import ManaCore
import SwiftUI

// swiftlint:disable file_length
// swiftlint:disable type_body_length

/// Publish eines privaten Decks in den Wordeck-Marketplace.
///
/// Modi: Erst-Publish (mit Author-Setup + Init + Publish 1.0.0) oder
/// neue Version eines existierenden Marketplace-Decks (Auto-Semver-Bump).
/// Image-Occlusion- und Audio-Front-Karten werden übersprungen — der
/// Server hat heute keinen Marketplace-Media-Re-Upload-Flow.
///
/// `type_body_length` ist bewusst übersprungen — Publish-Flow ist eine
/// zusammenhängende State-Maschine (Author → Init → Publish).
struct MarketplacePublishView: View {
    enum PublishMode: Hashable {
        case firstPublish
        case newVersion(slug: String)
    }

    let privateDeck: CachedDeck
    let onPublished: (MarketplacePublishResponse) -> Void

    @Environment(AuthClient.self) private var auth
    @Environment(\.dismiss) private var dismiss

    // Publish-Mode
    @State private var publishMode: PublishMode = .firstPublish
    @State private var ownedDecks: [OwnedMarketplaceDeck] = []
    @State private var selectedExistingSlug: String?

    // Author-Profil-State
    @State private var hasAuthor: Bool?
    @State private var authorSlug: String = ""
    @State private var authorDisplayName: String = ""
    @State private var authorBio: String = ""
    @State private var authorPseudonym: Bool = false

    // Deck-Metadaten
    @State private var slug: String = ""
    @State private var title: String = ""
    @State private var deckDescription: String = ""
    @State private var language: GenerationLanguage = .de
    @State private var license: MarketplaceLicense = .personalUse
    @State private var priceCredits: Int = 0
    @State private var category: DeckCategory?

    // Version-Metadaten
    @State private var semver: String = "1.0.0"
    @State private var changelog: String = ""

    // Submit-State
    @State private var isSubmitting = false
    @State private var errorMessage: String?
    @State private var result: MarketplacePublishResponse?
    @State private var skippedCardCount: Int = 0

    var body: some View {
        Form {
            if !ownedDecks.isEmpty {
                publishModeSection
            }
            if isFirstPublish, hasAuthor == false {
                authorSection
            }
            if isFirstPublish {
                deckMetadataSection
                licenseSection
                categorySection
            } else if let existing = currentExistingDeck {
                existingDeckInfoSection(deck: existing)
            }
            versionSection
            if skippedCardCount > 0 {
                skippedNoteSection
            }
            if let errorMessage {
                Section {
                    Text(errorMessage)
                        .font(.footnote)
                        .foregroundStyle(WordeckTheme.error)
                }
            }
        }
        .disabled(isSubmitting)
        .navigationTitle("Im Marketplace veröffentlichen")
        #if os(iOS)
            .navigationBarTitleDisplayMode(.inline)
        #endif
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Abbrechen") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Veröffentlichen") { Task { await submit() } }
                        .disabled(!canSubmit || isSubmitting)
                }
            }
            .overlay {
                if isSubmitting {
                    publishProgressOverlay
                }
            }
            .alert(item: $result) { response in
                Alert(
                    title: Text("Veröffentlicht: \(response.deck.title)"),
                    message: Text(alertMessage(for: response)),
                    dismissButton: .default(Text("OK")) {
                        onPublished(response)
                        dismiss()
                    }
                )
            }
            .task {
                await prefill()
            }
    }

    private var isFirstPublish: Bool {
        if case .firstPublish = publishMode { return true }
        return false
    }

    private var currentExistingDeck: OwnedMarketplaceDeck? {
        guard let slug = selectedExistingSlug else { return nil }
        return ownedDecks.first { $0.slug == slug }
    }

    private var publishModeSection: some View {
        Section {
            Picker("Modus", selection: $publishMode) {
                Text("Neues Marketplace-Deck").tag(PublishMode.firstPublish)
                ForEach(ownedDecks) { deck in
                    Text("Neue Version: \(deck.title)")
                        .tag(PublishMode.newVersion(slug: deck.slug))
                }
            }
            .pickerStyle(.menu)
            .onChange(of: publishMode) { _, newMode in
                applyPublishMode(newMode)
            }
        } header: {
            Text("Veröffentlichungs-Modus")
        } footer: {
            Text("Du hast schon Decks im Marketplace. Wähle eine, um eine neue Version zu publishen.")
        }
    }

    private func existingDeckInfoSection(deck: OwnedMarketplaceDeck) -> some View {
        Section {
            LabeledContent("Slug", value: deck.slug)
            LabeledContent("Titel", value: deck.title)
            if let latest = deck.latestVersion {
                LabeledContent("Aktuelle Version", value: "v\(latest.semver) · \(latest.cardCount) Karten")
            } else {
                LabeledContent("Aktuelle Version", value: "—")
            }
        } header: {
            Text("Bestehendes Deck")
        } footer: {
            Text("Metadaten ändern: Marketplace-Webansicht → Deck → Bearbeiten.")
        }
    }

    private var authorSection: some View {
        Section {
            TextField("Author-Slug (URL)", text: $authorSlug)
            #if os(iOS)
                .textInputAutocapitalization(.never)
            #endif
                .autocorrectionDisabled(true)
            TextField("Anzeigename", text: $authorDisplayName)
            TextField("Bio (optional)", text: $authorBio, axis: .vertical)
                .lineLimit(2 ... 4)
            Toggle("Pseudonym-Modus", isOn: $authorPseudonym)
        } header: {
            Text("Author-Profil anlegen")
        } footer: {
            Text("Pflicht-Schritt vor dem ersten Marketplace-Deck. Slug erscheint in Marketplace-URLs.")
        }
    }

    private var deckMetadataSection: some View {
        Section {
            TextField("Slug (URL)", text: $slug)
            #if os(iOS)
                .textInputAutocapitalization(.never)
            #endif
                .autocorrectionDisabled(true)
            TextField("Titel", text: $title)
            #if os(iOS)
                .textInputAutocapitalization(.sentences)
            #endif
            TextField("Beschreibung", text: $deckDescription, axis: .vertical)
                .lineLimit(2 ... 6)
            Picker("Sprache", selection: $language) {
                ForEach(GenerationLanguage.allCases, id: \.self) { lang in
                    Text(lang.label).tag(lang)
                }
            }
            .pickerStyle(.segmented)
        } header: {
            Text("Deck-Metadaten")
        } footer: {
            Text("Der Slug wird Teil der Marketplace-URL: wordeck.com/d/<slug>.")
        }
    }

    private var licenseSection: some View {
        Section("Lizenz") {
            Picker("Lizenz", selection: $license) {
                ForEach(MarketplaceLicense.allCases, id: \.self) { lic in
                    Text(lic.label).tag(lic)
                }
            }
            if license == .proOnly {
                Stepper(value: $priceCredits, in: 0 ... 100_000, step: 10) {
                    Text("Preis: \(priceCredits) Credits")
                }
            }
        }
    }

    private var categorySection: some View {
        Section("Kategorie") {
            Picker("Kategorie", selection: $category) {
                Text("Keine").tag(DeckCategory?.none)
                ForEach(DeckCategory.allCases, id: \.self) { cat in
                    Text(cat.label).tag(DeckCategory?.some(cat))
                }
            }
        }
    }

    private var versionSection: some View {
        Section {
            TextField("SemVer (z.B. 1.0.0)", text: $semver)
            #if os(iOS)
                .textInputAutocapitalization(.never)
            #endif
                .autocorrectionDisabled(true)
            #if os(iOS)
                .keyboardType(.numbersAndPunctuation)
            #endif
            TextField("Changelog (optional)", text: $changelog, axis: .vertical)
                .lineLimit(2 ... 4)
        } header: {
            Text("Version")
        } footer: {
            Text("Erst-Publish: 1.0.0. Spätere Versionen müssen semver-größer sein.")
        }
    }

    private var skippedNoteSection: some View {
        Section {
            Label(
                """
                \(skippedCardCount) Karten werden übersprungen — Bild-\
                Verdeckung und Audio brauchen Marketplace-Media-Upload.
                """,
                systemImage: "info.circle"
            )
            .font(.caption)
            .foregroundStyle(WordeckTheme.mutedForeground)
        }
    }

    private var publishProgressOverlay: some View {
        ZStack {
            Color.black.opacity(0.55).ignoresSafeArea()
            VStack(spacing: 12) {
                ProgressView().controlSize(.large).tint(WordeckTheme.primary)
                Text("Wird veröffentlicht …")
                    .font(.headline)
                    .foregroundStyle(WordeckTheme.foreground)
                Text("AI-Moderation läuft — kann ein paar Sekunden dauern.")
                    .font(.caption)
                    .foregroundStyle(WordeckTheme.mutedForeground)
                    .multilineTextAlignment(.center)
            }
            .padding(24)
            .frame(maxWidth: 320)
            .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 16, style: .continuous))
        }
    }

    private var canSubmit: Bool {
        let semverOK = semver.range(of: "^\\d+\\.\\d+\\.\\d+$", options: .regularExpression) != nil
        guard semverOK else { return false }
        switch publishMode {
        case .firstPublish:
            if hasAuthor == false {
                guard authorDisplayName.trimmed.count >= 1 else { return false }
                guard authorSlug.trimmed.count >= 3 else { return false }
            }
            return slug.trimmed.count >= 3 && !title.trimmed.isEmpty
        case .newVersion:
            return selectedExistingSlug != nil
        }
    }

    private func prefill() async {
        title = privateDeck.name
        deckDescription = privateDeck.deckDescription ?? ""
        category = privateDeck.category
        slug = slugify(privateDeck.name)
        let api = WordeckAPI(auth: auth)
        async let authorState = api.myAuthor()
        async let ownedState = api.myMarketplaceDecks()
        do {
            hasAuthor = try await authorState
        } catch {
            hasAuthor = false
            errorMessage = "Author-Profil konnte nicht geladen werden: \(error.localizedDescription)"
        }
        ownedDecks = await (try? ownedState) ?? []
    }

    /// State-Übergang beim Wechsel des Publish-Modus.
    /// - Erst-Publish: Slug aus dem privaten Deck-Namen, Semver 1.0.0.
    /// - Neue Version: Slug-Feld unbenutzt (Server kennt Slug),
    ///   Semver-Default = Bump der aktuellen Version.
    private func applyPublishMode(_ mode: PublishMode) {
        switch mode {
        case .firstPublish:
            selectedExistingSlug = nil
            semver = "1.0.0"
        case let .newVersion(existingSlug):
            selectedExistingSlug = existingSlug
            if let latest = ownedDecks.first(where: { $0.slug == existingSlug })?.latestVersion {
                semver = bumpMinor(latest.semver)
            } else {
                semver = "1.0.0"
            }
        }
    }

    /// `1.4.2` → `1.5.0`. Bei unparsbarem Input bleibt 1.0.0 als Default.
    private func bumpMinor(_ version: String) -> String {
        let parts = version.split(separator: ".")
        guard parts.count == 3,
              let major = Int(parts[0]),
              let minor = Int(parts[1])
        else { return "1.0.0" }
        return "\(major).\(minor + 1).0"
    }

    private func submit() async {
        isSubmitting = true
        errorMessage = nil
        defer { isSubmitting = false }
        let api = WordeckAPI(auth: auth)
        do {
            let targetSlug = try await prepareTargetSlug(api: api)
            try await publishCards(toSlug: targetSlug, api: api)
        } catch let error as AuthError {
            errorMessage = mapPublishError(error)
        } catch {
            errorMessage = error.localizedDescription
        }
    }

    /// Erst-Publish-Pfad: Author-Profil + Marketplace-Deck-Init.
    /// Liefert den Slug auf den `publishCards` veröffentlicht.
    private func prepareTargetSlug(api: WordeckAPI) async throws -> String {
        switch publishMode {
        case .firstPublish:
            if hasAuthor == false {
                try await api.upsertAuthor(AuthorUpsertBody(
                    slug: authorSlug.trimmed,
                    displayName: authorDisplayName.trimmed,
                    bio: authorBio.trimmed.isEmpty ? nil : authorBio.trimmed,
                    avatarUrl: nil,
                    pseudonym: authorPseudonym
                ))
                hasAuthor = true
            }
            _ = try await api.initMarketplaceDeck(MarketplaceDeckInitBody(
                slug: slug.trimmed,
                title: title.trimmed,
                description: deckDescription.trimmed.isEmpty ? nil : deckDescription.trimmed,
                language: language.rawValue,
                license: license.rawValue,
                priceCredits: license == .proOnly ? priceCredits : 0,
                category: category
            ))
            return slug.trimmed
        case let .newVersion(existingSlug):
            return existingSlug
        }
    }

    /// Lädt alle Karten des privaten Decks, konvertiert in Marketplace-
    /// Format und veröffentlicht die neue Version.
    private func publishCards(toSlug targetSlug: String, api: WordeckAPI) async throws {
        let cards = try await api.listCards(deckId: privateDeck.id)
        let converted = cards.compactMap(MarketplaceCardConverter.convert)
        skippedCardCount = cards.count - converted.count
        guard !converted.isEmpty else {
            errorMessage = "Keine Karten kompatibel mit dem Marketplace-Format."
            return
        }
        result = try await api.publishMarketplaceVersion(
            slug: targetSlug,
            body: MarketplacePublishBody(
                semver: semver.trimmed,
                changelog: changelog.trimmed.isEmpty ? nil : changelog.trimmed,
                cards: converted
            )
        )
    }

    private func mapPublishError(_ error: AuthError) -> String {
        if case let .serverError(status, _, message) = error {
            switch status {
            case 409:
                if let message, message.contains("slug_taken") {
                    return "Dieser Slug ist schon vergeben. Bitte einen anderen wählen."
                }
                return message ?? "Konflikt — Version-Bump nötig?"
            case 403:
                if let message, message.contains("moderation_block") {
                    return "AI-Moderation hat den Inhalt blockiert."
                }
                return message ?? "Aktion nicht erlaubt."
            case 422:
                return message ?? "Eingabe ungültig."
            default:
                break
            }
        }
        return error.errorDescription ?? "Veröffentlichen fehlgeschlagen."
    }

    private func alertMessage(for response: MarketplacePublishResponse) -> String {
        let parts = [
            "Version \(response.version.semver)",
            "\(response.version.cardCount) Karten",
            skippedCardCount > 0 ? "\(skippedCardCount) übersprungen" : nil,
            "Moderation: \(response.moderation.verdict)"
        ].compactMap(\.self)
        return parts.joined(separator: " · ")
    }

    private func slugify(_ input: String) -> String {
        let allowed = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyz0123456789-")
        let lowered = input
            .folding(options: .diacriticInsensitive, locale: .current)
            .lowercased()
        var result = ""
        for scalar in lowered.unicodeScalars {
            if allowed.contains(scalar) {
                result.unicodeScalars.append(scalar)
            } else {
                result.append("-")
            }
        }
        while result.hasPrefix("-") {
            result.removeFirst()
        }
        while result.hasSuffix("-") {
            result.removeLast()
        }
        while result.contains("--") {
            result = result.replacingOccurrences(of: "--", with: "-")
        }
        return String(result.prefix(60))
    }
}

// swiftlint:enable type_body_length

private extension String {
    var trimmed: String {
        trimmingCharacters(in: .whitespacesAndNewlines)
    }
}

extension MarketplacePublishResponse: Identifiable {
    var id: String {
        version.id
    }
}