import Foundation
import SwiftUI

enum ScoreDialogKind {
    case setWon
    case closeSet
    case closeSetAnyway
    case matchWon
}

struct ScoreDialogState: Identifiable {
    let id = UUID()
    let kind: ScoreDialogKind
    var winnerSide: ScoringSide?
    var homePoints: Int = 0
    var awayPoints: Int = 0
    var homeSets: Int = 0
    var awaySets: Int = 0
}

@MainActor
final class LiveScoreDialogHost: ObservableObject {
    @Published private(set) var pending: ScoreDialogState?
    private var waiter: CheckedContinuation<Bool, Never>?

    func show(_ state: ScoreDialogState) async -> Bool {
        guard pending == nil else { return false }
        return await withCheckedContinuation { continuation in
            pending = state
            waiter = continuation
        }
    }

    func resolve(_ value: Bool) {
        guard let continuation = waiter else { return }
        pending = nil
        waiter = nil
        continuation.resume(returning: value)
    }
}

@MainActor
final class LiveScoreActions {
    private let rules: MatchScoringContext
    private let scoreController: ScoreController
    private let dialogHost: LiveScoreDialogHost
    private let onStopStream: () async -> Void
    private let onScoreboardChanged: () -> Void

    init(
        rules: MatchScoringContext,
        scoreController: ScoreController,
        dialogHost: LiveScoreDialogHost,
        onStopStream: @escaping () async -> Void,
        onScoreboardChanged: @escaping () -> Void = {}
    ) {
        self.rules = rules
        self.scoreController = scoreController
        self.dialogHost = dialogHost
        self.onStopStream = onStopStream
        self.onScoreboardChanged = onScoreboardChanged
    }

    func afterPointChange(score: ScoreState) async {
        guard rules.usesSetLogic else { return }
        guard let winner = rules.setWinnerFromPoints(
            homePoints: score.homePoints,
            awayPoints: score.awayPoints,
            currentSet: score.currentSet
        ) else { return }

        let close = await dialogHost.show(
            ScoreDialogState(
                kind: .setWon,
                winnerSide: winner,
                homePoints: score.homePoints,
                awayPoints: score.awayPoints
            )
        )
        if close {
            guard await scoreController.closeSetAsync() else { return }
            onScoreboardChanged()
            await afterCloseSet()
        }
    }

    func requestCloseSet() async {
        guard rules.usesSetLogic else { return }

        let score = scoreController.score
        let winner = rules.setWinnerFromPoints(
            homePoints: score.homePoints,
            awayPoints: score.awayPoints,
            currentSet: score.currentSet
        )
        let ok = await dialogHost.show(
            ScoreDialogState(kind: winner == nil ? .closeSetAnyway : .closeSet)
        )
        if !ok { return }
        guard await scoreController.closeSetAsync() else { return }
        onScoreboardChanged()
        await afterCloseSet()
    }

    private func afterCloseSet() async {
        let score = scoreController.score
        guard let winner = rules.matchWinner(homeSets: score.homeSets, awaySets: score.awaySets) else { return }
        let stop = await dialogHost.show(
            ScoreDialogState(
                kind: .matchWon,
                winnerSide: winner,
                homeSets: score.homeSets,
                awaySets: score.awaySets
            )
        )
        if stop { await onStopStream() }
    }
}

struct ScoreDialogRouter: View {
    @ObservedObject var host: LiveScoreDialogHost
    let homeName: String
    let awayName: String

    var body: some View {
        Color.clear
            .frame(width: 0, height: 0)
            .alert(item: dialogBinding) { dialog in
                alert(for: dialog)
            }
    }

    private var dialogBinding: Binding<ScoreDialogState?> {
        Binding(
            get: { host.pending },
            set: { _ in
                // Non risolvere qui: su iPad la dismiss dell'alert può azzerare l'item
                // dopo il tap su «Chiudi set» e sovrascrivere resolve(true) con false.
            }
        )
    }

    private func alert(for dialog: ScoreDialogState) -> Alert {
        switch dialog.kind {
        case .setWon:
            let winner = dialog.winnerSide.map { scoringSideName($0, homeName: homeName, awayName: awayName) } ?? ""
            return Alert(
                title: Text(L10n.t("score.set.won.title")),
                message: Text(L10n.t("score.set.won.message", winner, dialog.homePoints, dialog.awayPoints)),
                primaryButton: .default(Text(L10n.t("score.action.close.set"))) { host.resolve(true) },
                secondaryButton: .cancel(Text(L10n.t("score.action.continue.scoring"))) { host.resolve(false) }
            )
        case .closeSet:
            return Alert(
                title: Text(L10n.t("score.action.close.set")),
                message: Text(L10n.t("broadcast.close.set.confirm.message")),
                primaryButton: .default(Text(L10n.t("score.action.close.set"))) { host.resolve(true) },
                secondaryButton: .cancel(Text(L10n.t("action.cancel"))) { host.resolve(false) }
            )
        case .closeSetAnyway:
            return Alert(
                title: Text(L10n.t("score.action.close.set")),
                message: Text(L10n.t("score.close.set.anyway.message")),
                primaryButton: .default(Text(L10n.t("score.action.close.anyway"))) { host.resolve(true) },
                secondaryButton: .cancel(Text(L10n.t("action.cancel"))) { host.resolve(false) }
            )
        case .matchWon:
            let winner = dialog.winnerSide.map { scoringSideName($0, homeName: homeName, awayName: awayName) } ?? ""
            return Alert(
                title: Text(L10n.t("score.match.won.title")),
                message: Text(L10n.t("score.match.won.message", winner, dialog.homeSets, dialog.awaySets)),
                primaryButton: .default(Text(L10n.t("score.action.close.live"))) { host.resolve(true) },
                secondaryButton: .cancel(Text(L10n.t("score.action.continue.live"))) { host.resolve(false) }
            )
        }
    }
}