smart_printer/smart_printer/FilePreviewView.swift

import Cocoa
import PDFKit
import UniformTypeIdentifiers

// MARK: - File Preview Service

enum FilePreviewService {
    static func present(urls: [URL], from window: NSWindow?) {
        guard !urls.isEmpty else { return }
        let hostWindow = window ?? NSApp.keyWindow
        guard let viewController = hostWindow?.contentViewController as? ViewController else { return }
        viewController.presentFilePreview(urls: urls)
    }
}

// MARK: - Overlay

final class FilePreviewOverlayView: NSView, AppearanceRefreshable {
    var onDismiss: (() -> Void)?

    private let urls: [URL]
    private var currentIndex = 0
    private var securityAccess: [URL: Bool] = [:]

    private let backButton = FileToolbarButton(symbolName: "chevron.left", accessibilityLabel: "Back")
    private let titleLabel = NSTextField(labelWithString: "Print a file")
    private let counterLabel = NSTextField(labelWithString: "")
    private let previewContainer = NSView()
    private var previewSubview: NSView?
    private let printButton = FilePrintButton()

    init(urls: [URL]) {
        self.urls = urls
        super.init(frame: .zero)
        translatesAutoresizingMaskIntoConstraints = false
        setup()
        refreshAppearance()
        showFile(at: 0)
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(appearanceDidChange),
            name: .appearanceDidChange,
            object: nil
        )
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    @objc private func appearanceDidChange() {
        refreshAppearance()
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { nil }

    func refreshAppearance() {
        layer?.backgroundColor = AppTheme.background.cgColor
        titleLabel.textColor = AppTheme.textPrimary
        counterLabel.textColor = AppTheme.textSecondary
        previewContainer.layer?.backgroundColor = AppTheme.cardBackground.cgColor
        previewContainer.layer?.borderColor = AppTheme.paywallBorder.cgColor
        backButton.refreshAppearance()
        printButton.refreshAppearance()
    }

    func present(in parent: NSView) {
        guard superview == nil else { return }
        parent.addSubview(self)
        NSLayoutConstraint.activate([
            leadingAnchor.constraint(equalTo: parent.leadingAnchor),
            trailingAnchor.constraint(equalTo: parent.trailingAnchor),
            topAnchor.constraint(equalTo: parent.topAnchor),
            bottomAnchor.constraint(equalTo: parent.bottomAnchor),
        ])
        alphaValue = 0
        NSAnimationContext.runAnimationGroup { context in
            context.duration = 0.2
            animator().alphaValue = 1
        }
    }

    func dismiss(animated: Bool = true) {
        stopSecurityAccess()
        let remove = { [weak self] in
            self?.removeFromSuperview()
            self?.onDismiss?()
        }
        guard animated else {
            remove()
            return
        }
        NSAnimationContext.runAnimationGroup({ context in
            context.duration = 0.15
            animator().alphaValue = 0
        }, completionHandler: remove)
    }

    private func setup() {
        wantsLayer = true

        titleLabel.font = AppTheme.semiboldFont(size: 18)
        titleLabel.alignment = .center
        titleLabel.translatesAutoresizingMaskIntoConstraints = false

        counterLabel.font = AppTheme.regularFont(size: 13)
        counterLabel.alignment = .center
        counterLabel.translatesAutoresizingMaskIntoConstraints = false
        counterLabel.isHidden = urls.count <= 1

        previewContainer.wantsLayer = true
        previewContainer.layer?.cornerRadius = AppTheme.contentPanelCornerRadius
        previewContainer.layer?.borderWidth = 1.5
        previewContainer.applyCardShadow()
        previewContainer.translatesAutoresizingMaskIntoConstraints = false
        previewContainer.setContentHuggingPriority(.defaultLow, for: .horizontal)
        previewContainer.setContentHuggingPriority(.defaultLow, for: .vertical)
        previewContainer.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
        previewContainer.setContentCompressionResistancePriority(.defaultLow, for: .vertical)

        backButton.translatesAutoresizingMaskIntoConstraints = false
        printButton.translatesAutoresizingMaskIntoConstraints = false

        backButton.onClick = { [weak self] in self?.dismiss() }
        printButton.onClick = { [weak self] in self?.printCurrentFile() }

        addSubview(backButton)
        addSubview(titleLabel)
        addSubview(counterLabel)
        addSubview(previewContainer)
        addSubview(printButton)

        NSLayoutConstraint.activate([
            backButton.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 24),
            backButton.topAnchor.constraint(equalTo: topAnchor, constant: 20),
            backButton.widthAnchor.constraint(equalToConstant: 40),
            backButton.heightAnchor.constraint(equalToConstant: 40),

            titleLabel.centerXAnchor.constraint(equalTo: centerXAnchor),
            titleLabel.centerYAnchor.constraint(equalTo: backButton.centerYAnchor),

            counterLabel.centerXAnchor.constraint(equalTo: centerXAnchor),
            counterLabel.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 4),

            previewContainer.leadingAnchor.constraint(equalTo: leadingAnchor, constant: AppTheme.contentPanelInset),
            previewContainer.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -AppTheme.contentPanelInset),
            previewContainer.topAnchor.constraint(equalTo: backButton.bottomAnchor, constant: 28),
            previewContainer.bottomAnchor.constraint(equalTo: printButton.topAnchor, constant: -28),

            printButton.centerXAnchor.constraint(equalTo: centerXAnchor),
            printButton.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -28),
            printButton.widthAnchor.constraint(greaterThanOrEqualToConstant: 220),
        ])
    }

    private func showFile(at index: Int) {
        guard urls.indices.contains(index) else { return }
        currentIndex = index
        let url = urls[index]

        if securityAccess[url] != true {
            securityAccess[url] = url.startAccessingSecurityScopedResource()
        }

        previewSubview?.removeFromSuperview()
        let preview = makePreview(for: url)
        preview.translatesAutoresizingMaskIntoConstraints = false
        previewContainer.addSubview(preview)
        NSLayoutConstraint.activate([
            preview.leadingAnchor.constraint(equalTo: previewContainer.leadingAnchor, constant: 12),
            preview.trailingAnchor.constraint(equalTo: previewContainer.trailingAnchor, constant: -12),
            preview.topAnchor.constraint(equalTo: previewContainer.topAnchor, constant: 12),
            preview.bottomAnchor.constraint(equalTo: previewContainer.bottomAnchor, constant: -12),
        ])
        previewSubview = preview

        if urls.count > 1 {
            counterLabel.stringValue = "\(index + 1) of \(urls.count) — \(url.lastPathComponent)"
            counterLabel.isHidden = false
        } else {
            counterLabel.stringValue = url.lastPathComponent
            counterLabel.isHidden = false
        }
    }

    private func makePreview(for url: URL) -> NSView {
        let ext = url.pathExtension.lowercased()

        if ext == "pdf", let document = PDFDocument(url: url) {
            let pdfView = PDFView()
            pdfView.document = document
            pdfView.autoScales = true
            pdfView.displayMode = .singlePageContinuous
            pdfView.backgroundColor = .clear
            return pdfView
        }

        if ext == "rtf",
           let data = try? Data(contentsOf: url),
           let attributed = NSAttributedString(rtf: data, documentAttributes: nil) {
            return makeTextPreview(attributed)
        }

        if ["txt", "md", "csv", "json", "xml", "html", "htm"].contains(ext),
           let text = try? String(contentsOf: url, encoding: .utf8) {
            return makeTextPreview(NSAttributedString(string: text))
        }

        return makePlaceholderPreview(for: url)
    }

    private func makeTextPreview(_ text: NSAttributedString) -> NSView {
        let scrollView = NSScrollView()
        scrollView.hasVerticalScroller = true
        scrollView.hasHorizontalScroller = false
        scrollView.autohidesScrollers = true
        scrollView.borderType = .noBorder
        scrollView.drawsBackground = false

        let textView = NSTextView()
        textView.isEditable = false
        textView.isSelectable = true
        textView.drawsBackground = false
        textView.textStorage?.setAttributedString(text)
        if textView.font == nil {
            textView.font = AppTheme.regularFont(size: 13)
        }
        textView.textColor = AppTheme.textPrimary

        scrollView.documentView = textView
        return scrollView
    }

    private func makePlaceholderPreview(for url: URL) -> NSView {
        let container = NSView()

        let iconView = NSImageView()
        iconView.image = NSWorkspace.shared.icon(forFile: url.path)
        iconView.imageScaling = .scaleProportionallyUpOrDown
        iconView.translatesAutoresizingMaskIntoConstraints = false

        let nameLabel = NSTextField(labelWithString: url.lastPathComponent)
        nameLabel.font = AppTheme.semiboldFont(size: 16)
        nameLabel.textColor = AppTheme.textPrimary
        nameLabel.alignment = .center
        nameLabel.lineBreakMode = .byTruncatingMiddle
        nameLabel.maximumNumberOfLines = 2
        nameLabel.translatesAutoresizingMaskIntoConstraints = false

        container.addSubview(iconView)
        container.addSubview(nameLabel)

        NSLayoutConstraint.activate([
            iconView.centerXAnchor.constraint(equalTo: container.centerXAnchor),
            iconView.centerYAnchor.constraint(equalTo: container.centerYAnchor, constant: -20),
            iconView.widthAnchor.constraint(equalToConstant: 72),
            iconView.heightAnchor.constraint(equalToConstant: 72),

            nameLabel.topAnchor.constraint(equalTo: iconView.bottomAnchor, constant: 16),
            nameLabel.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: 16),
            nameLabel.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -16),
        ])

        return container
    }

    private func currentURL() -> URL? {
        guard urls.indices.contains(currentIndex) else { return nil }
        return urls[currentIndex]
    }

    private func printCurrentFile() {
        guard let url = currentURL() else { return }
        PrintService.print(urls: [url], from: window)

        if currentIndex < urls.count - 1 {
            showFile(at: currentIndex + 1)
        } else {
            dismiss()
        }
    }

    private func stopSecurityAccess() {
        for (url, accessed) in securityAccess where accessed {
            url.stopAccessingSecurityScopedResource()
        }
        securityAccess.removeAll()
    }
}

// MARK: - Toolbar Button

private final class FileToolbarButton: NSControl, AppearanceRefreshable {
    var onClick: (() -> Void)?

    private let iconView = NSImageView()

    init(symbolName: String, accessibilityLabel: String) {
        super.init(frame: .zero)
        toolTip = accessibilityLabel

        wantsLayer = true
        layer?.cornerRadius = 12

        if let image = NSImage(systemSymbolName: symbolName, accessibilityDescription: accessibilityLabel) {
            let config = NSImage.SymbolConfiguration(pointSize: 15, weight: .semibold)
            iconView.image = image.withSymbolConfiguration(config)
        }
        iconView.translatesAutoresizingMaskIntoConstraints = false

        addSubview(iconView)
        NSLayoutConstraint.activate([
            iconView.centerXAnchor.constraint(equalTo: centerXAnchor),
            iconView.centerYAnchor.constraint(equalTo: centerYAnchor),
        ])
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { nil }

    func refreshAppearance() {
        layer?.backgroundColor = AppTheme.elevatedBackground.cgColor
        layer?.borderColor = AppTheme.paywallBorder.cgColor
        layer?.borderWidth = 1.5
        iconView.contentTintColor = AppTheme.textPrimary
    }

    override func mouseUp(with event: NSEvent) {
        guard bounds.contains(convert(event.locationInWindow, from: nil)) else { return }
        onClick?()
    }

    override func resetCursorRects() {
        addCursorRect(bounds, cursor: .pointingHand)
    }
}

// MARK: - Print Button

private final class FilePrintButton: NSControl, AppearanceRefreshable {
    var onClick: (() -> Void)?

    private let titleLabel = NSTextField(labelWithString: "Print File")
    private let iconView = NSImageView()
    private var hoverTracker: HoverTracker?
    private var isHovered = false

    init() {
        super.init(frame: .zero)
        wantsLayer = true
        layer?.cornerRadius = 22

        titleLabel.font = AppTheme.semiboldFont(size: 16)
        titleLabel.textColor = .white
        titleLabel.translatesAutoresizingMaskIntoConstraints = false

        if let image = NSImage(systemSymbolName: "printer.fill", accessibilityDescription: "Print") {
            let config = NSImage.SymbolConfiguration(pointSize: 14, weight: .semibold)
            iconView.image = image.withSymbolConfiguration(config)
        }
        iconView.contentTintColor = .white
        iconView.translatesAutoresizingMaskIntoConstraints = false

        addSubview(titleLabel)
        addSubview(iconView)

        NSLayoutConstraint.activate([
            heightAnchor.constraint(equalToConstant: 52),

            titleLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 28),
            titleLabel.centerYAnchor.constraint(equalTo: centerYAnchor),

            iconView.leadingAnchor.constraint(equalTo: titleLabel.trailingAnchor, constant: 10),
            iconView.centerYAnchor.constraint(equalTo: centerYAnchor),
            iconView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -28),
            iconView.widthAnchor.constraint(equalToConstant: 20),
            iconView.heightAnchor.constraint(equalToConstant: 20),
        ])

        hoverTracker = HoverTracker(view: self) { [weak self] hovering in
            self?.setHovered(hovering)
        }
        refreshAppearance()
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { nil }

    func refreshAppearance() {
        let color = isHovered
            ? AppTheme.blue.blended(withFraction: 0.15, of: .black) ?? AppTheme.blue
            : AppTheme.blue
        layer?.backgroundColor = color.cgColor
        titleLabel.textColor = .white
        iconView.contentTintColor = .white
    }

    private func setHovered(_ hovering: Bool) {
        isHovered = hovering
        animateHover {
            let color = hovering
                ? AppTheme.blue.blended(withFraction: 0.15, of: .black) ?? AppTheme.blue
                : AppTheme.blue
            layer?.backgroundColor = color.cgColor
            layer?.transform = hovering
                ? CATransform3DMakeScale(1.03, 1.03, 1)
                : CATransform3DIdentity
        }
    }

    override func mouseUp(with event: NSEvent) {
        guard bounds.contains(convert(event.locationInWindow, from: nil)) else { return }
        onClick?()
    }

    override func resetCursorRects() {
        addCursorRect(bounds, cursor: .pointingHand)
    }
}