using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Threading.Tasks;
using Newtonsoft.Json;
using RedundancyFinder;
using Spectre.Console;
using Spectre.Console.Cli;
namespace RedundancyFinderCLI
{
    internal sealed class FinderCommand : Command<FinderCommand.Settings>
    {
        public sealed class Settings : CommandSettings
        {
            [Description("Paths to search.")]
            [CommandArgument(0, "<searchPaths>")]
            public string[] SearchPaths { get; init; }

            [Description("File extensions to search for. Comma separated.")]
            [CommandOption("-e|--extensions")]
            [DefaultValue(".jpg,.webp,.raw,.pdf,.xsl,.xslx,.doc,.docx,.txt,.jpeg,.mov,.mp4,.mp3,.wav,.bmp,.gif,.png,.cu,.mid,.msb ,.mov,.avi,.wmv,.flv,.m4v,.bak ,.cpr ,.xml,.psd")]
            public string? Extensions { get; init; }

            [Description("Show all information.")]
            [CommandOption("-v|--verbose")]
            [DefaultValue(false)]
            public bool Verbose { get; init; }

            [Description("Output path.")]
            [CommandOption("-o|--output")]
            [DefaultValue("redundancies.json")]
            public string? OutputPath {get; init;}
        }
        public override int Execute([NotNull] CommandContext context, [NotNull] Settings settings)
        {
            var extensions = settings.Extensions.Split(",", StringSplitOptions.RemoveEmptyEntries);

            Finder finder = new Finder();
            int hashingTasks = 0;
            int hashingTasksFinished = 0;

            // Register the ProcessExit event to save redundancies on exit
            AppDomain.CurrentDomain.ProcessExit += (sender, e) =>
            {
                SaveRedundancies(finder, settings.OutputPath);
            };

            // Load existing redundancies if the output file exists
            if (File.Exists(settings.OutputPath))
            {
                try
                {
                    var existingData = File.ReadAllText(settings.OutputPath);
                    var existingRedundancies = JsonConvert.DeserializeObject<Dictionary<string, Redundancy>>(existingData);

                    if (existingRedundancies != null)
                    {
                        foreach (var entry in existingRedundancies)
                        {
                            finder.Redundancies[entry.Key] = entry.Value;
                        }

                        WriteLine($"[yellow]Resumed from existing output file: [/]'{settings.OutputPath}'");
                        WriteLine($"[yellow]Loaded {finder.Redundancies.Count} redundancies from the file.[/]");
                    }
                }
                catch (Exception ex)
                {
                    WriteLine($"[red]Failed to load existing output file: {ex.Message}[/]");
                }
            }

            finder.FileError += (sender, e) =>
            {
                if (e.Exception is UnauthorizedAccessException)
                {
                    if (settings.Verbose)
                    {
                        WriteLine($"[red]Access denied to file: [/]{e.Path}. Skipping. Error: [red]{e.Exception.Message}[/]");
                    }
                }
                else
                {
                    if (settings.Verbose)
                    {
                        WriteLine($"[red] Error processing file:\n[/]Path:{e.Path}\n[red]{e.Exception.Message}[/]");
                    }
                }
            };

            finder.DirectoryError += (sender, e) =>
            {
                if (e.Exception is UnauthorizedAccessException)
                {
                    if (settings.Verbose)
                    {
                        WriteLine($"[red]Access denied to directory: [/]{e.Path}. Skipping. Error: [red]{e.Exception.Message}[/]");
                    }
                }
                else
                {
                    if (settings.Verbose)
                    {
                        WriteLine($"[red] Error processing directory:\n[/]Path:{e.Path}\n[red]{e.Exception.Message}[/]");
                    }
                }
            };

            finder.ProcessingFile += (sender, e) =>
            {
                if (settings.Verbose)
                {
                    WriteLine($"[green]Processing file: [/]{e.Path}");
                }
            };

            try
            {
                var p = AnsiConsole.Progress();
                p.Start(ctx =>
                {
                    finder.TaskStarted += (sender, e) =>
                    {
                        hashingTasks++;
                        if (settings.Verbose)
                        {
                            WriteLine($"[green]Task started: [/]{e}");
                        }
                    };

                    finder.FileFound += (sender, e) =>
                    {
                        if (settings.Verbose)
                        {
                            WriteLine($"[green]File found: [/]{e.FilePath} {GetSizeFormat((ulong)e.Size)} ");
                        }
                        hashingTasksFinished++;
                    };

                    finder.FindRedundancies(settings.SearchPaths, extensions);
                });

                SaveRedundancies(finder, settings.OutputPath);

                ulong totalSize = finder.Redundancies.Select(x => (ulong)x.Value.FileSize).Aggregate((a, b) => a + b);
                string sizeFormat = GetSizeFormat(totalSize);
                WriteLine($"Total Size: [green]{sizeFormat}[/]");

                if (settings.Verbose)
                {
                    foreach (var redundancy in finder.Redundancies.Values)
                    {
                        AnsiConsole.WriteLine($"Hash: {redundancy.Hash}");
                        AnsiConsole.WriteLine("Paths:");
                        foreach (var path in redundancy.Paths)
                        {
                            AnsiConsole.WriteLine(path);
                        }
                        AnsiConsole.WriteLine();
                    }
                }
            }
            catch (Exception e)
            {
                WriteLine($"[red] Error:\n[/]{e.Message}");
            }
            return 0;
        }

        private void SaveRedundancies(Finder finder, string outputPath)
        {
            try
            {
                var json = JsonConvert.SerializeObject(finder.Redundancies, Formatting.Indented);

                // Check if path is relative or absolute
                if (!Path.IsPathRooted(outputPath))
                {
                    outputPath = Path.Combine(Directory.GetCurrentDirectory(), outputPath);
                }

                File.WriteAllText(outputPath, json);
                WriteLine($"[yellow]Wrote [/]{finder.Redundancies.Count}[yellow] redundancies to [/]'{outputPath}'");
            }
            catch (Exception ex)
            {
                WriteLine($"[red]Failed to save redundancies: {ex.Message}[/]");
            }
        }


        private void WriteLine(string v)
        {
            string now = Markup.Escape($"[{DateTime.Now.ToString("HH:mm:ss")}]");
            AnsiConsole.MarkupLine($"[gray]{now}[/] {v}");
        }

        private static string GetSizeFormat(ulong totalSize)
        {
            string sizeUnit = "B";
            while (totalSize > 1024)
            {
                totalSize /= 1024;
                sizeUnit = sizeUnit switch
                {
                    "B" => "KB",
                    "KB" => "MB",
                    "MB" => "GB",
                    "GB" => "TB",
                    _ => sizeUnit
                };

            }
            string sizeFormat = $"{totalSize:.##} {sizeUnit}";
            return sizeFormat;
        }
    }
}