//
//  ProfilesListPageView.swift
//  App for Indeed
//

import Cocoa

private enum ProfilesListPalette {
    static var brandBlue: NSColor { AppDashboardTheme.brandBlue }
    static var brandBlueHover: NSColor { AppDashboardTheme.brandBlueHover }
    static var pageBackground: NSColor { AppDashboardTheme.pageBackground }
    static var cardBackground: NSColor { AppDashboardTheme.cardBackground }
    static var primaryText: NSColor { AppDashboardTheme.primaryText }
    static var secondaryText: NSColor { AppDashboardTheme.secondaryText }
    static var border: NSColor { AppDashboardTheme.border }
    static var destructive: NSColor { AppDashboardTheme.profileDestructive }
    static var ctaText: NSColor { AppDashboardTheme.proCTAText }
}

/// Document view for the profiles `NSScrollView`; flipped coordinates keep short content aligned to the top of the clip (avoids a large empty band above the content on macOS).
private final class ProfilesListDocumentView: NSView {
    override var isFlipped: Bool { true }
}

/// Hub for saved job profiles: list, add, edit (opens editor elsewhere), delete.
final class ProfilesListPageView: NSView {
    var onAddProfile: (() -> Void)?
    var onEditProfile: ((UUID) -> Void)?
    var onDeleteProfile: ((UUID) -> Void)?
    /// Fired when the user taps **Build CV** on a row while a CV Maker template is pending.
    var onBuildCVWithProfile: ((UUID) -> Void)?

    private let scrollView = NSScrollView()
    private let documentView = ProfilesListDocumentView()
    private let contentStack = NSStackView()
    private let titleLabel = NSTextField(labelWithString: "Profiles")
    private let subtitleLabel = NSTextField(wrappingLabelWithString: "")
    private let emptyStateLabel = NSTextField(wrappingLabelWithString: "")
    private let addButton = ProfilesPrimaryButton(title: "Add new profile", target: nil, action: nil)
    private let pendingFlowLabel = NSTextField(wrappingLabelWithString: "")
    private var appearanceObserver: NSObjectProtocol?
    /// Non-`nil` after **Use Template & Select Profile** until the dashboard clears the flow (e.g. leaving Profile).
    private var pendingCVTemplateDisplayName: String?

    override var userInterfaceLayoutDirection: NSUserInterfaceLayoutDirection {
        get { .leftToRight }
        set { super.userInterfaceLayoutDirection = .leftToRight }
    }

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        setup()
        appearanceObserver = NotificationCenter.default.addObserver(
            forName: AppAppearanceManager.didChangeNotification,
            object: nil,
            queue: .main
        ) { [weak self] _ in
            self?.applyCurrentAppearance()
        }
        applyCurrentAppearance()
    }

    deinit {
        if let appearanceObserver {
            NotificationCenter.default.removeObserver(appearanceObserver)
        }
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }

    override func viewDidChangeEffectiveAppearance() {
        super.viewDidChangeEffectiveAppearance()
        applyCurrentAppearance()
    }

    func applyCurrentAppearance() {
        layer?.backgroundColor = ProfilesListPalette.pageBackground.cgColor
        titleLabel.textColor = ProfilesListPalette.primaryText
        subtitleLabel.textColor = ProfilesListPalette.secondaryText
        emptyStateLabel.textColor = ProfilesListPalette.secondaryText
        pendingFlowLabel.textColor = ProfilesListPalette.brandBlue
        addButton.applyCurrentAppearance()
        for case let row as ProfileListRowView in contentStack.arrangedSubviews {
            row.applyCurrentAppearance()
        }
    }

    func reloadFromStore() {
        for row in contentStack.arrangedSubviews {
            contentStack.removeArrangedSubview(row)
            row.removeFromSuperview()
        }

        let profiles = SavedProfilesStore.loadAll()
        emptyStateLabel.isHidden = !profiles.isEmpty

        let showBuildCV = pendingCVTemplateDisplayName != nil
        for profile in profiles {
            let row = ProfileListRowView(profile: profile, showBuildCV: showBuildCV)
            row.translatesAutoresizingMaskIntoConstraints = false
            row.onEdit = { [weak self] id in self?.onEditProfile?(id) }
            row.onDelete = { [weak self] id in self?.onDeleteProfile?(id) }
            row.onBuildCV = { [weak self] id in self?.onBuildCVWithProfile?(id) }
            contentStack.addArrangedSubview(row)
            row.widthAnchor.constraint(equalTo: contentStack.widthAnchor).isActive = true
        }
    }

    /// Shows the CV Maker hand-off banner and per-profile **Build CV** actions, or clears them when `nil`.
    func setPendingCVTemplateDisplayName(_ name: String?) {
        pendingCVTemplateDisplayName = name
        if let name, !name.isEmpty {
            pendingFlowLabel.stringValue = "You chose the “\(name)” template. Tap Build CV on a profile to preview your résumé with that layout."
            pendingFlowLabel.isHidden = false
        } else {
            pendingFlowLabel.isHidden = true
        }
        reloadFromStore()
    }

    private func setup() {
        wantsLayer = true
        layer?.backgroundColor = ProfilesListPalette.pageBackground.cgColor
        userInterfaceLayoutDirection = .leftToRight

        titleLabel.font = .systemFont(ofSize: 22, weight: .semibold)

        subtitleLabel.stringValue = "Create and manage CV profiles. Each profile stores your details on this Mac."
        subtitleLabel.font = .systemFont(ofSize: 13, weight: .regular)
        subtitleLabel.maximumNumberOfLines = 0

        emptyStateLabel.stringValue = "No profiles yet. Tap “Add new profile” to create your first one."
        emptyStateLabel.font = .systemFont(ofSize: 13, weight: .regular)
        emptyStateLabel.textColor = ProfilesListPalette.secondaryText
        emptyStateLabel.isHidden = true

        addButton.target = self
        addButton.action = #selector(didTapAdd)
        addButton.translatesAutoresizingMaskIntoConstraints = false
        addButton.setContentHuggingPriority(.required, for: .horizontal)
        addButton.setContentCompressionResistancePriority(.required, for: .horizontal)
        NSLayoutConstraint.activate([
            addButton.heightAnchor.constraint(equalToConstant: 32),
            addButton.widthAnchor.constraint(greaterThanOrEqualToConstant: 76)
        ])

        let titleSubtitleStack = NSStackView(views: [titleLabel, subtitleLabel])
        titleSubtitleStack.orientation = .vertical
        titleSubtitleStack.alignment = .leading
        titleSubtitleStack.spacing = 10
        titleSubtitleStack.translatesAutoresizingMaskIntoConstraints = false

        pendingFlowLabel.font = .systemFont(ofSize: 13, weight: .medium)
        pendingFlowLabel.textColor = ProfilesListPalette.brandBlue
        pendingFlowLabel.maximumNumberOfLines = 0
        pendingFlowLabel.isHidden = true

        let pageHeaderStack = NSStackView(views: [titleSubtitleStack, pendingFlowLabel])
        pageHeaderStack.orientation = .vertical
        pageHeaderStack.alignment = .leading
        pageHeaderStack.spacing = 12
        pageHeaderStack.translatesAutoresizingMaskIntoConstraints = false

        let footerStack = NSStackView(views: [emptyStateLabel, addButton])
        footerStack.orientation = .vertical
        footerStack.alignment = .leading
        footerStack.spacing = 10
        footerStack.translatesAutoresizingMaskIntoConstraints = false
        footerStack.setCustomSpacing(16, after: emptyStateLabel)

        contentStack.orientation = .vertical
        contentStack.alignment = .leading
        contentStack.spacing = 12
        contentStack.translatesAutoresizingMaskIntoConstraints = false

        documentView.translatesAutoresizingMaskIntoConstraints = false
        documentView.addSubview(pageHeaderStack)
        documentView.addSubview(contentStack)
        documentView.addSubview(footerStack)

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

        addSubview(scrollView)

        NSLayoutConstraint.activate([
            scrollView.leftAnchor.constraint(equalTo: leftAnchor),
            scrollView.rightAnchor.constraint(equalTo: rightAnchor),
            scrollView.topAnchor.constraint(equalTo: topAnchor),
            scrollView.bottomAnchor.constraint(equalTo: bottomAnchor),

            documentView.leftAnchor.constraint(equalTo: scrollView.contentView.leftAnchor),
            documentView.rightAnchor.constraint(equalTo: scrollView.contentView.rightAnchor),
            documentView.topAnchor.constraint(equalTo: scrollView.contentView.topAnchor),
            documentView.bottomAnchor.constraint(equalTo: footerStack.bottomAnchor, constant: 32),

            pageHeaderStack.leadingAnchor.constraint(equalTo: documentView.leadingAnchor, constant: 32),
            pageHeaderStack.trailingAnchor.constraint(equalTo: documentView.trailingAnchor, constant: -32),
            pageHeaderStack.topAnchor.constraint(equalTo: documentView.topAnchor, constant: 24),

            contentStack.leadingAnchor.constraint(equalTo: documentView.leadingAnchor, constant: 32),
            contentStack.trailingAnchor.constraint(equalTo: documentView.trailingAnchor, constant: -32),
            contentStack.topAnchor.constraint(equalTo: pageHeaderStack.bottomAnchor, constant: 24),

            footerStack.leadingAnchor.constraint(equalTo: documentView.leadingAnchor, constant: 32),
            footerStack.trailingAnchor.constraint(equalTo: documentView.trailingAnchor, constant: -32),
            footerStack.topAnchor.constraint(equalTo: contentStack.bottomAnchor, constant: 24),

            pageHeaderStack.widthAnchor.constraint(equalTo: documentView.widthAnchor, constant: -64),
            contentStack.widthAnchor.constraint(equalTo: documentView.widthAnchor, constant: -64),
            footerStack.widthAnchor.constraint(equalTo: documentView.widthAnchor, constant: -64)
        ])

        reloadFromStore()
    }

    @objc private func didTapAdd() {
        onAddProfile?()
    }
}

// MARK: - Row

private final class ProfileListRowView: NSView {
    var onEdit: ((UUID) -> Void)?
    var onDelete: ((UUID) -> Void)?
    var onBuildCV: ((UUID) -> Void)?

    private let profileID: UUID
    private let nameLabel = NSTextField(labelWithString: "")
    private let detailLabel = NSTextField(wrappingLabelWithString: "")
    private let buildCVButton = NSButton(title: "Build CV", target: nil, action: nil)
    private let editButton = NSButton(title: "Edit", target: nil, action: nil)
    private let deleteButton = NSButton(title: "Delete", target: nil, action: nil)

    init(profile: SavedProfile, showBuildCV: Bool) {
        self.profileID = profile.id
        super.init(frame: .zero)
        translatesAutoresizingMaskIntoConstraints = false
        wantsLayer = true
        layer?.cornerRadius = 14
        layer?.borderWidth = 1
        layer?.borderColor = ProfilesListPalette.border.cgColor
        layer?.backgroundColor = ProfilesListPalette.cardBackground.cgColor
        if #available(macOS 11.0, *) {
            layer?.cornerCurve = .continuous
        }

        nameLabel.stringValue = profile.profileDisplayName.isEmpty ? "Untitled profile" : profile.profileDisplayName
        nameLabel.font = .systemFont(ofSize: 15, weight: .semibold)

        let detailParts = [profile.personal.fullName, profile.personal.email].filter { !$0.isEmpty }
        detailLabel.stringValue = detailParts.isEmpty ? "No contact details yet" : detailParts.joined(separator: " · ")
        detailLabel.font = .systemFont(ofSize: 12, weight: .regular)
        detailLabel.maximumNumberOfLines = 2

        let textStack = NSStackView(views: [nameLabel, detailLabel])
        textStack.orientation = .vertical
        textStack.alignment = .leading
        textStack.spacing = 4
        textStack.translatesAutoresizingMaskIntoConstraints = false

        buildCVButton.translatesAutoresizingMaskIntoConstraints = false
        buildCVButton.bezelStyle = .rounded
        buildCVButton.isBordered = true
        buildCVButton.font = .systemFont(ofSize: 12, weight: .semibold)
        buildCVButton.contentTintColor = ProfilesListPalette.brandBlue
        buildCVButton.target = self
        buildCVButton.action = #selector(didTapBuildCV)
        buildCVButton.isHidden = !showBuildCV

        editButton.translatesAutoresizingMaskIntoConstraints = false
        editButton.bezelStyle = .rounded
        editButton.isBordered = true
        editButton.font = .systemFont(ofSize: 12, weight: .medium)
        editButton.target = self
        editButton.action = #selector(didTapEdit)

        deleteButton.translatesAutoresizingMaskIntoConstraints = false
        deleteButton.bezelStyle = .rounded
        deleteButton.isBordered = false
        deleteButton.font = .systemFont(ofSize: 12, weight: .medium)
        deleteButton.contentTintColor = ProfilesListPalette.destructive
        deleteButton.target = self
        deleteButton.action = #selector(didTapDelete)

        let spacer = NSView()
        spacer.setContentHuggingPriority(.defaultLow, for: .horizontal)

        let actionViews: [NSView] = showBuildCV ? [buildCVButton, editButton, deleteButton] : [editButton, deleteButton]
        let actions = NSStackView(views: actionViews)
        actions.orientation = .horizontal
        actions.spacing = 8
        actions.alignment = .centerY
        actions.translatesAutoresizingMaskIntoConstraints = false

        let row = NSStackView(views: [textStack, spacer, actions])
        row.orientation = .horizontal
        row.alignment = .top
        row.spacing = 16
        row.translatesAutoresizingMaskIntoConstraints = false

        addSubview(row)
        NSLayoutConstraint.activate([
            row.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20),
            row.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -20),
            row.topAnchor.constraint(equalTo: topAnchor, constant: 16),
            row.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -16)
        ])
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    @objc private func didTapEdit() {
        onEdit?(profileID)
    }

    @objc private func didTapBuildCV() {
        onBuildCV?(profileID)
    }

    @objc private func didTapDelete() {
        onDelete?(profileID)
    }

    func applyCurrentAppearance() {
        layer?.borderColor = ProfilesListPalette.border.cgColor
        layer?.backgroundColor = ProfilesListPalette.cardBackground.cgColor
        nameLabel.textColor = ProfilesListPalette.primaryText
        detailLabel.textColor = ProfilesListPalette.secondaryText
        buildCVButton.contentTintColor = ProfilesListPalette.brandBlue
        deleteButton.contentTintColor = ProfilesListPalette.destructive
    }
}

// MARK: - Primary CTA (matches job cards’ Apply: 13pt semibold, 32pt tall, 8pt corners)

private final class ProfilesPrimaryButton: NSButton {
    private static let horizontalOutset: CGFloat = 20

    private var trackingArea: NSTrackingArea?
    private var didPushCursor = false

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        commonInit()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }

    convenience init(title: String, target: AnyObject?, action: Selector?) {
        self.init(frame: .zero)
        self.title = title
        self.target = target
        self.action = action
    }

    private func commonInit() {
        translatesAutoresizingMaskIntoConstraints = false
        bezelStyle = .rounded
        isBordered = false
        font = .systemFont(ofSize: 13, weight: .semibold)
        contentTintColor = ProfilesListPalette.ctaText
        focusRingType = .none
        wantsLayer = true
        layer?.cornerRadius = 8
        applyCurrentAppearance()
    }

    func applyCurrentAppearance() {
        contentTintColor = ProfilesListPalette.ctaText
        layer?.backgroundColor = (isHovering ? ProfilesListPalette.brandBlueHover : ProfilesListPalette.brandBlue).cgColor
    }

    private var isHovering = false

    override var intrinsicContentSize: NSSize {
        let base = super.intrinsicContentSize
        guard base.width != NSView.noIntrinsicMetric, base.width >= 1 else { return base }
        return NSSize(width: base.width + Self.horizontalOutset, height: base.height)
    }

    override func updateTrackingAreas() {
        super.updateTrackingAreas()
        if let trackingArea { removeTrackingArea(trackingArea) }
        let area = NSTrackingArea(
            rect: bounds,
            options: [.activeInKeyWindow, .mouseEnteredAndExited, .inVisibleRect],
            owner: self,
            userInfo: nil
        )
        addTrackingArea(area)
        trackingArea = area
    }

    override func mouseEntered(with event: NSEvent) {
        super.mouseEntered(with: event)
        isHovering = true
        applyCurrentAppearance()
        if !didPushCursor {
            NSCursor.pointingHand.push()
            didPushCursor = true
        }
    }

    override func mouseExited(with event: NSEvent) {
        super.mouseExited(with: event)
        isHovering = false
        applyCurrentAppearance()
        if didPushCursor {
            NSCursor.pop()
            didPushCursor = false
        }
    }

    override func viewWillMove(toWindow newWindow: NSWindow?) {
        super.viewWillMove(toWindow: newWindow)
        if newWindow == nil, didPushCursor {
            NSCursor.pop()
            didPushCursor = false
        }
    }
}