import Foundation
import Combine

import Moya

enum CreatorChannelCommunityViewMode {
    case list
    case thumbnail
}

final class CreatorChannelCommunityViewModel: ObservableObject {
    private let repository = CreatorChannelCommunityRepository()
    private let communityRepository = CreatorCommunityRepository()
    private let reportRepository = ReportRepository()
    private var subscription = Set<AnyCancellable>()
    private let pageSize = 20
    private var latestRequestId = 0

    @Published var isLoading = false
    @Published var isLoadingNextPage = false
    @Published var response: CreatorChannelCommunityTabResponse?
    @Published var communityPosts = [CreatorChannelCommunityPostItem]()
    @Published var viewMode: CreatorChannelCommunityViewMode = .list
    @Published var page = 0
    @Published var size = 20
    @Published var hasNext = false
    @Published var hasLoaded = false
    @Published var errorMessage = ""
    @Published var isShowPopup = false
    @Published var isShowCommentListView = false {
        didSet {
            if !isShowCommentListView {
                selectedPostId = 0
                isShowSecret = false
            }
        }
    }
    @Published var isShowReportMenu = false
    @Published var isShowReportView = false {
        didSet {
            if !isShowReportView {
                selectedPostId = 0
            }
        }
    }
    @Published var isShowDeleteConfirm = false {
        didSet {
            if !isShowDeleteConfirm {
                selectedPostId = 0
            }
        }
    }
    @Published var isShowPostPurchaseView = false {
        didSet {
            if !isShowPostPurchaseView {
                selectedPostId = 0
                selectedPostPrice = 0
            }
        }
    }
    @Published var selectedPostId = 0
    @Published var selectedPostPrice = 0
    @Published var selectedPostIsPinned = false
    @Published var isShowSecret = false

    var communityPostCount: Int {
        response?.communityPostCount ?? 0
    }

    func fetchFirstPage(creatorId: Int) {
        fetchCommunity(creatorId: creatorId, page: 0, isNextPage: false)
    }

    func fetchNextPageIfNeeded(creatorId: Int, currentItem: CreatorChannelCommunityPostItem) {
        guard communityPosts.last?.postId == currentItem.postId else { return }
        guard hasNext, isLoadingNextPage == false, isLoading == false else { return }

        fetchCommunity(creatorId: creatorId, page: page + 1, isNextPage: true)
    }

    func toggleViewMode() {
        viewMode = viewMode == .list ? .thumbnail : .list
    }

    func isPaidLocked(_ post: CreatorChannelCommunityPostItem, isOwnPost: Bool) -> Bool {
        post.price > 0 && post.existOrdered == false && isOwnPost == false
    }

    func openCommentList(post: CreatorChannelCommunityPostItem) {
        selectedPostId = post.postId
        isShowSecret = post.price > 0 && post.existOrdered && post.creatorId != UserDefaults.int(forKey: .userId)
        isShowCommentListView = true
    }

    func openReportMenu(post: CreatorChannelCommunityPostItem) {
        selectedPostId = post.postId
        selectedPostPrice = post.price
        selectedPostIsPinned = post.isPinned
        isShowReportMenu = true
    }

    func openPurchaseDialog(post: CreatorChannelCommunityPostItem) {
        selectedPostId = post.postId
        selectedPostPrice = post.price
        isShowPostPurchaseView = true
    }

    func communityPostLike(postId: Int) {
        communityRepository.communityPostLike(postId: postId)
            .sink { result in
                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                }
            } receiveValue: { _ in }
            .store(in: &subscription)
    }

    func report(reason: String) {
        guard selectedPostId > 0 else { return }

        isLoading = true
        let request = ReportRequest(type: .COMMUNITY_POST, reason: reason, communityPostId: selectedPostId)
        reportRepository.report(request: request)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false
                self.selectedPostId = 0

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    self.errorMessage = decoded.message ?? I18n.Common.commonError
                    self.isShowPopup = true
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }
            }
            .store(in: &subscription)
    }

    func deleteCommunityPost(creatorId: Int) {
        guard selectedPostId > 0 else { return }

        isLoading = true
        let request = ModifyCommunityPostRequest(creatorCommunityId: selectedPostId, isActive: false)
        var multipartData = [MultipartFormData]()
        let encoder = JSONEncoder()
        encoder.outputFormatting = .withoutEscapingSlashes

        guard let jsonData = try? encoder.encode(request) else {
            applyFailureState()
            return
        }

        multipartData.append(MultipartFormData(provider: .data(jsonData), name: "request"))
        communityRepository.modifyCommunityPost(parameters: multipartData)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false
                self.selectedPostId = 0

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    if decoded.success {
                        self.errorMessage = I18n.Explorer.deleted
                        self.isShowPopup = true
                        self.fetchFirstPage(creatorId: creatorId)
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }
            }
            .store(in: &subscription)
    }

    func updateCommunityPostFixed(creatorId: Int) {
        guard selectedPostId > 0 else { return }

        isLoading = true
        let request = UpdateCommunityPostFixedRequest(postId: selectedPostId, isFixed: !selectedPostIsPinned)
        communityRepository.updateCommunityPostFixed(request: request)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    if decoded.success {
                        self.fetchFirstPage(creatorId: creatorId)
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }
            }
            .store(in: &subscription)
    }

    func purchaseCommunityPost(creatorId: Int) {
        guard selectedPostId > 0 else { return }

        isLoading = true
        communityRepository.purchaseCommunityPost(postId: selectedPostId)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false
                self.selectedPostId = 0

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    if decoded.success {
                        self.fetchFirstPage(creatorId: creatorId)
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.fetchFirstPage(creatorId: creatorId)
                }
            }
            .store(in: &subscription)
    }

    private func fetchCommunity(creatorId: Int, page requestPage: Int, isNextPage: Bool) {
        latestRequestId += 1
        let requestId = latestRequestId

        if isNextPage {
            isLoadingNextPage = true
        } else {
            isLoading = true
        }

        repository.getCommunity(creatorId: creatorId, page: requestPage, size: pageSize)
            .sink { [weak self] result in
                guard let self else { return }
                guard requestId == self.latestRequestId else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                    self.isLoading = false
                    self.isLoadingNextPage = false
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }
                guard requestId == self.latestRequestId else { return }

                do {
                    let decoded = try JSONDecoder().decode(ApiResponse<CreatorChannelCommunityTabResponse>.self, from: response.data)
                    if let data = decoded.data, decoded.success {
                        self.applySuccessState(data, isNextPage: isNextPage)
                        self.hasLoaded = true
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }

                self.isLoading = false
                self.isLoadingNextPage = false
            }
            .store(in: &subscription)
    }

    private func applySuccessState(_ data: CreatorChannelCommunityTabResponse, isNextPage: Bool) {
        response = data
        page = data.page
        size = data.size
        hasNext = data.hasNext

        if isNextPage {
            communityPosts.append(contentsOf: data.communityPosts)
        } else {
            communityPosts = data.communityPosts
        }
    }

    private func applyFailureState() {
        errorMessage = I18n.Common.commonError
        isShowPopup = true
        hasLoaded = true
        isLoading = false
        isLoadingNextPage = false
    }
}