import Foundation

struct CRDTProjection: Decodable, Sendable {
    var children: [CRDTNode]
    var canUndo: Bool
    var canRedo: Bool
}
struct CRDTNode: Decodable, Identifiable, Sendable {
    let id: String
    let type: String
    var attrs: [String: String]?
    var children: [CRDTNode]?
    var runs: [CRDTRun]?
    var plainText: String { runs?.map(\.insert).joined() ?? children?.map(\.plainText).joined() ?? "" }
}
struct CRDTRun: Decodable, Sendable {
    var insert: String
    var marks: [String: JSONValue]?
}
indirect enum JSONValue: Codable, Sendable, Equatable {
    case object([String: JSONValue]), array([JSONValue]), string(String), number(Double), bool(Bool), null
    init(from decoder: any Decoder) throws {
        let c = try decoder.singleValueContainer()
        if c.decodeNil() { self = .null }
        else if let v = try? c.decode(Bool.self) { self = .bool(v) }
        else if let v = try? c.decode(String.self) { self = .string(v) }
        else if let v = try? c.decode(Double.self) { self = .number(v) }
        else if let v = try? c.decode([String: JSONValue].self) { self = .object(v) }
        else { self = .array(try c.decode([JSONValue].self)) }
    }
    func encode(to encoder: any Encoder) throws {
        var c = encoder.singleValueContainer()
        switch self {
        case .object(let v): try c.encode(v)
        case .array(let v): try c.encode(v)
        case .string(let v): try c.encode(v)
        case .number(let v): try c.encode(v)
        case .bool(let v): try c.encode(v)
        case .null: try c.encodeNil()
        }
    }
}