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

using static PKHeX.Core.MessageStrings;

namespace PKHeX.Core
{
    /// <summary>
    /// Contains extension methods for use with a <see cref="SaveFile"/>.
    /// </summary>
    public static class BoxUtil
    {
        /// <summary>
        /// Dumps a folder of files to the <see cref="SaveFile"/>.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> that is being dumped from.</param>
        /// <param name="path">Folder to store <see cref="PKM"/> files.</param>
        /// <param name="boxFolders">Option to save in child folders with the Box Name as the folder name.</param>
        /// <returns>-1 if aborted, otherwise the amount of files dumped.</returns>
        public static int DumpBoxes(this SaveFile sav, string path, bool boxFolders = false)
        {
            if (!sav.HasBox)
                return -1;

            var boxData = sav.BoxData;
            int boxSlotCount = sav.BoxSlotCount;
            var ctr = 0;
            for (var slot = 0; slot < boxData.Count; slot++)
            {
                var pk = boxData[slot];
                var box = slot / boxSlotCount;
                if (pk.Species == 0 || !pk.Valid)
                    continue;

                var boxFolder = path;
                if (boxFolders)
                {
                    var boxName = Util.CleanFileName(sav.GetBoxName(box));
                    boxFolder = Path.Combine(path, boxName);
                    Directory.CreateDirectory(boxFolder);
                }

                var fileName = Util.CleanFileName(pk.FileName);
                var fn = Path.Combine(boxFolder, fileName);
                if (File.Exists(fn))
                    continue;

                File.WriteAllBytes(fn, pk.DecryptedPartyData);
                ctr++;
            }
            return ctr;
        }

        /// <summary>
        /// Dumps the <see cref="SaveFile.BoxData"/> to a folder with individual decrypted files.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> that is being dumped from.</param>
        /// <param name="path">Folder to store <see cref="PKM"/> files.</param>
        /// <param name="currentBox">Box contents to be dumped.</param>
        /// <returns>-1 if aborted, otherwise the amount of files dumped.</returns>
        public static int DumpBox(this SaveFile sav, string path, int currentBox)
        {
            if (!sav.HasBox)
                return -1;

            var boxData = sav.BoxData;
            int boxSlotCount = sav.BoxSlotCount;
            var ctr = 0;
            for (var slot = 0; slot < boxData.Count; slot++)
            {
                var pk = boxData[slot];
                var box = slot / boxSlotCount;
                if (pk.Species == 0 || !pk.Valid || box != currentBox)
                    continue;

                var fileName = Path.Combine(path, Util.CleanFileName(pk.FileName));
                if (File.Exists(fileName))
                    continue;

                File.WriteAllBytes(fileName, pk.DecryptedPartyData);
                ctr++;
            }
            return ctr;
        }

        /// <summary>
        /// Loads a folder of files to the <see cref="SaveFile"/>.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> to load folder to.</param>
        /// <param name="path">Folder to load <see cref="PKM"/> files from. Files are only loaded from the top directory.</param>
        /// <param name="result">Result message from the method.</param>
        /// <param name="boxStart">First box to start loading to. All prior boxes are not modified.</param>
        /// <param name="boxClear">Instruction to clear boxes after the starting box.</param>
        /// <param name="overwrite">Overwrite existing full slots. If true, will only overwrite empty slots.</param>
        /// <param name="noSetb">Bypass option to not modify <see cref="PKM"/> properties when setting to Save File.</param>
        /// <param name="all">Enumerate all files even in sub-folders.</param>
        /// <returns>Count of files imported.</returns>
        public static int LoadBoxes(this SaveFile sav, string path, out string result, int boxStart = 0, bool boxClear = false, bool overwrite = false, PKMImportSetting noSetb = PKMImportSetting.UseDefault, bool all = false)
        {
            if (string.IsNullOrWhiteSpace(path) || !Directory.Exists(path))
            { result = MsgSaveBoxExportPathInvalid; return -1; }

            var option = all ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly;
            var files = Directory.EnumerateFiles(path, "*.*", option);
            return sav.LoadBoxes(files, out result, boxStart, boxClear, overwrite, noSetb);
        }

        /// <summary>
        /// Loads a folder of files to the <see cref="SaveFile"/>.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> to load folder to.</param>
        /// <param name="files">Files to load <see cref="PKM"/> files from.</param>
        /// <param name="result">Result message from the method.</param>
        /// <param name="boxStart">First box to start loading to. All prior boxes are not modified.</param>
        /// <param name="boxClear">Instruction to clear boxes after the starting box.</param>
        /// <param name="overwrite">Overwrite existing full slots. If true, will only overwrite empty slots.</param>
        /// <param name="noSetb">Bypass option to not modify <see cref="PKM"/> properties when setting to Save File.</param>
        /// <returns>Count of files imported.</returns>
        public static int LoadBoxes(this SaveFile sav, IEnumerable<string> files, out string result, int boxStart = 0, bool boxClear = false, bool overwrite = false, PKMImportSetting noSetb = PKMImportSetting.UseDefault)
        {
            var pks = GetPossiblePKMsFromPaths(sav, files);
            return sav.LoadBoxes(pks, out result, boxStart, boxClear, overwrite, noSetb);
        }

        /// <summary>
        /// Loads a folder of files to the <see cref="SaveFile"/>.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> to load folder to.</param>
        /// <param name="encounters">Encounters to create <see cref="PKM"/> files from.</param>
        /// <param name="result">Result message from the method.</param>
        /// <param name="boxStart">First box to start loading to. All prior boxes are not modified.</param>
        /// <param name="boxClear">Instruction to clear boxes after the starting box.</param>
        /// <param name="overwrite">Overwrite existing full slots. If true, will only overwrite empty slots.</param>
        /// <param name="noSetb">Bypass option to not modify <see cref="PKM"/> properties when setting to Save File.</param>
        /// <returns>Count of files imported.</returns>
        public static int LoadBoxes(this SaveFile sav, IEnumerable<IEncounterConvertible> encounters, out string result, int boxStart = 0, bool boxClear = false, bool overwrite = false, PKMImportSetting noSetb = PKMImportSetting.UseDefault)
        {
            var pks = encounters.Select(z => z.ConvertToPKM(sav));
            return sav.LoadBoxes(pks, out result, boxStart, boxClear, overwrite, noSetb);
        }

        /// <summary>
        /// Loads a folder of files to the <see cref="SaveFile"/>.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> to load folder to.</param>
        /// <param name="pks">Unconverted <see cref="PKM"/> objects to load.</param>
        /// <param name="result">Result message from the method.</param>
        /// <param name="boxStart">First box to start loading to. All prior boxes are not modified.</param>
        /// <param name="boxClear">Instruction to clear boxes after the starting box.</param>
        /// <param name="overwrite">Overwrite existing full slots. If true, will only overwrite empty slots.</param>
        /// <param name="noSetb">Bypass option to not modify <see cref="PKM"/> properties when setting to Save File.</param>
        /// <returns>True if any files are imported.</returns>
        public static int LoadBoxes(this SaveFile sav, IEnumerable<PKM> pks, out string result, int boxStart = 0, bool boxClear = false, bool overwrite = false, PKMImportSetting noSetb = PKMImportSetting.UseDefault)
        {
            if (!sav.HasBox)
            { result = MsgSaveBoxFailNone; return -1; }

            var compat = sav.GetCompatible(pks);
            if (boxClear)
                sav.ClearBoxes(boxStart);

            int ctr = sav.ImportPKMs(compat, overwrite, boxStart, noSetb);
            if (ctr <= 0)
            {
                result = MsgSaveBoxImportNoFiles;
                return -1;
            }

            result = string.Format(MsgSaveBoxImportSuccess, ctr);
            return ctr;
        }

        public static IEnumerable<PKM> GetPKMsFromPaths(IEnumerable<string> files, int generation)
        {
            var result = files
                .Where(file => PKX.IsPKM(new FileInfo(file).Length))
                .Select(File.ReadAllBytes)
                .Select(data => PKMConverter.GetPKMfromBytes(data, prefer: generation));

            foreach (var pkm in result)
            {
                if (pkm?.Species is > 0)
                    yield return pkm;
            }
        }

        private static IEnumerable<PKM> GetPossiblePKMsFromPaths(SaveFile sav, IEnumerable<string> files)
        {
            foreach (var f in files)
            {
                var obj = FileUtil.GetSupportedFile(f, sav);
                switch (obj)
                {
                    case PKM pk:
                        yield return pk;
                        break;
                    case MysteryGift {IsPokémon: true} g:
                        yield return g.ConvertToPKM(sav);
                        break;
                    case GP1 g when g.Species != 0:
                        yield return g.ConvertToPB7(sav);
                        break;
                    case IPokeGroup g:
                        foreach (var p in g.Contents)
                            yield return p;
                        break;
                }
            }
        }

        /// <summary>
        /// Gets box names for all boxes in the save file.
        /// </summary>
        /// <param name="sav"><see cref="SaveFile"/> that box names are being dumped for.</param>
        /// <returns>Returns default English box names in the event the save file does not have names (not exportable), or fails to return a box name.</returns>
        public static string[] GetBoxNames(SaveFile sav)
        {
            int count = sav.BoxCount;
            var result = new string[count];
            if (!sav.State.Exportable)
            {
                for (int i = 0; i < count; i++)
                    result[i] = $"Box {i + 1}";
                return result;
            }

            for (int i = 0; i < count; i++)
            {
                try { result[i] = sav.GetBoxName(i); }
                catch { result[i] = $"Box {i + 1}"; }
            }

            return result;
        }
    }
}