using System;
using System.IO;
using System.Threading.Tasks;

namespace BetterSeewo.Manager.Services.Conversion
{
    public class ConversionEngine
    {
        private readonly PptxImporter _pptxImporter = new();
        private readonly PptxExporter _pptxExporter = new();
        private readonly EnbxWriter _enbxWriter = new();
        private readonly EnbxReader _enbxReader = new();

        public async Task<string> ConvertPptxToEnbxAsync(string pptxPath, IProgress<ConversionProgress>? progress = null)
        {
            if (!File.Exists(pptxPath))
                throw new FileNotFoundException("PPT 文件未找到", pptxPath);

            var outputPath = Path.ChangeExtension(pptxPath, ".enbx");
            return await Task.Run(() =>
            {
                progress?.Report(new ConversionProgress(0, "读取 PPTX..."));

                var doc = _pptxImporter.Import(pptxPath);

                progress?.Report(new ConversionProgress(50, "写入 ENBX..."));

                _enbxWriter.Export(doc, outputPath);

                progress?.Report(new ConversionProgress(100, "转换完成"));

                return outputPath;
            });
        }

        public async Task<string> ConvertEnbxToPptxAsync(string enbxPath, IProgress<ConversionProgress>? progress = null)
        {
            if (!File.Exists(enbxPath))
                throw new FileNotFoundException("ENBX 文件未找到", enbxPath);

            var outputPath = Path.ChangeExtension(enbxPath, ".pptx");
            return await Task.Run(() =>
            {
                progress?.Report(new ConversionProgress(0, "读取 ENBX..."));

                var doc = _enbxReader.Import(enbxPath);

                progress?.Report(new ConversionProgress(50, "写入 PPTX..."));

                _pptxExporter.Export(doc, outputPath);

                progress?.Report(new ConversionProgress(100, "转换完成"));

                return outputPath;
            });
        }

        public async Task<SmfDocument> LoadPptxAsync(string pptxPath)
        {
            return await Task.Run(() => _pptxImporter.Import(pptxPath));
        }

        public async Task<SmfDocument> LoadEnbxAsync(string enbxPath)
        {
            return await Task.Run(() => _enbxReader.Import(enbxPath));
        }

        public async Task SaveAsPptxAsync(SmfDocument doc, string outputPath)
        {
            await Task.Run(() => _pptxExporter.Export(doc, outputPath));
        }

        public async Task SaveAsEnbxAsync(SmfDocument doc, string outputPath)
        {
            await Task.Run(() => _enbxWriter.Export(doc, outputPath));
        }

        public async Task BatchConvertAsync(string[] inputPaths, string outputDir, bool toEnbx, IProgress<ConversionProgress>? progress = null)
        {
            int total = inputPaths.Length;
            for (int i = 0; i < total; i++)
            {
                var input = inputPaths[i];
                var fileName = Path.GetFileNameWithoutExtension(input);
                var ext = toEnbx ? ".enbx" : ".pptx";
                var output = Path.Combine(outputDir, fileName + ext);

                if (toEnbx)
                    await ConvertPptxToEnbxAsync(input, progress);
                else
                    await ConvertEnbxToPptxAsync(input, progress);

                progress?.Report(new ConversionProgress((i + 1) * 100 / total, $"({i + 1}/{total}) 完成"));
            }
        }

        public void FixConversionErrors()
        {
            var en5Path = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
                "Seewo", "EasiNote5");
            var tempDir = Path.Combine(en5Path, "Temp", "Conversion");
            if (Directory.Exists(tempDir))
            {
                try { Directory.Delete(tempDir, true); } catch { }
            }
        }
    }

    public class ConversionProgress
    {
        public int Percentage { get; }
        public string Message { get; }

        public ConversionProgress(int percentage, string message)
        {
            Percentage = percentage;
            Message = message;
        }
    }
}