using System;
using System.Collections.Generic;
using System.IO;
using System.Xml.Linq;

namespace TapeCatalog.Methods
{
    /// <summary>
    /// Helpers to read XML files and produce a compact summary used by the UI.
    /// </summary>
    public static class Xml
    {
        public static List<TapeCatalog.FileEntry> ParseSummary(string filePath)
        {
            var result = new List<TapeCatalog.FileEntry>();
            if (string.IsNullOrWhiteSpace(filePath) || !File.Exists(filePath))
                return result;

            try
            {
                var doc = XDocument.Load(filePath);
                var root = doc.Root;
                if (root == null) return result;

                if (string.Equals(root.Name.LocalName, "Files", StringComparison.OrdinalIgnoreCase))
                {
                    foreach (var fe in root.Elements("File"))
                    {
                        try
                        {
                            var fn = fe.Element("Filename")?.Value ?? string.Empty;
                            var fd = fe.Element("FileDir")?.Value ?? string.Empty;
                            var st = fe.Element("Status")?.Value ?? string.Empty;
                            result.Add(new TapeCatalog.FileEntry { Filename = fn, FileDir = fd, Status = st });
                        }
                        catch
                        {
                            // ignore malformed entries
                        }
                    }
                }
                else if (string.Equals(root.Name.LocalName, "TapeEntries", StringComparison.OrdinalIgnoreCase))
                {
                    foreach (var entry in root.Elements("Entry"))
                    {
                        try
                        {
                            var fn = entry.Element("Filename")?.Value ?? string.Empty;
                            var med = entry.Element("Medium")?.Value ?? string.Empty;
                            var mod = entry.Element("Modified")?.Value ?? string.Empty;
                            result.Add(new TapeCatalog.FileEntry { Filename = fn, FileDir = med, Status = mod });
                        }
                        catch
                        {
                            // ignore malformed entries
                        }
                    }
                }
            }
            catch
            {
                // ignore parse errors and return empty list
            }

            return result;
        }

        public static string[] GetXmlFiles(string xmlDirectory)
        {
            if (string.IsNullOrWhiteSpace(xmlDirectory) || !Directory.Exists(xmlDirectory))
                return Array.Empty<string>();

            try
            {
                return Directory.GetFiles(xmlDirectory, "*.xml", SearchOption.TopDirectoryOnly);
            }
            catch
            {
                return Array.Empty<string>();
            }
        }
    }
}