//
//  PhotoPickerView.swift
//  Reflect
//
//  Photo picker and gallery for mood entry attachments.
//

import SwiftUI
import PhotosUI

// MARK: - Photo Picker View

struct PhotoPickerView: View {

    @Environment(\.dismiss) private var dismiss

    let entry: MoodEntryModel
    let onPhotoSelected: (UIImage) -> Void

    @State private var selectedItem: PhotosPickerItem?
    @State private var showCamera = false
    @State private var isProcessing = false

    var body: some View {
        NavigationStack {
            VStack(spacing: 24) {
                // Header
                VStack(spacing: 8) {
                    Image(systemName: "photo.on.rectangle.angled")
                        .font(.largeTitle)
                        .foregroundStyle(.secondary)

                    Text("Add a Photo")
                        .font(.title2)
                        .fontWeight(.semibold)

                    Text("Capture how you're feeling today")
                        .font(.subheadline)
                        .foregroundStyle(.secondary)
                }
                .padding(.top, 40)

                Spacer()

                // Options
                VStack(spacing: 16) {
                    // Photo Library
                    PhotosPicker(selection: $selectedItem, matching: .images) {
                        HStack(spacing: 16) {
                            Image(systemName: "photo.stack")
                                .font(.title2)
                                .frame(width: 44, height: 44)
                                .background(Color.blue.opacity(0.15))
                                .foregroundColor(.blue)
                                .clipShape(Circle())

                            VStack(alignment: .leading, spacing: 2) {
                                Text("Photo Library")
                                    .font(.headline)
                                    .foregroundColor(.primary)

                                Text("Choose from your photos")
                                    .font(.subheadline)
                                    .foregroundStyle(.secondary)
                            }

                            Spacer()

                            Image(systemName: "chevron.right")
                                .foregroundStyle(.tertiary)
                        }
                        .padding()
                        .background(
                            RoundedRectangle(cornerRadius: 16)
                                .fill(Color(.systemBackground))
                        )
                    }
                    .disabled(isProcessing)
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.photosPicker)

                    // Camera
                    Button {
                        showCamera = true
                    } label: {
                        HStack(spacing: 16) {
                            Image(systemName: "camera")
                                .font(.title2)
                                .frame(width: 44, height: 44)
                                .background(Color.green.opacity(0.15))
                                .foregroundColor(.green)
                                .clipShape(Circle())

                            VStack(alignment: .leading, spacing: 2) {
                                Text("Take Photo")
                                    .font(.headline)
                                    .foregroundColor(.primary)

                                Text("Use your camera")
                                    .font(.subheadline)
                                    .foregroundStyle(.secondary)
                            }

                            Spacer()

                            Image(systemName: "chevron.right")
                                .foregroundStyle(.tertiary)
                        }
                        .padding()
                        .background(
                            RoundedRectangle(cornerRadius: 16)
                                .fill(Color(.systemBackground))
                        )
                    }
                    .disabled(isProcessing)
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.cameraButton)
                }
                .padding(.horizontal)

                Spacer()

                // Loading indicator
                if isProcessing {
                    ProgressView("Processing...")
                        .padding()
                }
            }
            .background(Color(.systemGroupedBackground))
            .navigationTitle("Add Photo")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") {
                        dismiss()
                    }
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.cancelButton)
                }
            }
            .onChange(of: selectedItem) { _, newItem in
                Task {
                    await loadImage(from: newItem)
                }
            }
            .fullScreenCover(isPresented: $showCamera) {
                CameraView { image in
                    handleSelectedImage(image)
                }
            }
        }
    }

    private func loadImage(from item: PhotosPickerItem?) async {
        guard let item = item else { return }

        isProcessing = true
        defer { isProcessing = false }

        do {
            if let data = try await item.loadTransferable(type: Data.self),
               let image = UIImage(data: data) {
                handleSelectedImage(image)
            }
        } catch {
            #if DEBUG
            print("PhotoPickerView: Failed to load image: \(error)")
            #endif
        }
    }

    private func handleSelectedImage(_ image: UIImage) {
        onPhotoSelected(image)
        dismiss()
    }
}

// MARK: - Camera View

struct CameraView: UIViewControllerRepresentable {

    @Environment(\.dismiss) private var dismiss
    let onImageCaptured: (UIImage) -> Void

    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.sourceType = .camera
        picker.delegate = context.coordinator
        return picker
    }

    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {}

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        let parent: CameraView

        init(_ parent: CameraView) {
            self.parent = parent
        }

        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
            if let image = info[.originalImage] as? UIImage {
                parent.onImageCaptured(image)
            }
            parent.dismiss()
        }

        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            parent.dismiss()
        }
    }
}

// MARK: - Photo Gallery View (Full screen photo viewer)

struct PhotoGalleryView: View {

    @Environment(\.dismiss) private var dismiss

    let photoID: UUID
    let onDelete: () -> Void

    @State private var showDeleteConfirmation = false
    @State private var scale: CGFloat = 1.0
    @State private var lastScale: CGFloat = 1.0
    @State private var offset: CGSize = .zero
    @State private var lastOffset: CGSize = .zero

    var body: some View {
        NavigationStack {
            GeometryReader { geometry in
                ZStack {
                    Color.black.ignoresSafeArea()

                    if let image = PhotoManager.shared.image(for: photoID) {
                        image
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                            .scaleEffect(scale)
                            .offset(offset)
                            .gesture(
                                MagnificationGesture()
                                    .onChanged { value in
                                        scale = lastScale * value
                                    }
                                    .onEnded { _ in
                                        lastScale = scale
                                        if scale < 1 {
                                            withAnimation {
                                                scale = 1
                                                lastScale = 1
                                                offset = .zero
                                                lastOffset = .zero
                                            }
                                        }
                                    }
                            )
                            .simultaneousGesture(
                                DragGesture()
                                    .onChanged { value in
                                        if scale > 1 {
                                            offset = CGSize(
                                                width: lastOffset.width + value.translation.width,
                                                height: lastOffset.height + value.translation.height
                                            )
                                        }
                                    }
                                    .onEnded { _ in
                                        lastOffset = offset
                                    }
                            )
                            .onTapGesture(count: 2) {
                                withAnimation {
                                    if scale > 1 {
                                        scale = 1
                                        lastScale = 1
                                        offset = .zero
                                        lastOffset = .zero
                                    } else {
                                        scale = 2
                                        lastScale = 2
                                    }
                                }
                            }
                            .accessibilityIdentifier(AccessibilityID.PhotoPicker.photoImage)
                    } else {
                        VStack(spacing: 16) {
                            Image(systemName: "photo.badge.exclamationmark")
                                .font(.largeTitle)
                                .foregroundColor(.gray)

                            Text("Photo not found")
                                .foregroundColor(.gray)
                        }
                    }
                }
            }
            .navigationBarTitleDisplayMode(.inline)
            .toolbarBackground(.hidden, for: .navigationBar)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button {
                        dismiss()
                    } label: {
                        Image(systemName: "xmark.circle.fill")
                            .font(.title2)
                            .foregroundStyle(.white.opacity(0.7))
                    }
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.closeButton)
                }

                ToolbarItem(placement: .primaryAction) {
                    Menu {
                        Button {
                            sharePhoto()
                        } label: {
                            Label("Share", systemImage: "square.and.arrow.up")
                        }
                        .accessibilityIdentifier(AccessibilityID.PhotoPicker.shareButton)

                        Button(role: .destructive) {
                            showDeleteConfirmation = true
                        } label: {
                            Label("Delete", systemImage: "trash")
                        }
                        .accessibilityIdentifier(AccessibilityID.PhotoPicker.deleteButton)
                    } label: {
                        Image(systemName: "ellipsis.circle.fill")
                            .font(.title2)
                            .foregroundStyle(.white.opacity(0.7))
                    }
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.menuButton)
                }
            }
            .confirmationDialog("Delete Photo", isPresented: $showDeleteConfirmation, titleVisibility: .visible) {
                Button("Delete", role: .destructive) {
                    onDelete()
                    dismiss()
                }
                .accessibilityIdentifier(AccessibilityID.PhotoPicker.deleteConfirmButton)
                Button("Cancel", role: .cancel) { }
                    .accessibilityIdentifier(AccessibilityID.PhotoPicker.deleteCancelButton)
            } message: {
                Text("Are you sure you want to delete this photo?")
            }
        }
    }

    private func sharePhoto() {
        guard let uiImage = PhotoManager.shared.loadPhoto(id: photoID) else { return }

        let activityVC = UIActivityViewController(
            activityItems: [uiImage],
            applicationActivities: nil
        )

        if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
           let rootVC = windowScene.windows.first?.rootViewController {
            rootVC.present(activityVC, animated: true)
        }
    }
}

// MARK: - Photo Thumbnail View (for list display)

struct PhotoThumbnailView: View {

    let photoID: UUID?
    let size: CGFloat

    var body: some View {
        if let photoID = photoID,
           let image = PhotoManager.shared.thumbnail(for: photoID) {
            image
                .resizable()
                .aspectRatio(contentMode: .fill)
                .frame(width: size, height: size)
                .clipShape(RoundedRectangle(cornerRadius: 8))
        } else {
            RoundedRectangle(cornerRadius: 8)
                .fill(Color(.systemGray5))
                .frame(width: size, height: size)
                .overlay(
                    Image(systemName: "photo")
                        .foregroundStyle(.tertiary)
                )
        }
    }
}