//
//  CVFilledPreviewPageView.swift
//  App for Indeed
//
//  Full-screen preview of a profile merged into the selected CV template.
//

import Cocoa

private final class CVPreviewFlippedDocumentView: NSView {
    override var isFlipped: Bool { true }
}

/// Hosts a scrollable `CVProfileDocumentView` with a simple chrome header and back navigation.
final class CVFilledPreviewPageView: NSView {

    var onDismiss: (() -> Void)?

    private let backButton = NSButton(title: "← Profiles", target: nil, action: nil)
    private let titleLabel = NSTextField(labelWithString: "CV preview")
    private let scrollView = NSScrollView()
    private let documentView = CVPreviewFlippedDocumentView()
    private let contentStack = NSStackView()

    private static let pageBackground = NSColor(srgbRed: 1, green: 1, blue: 1, alpha: 1)
    private static let secondaryText = NSColor(srgbRed: 100 / 255, green: 116 / 255, blue: 139 / 255, alpha: 1)
    private static let brandBlue = NSColor(srgbRed: 37 / 255, green: 87 / 255, blue: 167 / 255, alpha: 1)

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        wantsLayer = true
        layer?.backgroundColor = Self.pageBackground.cgColor
        userInterfaceLayoutDirection = .leftToRight

        backButton.translatesAutoresizingMaskIntoConstraints = false
        backButton.bezelStyle = .rounded
        backButton.isBordered = false
        backButton.font = .systemFont(ofSize: 13, weight: .semibold)
        backButton.contentTintColor = Self.brandBlue
        backButton.target = self
        backButton.action = #selector(didTapBack)

        titleLabel.font = .systemFont(ofSize: 18, weight: .semibold)
        titleLabel.textColor = NSColor(srgbRed: 31 / 255, green: 41 / 255, blue: 55 / 255, alpha: 1)

        let subtitle = NSTextField(wrappingLabelWithString: "Your profile fields are laid out using the template you chose in CV Maker.")
        subtitle.font = .systemFont(ofSize: 12, weight: .regular)
        subtitle.textColor = Self.secondaryText
        subtitle.maximumNumberOfLines = 0

        let headerCol = NSStackView(views: [backButton, titleLabel, subtitle])
        headerCol.orientation = .vertical
        headerCol.alignment = .leading
        headerCol.spacing = 6
        headerCol.setCustomSpacing(14, after: backButton)
        headerCol.translatesAutoresizingMaskIntoConstraints = false

        contentStack.orientation = .vertical
        contentStack.alignment = .leading
        contentStack.spacing = 20
        contentStack.translatesAutoresizingMaskIntoConstraints = false

        documentView.translatesAutoresizingMaskIntoConstraints = false
        documentView.addSubview(contentStack)

        scrollView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.drawsBackground = false
        scrollView.hasVerticalScroller = true
        scrollView.hasHorizontalScroller = false
        scrollView.autohidesScrollers = true
        scrollView.borderType = .noBorder
        scrollView.documentView = documentView

        addSubview(headerCol)
        addSubview(scrollView)

        NSLayoutConstraint.activate([
            headerCol.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 32),
            headerCol.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -32),
            headerCol.topAnchor.constraint(equalTo: topAnchor, constant: 16),

            scrollView.leadingAnchor.constraint(equalTo: leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: trailingAnchor),
            scrollView.topAnchor.constraint(equalTo: headerCol.bottomAnchor, constant: 16),
            scrollView.bottomAnchor.constraint(equalTo: bottomAnchor),

            documentView.leadingAnchor.constraint(equalTo: scrollView.contentView.leadingAnchor),
            documentView.widthAnchor.constraint(equalTo: scrollView.contentView.widthAnchor),
            documentView.topAnchor.constraint(equalTo: scrollView.contentView.topAnchor),
            documentView.bottomAnchor.constraint(equalTo: contentStack.bottomAnchor, constant: 40),

            contentStack.leadingAnchor.constraint(equalTo: documentView.leadingAnchor, constant: 32),
            contentStack.trailingAnchor.constraint(lessThanOrEqualTo: documentView.trailingAnchor, constant: -32),
            contentStack.topAnchor.constraint(equalTo: documentView.topAnchor, constant: 8),
            contentStack.widthAnchor.constraint(lessThanOrEqualTo: documentView.widthAnchor, constant: -64)
        ])
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func configure(profile: SavedProfile, template: CVTemplate) {
        for v in contentStack.arrangedSubviews {
            contentStack.removeArrangedSubview(v)
            v.removeFromSuperview()
        }
        let doc = CVProfileDocumentView(profile: profile, template: template)
        contentStack.addArrangedSubview(doc)
        let profileTitle = profile.profileDisplayName.isEmpty ? "Untitled profile" : profile.profileDisplayName
        titleLabel.stringValue = "\(template.name) · \(profileTitle)"
    }

    @objc private func didTapBack() {
        onDismiss?()
    }
}