using System;
using System.Collections.Generic;

using SabreTools.Library.Data;
using SabreTools.Library.DatItems;
using SabreTools.Library.IO;
using SabreTools.Library.Tools;

namespace SabreTools.Library.Filtering
{
    public class ExtraIniItem
    {
        #region Fields

        /// <summary>
        /// Field to update with INI information
        /// </summary>
        public Field Field { get; set; }

        /// <summary>
        /// Mappings from value to machine name
        /// </summary>
        public Dictionary<string, List<string>> Mappings { get; set; } = new Dictionary<string, List<string>>();

        #endregion

        #region Extras Population

        /// <summary>
        /// Populate item using a field:file input
        /// </summary>
        /// <param name="ini">Field and file combination</param>
        public void PopulateFromInput(string ini)
        {
            // If we don't even have a possible field and file combination
            if (!ini.Contains(":"))
            {
                Globals.Logger.Warning($"'{ini}` is not a valid INI extras string. Valid INI extras strings are of the form 'key:value'. Please refer to README.1ST or the help feature for more details.");
                return;
            }

            string iniTrimmed = ini.Trim('"', ' ', '\t');
            string iniFieldString = iniTrimmed.Split(':')[0].ToLowerInvariant().Trim('"', ' ', '\t');
            string iniFileString = iniTrimmed.Substring(iniFieldString.Length + 1).Trim('"', ' ', '\t');

            Field = iniFieldString.AsField();
            PopulateFromFile(iniFileString);
        }

        /// <summary>
        /// Populate the dictionary from an INI file
        /// </summary>
        /// <param name="ini">Path to INI file to populate from</param>
        /// <remarks>
        /// The INI file format that is supported here is not exactly the same
        /// as a traditional one. This expects a MAME extras format, which usually
        /// doesn't contain key value pairs and always at least contains one section
        /// called `ROOT_FOLDER`. If that's the name of a section, then we assume
        /// the value is boolean. If there's another section name, then that is set
        /// as the value instead.
        /// </remarks>
        public void PopulateFromFile(string ini)
        {
            // Prepare all intenral variables
            IniReader ir = ini.GetIniReader(false);
            bool foundRootFolder = false;

            // If we got a null reader, just return
            if (ir == null)
                return;

            // Otherwise, read the file to the end
            try
            {
                ir.ReadNextLine();
                while (!ir.EndOfStream)
                {
                    // We don't care about whitespace or comments
                    if (ir.RowType == IniRowType.None || ir.RowType == IniRowType.Comment)
                    {
                        ir.ReadNextLine();
                        continue;
                    }

                    // If we have a section, just read it in
                    if (ir.RowType == IniRowType.SectionHeader)
                    {
                        ir.ReadNextLine();

                        // If we've found the start of the extras, set the flag
                        if (string.Equals(ir.Section, "ROOT_FOLDER", StringComparison.OrdinalIgnoreCase))
                            foundRootFolder = true;

                        continue;
                    }

                    // If we have a value, then we start populating the dictionary
                    else if (foundRootFolder)
                    {
                        // Get the key and value
                        string key = ir.Section;
                        string value = ir.Line.Trim();

                        // Ensure the key exists
                        if (!Mappings.ContainsKey(key))
                            Mappings[key] = new List<string>();

                        // Add the new mapping
                        Mappings[key].Add(value);
                    }
                }
            }
            catch (Exception ex)
            {
                Globals.Logger.Warning($"Exception found while parsing '{ini}': {ex}");
            }

            ir.Dispose();
        }

        #endregion
    }
}