using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Neo.Afx.Services.Documents.Entities;

namespace Neo.Afx.Services.Documents
{
    /// <summary>
    /// Document logic for generating templates, database actions ect
    /// </summary>
    public partial class DocumentUtilities
    {
        readonly DocumentsDatabase _database = new DocumentsDatabase();

        #region Upload

        /// <summary>
        /// Uploads the specified document.
        /// </summary>
        /// <param name="userID">The user ID.</param>
        /// <param name="userName">The NT account name of the user.</param>
        /// <param name="documentID">The document ID.</param>
        /// <param name="entityID">The entity ID.</param>
        /// <param name="itemID">The item ID.</param>
        /// <param name="documentTypeID">The document type ID.</param>
        /// <param name="documentStoreLocationID">The document store location ID.</param>
        /// <param name="fileName">Name of the file.</param>
        /// <param name="contentType">Type of the content.</param>
        /// <param name="fileContents">The file contents.</param>
        /// <returns></returns>
        public Document Upload(long userID, string userName, long documentID, int entityID, long itemID, short documentTypeID, long documentStoreLocationID, string fileName, string contentType, byte[] fileContents)
        {
            var name = fileName.Contains("\\") ? fileName.Substring(fileName.LastIndexOf("\\") + 1) : fileName;

            return _database.UploadFile(userID, userName, documentID, entityID, itemID, documentTypeID, documentStoreLocationID, name, contentType, fileContents);
        }

        #endregion

        #region Copy

        /// <summary>
        /// Copies the specified document.
        /// </summary>
        /// <param name="userID">The user ID.</param>
        /// <param name="sourceDocumentIDs">The source document I ds.</param>
        /// <param name="targetEntityID">The target entity ID.</param>
        /// <param name="targetItemID">The target item ID.</param>
        /// <returns></returns>
        public KeyValuePair<long, string> Copy(long userID, string sourceDocumentIDs, int targetEntityID, long targetItemID)
        {
            return _database.CopyDocuments(userID, sourceDocumentIDs, targetEntityID, targetItemID);
        }

        #endregion

        #region Get

        /// <summary>
        /// Gets the specified document.
        /// </summary>
        /// <param name="documentID">The document ID.</param>
        /// <returns></returns>
        public Document Get(long documentID)
        {
            return _database.GetDocument(documentID);
        }

        #endregion

        #region Get

        /// <summary>
        /// Gets the specified documents.
        /// </summary>
        /// <param name="entityID">The entity ID.</param>
        /// <param name="itemID">The item ID.</param>
        /// <returns></returns>
        public IEnumerable<Document> Get(int entityID, long itemID)
        {
            return _database.GetDocuments(entityID, itemID);
        }
        #endregion

        #region Create

        /// <summary>
        /// Creates the specified user ID.
        /// </summary>
        /// <param name="userID">The user ID.</param>
        /// <param name="userName">The NT account of the user.</param>
        /// <param name="templateDocumentID">The template document ID.</param>
        /// <param name="entityID">The entity ID.</param>
        /// <param name="itemID">The item ID.</param>
        /// <param name="documentTypeID">The document type ID.</param>
        /// <param name="documentStoreLocationID">The document store location ID.</param>
        /// <returns></returns>
        public Document Create(long userID, string userName, long templateDocumentID, int entityID, long itemID, short documentTypeID, long documentStoreLocationID)
        {
            var docStoreData = _database.GetDocumentStores(templateDocumentID);
            if(docStoreData == null)
            {
                throw new Exception("System could not find the document template.");
            }

            var docStore = docStoreData.FirstOrDefault();
            var template = _database.GetDocumentTemplateData(docStore.Document.EntityID, itemID);
            if(template == null)
            {
                throw new Exception("System could not retrieve the data needed to populate the document template.");
            }

            var templateValuesDic = template.Descendants().Select(d => new KeyValuePair<string, string>(d.Name.LocalName, d.Value)).ToList();
            if(templateValuesDic.Count == 0)
            {
                throw new Exception("System failed to convert the data necessary to fill the document template.");
            }

            var templateBytes = FillTemplatedDocument(docStore.ContentBLOB, templateValuesDic);
            if(templateBytes == null)
            {
                throw new Exception("Document template failed to generate.");
            }

            return _database.UploadFile(userID,
                userName,
                -1,
                entityID,
                itemID,
                documentTypeID,
                documentStoreLocationID,
                docStore.Name,
                docStore.MimeType,
                templateBytes);
        }

        #endregion

        #region UpdateItemID

        /// <summary>
        /// Updates the item ID.
        /// </summary>
        /// <param name="userID">The user ID.</param>
        /// <param name="entityID">The entity ID.</param>
        /// <param name="oldItemID">The old item ID.</param>
        /// <param name="newItemID">The new item ID.</param>
        public void UpdateItemID(long userID, long entityID, long oldItemID, long newItemID)
        {
            _database.UpdateDocumentItemID(userID, entityID, oldItemID, newItemID);
        }

        #endregion

        #region Delete

        /// <summary>
        /// Deletes the specified document.
        /// </summary>
        /// <param name="userID">The user ID.</param>
        /// <param name="documentID">The document ID.</param>
        /// <returns></returns>
        public string Delete(long userID, long documentID)
        {
            return _database.Delete(userID, documentID);
        }

        #endregion

        #region HexStringToByteArray
        /// <summary>
        /// Converts a file hex encoded string to a file byte array
        /// </summary>
        /// <param name="s">The s.</param>
        /// <returns></returns>
        public static byte[] HexStringToByteArray(string s)
        {
            var buffer = new byte[s.Length / 2];
            for(var i = 0; i < buffer.Length; i++)
            {
                buffer[i] = (byte)Int32.Parse(s.Substring(2 * i, 2), System.Globalization.NumberStyles.HexNumber);
            }
            return buffer;
        }
        #endregion

        #region ByteArrayToHexString
        /// <summary>
        /// Converts a file byte array to a Hex encoded string.
        /// </summary>
        /// <param name="buffer">The buffer.</param>
        /// <returns></returns>
        public static string ByteArrayToHexString(byte[] buffer)
        {
            if(buffer == null || buffer.Length <= 0)
            {
                return null;
            }

            const string digits = "0123456789ABCDEF";
            byte ch = 0x00;
            var i = 0;

            var sb = new StringBuilder(buffer.Length * 2);

            while(i < buffer.Length)
            {
                ch = (byte)(buffer[i] & 0xF0); // strip off high nibble
                ch = (byte)(ch >> 4);       // shift the bits down
                ch = (byte)(ch & 0x0F);     // must do this if high order bit is on!
                sb.Append(digits[(int)ch]); // convert the nibble to a String Character
                ch = (byte)(buffer[i] & 0x0F); // strip off low nibble 
                sb.Append(digits[(int)ch]); // convert the nibble to a String Character
                i++;
            }

            return sb.ToString();
        }
        #endregion
    }
}