import ActiveApplicationMonitor
import AppKit
import ChatTab
import ComposableArchitecture
import GitHubCopilotService
import SwiftUI

public enum ChatTabBuilderCollection: Equatable {
    case folder(title: String, kinds: [ChatTabKind])
    case kind(ChatTabKind)
}

public struct ChatTabKind: Equatable {
    public var builder: any ChatTabBuilder
    var title: String { builder.title }

    public init(_ builder: any ChatTabBuilder) {
        self.builder = builder
    }

    public static func == (lhs: Self, rhs: Self) -> Bool {
        lhs.title == rhs.title
    }
}

@ObservableState
public struct ChatHistory: Equatable {
    public var workspaces: IdentifiedArray<String, ChatWorkspace>
    public var selectedWorkspacePath: String?
    public var selectedWorkspaceName: String?

    public var currentChatWorkspace: ChatWorkspace? {
        guard let id = selectedWorkspacePath else { return workspaces.first }
        return workspaces[id: id]
    }

    init(workspaces: IdentifiedArray<String, ChatWorkspace> = [],
         selectedWorkspacePath: String? = nil,
         selectedWorkspaceName: String? = nil) {
        self.workspaces = workspaces
        self.selectedWorkspacePath = selectedWorkspacePath
        self.selectedWorkspaceName = selectedWorkspaceName
    }

    mutating func updateHistory(_ workspace: ChatWorkspace) {
        if let index = workspaces.firstIndex(where: { $0.id == workspace.id }) {
            workspaces[index] = workspace
        }
    }
}

@ObservableState
public struct ChatWorkspace: Identifiable, Equatable {
    public var id: String
    public var tabInfo: IdentifiedArray<String, ChatTabInfo>
    public var tabCollection: [ChatTabBuilderCollection]
    public var selectedTabId: String?

    public var selectedTabInfo: ChatTabInfo? {
        guard let tabId = selectedTabId else { return tabInfo.first }
        return tabInfo[id: tabId]
    }

    public init(
        id: String = UUID().uuidString,
        tabInfo: IdentifiedArray<String, ChatTabInfo> = [],
        tabCollection: [ChatTabBuilderCollection] = [],
        selectedTabId: String? = nil
    ) {
        self.id = id
        self.tabInfo = tabInfo
        self.tabCollection = tabCollection
        self.selectedTabId = selectedTabId
    }
}

@Reducer
public struct ChatPanelFeature {
    @ObservableState
    public struct State: Equatable {
        public var chatHistory = ChatHistory()
        public var currentChatWorkspace: ChatWorkspace? {
            return chatHistory.currentChatWorkspace
        }

        var colorScheme: ColorScheme = .light
        public internal(set) var isPanelDisplayed = false
        var isDetached = false
        var isFullScreen = false
    }

    public enum Action: Equatable {
        // Window
        case hideButtonClicked
        case closeActiveTabClicked
        case toggleChatPanelDetachedButtonClicked
        case detachChatPanel
        case attachChatPanel
        case enterFullScreen
        case exitFullScreen
        case presentChatPanel(forceDetach: Bool)
        case switchWorkspace(String, String)

        // Tabs
        case updateChatHistory(ChatWorkspace)
//        case updateChatTabInfo(IdentifiedArray<String, ChatTabInfo>)
//        case createNewTapButtonHovered
        case closeTabButtonClicked(id: String)
        case createNewTapButtonClicked(kind: ChatTabKind?)
        case tabClicked(id: String)
        case appendAndSelectTab(ChatTabInfo)
        case appendTabToWorkspace(ChatTabInfo, ChatWorkspace)
//        case switchToNextTab
//        case switchToPreviousTab
//        case moveChatTab(from: Int, to: Int)
        case focusActiveChatTab
        
        // Chat History
        case chatHistoryItemClicked(id: String)
        case chatHisotryDeleteButtonClicked(id: String)

        case chatTab(id: String, action: ChatTabItem.Action)
    }

    @Dependency(\.suggestionWidgetControllerDependency) var suggestionWidgetControllerDependency
    @Dependency(\.xcodeInspector) var xcodeInspector
    @Dependency(\.activatePreviousActiveXcode) var activatePreviouslyActiveXcode
    @Dependency(\.activateThisApp) var activateExtensionService
    @Dependency(\.chatTabBuilderCollection) var chatTabBuilderCollection

    @MainActor func toggleFullScreen() {
        let window = suggestionWidgetControllerDependency.windowsController?.windows
            .chatPanelWindow
        window?.toggleFullScreen(nil)
    }

    public var body: some ReducerOf<Self> {
        Reduce { state, action in
            switch action {
            case .hideButtonClicked:
                state.isPanelDisplayed = false

                if state.isFullScreen {
                    return .run { _ in
                        await MainActor.run { toggleFullScreen() }
                        activatePreviouslyActiveXcode()
                    }
                }

                return .run { _ in
                    activatePreviouslyActiveXcode()
                }

            case .closeActiveTabClicked:
                if let id = state.currentChatWorkspace?.selectedTabId {
                    return .run { send in
                        await send(.closeTabButtonClicked(id: id))
                    }
                }

                state.isPanelDisplayed = false
                return .none

            case .toggleChatPanelDetachedButtonClicked:
                if state.isFullScreen, state.isDetached {
                    return .run { send in
                        await send(.attachChatPanel)
                    }
                }
                
                state.isDetached.toggle()
                return .none

            case .detachChatPanel:
                state.isDetached = true
                return .none

            case .attachChatPanel:
                if state.isFullScreen {
                    return .run { send in
                        await MainActor.run { toggleFullScreen() }
                        try await Task.sleep(nanoseconds: 1_000_000_000)
                        await send(.attachChatPanel)
                    }
                }

                state.isDetached = false
                return .none

            case .enterFullScreen:
                state.isFullScreen = true
                return .run { send in
                    await send(.detachChatPanel)
                }

            case .exitFullScreen:
                state.isFullScreen = false
                return .none

            case let .presentChatPanel(forceDetach):
                if forceDetach {
                    state.isDetached = true
                }
                state.isPanelDisplayed = true
                return .run { send in
                    activateExtensionService()
                    await send(.focusActiveChatTab)
                }
            case let .switchWorkspace(path, name):
                state.chatHistory.selectedWorkspacePath = path
                state.chatHistory.selectedWorkspaceName = name
                if state.chatHistory.currentChatWorkspace == nil {
                    state.chatHistory.workspaces[id: path] = ChatWorkspace(id: path)
                }
                return .none
            case let .updateChatHistory(chatWorkspace):
                state.chatHistory.updateHistory(chatWorkspace)
                return .none
//            case let .updateChatTabInfo(chatTabInfo):
//                let previousSelectedIndex = state.chatTabGroup.tabInfo
//                    .firstIndex(where: { $0.id == state.chatTabGroup.selectedTabId })
//                state.chatTabGroup.tabInfo = chatTabInfo
//                if !chatTabInfo.contains(where: { $0.id == state.chatTabGroup.selectedTabId }) {
//                    if let previousSelectedIndex {
//                        let proposedSelectedIndex = previousSelectedIndex - 1
//                        if proposedSelectedIndex >= 0,
//                           proposedSelectedIndex < chatTabInfo.endIndex
//                        {
//                            state.chatTabGroup.selectedTabId = chatTabInfo[proposedSelectedIndex].id
//                        } else {
//                            state.chatTabGroup.selectedTabId = chatTabInfo.first?.id
//                        }
//                    } else {
//                        state.chatTabGroup.selectedTabId = nil
//                    }
//                }
//                return .none

            case let .closeTabButtonClicked(id):
                guard var currentChatWorkspace = state.currentChatWorkspace else {
                    return .none
                }
                let firstIndex = currentChatWorkspace.tabInfo.firstIndex { $0.id == id }
                let nextIndex = {
                    guard let firstIndex else { return 0 }
                    let nextIndex = firstIndex - 1
                    return max(nextIndex, 0)
                }()
                currentChatWorkspace.tabInfo.removeAll { $0.id == id }
                if currentChatWorkspace.tabInfo.isEmpty {
                    state.isPanelDisplayed = false
                }
                if nextIndex < currentChatWorkspace.tabInfo.count {
                    currentChatWorkspace.selectedTabId = currentChatWorkspace.tabInfo[nextIndex].id
                } else {
                    currentChatWorkspace.selectedTabId = nil
                }
                state.chatHistory.updateHistory(currentChatWorkspace)
                return .none
            
            case let .chatHisotryDeleteButtonClicked(id):
                // the current chat should not be deleted
                guard var currentChatWorkspace = state.currentChatWorkspace, id != currentChatWorkspace.selectedTabId else {
                    return .none
                }
                currentChatWorkspace.tabInfo.removeAll { $0.id == id }
                state.chatHistory.updateHistory(currentChatWorkspace)
                return .none

//            case .createNewTapButtonHovered:
//                state.chatTabGroup.tabCollection = chatTabBuilderCollection()
//                return .none

            case .createNewTapButtonClicked:
                return .none // handled elsewhere

            case let .tabClicked(id):
                guard var currentChatWorkspace = state.currentChatWorkspace, currentChatWorkspace.tabInfo.contains(where: { $0.id == id }) else {
//                    chatTabGroup.selectedTabId = nil
                    return .none
                }
                currentChatWorkspace.selectedTabId = id
                state.chatHistory.updateHistory(currentChatWorkspace)
                return .run { send in
                    await send(.focusActiveChatTab)
                }
                
            case let .chatHistoryItemClicked(id):
                guard var chatWorkspace = state.currentChatWorkspace, chatWorkspace.tabInfo.contains(where: { $0.id == id }) else {
//                    state.chatGroupCollection.selectedChatGroup?.selectedTabId = nil
                    return .none
                }
                chatWorkspace.selectedTabId = id
                state.chatHistory.updateHistory(chatWorkspace)
                return .run { send in
                    await send(.focusActiveChatTab)
                }

            case let .appendAndSelectTab(tab):
                guard var chatWorkspace = state.currentChatWorkspace, !chatWorkspace.tabInfo.contains(where: { $0.id == tab.id })
                else { return .none }
                chatWorkspace.tabInfo.append(tab)
                chatWorkspace.selectedTabId = tab.id
                state.chatHistory.updateHistory(chatWorkspace)
                return .run { send in
                    await send(.focusActiveChatTab)
                }
            case let .appendTabToWorkspace(tab, chatWorkspace):
                guard !chatWorkspace.tabInfo.contains(where: { $0.id == tab.id })
                else { return .none }
                var targetWorkspace = chatWorkspace
                targetWorkspace.tabInfo.append(tab)
                targetWorkspace.selectedTabId = tab.id
                state.chatHistory.updateHistory(targetWorkspace)
                return .none

//            case .switchToNextTab:
//                let selectedId = state.chatTabGroup.selectedTabId
//                guard let index = state.chatTabGroup.tabInfo
//                    .firstIndex(where: { $0.id == selectedId })
//                else { return .none }
//                let nextIndex = index + 1
//                if nextIndex >= state.chatTabGroup.tabInfo.endIndex {
//                    return .none
//                }
//                let targetId = state.chatTabGroup.tabInfo[nextIndex].id
//                state.chatTabGroup.selectedTabId = targetId
//                return .run { send in
//                    await send(.focusActiveChatTab)
//                }

//            case .switchToPreviousTab:
//                let selectedId = state.chatTabGroup.selectedTabId
//                guard let index = state.chatTabGroup.tabInfo
//                    .firstIndex(where: { $0.id == selectedId })
//                else { return .none }
//                let previousIndex = index - 1
//                if previousIndex < 0 || previousIndex >= state.chatTabGroup.tabInfo.endIndex {
//                    return .none
//                }
//                let targetId = state.chatTabGroup.tabInfo[previousIndex].id
//                state.chatTabGroup.selectedTabId = targetId
//                return .run { send in
//                    await send(.focusActiveChatTab)
//                }

//            case let .moveChatTab(from, to):
//                guard from >= 0, from < state.chatTabGroup.tabInfo.endIndex, to >= 0,
//                      to <= state.chatTabGroup.tabInfo.endIndex
//                else {
//                    return .none
//                }
//                let tab = state.chatTabGroup.tabInfo[from]
//                state.chatTabGroup.tabInfo.remove(at: from)
//                state.chatTabGroup.tabInfo.insert(tab, at: to)
//                return .none

            case .focusActiveChatTab:
                guard FeatureFlagNotifierImpl.shared.featureFlags.chat else {
                    return .none
                }
                let id = state.currentChatWorkspace?.selectedTabInfo?.id
                guard let id else { return .none }
                return .run { send in
                    await send(.chatTab(id: id, action: .focus))
                }

//            case let .chatTab(id, .close):
//                return .run { send in
//                    await send(.closeTabButtonClicked(id: id))
//                }

            case .chatTab:
                return .none
            }
        }
//        .forEach(\.chatGroupCollection.selectedChatGroup?.tabInfo, action: /Action.chatTab) {
//            ChatTabItem()
//        }
    }
}