using Newtonsoft.Json;
using S7Explorer.Models;
using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace S7Explorer.Services
{
    public class ExportService
    {
        private readonly LogService _logService;

        public ExportService()
        {
            _logService = LogService.Instance;
        }

        public async Task<bool> ExportProjectAsync(ProjectStructure project, ExportSettings settings)
        {
            return await Task.Run(() => ExportProject(project, settings));
        }

        private bool ExportProject(ProjectStructure project, ExportSettings settings)
        {
            try
            {
                _logService.LogInfo($"Starting export to {settings.ExportPath}");

                string exportContent = GenerateExportContent(project, settings);

                // Ensure directory exists
                string directory = Path.GetDirectoryName(settings.ExportPath) ?? string.Empty;
                if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
                {
                    Directory.CreateDirectory(directory);
                }

                // Write to file based on format
                switch (settings.ExportFormat)
                {
                    case ExportFormat.PlainText:
                        File.WriteAllText(settings.ExportPath, exportContent);
                        break;
                    case ExportFormat.MarkDown:
                        File.WriteAllText(settings.ExportPath, GenerateMarkdownContent(project, settings));
                        break;
                    case ExportFormat.HTML:
                        File.WriteAllText(settings.ExportPath, GenerateHtmlContent(project, settings));
                        break;
                    case ExportFormat.JSON:
                        File.WriteAllText(settings.ExportPath, GenerateJsonContent(project, settings));
                        break;
                }

                _logService.LogInfo($"Export completed successfully to {settings.ExportPath}");
                return true;
            }
            catch (Exception ex)
            {
                _logService.LogError($"Error during export: {ex.Message}");
                return false;
            }
        }

        private string GenerateExportContent(ProjectStructure project, ExportSettings settings)
        {
            StringBuilder sb = new StringBuilder();

            // Project info
            sb.AppendLine("==========================================================");
            sb.AppendLine($"PROJECT DOCUMENTATION: {project.Name}");
            sb.AppendLine("==========================================================");
            sb.AppendLine();
            sb.AppendLine(project.GetExportText());

            // Hardware configuration
            if (settings.ExportHardware)
            {
                sb.AppendLine("==========================================================");
                sb.AppendLine("HARDWARE CONFIGURATION");
                sb.AppendLine("==========================================================");
                sb.AppendLine();

                ExportChildren(project.HardwareFolder, sb, settings, 0);
            }

            // Symbols
            if (settings.ExportSymbols)
            {
                sb.AppendLine("==========================================================");
                sb.AppendLine("SYMBOL TABLE");
                sb.AppendLine("==========================================================");
                sb.AppendLine();

                ExportChildren(project.SymbolsFolder, sb, settings, 0);
            }

            // Blocks
            if (settings.ExportBlocks)
            {
                sb.AppendLine("==========================================================");
                sb.AppendLine("PROGRAM BLOCKS");
                sb.AppendLine("==========================================================");
                sb.AppendLine();

                ExportChildren(project.BlocksFolder, sb, settings, 0);
            }

            return sb.ToString();
        }

        private void ExportChildren(ProjectItem item, StringBuilder sb, ExportSettings settings, int level)
        {
            // Don't export if no children
            if (item.Children.Count == 0)
                return;

            string indent = new string(' ', level * 2);

            foreach (var child in item.Children)
            {
                // Skip block code if settings say so
                if (child is BlockItem blockItem && !settings.IncludeBlockCode)
                {
                    string text = blockItem.GetExportText();
                    // Remove the block content section
                    int contentIndex = text.IndexOf("// Block Content");
                    if (contentIndex > 0)
                    {
                        text = text.Substring(0, contentIndex) + "// Block Content omitted per export settings\r\n\r\n";
                    }
                    sb.Append(indent);
                    sb.AppendLine(text.Replace("\r\n", "\r\n" + indent));
                }
                else
                {
                    // For other item types, just get export text
                    sb.Append(indent);
                    sb.AppendLine(child.GetExportText().Replace("\r\n", "\r\n" + indent));
                }

                // Recursively export children
                ExportChildren(child, sb, settings, level + 1);
            }
        }

        private string GenerateMarkdownContent(ProjectStructure project, ExportSettings settings)
        {
            // This would generate Markdown-formatted content
            // Simplified implementation
            StringBuilder sb = new StringBuilder();

            sb.AppendLine($"# PROJECT DOCUMENTATION: {project.Name}");
            sb.AppendLine();
            sb.AppendLine($"**Project Path:** {project.ProjectPath}");
            sb.AppendLine($"**Version:** {project.ProjectVersion}");
            sb.AppendLine($"**Created:** {project.CreationDate}");
            sb.AppendLine($"**Last Modified:** {project.LastModifiedDate}");
            sb.AppendLine();

            // Rest of the implementation similar to plain text but with Markdown formatting
            // ...

            return sb.ToString();
        }

        private string GenerateHtmlContent(ProjectStructure project, ExportSettings settings)
        {
            // This would generate HTML-formatted content
            // Simplified implementation
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("<!DOCTYPE html>");
            sb.AppendLine("<html>");
            sb.AppendLine("<head>");
            sb.AppendLine($"<title>Project Documentation: {project.Name}</title>");
            sb.AppendLine("<style>");
            sb.AppendLine("body { font-family: Arial, sans-serif; margin: 20px; }");
            sb.AppendLine("h1, h2 { color: #0066cc; }");
            sb.AppendLine("pre { background-color: #f5f5f5; padding: 10px; border: 1px solid #ddd; }");
            sb.AppendLine("</style>");
            sb.AppendLine("</head>");
            sb.AppendLine("<body>");
            sb.AppendLine($"<h1>PROJECT DOCUMENTATION: {project.Name}</h1>");

            // Rest of the implementation similar to plain text but with HTML formatting
            // ...

            sb.AppendLine("</body>");
            sb.AppendLine("</html>");

            return sb.ToString();
        }

        private string GenerateJsonContent(ProjectStructure project, ExportSettings settings)
        {
            // Create an object structure to export to JSON
            var exportObject = new
            {
                Project = new
                {
                    Name = project.Name,
                    Path = project.ProjectPath,
                    Version = project.ProjectVersion,
                    CreationDate = project.CreationDate,
                    LastModifiedDate = project.LastModifiedDate
                },
                Hardware = settings.ExportHardware ? GetExportObjectForItem(project.HardwareFolder) : null,
                Symbols = settings.ExportSymbols ? GetExportObjectForItem(project.SymbolsFolder) : null,
                Blocks = settings.ExportBlocks ? GetExportObjectForItem(project.BlocksFolder) : null
            };

            return JsonConvert.SerializeObject(exportObject, Formatting.Indented);
        }

        private object GetExportObjectForItem(ProjectItem item)
        {
            // Create a JSON-friendly object structure for an item and its children
            var result = new
            {
                Name = item.Name,
                Children = item.Children.Select(c => GetExportObjectForItem(c)).ToArray()
            };

            return result;
        }
    }
}