//
//  RouterConfigStore.swift
//  Zyquo Router
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//
//  User routing configuration: aliases (fast → cerebras/…), fallback chains,
//  disabled models, favorites. Persisted to router-config.json; the server
//  takes a snapshot at Start (restart applies changes to a running server).
//

import Foundation

struct RouterConfig: Codable {
    static let fileName = "router-config.json"

    var aliases: [String: String] = [:]
    var fallbackChains: [String: [String]] = [:]
    var disabledIDs: Set<String> = []
    var favoriteIDs: Set<String> = []
}

@MainActor
final class RouterConfigStore: ObservableObject {
    static var fileName: String { RouterConfig.fileName }

    @Published var config: RouterConfig {
        didSet { persistence.save(config, to: Self.fileName) }
    }

    private let persistence: PersistenceService

    init(persistence: PersistenceService = .shared) {
        self.persistence = persistence
        config = persistence.load(RouterConfig.self, from: Self.fileName) ?? RouterConfig()
    }

    /// Snapshot for the server thread (also used headless via `load`).
    static func snapshot() -> RouterConfig {
        PersistenceService.shared.load(RouterConfig.self, from: fileName) ?? RouterConfig()
    }

    func isDisabled(_ namespacedID: String) -> Bool {
        config.disabledIDs.contains(namespacedID)
    }

    func setDisabled(_ disabled: Bool, for namespacedID: String) {
        if disabled {
            config.disabledIDs.insert(namespacedID)
        } else {
            config.disabledIDs.remove(namespacedID)
        }
    }

    func isFavorite(_ namespacedID: String) -> Bool {
        config.favoriteIDs.contains(namespacedID)
    }

    func toggleFavorite(_ namespacedID: String) {
        if !config.favoriteIDs.insert(namespacedID).inserted {
            config.favoriteIDs.remove(namespacedID)
        }
    }

    func setAlias(_ alias: String, target: String) {
        let name = alias.trimmingCharacters(in: .whitespaces)
        guard !name.isEmpty else { return }
        config.aliases[name] = target
    }

    func removeAlias(_ alias: String) {
        config.aliases.removeValue(forKey: alias)
    }

    func setChain(for namespacedID: String, chain: [String]) {
        if chain.isEmpty {
            config.fallbackChains.removeValue(forKey: namespacedID)
        } else {
            config.fallbackChains[namespacedID] = chain
        }
    }

    /// Export for Settings → Advanced (never includes keys).
    func exportData() throws -> Data {
        let encoder = JSONEncoder()
        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
        return try encoder.encode(config)
    }

    func importData(_ data: Data) throws {
        config = try JSONDecoder().decode(RouterConfig.self, from: data)
    }
}