mana-swift-ui/Sources/ManaFeedbackUI/FeedbackFormModel.swift

import Foundation
import ManaCore
import Observation
import PhotosUI
import SwiftUI

/// State-Maschine für ``ManaFeedbackSheet``. Wraps ``FeedbackClient``.
///
/// Bei `isLoggedIn == false` wird zusätzlich ein optionales Kontakt-Mail-Feld
/// angeboten (Rückfrage-Adresse) und der Hinweis gezeigt, dass die
/// Einreichung erst durch die Moderation geht.
@MainActor
@Observable
public final class FeedbackFormModel {
    public enum Status: Equatable, Sendable {
        case idle
        case sending
        case sent
        case error(String)
    }

    public var kind: FeedbackKind = .feedback
    public var title: String = ""
    public var details: String = ""
    public var contactEmail: String = ""
    public private(set) var status: Status = .idle

    /// Höchstzahl Screenshot-Anhänge — deckt sich mit Web + Backend (`MAX_IMAGES`).
    public let maxImages = 3
    /// Auswahl aus dem ``PhotosPicker``; ``loadPickedImages()`` verarbeitet sie.
    public var pickedItems: [PhotosPickerItem] = []
    /// Aufbereitete (herunterskalierte, EXIF-freie) JPEG-Bytes — Quelle für
    /// Thumbnails **und** den Upload.
    public private(set) var images: [Data] = []

    private let client: FeedbackClient
    public let isLoggedIn: Bool

    public init(client: FeedbackClient, isLoggedIn: Bool) {
        self.client = client
        self.isLoggedIn = isLoggedIn
    }

    public var canAddImages: Bool { images.count < maxImages }

    /// Lädt die `PhotosPicker`-Auswahl, skaliert herunter (EXIF-frei) und füllt
    /// ``images``. Wird `onChange(of: pickedItems)` aufgerufen.
    public func loadPickedImages() async {
        guard !pickedItems.isEmpty else { return }
        var collected: [Data] = []
        for item in pickedItems {
            if images.count + collected.count >= maxImages { break }
            guard let raw = try? await item.loadTransferable(type: Data.self),
                  let prepped = FeedbackImagePrep.prepare(raw) else { continue }
            collected.append(prepped)
        }
        images = Array((images + collected).prefix(maxImages))
        pickedItems = []
    }

    public func removeImage(at index: Int) {
        guard images.indices.contains(index) else { return }
        images.remove(at: index)
    }

    /// Anonyme Einreichung → Kontakt-Feld + Moderations-Hinweis zeigen.
    public var showsContactField: Bool { !isLoggedIn }

    public var canSubmit: Bool {
        guard trimmed(title).count >= 3 else { return false }
        if case .sending = status { return false }
        return true
    }

    public var isSending: Bool {
        if case .sending = status { return true }
        return false
    }

    public var errorMessage: String? {
        if case .error(let message) = status { return message }
        return nil
    }

    public func submit() async {
        guard canSubmit else { return }
        status = .sending

        let submission = FeedbackSubmission(
            kind: kind,
            title: trimmed(title),
            description: trimmed(details),
            contactEmail: isLoggedIn ? nil : nilIfEmpty(trimmed(contactEmail)),
            images: images.map { FeedbackImage(mime: "image/jpeg", b64: $0.base64EncodedString()) }
        )

        do {
            _ = try await client.submit(submission)
            status = .sent
        } catch {
            let message = (error as? LocalizedError)?.errorDescription
                ?? "Senden fehlgeschlagen. Bitte später erneut versuchen."
            status = .error(message)
        }
    }

    private func trimmed(_ value: String) -> String {
        value.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    private func nilIfEmpty(_ value: String) -> String? {
        value.isEmpty ? nil : value
    }
}

extension FeedbackKind {
    /// Deutsche Anzeige-Bezeichnung — neutral, nicht „Wunsch"-lastig.
    public var displayName: String {
        switch self {
        case .wunsch: return "Wunsch"
        case .bug: return "Problem"
        case .feedback: return "Feedback"
        }
    }
}