate: 0, version: 0)
    
    entries.append(.groupInfo(presentationData.theme, presentationData.strings, presentationData.dateTimeFormat, peer, groupInfoState, state.avatar))
    entries.append(.setProfilePhoto(presentationData.theme, presentationData.strings.GroupInfo_SetGroupPhoto))
    
    var peers: [Peer] = []
    for peerId in peerIds {
        if let peer = view.peers[peerId] {
            peers.append(peer)
        }
    }
    
    peers.sort(by: { lhs, rhs in
        let lhsPresence = view.presences[lhs.id] as? TelegramUserPresence
        let rhsPresence = view.presences[rhs.id] as? TelegramUserPresence
        if let lhsPresence = lhsPresence, let rhsPresence = rhsPresence {
            if lhsPresence.status < rhsPresence.status {
                return false
            } else if lhsPresence.status > rhsPresence.status {
                return true
            } else {
                return lhs.id < rhs.id
            }
        } else if let _ = lhsPresence {
            return true
        } else if let _ = rhsPresence {
            return false
        } else {
            return lhs.id < rhs.id
        }
    })
    
    for i in 0 ..< peers.count {
        entries.append(.member(Int32(i), presentationData.theme, presentationData.strings, presentationData.dateTimeFormat, presentationData.nameDisplayOrder, peers[i], view.presences[peers[i].id]))
    }
    
    return entries
}

public func createGroupController(context: AccountContext, peerIds: [PeerId]) -> ViewController {
    let initialState = CreateGroupState(creating: false, editingName: .title(title: "", type: .group), avatar: nil)
    let statePromise = ValuePromise(initialState, ignoreRepeated: true)
    let stateValue = Atomic(value: initialState)
    let updateState: ((CreateGroupState) -> CreateGroupState) -> Void = { f in
        statePromise.set(stateValue.modify { f($0) })
    }
    
    var replaceControllerImpl: ((ViewController) -> Void)?
    var presentControllerImpl: ((ViewController, Any?) -> Void)?
    var endEditingImpl: (() -> Void)?
    
    let actionsDisposable = DisposableSet()
    
    let currentAvatarMixin = Atomic<TGMediaAvatarMenuMixin?>(value: nil)
    
    let uploadedAvatar = Promise<UploadedPeerPhotoData>()
    
    let arguments = CreateGroupArguments(account: context.account, updateEditingName: { editingName in
        updateState { current in
            var current = current
            current.editingName = editingName
            return current
        }
    }, done: {
        let (creating, title) = stateValue.with { state -> (Bool, String) in
            return (state.creating, state.editingName.composedTitle)
        }
        
        if !creating && !title.isEmpty {
            updateState { current in
                var current = current
                current.creating = true
                return current
            }
            endEditingImpl?()
            actionsDisposable.add((createGroup(account: context.account, title: title, peerIds: peerIds)
            |> deliverOnMainQueue
            |> afterDisposed {
                Queue.mainQueue().async {
                    updateState { current in
                        var current = current
                        current.creating = false
                        return current
                    }
                }
            }).start(next: { peerId in
                if let peerId = peerId {
                    let updatingAvatar = stateValue.with {
                        return $0.avatar
                    }
                    if let _ = updatingAvatar {
                        let _ = updatePeerPhoto(postbox: context.account.postbox, network: context.account.network, stateManager: context.account.stateManager, accountPeerId: context.account.peerId, peerId: peerId, photo: uploadedAvatar.get(), mapResourceToAvatarSizes: { resource, representations in
                            return mapResourceToAvatarSizes(postbox: context.account.postbox, resource: resource, representations: representations)
                        }).start()
                    }
                    let controller = ChatController(context: context, chatLocation: .peer(peerId))
                    replaceControllerImpl?(controller)
                }
            }))
        }
    }, changeProfilePhoto: {
        endEditingImpl?()
        
        let title = stateValue.with { state -> String in
            return state.editingName.composedTitle
        }
        
        let _ = (context.account.postbox.transaction { transaction -> (Peer?, SearchBotsConfiguration) in
            return (transaction.getPeer(context.account.peerId), currentSearchBotsConfiguration(transaction: transaction))
        }
        |> deliverOnMainQueue).start(next: { peer, searchBotsConfiguration in
            let presentationData = context.currentPresentationData.with { $0 }
            
            let legacyController = LegacyController(presentation: .custom, theme: presentationData.theme)
            legacyController.statusBar.statusBarStyle = .Ignore
            
            let emptyController = LegacyEmptyController(context: legacyController.context)!
            let navigationController = makeLegacyNavigationController(rootController: emptyController)
            navigationController.setNavigationBarHidden(true, animated: false)
            navigationController.navigationBar.transform = CGAffineTransform(translationX: -1000.0, y: 0.0)
            
            legacyController.bind(controller: navigationController)
            
            endEditingImpl?()
            presentControllerImpl?(legacyController, nil)
            
            let completedImpl: (UIImage) -> Void = { image in
                if let data = UIImageJPEGRepresentation(image, 0.6) {
                    let resource = LocalFileMediaResource(fileId: arc4random64())
                    context.account.postbox.mediaBox.storeResourceData(resource.id, data: data)
                    let representation = TelegramMediaImageRepresentation(dimensions: CGSize(width: 640.0, height: 640.0), resource: resource)
                    uploadedAvatar.set(uploadedPeerPhoto(postbox: context.account.postbox, network: context.account.network, resource: resource))
                    updateState { current in
                        var current = current
                        current.avatar = .image(representation, false)
                        return current
                    }
                }
            }
            
            let mixin = TGMediaAvatarMenuMixin(context: legacyController.context, parentController: emptyController, hasSearchButton: true, hasDeleteButton: stateValue.with({ $0.avatar }) != nil, hasViewButton: false, personalPhoto: false, saveEditedPhotos: false, saveCapturedMedia: false, signup: false)!
            let _ = currentAvatarMixin.swap(mixin)
            mixin.requestSearchController = { assetsController in
                let controller = WebSearchController(context: context, peer: peer, configuration: searchBotsConfiguration, mode: .avatar(initialQuery: title, completion: { result in
                    assetsController?.dismiss()
                    completedImpl(result)
                }))
                presentControllerImpl?(controller, ViewControllerPresentationArguments(presentationAnimation: .modalSheet))
            }
            mixin.didFinishWithImage = { image in
                if let image = image {
                    completedImpl(image)
                }
            }
            if stateValue.with({ $0.avatar }) != nil {
                mixin.didFinishWithDelete = {
                    updateState { current in
                        var current = current
                        current.avatar = nil
                        return current
                    }
                    uploadedAvatar.set(.never())
                }
            }
            mixin.didDismiss = { [weak legacyController] in
                let _ = currentAvatarMixin.swap(nil)
                legacyController?.dismiss()
            }
            let menuController = mixin.present()
            if let menuController = menuController {
                menuController.customRemoveFromParentViewController = { [weak legacyController] in
                    legacyController?.dismiss()
                }
            }
        })
    })
    
    let signal = combineLatest(context.presentationData, statePromise.get(), context.account.postbox.multiplePeersView(peerIds))
    |> map { presentationData, state, view -> (ItemListControllerState, (ItemListNodeState<CreateGroupEntry>, CreateGroupEntry.ItemGenerationArguments)) in
        
        let rightNavigationButton: ItemListNavigationButton
        if state.creating {
            rightNavigationButton = ItemListNavigationButton(content: .none, style: .activity, enabled: true, action: {})
        } else {
            rightNavigationButton = ItemListNavigationButton(content: .text(presentationData.strings.Compose_Create), style: .bold, enabled: !state.editingName.composedTitle.isEmpty, action: {
                arguments.done()
            })
        }
        
        let controllerState = ItemListControllerState(theme: presentationData.theme, title: .text(presentationData.strings.Compose_NewGroupTitle), leftNavigationButton: nil, rightNavigationButton: rightNavigationButton, backNavigationButton: ItemListBackButton(title: presentationData.strings.Common_Back))
        let listState = ItemListNodeState(entries: createGroupEntries(presentationData: presentationData, state: state, peerIds: peerIds, view: view), style: .blocks, focusItemTag: CreateGroupEntryTag.info)
        
        return (controllerState, (listState, arguments))
    }
    |> afterDisposed {
        actionsDisposable.dispose()
    }
    
    let controller = ItemListController(context: context, state: signal)
    replaceControllerImpl = { [weak controller] value in
        (controller?.navigationController as? NavigationController)?.replaceAllButRootController(value, animated: true)
    }
    presentControllerImpl = { [weak controller] c, a in
        controller?.present(c, in: .window(.root), with: a)
    }
    controller.willDisappear = { _ in
        endEditingImpl?()
    }
    endEditingImpl = {
        [weak controller] in
        controller?.view.endEditing(true)
    }
    return controller
}