import Foundation
import ComposableArchitecture
import SwiftUI
import PhotosUI // 修正：导入PhotosUI

@Reducer
struct EditFeedFeature {
    @ObservableState
    struct State: Equatable {
        var content: String = ""
        var isLoading: Bool = false
        var errorMessage: String? = nil
        var shouldDismiss: Bool = false

        var selectedImages: [PhotosPickerItem] = []
        var processedImages: [UIImage] = []
        var canAddMoreImages: Bool {
            processedImages.count < 9
        }

        var canPublish: Bool {
            (!content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty || !processedImages.isEmpty) && !isLoading && !isUploadingImages
        }
        // 新增：图片上传相关状态
        var isUploadingImages: Bool = false
        var imageUploadProgress: Double = 0.0 // 0.0~1.0
        var uploadedResList: [ResListItem] = []
        // 手动实现Equatable，selectedImages只比较数量（PhotosPickerItem不支持Equatable）
        static func == (lhs: State, rhs: State) -> Bool {
            lhs.content == rhs.content &&
            lhs.isLoading == rhs.isLoading &&
            lhs.errorMessage == rhs.errorMessage &&
            lhs.shouldDismiss == rhs.shouldDismiss &&
            lhs.processedImages == rhs.processedImages &&
            lhs.selectedImages.count == rhs.selectedImages.count &&
            lhs.isUploadingImages == rhs.isUploadingImages &&
            lhs.imageUploadProgress == rhs.imageUploadProgress &&
            lhs.uploadedResList == rhs.uploadedResList
        }
    }

    enum Action {
        case contentChanged(String)
        case publishButtonTapped
        case publishResponse(Result<PublishFeedResponse, Error>)
        case clearError
        case dismissView
        case clearDismissFlag
        // 新增图片相关Action
        case photosPickerItemsChanged([PhotosPickerItem])
        case processPhotosPickerItems([PhotosPickerItem])
        case updateProcessedImages([UIImage])
        case removeImage(Int)
        // 新增：图片上传Action
        case uploadImages
        case uploadImagesResponse(Result<[ResListItem], Error>)
        // 新增：图片上传进度
        case updateImageUploadProgress(Double)
    }

    @Dependency(\.apiService) var apiService
    @Dependency(\.dismiss) var dismiss
    @Dependency(\.isPresented) var isPresented

    var body: some ReducerOf<Self> {
        Reduce { state, action in
            switch action {
            case .contentChanged(let newContent):
                state.content = newContent
                return .none

            case .publishButtonTapped:
                guard state.canPublish else {
                    state.errorMessage = "请输入内容"
                    return .none
                }
                // 有图片时先上传图片
                if !state.processedImages.isEmpty {
                    state.isUploadingImages = true
                    state.imageUploadProgress = 0.0
                    state.errorMessage = nil
                    return .send(.uploadImages)
                } else {
                    state.isLoading = true
                    state.errorMessage = nil
                    return .run { [content = state.content] send in
                        let userId = await UserInfoManager.getCurrentUserId() ?? ""
                        let type = content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ? "2" : "0"
                        let request = await PublishFeedRequest.make(
                            content: content.trimmingCharacters(in: .whitespacesAndNewlines),
                            uid: userId,
                            type: type,
                            resList: nil
                        )
                        do {
                            let response = try await apiService.request(request)
                            await send(.publishResponse(.success(response)))
                        } catch {
                            await send(.publishResponse(.failure(error)))
                        }
                    }
                }
            case .uploadImages:
                let images = state.processedImages
                return .run { send in
                    var resList: [ResListItem] = []
                    for (idx, image) in images.enumerated() {
                        guard let data = image.jpegData(compressionQuality: 0.9) else { continue }
                        if let url = await COSManager.shared.uploadImage(data, apiService: apiService),
                           let cgImage = image.cgImage {
                            let width = cgImage.width
                            let height = cgImage.height
                            let format = "jpeg"
                            let item = ResListItem(resUrl: url, width: width, height: height, format: format)
                            resList.append(item)
                        }
                        // 可选：进度回调
                        await MainActor.run {
                            send(.updateImageUploadProgress(Double(idx + 1) / Double(images.count)))
                        }
                    }
                    if resList.count == images.count {
                        await send(.uploadImagesResponse(.success(resList)))
                    } else {
                        await send(.uploadImagesResponse(.failure(NSError(domain: "COSUpload", code: -1, userInfo: [NSLocalizedDescriptionKey: "部分图片上传失败"])) ))
                    }
                }
            case .uploadImagesResponse(let result):
                state.isUploadingImages = false
                state.imageUploadProgress = 1.0
                switch result {
                case .success(let resList):
                    state.uploadedResList = resList
                    state.isLoading = true
                    return .run { [content = state.content, resList] send in
                        let userId = await UserInfoManager.getCurrentUserId() ?? ""
                        // type: 2 表示图片/图文
                        let type = resList.isEmpty ? "0" : (content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ? "2" : "2")
                        let request = await PublishFeedRequest.make(
                            content: content.trimmingCharacters(in: .whitespacesAndNewlines),
                            uid: userId,
                            type: type,
                            resList: resList
                        )
                        do {
                            let response = try await apiService.request(request)
                            await send(.publishResponse(.success(response)))
                        } catch {
                            await send(.publishResponse(.failure(error)))
                        }
                    }
                case .failure(let error):
                    state.errorMessage = error.localizedDescription
                    return .none
                }
            case .publishResponse(.success(let response)):
                state.isLoading = false
                if response.code == 200 {
                    return .send(.dismissView)
                } else {
                    state.errorMessage = response.message.isEmpty ? "发布失败" : response.message
                    return .none
                }
            case .publishResponse(.failure(let error)):
                state.isLoading = false
                state.errorMessage = error.localizedDescription
                return .none
            case .clearError:
                state.errorMessage = nil
                return .none
            case .dismissView:
                state.shouldDismiss = true
                return .none
            case .clearDismissFlag:
                state.shouldDismiss = false
                return .none
            case .photosPickerItemsChanged(let items):
                state.selectedImages = items
                return .run { send in
                    await send(.processPhotosPickerItems(items))
                }
            case .processPhotosPickerItems(let items):
                let currentImages = state.processedImages
                return .run { send in
                    var newImages = currentImages
                    for item in items {
                        guard let data = try? await item.loadTransferable(type: Data.self),
                              let image = UIImage(data: data) else { continue }
                        if newImages.count < 9 {
                            newImages.append(image)
                        }
                    }
                    await MainActor.run {
                        send(.updateProcessedImages(newImages))
                    }
                }
            case .updateProcessedImages(let images):
                state.processedImages = images
                return .none
            case .removeImage(let index):
                guard index < state.processedImages.count else { return .none }
                state.processedImages.remove(at: index)
                if index < state.selectedImages.count {
                    state.selectedImages.remove(at: index)
                }
                return .none
            // 新增：图片上传进度
            case .updateImageUploadProgress(let progress):
                state.imageUploadProgress = progress
                return .none
            }
        }
    }
}