import SwiftUI
import ComposableArchitecture
import PhotosUI

struct EditFeedView: View {
    let onDismiss: () -> Void
    let store: StoreOf<EditFeedFeature>
    @State private var isKeyboardVisible = false
    private let maxCount = 500
    
    private func hideKeyboard() {
        UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
    }
    
    var body: some View {
        GeometryReader { geometry in
            ZStack {
                backgroundView
                mainContent(geometry: geometry)
                if store.isUploadingImages {
                    uploadingImagesOverlay(progress: store.imageUploadProgress)
                } else if store.isLoading {
                    loadingOverlay
                }
            }
            .contentShape(Rectangle())
            .onTapGesture {
                if isKeyboardVisible {
                    hideKeyboard()
                }
            }
            .onReceive(NotificationCenter.default.publisher(for: UIResponder.keyboardWillShowNotification)) { _ in
                withAnimation(.easeInOut(duration: 0.3)) {
                    isKeyboardVisible = true
                }
            }
            .onReceive(NotificationCenter.default.publisher(for: UIResponder.keyboardWillHideNotification)) { _ in
                withAnimation(.easeInOut(duration: 0.3)) {
                    isKeyboardVisible = false
                }
            }
        }
        .navigationBarHidden(true)
        .onAppear {
            store.send(.clearError)
        }
        .onChange(of: store.shouldDismiss) {
            if store.shouldDismiss {
                onDismiss()
            }
        }
        .photosPicker(
            isPresented: Binding(
                get: { store.showPhotosPicker },
                set: { _ in store.send(.photosPickerDismissed) }
            ),
            selection: Binding(
                get: { store.selectedPhotoItems },
                set: { store.send(.photosPickerItemsChanged($0)) }
            ),
            maxSelectionCount: 9,
            matching: .images
        )
        .alert("删除图片", isPresented: Binding(
            get: { store.showDeleteImageAlert },
            set: { _ in store.send(.deleteImageAlertDismissed) }
        )) {
            Button("删除", role: .destructive) {
                if let indexToDelete = store.imageToDeleteIndex {
                    store.send(.removeImage(indexToDelete))
                }
            }
            Button("取消", role: .cancel) {
                store.send(.deleteImageAlertDismissed)
            }
        } message: {
            Text("确定要删除这张图片吗？")
        }
    }
    
    private var backgroundView: some View {
        Color(hex: 0x0C0527)
            .ignoresSafeArea()
    }
    
    private func mainContent(geometry: GeometryProxy) -> some View {
        VStack(spacing: 0) {
            topNavigationBar
            
            ScrollView {
                VStack(spacing: 20) {
                    textInputSection
                    imageSelectionSection
                    publishButton
                }
                .padding(.horizontal, 20)
                .padding(.bottom, 40)
            }
        }
    }
    
    private var topNavigationBar: some View {
        HStack {
            Button(action: {
                store.send(.clearDismissFlag)
                onDismiss()
            }) {
                Image(systemName: "xmark")
                    .font(.system(size: 20, weight: .medium))
                    .foregroundColor(.white)
                    .frame(width: 44, height: 44)
            }
            
            Spacer()
            
            Text("编辑动态")
                .font(.system(size: 18, weight: .medium))
                .foregroundColor(.white)
            
            Spacer()
            
            Color.clear
                .frame(width: 44, height: 44)
        }
        .padding(.horizontal, 16)
        .padding(.top, 8)
        .padding(.bottom, 16)
    }
    
    private var textInputSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("分享你的想法...")
                .font(.system(size: 16, weight: .medium))
                .foregroundColor(.white)
            
            TextEditor(text: Binding(
                get: { store.content },
                set: { store.send(.contentChanged($0)) }
            ))
            .font(.system(size: 16))
            .foregroundColor(.white)
            .background(Color.clear)
            .frame(minHeight: 120)
            .padding(12)
            .background(Color.white.opacity(0.1))
            .cornerRadius(12)
            .overlay(
                RoundedRectangle(cornerRadius: 12)
                    .stroke(Color.white.opacity(0.2), lineWidth: 1)
            )
            
            HStack {
                Spacer()
                Text("\(store.content.count)/\(maxCount)")
                    .font(.system(size: 12))
                    .foregroundColor(.white.opacity(0.6))
            }
        }
    }
    
    private var imageSelectionSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("添加图片")
                .font(.system(size: 16, weight: .medium))
                .foregroundColor(.white)
            
            ImageGrid(
                images: store.processedImages,
                onRemoveImage: { index in
                    store.send(.showDeleteImageAlert(index))
                },
                onAddImage: {
                    store.send(.addImageButtonTapped)
                }
            )
        }
    }
    
    private var publishButton: some View {
        Button(action: {
            store.send(.publishButtonTapped)
        }) {
            if store.isLoading {
                ProgressView()
                    .progressViewStyle(CircularProgressViewStyle(tint: .white))
                    .scaleEffect(1.2)
            } else {
                Text("发布")
                    .font(.system(size: 16, weight: .medium))
                    .foregroundColor(.white)
            }
        }
        .frame(maxWidth: .infinity)
        .padding(.vertical, 16)
        .background(store.content.isEmpty ? Color.gray : Color.blue)
        .cornerRadius(12)
        .disabled(store.isLoading || store.content.isEmpty)
    }
    
    private func uploadingImagesOverlay(progress: Double) -> some View {
        WithPerceptionTracking {
            ZStack {
                Color.black.opacity(0.5)
                    .ignoresSafeArea()
                
                VStack(spacing: 16) {
                    ProgressView(value: progress)
                        .progressViewStyle(LinearProgressViewStyle(tint: .white))
                        .frame(width: 200)
                    
                    Text("上传图片中... \(Int(progress * 100))%")
                        .font(.system(size: 16))
                        .foregroundColor(.white)
                }
                .padding(24)
                .background(Color.black.opacity(0.8))
                .cornerRadius(12)
            }
        }
    }
    
    private var loadingOverlay: some View {
        WithPerceptionTracking {
            ZStack {
                Color.black.opacity(0.5)
                    .ignoresSafeArea()
                
                ProgressView()
                    .progressViewStyle(CircularProgressViewStyle(tint: .white))
                    .scaleEffect(1.5)
            }
        }
    }
}

// MARK: - 简化的图片网格组件
struct ImageGrid: View {
    let images: [UIImage]
    let onRemoveImage: (Int) -> Void
    let onAddImage: () -> Void
    
    private let columns = Array(repeating: GridItem(.flexible(), spacing: 8), count: 3)
    
    var body: some View {
        LazyVGrid(columns: columns, spacing: 8) {
            ForEach(Array(images.enumerated()), id: \.offset) { index, image in
                ImageGridItem(
                    image: image,
                    onRemove: { onRemoveImage(index) }
                )
            }
            
            if images.count < 9 {
                AddImageButton(onTap: onAddImage)
            }
        }
    }
}

// MARK: - 图片网格项组件
struct ImageGridItem: View {
    let image: UIImage
    let onRemove: () -> Void
    
    var body: some View {
        ZStack(alignment: .topTrailing) {
            Image(uiImage: image)
                .resizable()
                .aspectRatio(contentMode: .fill)
                .frame(height: 100)
                .clipped()
                .cornerRadius(8)
            
            Button(action: onRemove) {
                Image(systemName: "xmark.circle.fill")
                    .font(.system(size: 20))
                    .foregroundColor(.white)
                    .background(Color.black.opacity(0.5))
                    .clipShape(Circle())
            }
            .padding(4)
        }
    }
}

// MARK: - 添加图片按钮组件
struct AddImageButton: View {
    let onTap: () -> Void
    
    var body: some View {
        Button(action: onTap) {
            VStack {
                Image(systemName: "plus")
                    .font(.system(size: 24))
                    .foregroundColor(.white.opacity(0.7))
                Text("添加")
                    .font(.system(size: 12))
                    .foregroundColor(.white.opacity(0.7))
            }
            .frame(height: 100)
            .frame(maxWidth: .infinity)
            .background(Color.white.opacity(0.1))
            .cornerRadius(8)
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(Color.white.opacity(0.2), lineWidth: 1)
            )
        }
    }
}