1 files changed, 201 insertions, 0 deletions
diff --git a/FireBase/Offline/OfflineDatabase.cs b/FireBase/Offline/OfflineDatabase.cs
new file mode 100644
index 0000000..9cebf9c
--- /dev/null
+++ b/FireBase/Offline/OfflineDatabase.cs
@@ -0,0 +1,201 @@
+namespace Firebase.Database.Offline
+{
+    using System;
+    using System.Collections;
+    using System.Collections.Generic;
+    using System.IO;
+    using System.Linq;
+
+    using LiteDB;
+
+    /// <summary>
+    /// The offline database.
+    /// </summary>
+    public class OfflineDatabase : IDictionary<string, OfflineEntry>
+    {
+        private readonly LiteRepository db;
+        private readonly IDictionary<string, OfflineEntry> cache;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="OfflineDatabase"/> class.
+        /// </summary>
+        /// <param name="itemType"> The item type which is used to determine the database file name.  </param>
+        /// <param name="filenameModifier"> Custom string which will get appended to the file name. </param>
+        public OfflineDatabase(Type itemType, string filenameModifier)
+        {
+            var fullName = this.GetFileName(itemType.ToString());
+            if(fullName.Length > 100)
+            {
+                fullName = fullName.Substring(0, 100);
+            }
+
+            BsonMapper mapper = BsonMapper.Global;
+            mapper.Entity<OfflineEntry>().Id(o => o.Key);
+
+            string root = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            string filename = fullName + filenameModifier + ".db";
+            var path = Path.Combine(root, filename);
+            this.db = new LiteRepository(new LiteDatabase(path, mapper));
+
+            this.cache = db.Database.GetCollection<OfflineEntry>().FindAll()
+                .ToDictionary(o => o.Key, o => o);
+        }
+
+        /// <summary>
+        /// Gets the number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </summary>
+        /// <returns> The number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>. </returns>
+        public int Count => this.cache.Count;
+
+        /// <summary>
+        /// Gets a value indicating whether this is a read-only collection.
+        /// </summary>
+        public bool IsReadOnly => this.cache.IsReadOnly;
+
+        /// <summary>
+        /// Gets an <see cref="T:System.Collections.Generic.ICollection`1"/> containing the keys of the <see cref="T:System.Collections.Generic.IDictionary`2"/>.
+        /// </summary>
+        /// <returns> An <see cref="T:System.Collections.Generic.ICollection`1"/> containing the keys of the object that implements <see cref="T:System.Collections.Generic.IDictionary`2"/>. </returns>
+        public ICollection<string> Keys => this.cache.Keys;
+
+        /// <summary>
+        /// Gets an <see cref="T:System.Collections.Generic.ICollection`1"/> containing the values in the <see cref="T:System.Collections.Generic.IDictionary`2"/>.
+        /// </summary>
+        /// <returns> An <see cref="T:System.Collections.Generic.ICollection`1"/> containing the values in the object that implements <see cref="T:System.Collections.Generic.IDictionary`2"/>. </returns>
+        public ICollection<OfflineEntry> Values => this.cache.Values;
+
+        /// <summary>
+        /// Gets or sets the element with the specified key.
+        /// </summary>
+        /// <param name="key">The key of the element to get or set.</param>
+        /// <returns> The element with the specified key. </returns>   
+        public OfflineEntry this[string key]
+        {
+            get
+            {
+                return this.cache[key];
+            }
+
+            set
+            {
+                this.cache[key] = value;
+                this.db.Upsert(value);
+            }
+        }
+
+        /// <summary>
+        /// Returns an enumerator that iterates through the collection.
+        /// </summary>
+        /// <returns> An enumerator that can be used to iterate through the collection. </returns>
+        public IEnumerator<KeyValuePair<string, OfflineEntry>> GetEnumerator()
+        {
+            return this.cache.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return this.GetEnumerator();
+        }
+
+        /// <summary>
+        /// Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </summary>
+        /// <param name="item">The object to add to the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
+        public void Add(KeyValuePair<string, OfflineEntry> item)
+        {
+            this.Add(item.Key, item.Value);
+        }
+
+        /// <summary>
+        /// Removes all items from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </summary> 
+        public void Clear()
+        {
+            this.cache.Clear();
+            this.db.Delete<OfflineEntry>(Query.All());
+        }
+
+        /// <summary>
+        /// Determines whether the <see cref="T:System.Collections.Generic.ICollection`1"/> contains a specific value.
+        /// </summary>
+        /// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param> 
+        /// <returns> True if <paramref name="item"/> is found in the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. </returns>
+        public bool Contains(KeyValuePair<string, OfflineEntry> item)
+        {
+            return this.ContainsKey(item.Key);
+        }
+
+        /// <summary>
+        /// Copies the elements of the <see cref="T:System.Collections.Generic.ICollection`1"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
+        /// </summary>
+        /// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the elements copied from <see cref="T:System.Collections.Generic.ICollection`1"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param>
+        /// <param name="arrayIndex">The zero-based index in <paramref name="array"/> at which copying begins.</param>
+        public void CopyTo(KeyValuePair<string, OfflineEntry>[] array, int arrayIndex)
+        {
+            this.cache.CopyTo(array, arrayIndex);
+        }
+
+        /// <summary>
+        /// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </summary>
+        /// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
+        /// <returns> True if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>. </returns>
+        public bool Remove(KeyValuePair<string, OfflineEntry> item)
+        {
+            return this.Remove(item.Key);
+        }
+
+        /// <summary>
+        /// Determines whether the <see cref="T:System.Collections.Generic.IDictionary`2"/> contains an element with the specified key.
+        /// </summary>
+        /// <param name="key">The key to locate in the <see cref="T:System.Collections.Generic.IDictionary`2"/>.</param>
+        /// <returns> True if the <see cref="T:System.Collections.Generic.IDictionary`2"/> contains an element with the key; otherwise, false. </returns>
+        public bool ContainsKey(string key)
+        {
+            return this.cache.ContainsKey(key);
+        }
+
+        /// <summary>
+        /// Adds an element with the provided key and value to the <see cref="T:System.Collections.Generic.IDictionary`2"/>.
+        /// </summary>
+        /// <param name="key">The object to use as the key of the element to add.</param>
+        /// <param name="value">The object to use as the value of the element to add.</param>
+        public void Add(string key, OfflineEntry value)
+        {
+            this.cache.Add(key, value);
+            this.db.Insert(value);
+        }
+
+        /// <summary>
+        /// Removes the element with the specified key from the <see cref="T:System.Collections.Generic.IDictionary`2"/>.
+        /// </summary>
+        /// <param name="key">The key of the element to remove.</param>
+        /// <returns> True if the element is successfully removed; otherwise, false.  This method also returns false if <paramref name="key"/> was not found in the original <see cref="T:System.Collections.Generic.IDictionary`2"/>. </returns>
+        public bool Remove(string key)
+        {
+            this.cache.Remove(key);
+            return this.db.Delete<OfflineEntry>(key);
+        }
+
+        /// <summary>
+        /// Gets the value associated with the specified key.
+        /// </summary> 
+        /// <param name="key">The key whose value to get.</param><param name="value">When this method returns, the value associated with the specified key, if the key is found; otherwise, the default value for the type of the <paramref name="value"/> parameter. This parameter is passed uninitialized.</param>
+        /// <returns> True if the object that implements <see cref="T:System.Collections.Generic.IDictionary`2"/> contains an element with the specified key; otherwise, false. </returns>
+        public bool TryGetValue(string key, out OfflineEntry value)
+        {
+            return this.cache.TryGetValue(key, out value);
+        }
+
+        private string GetFileName(string fileName)
+        {
+            var invalidChars = new[] { '`', '[', ',', '=' };
+            foreach(char c in invalidChars.Concat(System.IO.Path.GetInvalidFileNameChars()).Distinct())
+            {
+                fileName = fileName.Replace(c, '_');
+            }
+
+            return fileName;
+        }
+    }
+}