using System;
using Newtonsoft.Json;

namespace Firebase.Database.Offline {
    /// <summary>
    ///     Represents an object stored in offline storage.
    /// </summary>
    public class OfflineEntry {
        private object dataInstance;

        /// <summary>
        ///     Initializes a new instance of the <see cref="OfflineEntry" /> class with an already serialized object.
        /// </summary>
        /// <param name="key"> The key. </param>
        /// <param name="obj"> The object. </param>
        /// <param name="priority">
        ///     The priority. Objects with higher priority will be synced first. Higher number indicates higher
        ///     priority.
        /// </param>
        /// <param name="syncOptions"> The sync options. </param>
        public OfflineEntry(string key, object obj, string data, int priority, SyncOptions syncOptions,
            bool isPartial = false) {
            Key = key;
            Priority = priority;
            Data = data;
            Timestamp = DateTime.UtcNow;
            SyncOptions = syncOptions;
            IsPartial = isPartial;

            dataInstance = obj;
        }

        /// <summary>
        ///     Initializes a new instance of the <see cref="OfflineEntry" /> class.
        /// </summary>
        /// <param name="key"> The key. </param>
        /// <param name="obj"> The object. </param>
        /// <param name="priority">
        ///     The priority. Objects with higher priority will be synced first. Higher number indicates higher
        ///     priority.
        /// </param>
        /// <param name="syncOptions"> The sync options. </param>
        public OfflineEntry(string key, object obj, int priority, SyncOptions syncOptions, bool isPartial = false)
            : this(key, obj, JsonConvert.SerializeObject(obj), priority, syncOptions, isPartial) {
        }

        /// <summary>
        ///     Initializes a new instance of the <see cref="OfflineEntry" /> class.
        /// </summary>
        public OfflineEntry() {
        }

        /// <summary>
        ///     Gets or sets the key of this entry.
        /// </summary>
        public string Key { get; set; }

        /// <summary>
        ///     Gets or sets the priority. Objects with higher priority will be synced first. Higher number indicates higher
        ///     priority.
        /// </summary>
        public int Priority { get; set; }

        /// <summary>
        ///     Gets or sets the timestamp when this entry was last touched.
        /// </summary>
        public DateTime Timestamp { get; set; }

        /// <summary>
        ///     Gets or sets the <see cref="SyncOptions" /> which define what sync state this entry is in.
        /// </summary>
        public SyncOptions SyncOptions { get; set; }

        /// <summary>
        ///     Gets or sets serialized JSON data.
        /// </summary>
        public string Data { get; set; }

        /// <summary>
        ///     Specifies whether this is only a partial object.
        /// </summary>
        public bool IsPartial { get; set; }

        /// <summary>
        ///     Deserializes <see cref="Data" /> into <typeparamref name="T" />. The result is cached.
        /// </summary>
        /// <typeparam name="T"> Type of object to deserialize into. </typeparam>
        /// <returns> Instance of <typeparamref name="T" />. </returns>
        public T Deserialize<T>() {
            return (T) (dataInstance ?? (dataInstance = JsonConvert.DeserializeObject<T>(Data)));
        }
    }
}