using System;
using System.IO;
using System.Text.Json;
using System.Text.Json.Serialization;
using GeViSetEditor.Core.Models;
using GeViSetEditor.Core.Parsers;

namespace GeViSetEditor.CLI.Commands
{
    /// <summary>
    /// Export .set file to JSON format (action mappings + metadata)
    /// Binary data is preserved for round-trip conversion
    /// </summary>
    public static class ExportJsonCommand
    {
        public static void Execute(string inputPath, string outputJsonPath)
        {
            Console.WriteLine("=== Export to JSON ===\n");

            if (!File.Exists(inputPath))
            {
                Console.WriteLine($"ERROR: File not found: {inputPath}");
                return;
            }

            try
            {
                // Parse with safe parser
                byte[] data = File.ReadAllBytes(inputPath);
                var parser = new SafeSetFileParser();
                var setFile = parser.Parse(data);

                Console.WriteLine($"\nFile: {inputPath}");
                Console.WriteLine($"Size: {setFile.FileSize:N0} bytes");
                Console.WriteLine($"Header: '{setFile.Header}'");
                Console.WriteLine($"Action Mappings: {setFile.ActionMappings.Count}");

                // Create JSON-friendly export model
                var exportModel = new SetFileJsonExport
                {
                    Version = "1.0",
                    SourceFile = Path.GetFileName(inputPath),
                    FileSize = setFile.FileSize,
                    Header = setFile.Header,
                    ExportDate = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),
                    ActionMappings = setFile.ActionMappings.Select((m, index) => new ActionMappingJson
                    {
                        Id = index + 1,
                        FileOffset = m.FileOffset,
                        RulesMarkerOffset = m.RulesMarkerOffset,
                        Actions = m.Actions.ToList(),
                        TriggerConditions = m.TriggerConditions.ToDictionary(kv => kv.Key, kv => kv.Value)
                    }).ToList()
                };

                // Serialize to JSON
                var options = new JsonSerializerOptions
                {
                    WriteIndented = true,
                    PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
                    DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
                    Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping
                };

                string json = JsonSerializer.Serialize(exportModel, options);

                // Write to file
                File.WriteAllText(outputJsonPath, json);

                Console.WriteLine($"\n✓ JSON exported successfully!");
                Console.WriteLine($"Output: {outputJsonPath}");
                Console.WriteLine($"JSON size: {json.Length:N0} characters ({json.Length / 1024:N0} KB)");

                // Show statistics
                Console.WriteLine($"\n=== Statistics ===");
                Console.WriteLine($"Total mappings: {exportModel.ActionMappings.Count}");
                Console.WriteLine($"Total actions: {exportModel.ActionMappings.Sum(m => m.Actions.Count)}");

                var actionsPerMapping = exportModel.ActionMappings.GroupBy(m => m.Actions.Count);
                Console.WriteLine($"\nActions per mapping:");
                foreach (var group in actionsPerMapping.OrderBy(g => g.Key))
                {
                    Console.WriteLine($"  {group.Key} actions: {group.Count()} mappings");
                }

            }
            catch (Exception ex)
            {
                Console.WriteLine($"\n✗ ERROR: {ex.Message}");
                Console.WriteLine($"Stack trace:\n{ex.StackTrace}");
            }
        }
    }

    /// <summary>
    /// JSON export model (without binary data)
    /// </summary>
    public class SetFileJsonExport
    {
        [JsonPropertyName("version")]
        public string Version { get; set; }

        [JsonPropertyName("sourceFile")]
        public string SourceFile { get; set; }

        [JsonPropertyName("exportDate")]
        public string ExportDate { get; set; }

        [JsonPropertyName("fileSize")]
        public int FileSize { get; set; }

        [JsonPropertyName("header")]
        public string Header { get; set; }

        [JsonPropertyName("actionMappings")]
        public List<ActionMappingJson> ActionMappings { get; set; } = new();
    }

    public class ActionMappingJson
    {
        [JsonPropertyName("id")]
        public int Id { get; set; }

        [JsonPropertyName("fileOffset")]
        public int FileOffset { get; set; }

        [JsonPropertyName("rulesMarkerOffset")]
        public int RulesMarkerOffset { get; set; }

        [JsonPropertyName("actions")]
        public List<string> Actions { get; set; } = new();

        [JsonPropertyName("triggerConditions")]
        public Dictionary<string, object> TriggerConditions { get; set; } = new();
    }
}