e-party-iOS/yana/Views/Components/ImagePickerWithPreview/ImagePickerWithPreviewReducer.swift

import Foundation
import ComposableArchitecture
import SwiftUI
import PhotosUI

public enum ImagePickerSelectionMode: Equatable {
    case single
    case multiple(max: Int)
}

public struct ImagePickerWithPreviewState: Equatable {
    public var selectionMode: ImagePickerSelectionMode = .single
    public var showActionSheet: Bool = false
    public var showPhotoPicker: Bool = false
    public var showCamera: Bool = false
    public var showPreview: Bool = false
    public var isLoading: Bool = false
    public var errorMessage: String? = nil
    public var selectedPhotoItems: [PhotosPickerItem] = []
    public var selectedImages: [UIImage] = []
    public var cameraImage: UIImage? = nil
    public var previewIndex: Int = 0 // 多选时预览当前索引
    
    public init(selectionMode: ImagePickerSelectionMode = .single) {
        self.selectionMode = selectionMode
    }
}

public enum ImagePickerWithPreviewAction: Equatable {
    case showActionSheet(Bool)
    case selectSource(ImageSource)
    case photoPickerItemsChanged([PhotosPickerItem])
    case cameraImagePicked(UIImage?)
    case previewConfirm
    case previewCancel
    case uploadStart
    case uploadSuccess
    case uploadFailure(String)
    case setLoading(Bool)
    case setError(String?)
    case setPreviewIndex(Int)
    case setShowCamera(Bool)
    case setShowPhotoPicker(Bool)
    case reset
}

public enum ImageSource: Equatable {
    case camera
    case photoLibrary
}

public struct ImagePickerWithPreviewReducer: Reducer {
    public init() {}
    public struct State: Equatable {
        public var inner: ImagePickerWithPreviewState
        public init(inner: ImagePickerWithPreviewState) { self.inner = inner }
    }
    public enum Action: Equatable {
        case inner(ImagePickerWithPreviewAction)
    }
    public var body: some ReducerOf<Self> {
        Reduce { state, action in
            switch action {
            case .inner(let action):
                switch action {
                case .showActionSheet(let show):
                    state.inner.showActionSheet = show
                    return .none
                case .selectSource(let source):
                    state.inner.showActionSheet = false
                    switch source {
                    case .camera:
                        state.inner.showCamera = true
                        state.inner.showPhotoPicker = false
                    case .photoLibrary:
                        state.inner.showPhotoPicker = true
                        state.inner.showCamera = false
                    }
                    return .none
                case .photoPickerItemsChanged(let items):
                    state.inner.selectedPhotoItems = items
                    // 选完后进入预览
                    state.inner.showPreview = !items.isEmpty
                    state.inner.previewIndex = 0
                    return .none
                case .cameraImagePicked(let image):
                    state.inner.cameraImage = image
                    state.inner.selectedImages = image.map { [$0] } ?? []
                    state.inner.showPreview = image != nil
                    state.inner.previewIndex = 0
                    return .none
                case .previewConfirm:
                    state.inner.showPreview = false
                    state.inner.isLoading = true
                    state.inner.errorMessage = nil
                    return .none // 上传逻辑由外部Effect注入
                case .previewCancel:
                    state.inner.showPreview = false
                    state.inner.selectedPhotoItems = []
                    state.inner.selectedImages = []
                    state.inner.cameraImage = nil
                    return .none
                case .uploadStart:
                    state.inner.isLoading = true
                    state.inner.errorMessage = nil
                    return .none
                case .uploadSuccess:
                    state.inner.isLoading = false
                    state.inner.selectedPhotoItems = []
                    state.inner.selectedImages = []
                    state.inner.cameraImage = nil
                    return .none
                case .uploadFailure(let msg):
                    state.inner.isLoading = false
                    state.inner.errorMessage = msg
                    return .none
                case .setLoading(let loading):
                    state.inner.isLoading = loading
                    return .none
                case .setError(let msg):
                    state.inner.errorMessage = msg
                    return .none
                case .setPreviewIndex(let idx):
                    state.inner.previewIndex = idx
                    return .none
                case .setShowCamera(let show):
                    state.inner.showCamera = show
                    return .none
                case .setShowPhotoPicker(let show):
                    state.inner.showPhotoPicker = show
                    return .none
                case .reset:
                    let mode = state.inner.selectionMode
                    state.inner = ImagePickerWithPreviewState(selectionMode: mode)
                    return .none
                }
            }
        }
    }
}