using System;
using System.Collections.ObjectModel;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Input;
using Avalonia.Media.Imaging;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using finder2e_foundry_converter.Models;
using finder2e_foundry_converter.Services;
using System.Text.Json.Nodes;
using System.Text.Json;
using finder2e_foundry_converter.Converters;

namespace finder2e_foundry_converter.ViewModels
{
    public partial class MainWindowViewModel : ViewModelBase
    {
        private readonly LmStudioService _lmStudioService = new();
        private readonly OllamaService _ollamaService = new();

        private ILlmService CurrentService => SelectedProvider == "Ollama" ? (ILlmService)_ollamaService : _lmStudioService;

        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(CurrentAddress))]
        private string _lmStudioAddress = "http://localhost:1234";

        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(CurrentAddress))]
        private string _ollamaAddress = "http://localhost:11434";

        public string CurrentAddress
        {
            get => SelectedProvider == "Ollama" ? OllamaAddress : LmStudioAddress;
            set
            {
                if (SelectedProvider == "Ollama") OllamaAddress = value;
                else LmStudioAddress = value;
                OnPropertyChanged(nameof(CurrentAddress));
            }
        }

        [ObservableProperty]
        private bool _isAddressVisible = false;

        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(CurrentAddress))]
        private string _selectedProvider = "LM Studio";

        public ObservableCollection<string> Providers { get; } = new() { "LM Studio", "Ollama" };

        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(CanGenerate))]
        private string? _selectedModel;
 
        public ObservableCollection<string> Models { get; } = new();
 
        [ObservableProperty]
        [NotifyPropertyChangedFor(nameof(IsNpcSelected))]
        [NotifyPropertyChangedFor(nameof(CanGenerate))]
        private string? _selectedCategory;

        public ObservableCollection<string> Categories { get; } = new() { "NPCs" };

        [ObservableProperty]
        private int _selectedLevel = 1;

        public ObservableCollection<int> Levels { get; } = new();
 
        [ObservableProperty]
        private string _selectedSystem = "pf2e";

        public ObservableCollection<string> Systems { get; } = new() { "pf2e", "sf2e" };

        [ObservableProperty]
        private string _name = string.Empty;
 
        [ObservableProperty]
        private string _description = string.Empty;
 
        public bool IsNpcSelected => SelectedCategory == "NPCs";
 
        public ObservableCollection<ImageItem> ImageItems { get; } = new();
 
        [ObservableProperty]
        private string _statusMessage = string.Empty;
 
        [ObservableProperty]
        private bool _isErrorVisible = false;
 
        [ObservableProperty]
        private string _errorText = string.Empty;

        [ObservableProperty]
        private bool _isGenerating = false;

        [ObservableProperty]
        private double _progress = 0.0;

        [ObservableProperty]
        private string _generatedNpcJson = string.Empty;

        [ObservableProperty]
        private string _temporaryNpcPath = string.Empty;

        // Holds the raw TOML prompts and retry prefix
        private Dictionary<string, (string question, string constraints)> _npcPrompts = new();
        private string _npcRetryPrefix = "";

        public MainWindowViewModel()
        {
            // Load saved preferences would go here if we had a settings service
            for (int i = -1; i <= 24; i++)
            {
                Levels.Add(i);
            }
            _ = StartModelRefreshLoop();
        }

        public bool CanGenerate => !IsGenerating && !string.IsNullOrEmpty(SelectedModel);

        partial void OnIsGeneratingChanged(bool value)
        {
            OnPropertyChanged(nameof(CanGenerate));
        }
        partial void OnSelectedProviderChanged(string value)
        {
            Models.Clear();
            SelectedModel = null;
            _ = RefreshModels();
        }

        [RelayCommand]
        private void ToggleAddress()
        {
            IsAddressVisible = !IsAddressVisible;
        }

        [RelayCommand]
        private async Task RefreshModels()
        {
            var models = await CurrentService.GetModelsAsync(CurrentAddress);

            Models.Clear();
            foreach (var m in models)
            {
                Models.Add(m);
            }

            if (models.Count > 0 && !models[0].StartsWith("Error"))
            {
                IsErrorVisible = false;
                if (SelectedModel == null || !Models.Contains(SelectedModel))
                {
                    SelectedModel = Models.FirstOrDefault();
                }
            }
            else
            {
                ErrorText = models.FirstOrDefault() ?? $"Error connecting to {SelectedProvider}";
                IsErrorVisible = true;
                IsAddressVisible = true; // Auto-show on failure
            }
        }


        [RelayCommand]
        private async Task Generate()
        {
            if (string.IsNullOrEmpty(SelectedModel))
            {
                StatusMessage = "Please select a model first.";
                return;
            }

            IsGenerating = true;
            Progress = 0.0;
            GeneratedNpcJson = string.Empty;
            StatusMessage = "Starting NPC generation...";

            try
            {
                // Load the prompts from llmflow/npc.toml
                var cwd = Directory.GetCurrentDirectory();
                var tomlPath = Path.Combine(cwd, "llmflow", "npc.toml");
                _npcPrompts.Clear();
                _npcRetryPrefix = "";
                if (File.Exists(tomlPath))
                {
                    var lines = await File.ReadAllLinesAsync(tomlPath);
                    string? current = null;
                    foreach (var raw in lines)
                    {
                        var line = raw.Trim();
                        if (string.IsNullOrEmpty(line) || line.StartsWith("#")) continue;
                        if (line.StartsWith("[") && line.EndsWith("]"))
                        {
                            current = line.Substring(1, line.Length - 2).Trim();
                            continue;
                        }
                        if (line.StartsWith("retry_prefix"))
                        {
                            var idx = line.IndexOf('=');
                            if (idx >= 0) _npcRetryPrefix = line.Substring(idx + 1).Trim().Trim('"');
                            continue;
                        }
                        if (current != null && line.Contains("= "))
                        {
                            var idx = line.IndexOf('=');
                            var key = line.Substring(0, idx).Trim();
                            var val = line.Substring(idx + 1).Trim().Trim('"');
                            if (key == "question")
                            {
                                if (!_npcPrompts.ContainsKey(current)) _npcPrompts[current] = (val, string.Empty);
                                else _npcPrompts[current] = (val, _npcPrompts[current].constraints);
                            }
                            else if (key == "constraints")
                            {
                                if (!_npcPrompts.ContainsKey(current)) _npcPrompts[current] = (string.Empty, val);
                                else _npcPrompts[current] = (_npcPrompts[current].question, val);
                            }
                        }
                    }
                }

                Progress = 0.05;

                // Ask LLM for tiers per-stat
                var statKeys = new[] { "ability_score_modifier", "perception_modifier", "skill_modifier", "ac", "saving_throw", "hp", "resistance_or_weakness", "strike_attack_bonus", "strike_damage_roll" };
                var responses = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
                int total = statKeys.Length;
                int done = 0;

                foreach (var key in statKeys)
                {
                    string questionTemplate = _npcPrompts.ContainsKey(key) ? _npcPrompts[key].question : null;
                    string constraints = _npcPrompts.ContainsKey(key) ? _npcPrompts[key].constraints : string.Empty;
                    if (string.IsNullOrWhiteSpace(questionTemplate))
                    {
                        // Fallback question
                        questionTemplate = key switch
                        {
                            "ability_score_modifier" => "Based on the description, how would you rate ability scores for this character?",
                            "perception_modifier" => "Based on the description, how would you rate perception for this character?",
                            "skill_modifier" => "Based on the description, how would you rate skills for this character?",
                            "ac" => "Based on the description, how would you rate the armor class (AC) for this character?",
                            "saving_throw" => "Based on the description, how would you rate saving throws for this character?",
                            "hp" => "Based on the description, how would you rate hit points for this character?",
                            "resistance_or_weakness" => "Based on the description, does this character have notable resistances or weaknesses?",
                            "strike_attack_bonus" => "Based on the description, how would you rate the strike attack bonus for this character?",
                            "strike_damage_roll" => "Based on the description, what is the strike damage dice roll for this character?",
                            _ => $"Based on the description, provide a value for {key}."
                        };
                    }

                    // Replace placeholders
                    var prompt = questionTemplate.Replace("{level}", SelectedLevel.ToString()).Replace("{system}", SelectedSystem).Replace("{description}", Description ?? string.Empty).Replace("{name}", Name ?? string.Empty).Replace("{modifierTier}", "");
                    string lastResponse = string.Empty;
                    bool ok = false;
                    string finalResp = string.Empty;
                    for (int attempt = 1; attempt <= 3; attempt++)
                    {
                        StatusMessage = $"Asking LLM for {key} (attempt {attempt})...";
                        var resp = await CurrentService.AskAsync(CurrentAddress, SelectedModel!, prompt, ImageItems.Select(i => i.Path).ToList());
                        var trimmed = resp?.Trim() ?? string.Empty;

                        // If LLM returned an explicit Error: prefix, consider that a failure
                        if (trimmed.StartsWith("Error:", StringComparison.OrdinalIgnoreCase))
                        {
                            // feed back to next attempt
                            prompt = _npcRetryPrefix + "\nPrevious error: " + trimmed + "\n" + prompt;
                            lastResponse = trimmed;
                            continue;
                        }

                        // Validate against constraints if available (simple check for listed words)
                        if (!string.IsNullOrWhiteSpace(constraints))
                        {
                            var allowed = constraints.Trim();
                            // extract words inside the constraint description (e.g., Respond with only a single word: Extreme, High, Moderate, or Low.)
                            var optionsStart = allowed.IndexOf(":");
                            List<string> options = new();
                            if (optionsStart >= 0)
                            {
                                var after = allowed.Substring(optionsStart + 1);
                                // split by commas and 'or'
                                var parts = after.Split(new[] { ',', '\n' }, StringSplitOptions.RemoveEmptyEntries);
                                foreach (var p in parts)
                                {
                                    var t = p.Replace("or", "", StringComparison.OrdinalIgnoreCase).Trim();
                                    if (!string.IsNullOrEmpty(t)) options.Add(t.Trim().Trim('.'));
                                }
                            }

                            if (options.Count > 0)
                            {
                                // check if trimmed matches one of options
                                if (options.Any(o => string.Equals(o, trimmed, StringComparison.OrdinalIgnoreCase)))
                                {
                                    ok = true;
                                    finalResp = trimmed;
                                    break;
                                }
                                else
                                {
                                    // try extracting first word
                                    var firstWord = trimmed.Split(new[] { ' ', '\t', '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries).FirstOrDefault() ?? string.Empty;
                                    if (options.Any(o => string.Equals(o, firstWord, StringComparison.OrdinalIgnoreCase)))
                                    {
                                        ok = true;
                                        finalResp = firstWord;
                                        break;
                                    }
                                }
                            }
                            else
                            {
                                // no options parsed, accept any non-empty response
                                if (!string.IsNullOrWhiteSpace(trimmed)) { ok = true; finalResp = trimmed; break; }
                            }

                            // not valid: prepare retry prompt
                            prompt = _npcRetryPrefix + "\nPrevious response: " + trimmed + "\nPlease respond with the format required: " + constraints + "\n" + questionTemplate.Replace("{level}", SelectedLevel.ToString()).Replace("{system}", SelectedSystem);
                            lastResponse = trimmed;
                            continue;
                        }
                        else
                        {
                            if (!string.IsNullOrWhiteSpace(trimmed)) { ok = true; finalResp = trimmed; break; }
                            prompt = _npcRetryPrefix + "\nPrevious response: " + trimmed + "\n" + prompt;
                            lastResponse = trimmed;
                        }
                    }

                    if (!ok)
                    {
                        StatusMessage = $"LLM failed to provide valid response for {key} after 3 attempts. Last response: {lastResponse}";
                        IsGenerating = false;
                        return;
                    }

                    responses[key] = finalResp;
                    done++;
                    Progress = 0.05 + 0.85 * ((double)done / total);
                }

                // Finished LLM prompts
                Progress = 0.95;

                // Load template JSON
                var templatePath = Path.Combine(cwd, "foundry_templates", "npc_template.json");
                if (!File.Exists(templatePath))
                {
                    StatusMessage = $"Template not found at {templatePath}";
                    IsGenerating = false;
                    return;
                }

                var templateText = await File.ReadAllTextAsync(templatePath);
                var node = JsonNode.Parse(templateText)!.AsObject();

                // Fill basic fields
                node["name"] = string.IsNullOrWhiteSpace(Name) ? "NPC" : Name;
                node["img"] = node["img"] ?? "systems/pf2e/icons/default-icons/npc.svg";

                // system defaults
                var systemNode = node["system"] as JsonObject ?? new JsonObject();
                node["system"] = systemNode;

                // Set description/blurb and level
                if (!systemNode.TryGetPropertyValue("details", out var detailsNode) || detailsNode is null)
                {
                    detailsNode = new JsonObject();
                    systemNode["details"] = detailsNode;
                }
                var details = detailsNode.AsObject();
                details["blurb"] = Description ?? string.Empty;
                if (!details.TryGetPropertyValue("level", out var levelNode) || levelNode is null)
                {
                    details["level"] = new JsonObject();
                }
                details["level"].AsObject()["value"] = SelectedLevel;

                string gameSystem = SelectedSystem ?? "pf2e";

                // Map tiers (normalize)
                string GetTier(string key)
                {
                    if (!responses.TryGetValue(key, out var r)) return "moderate";
                    var t = r.Trim().ToLowerInvariant();
                    if (t.StartsWith("extreme")) return "extreme";
                    if (t.StartsWith("high")) return "high";
                    if (t.StartsWith("moderate")) return "moderate";
                    if (t.StartsWith("low")) return "low";
                    if (t.StartsWith("terrible")) return "terrible";
                    if (t.StartsWith("yes")) return "yes";
                    if (t.StartsWith("no")) return "no";
                    return t;
                }

                var abilityTier = GetTier("ability_score_modifier");
                var perceptionTier = GetTier("perception_modifier");
                var skillTier = GetTier("skill_modifier");
                var acTier = GetTier("ac");
                var savingTier = GetTier("saving_throw");
                var hpTier = GetTier("hp");

                var abilities = new JsonObject();
                string[] abilityNames = new[] { "str", "dex", "con", "int", "wis", "cha" };
                foreach (var ab in abilityNames)
                {
                    var modRes = NpcConverter.AbilityScoreModifier(SelectedLevel, abilityTier, gameSystem);
                    abilities[ab] = new JsonObject { ["mod"] = modRes.IsSuccess ? modRes.Value : 0 };
                }
                systemNode["abilities"] = abilities;

                // Perception
                var percRes = NpcConverter.PerceptionModifier(SelectedLevel, perceptionTier, gameSystem);
                systemNode["perception"] = new JsonObject { ["mod"] = percRes.IsSuccess ? percRes.Value : 0, ["details"] = string.Empty };

                // Saves
                var fort = NpcConverter.SavingThrow(SelectedLevel, savingTier, gameSystem);
                var reflex = NpcConverter.SavingThrow(SelectedLevel, savingTier, gameSystem);
                var will = NpcConverter.SavingThrow(SelectedLevel, savingTier, gameSystem);
                systemNode["saves"] = new JsonObject
                {
                    ["fortitude"] = new JsonObject { ["value"] = fort.IsSuccess ? fort.Value : 0, ["saveDetail"] = string.Empty },
                    ["reflex"] = new JsonObject { ["value"] = reflex.IsSuccess ? reflex.Value : 0, ["saveDetail"] = string.Empty },
                    ["will"] = new JsonObject { ["value"] = will.IsSuccess ? will.Value : 0, ["saveDetail"] = string.Empty }
                };

                // AC
                var acRes = NpcConverter.Ac(SelectedLevel, acTier, gameSystem);
                if (!systemNode.TryGetPropertyValue("attributes", out var attributesNode) || attributesNode is null)
                {
                    attributesNode = new JsonObject();
                    systemNode["attributes"] = attributesNode;
                }
                var attributes = attributesNode.AsObject();
                attributes["ac"] = new JsonObject { ["value"] = acRes.IsSuccess ? acRes.Value : 10, ["details"] = string.Empty };

                // HP
                var hpRes = NpcConverter.Hp(SelectedLevel, hpTier, gameSystem);
                attributes["hp"] = new JsonObject { ["value"] = hpRes.IsSuccess ? hpRes.Value : 10, ["temp"] = 0, ["max"] = hpRes.IsSuccess ? hpRes.Value : 10, ["details"] = string.Empty };

                // Skills: populate common PF2e skills using skillTier
                var skillsNode = new JsonObject();
                var skillList = new[] { "acrobatics", "arcana", "athletics", "crafting", "deception", "diplomacy", "intimidation", "lore", "medicine", "nature", "occultism", "performance", "religion", "society", "stealth", "survival", "thievery" };
                foreach (var sk in skillList)
                {
                    var skRes = NpcConverter.SkillModifier(SelectedLevel, skillTier, gameSystem);
                    skillsNode[sk] = new JsonObject { ["value"] = skRes.IsSuccess ? skRes.Value : 0 };
                }
                systemNode["skills"] = skillsNode;

                // Items: create a basic Strike item using strike attack bonus and damage from LLM response tiers
                var items = new JsonArray();
                var strikeTier = GetTier("strike_attack_bonus");
                var strikeAttack = NpcConverter.StrikeAttackBonus(SelectedLevel, strikeTier, gameSystem);
                var strikeDamage = NpcConverter.StrikeDamageRoll(SelectedLevel, strikeTier, gameSystem);
                var strikeAvgRes = NpcConverter.StrikeDamageAverage(SelectedLevel, strikeTier, gameSystem);

                if (strikeAttack.IsSuccess || strikeDamage.IsSuccess)
                {
                    var itemObj = new JsonObject
                    {
                        ["name"] = "Strike",
                        ["type"] = "weapon",
                        ["system"] = new JsonObject
                        {
                            ["attack"] = new JsonObject { ["value"] = strikeAttack.IsSuccess ? strikeAttack.Value : 0 },
                            ["damage"] = new JsonObject { ["dice"] = strikeDamage.IsSuccess ? strikeDamage.Value : string.Empty, ["average"] = strikeAvgRes.IsSuccess ? strikeAvgRes.Value : 0 }
                        }
                    };
                    items.Add(itemObj);
                }

                node["items"] = items;

                // Finalize JSON text
                GeneratedNpcJson = node.ToJsonString(new JsonSerializerOptions { WriteIndented = true });

                // Save to a temporary file while generating
                var tempDir = Path.Combine(Path.GetTempPath(), "Finder2eFoundryConverter");
                if (!Directory.Exists(tempDir)) Directory.CreateDirectory(tempDir);
                var safeName = string.IsNullOrWhiteSpace(Name) ? "npc" : string.Concat(Name.Select(ch => Path.GetInvalidFileNameChars().Contains(ch) ? '_' : ch));
                var tempPath = Path.Combine(tempDir, $"{safeName}_{DateTime.Now:yyyyMMddHHmmss}.json");
                await File.WriteAllTextAsync(tempPath, GeneratedNpcJson);
                TemporaryNpcPath = tempPath;

                StatusMessage = $"NPC generated and saved to temporary path: {tempPath}";
                Progress = 1.0;
            }
            catch (Exception ex)
            {
                StatusMessage = $"Error generating NPC: {ex.Message}";
            }
            finally
            {
                IsGenerating = false;
            }
        }

        [RelayCommand]
        private void AddImagePath(string path)
        {
            if (!string.IsNullOrWhiteSpace(path) && File.Exists(path))
            {
                if (ImageItems.Any(i => i.Path == path)) return;

                try
                {
                    // Load thumbnail
                    using var stream = File.OpenRead(path);
                    var bitmap = new Bitmap(stream);
                    // We could resize it here for efficiency if needed, but for now let's just use it
                    ImageItems.Add(new ImageItem { Path = path, Thumbnail = bitmap });
                }
                catch (Exception ex)
                {
                    StatusMessage = $"Error loading image: {ex.Message}";
                }
            }
        }

        [RelayCommand]
        private void RemoveImage(ImageItem item)
        {
            ImageItems.Remove(item);
        }

        private async Task StartModelRefreshLoop()
        {
            while (true)
            {
                await RefreshModels();
                await Task.Delay(IsErrorVisible ? 3000 : 10000);
            }
        }
    }
}