using Microsoft.AspNetCore.Components.Authorization;
using RobotNet10.CustomConfigurationEditor.Models;
using RobotNet10.CustomConfigurationEditor.Services.API;
using System.Net.Http;
using System.Security.Claims;
using System.Threading;

namespace RobotNet10.CustomConfigurationEditor.Services.State;

/// <summary>
/// State management cho Config Manager
/// </summary>
public class ConfigManagerState(ConfigApiService apiService, AuthenticationStateProvider? authStateProvider = null, string editorRole = "")
{
    private readonly ConfigApiService _apiService = apiService;
    private readonly AuthenticationStateProvider? _authStateProvider = authStateProvider;
    private readonly SemaphoreSlim _stateLock = new(1, 1);

    // ===== DATA =====
    public List<ConfigFileMetadataModel> Configs { get; private set; } = [];
    public ConfigFileModel? SelectedConfig { get; private set; }
    
    // ===== FILTERS & SEARCH =====
    public string? SearchQuery { get; set; }
    
    // ===== UI STATE =====
    public bool IsLoading { get; private set; }
    public bool IsSaving { get; private set; }
    public string? ErrorMessage { get; private set; }
    
    // ===== EVENTS =====
    public event Action? OnStateChanged;

    // ==========================================
    // PUBLIC METHODS
    // ==========================================

    // Role Editor
    public string EditorRole { get; } = editorRole;

    /// <summary>
    /// Load tất cả configs
    /// </summary>
    public async Task LoadConfigsAsync(string? searchQuery = null)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsLoading = true;
            SearchQuery = searchQuery;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                Configs = await _apiService.GetAllConfigsAsync(searchQuery);
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                Configs = [];
            }

            IsLoading = false;
            NotifyStateChanged();
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Load config theo ID
    /// </summary>
    public async Task LoadConfigByIdAsync(Guid id)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsLoading = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.GetConfigByIdAsync(id);
                if (SelectedConfig == null)
                {
                    ErrorMessage = "Config not found";
                }
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                SelectedConfig = null;
            }

            IsLoading = false;
            NotifyStateChanged();
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Load config theo ConfigType
    /// </summary>
    public async Task LoadConfigByTypeAsync(string configType)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsLoading = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.GetConfigByTypeAsync(configType);
                if (SelectedConfig == null)
                {
                    ErrorMessage = "Config not found";
                }
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                SelectedConfig = null;
            }

            IsLoading = false;
            NotifyStateChanged();
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Select config
    /// </summary>
    public async Task SelectConfigAsync(ConfigFileMetadataModel configMetadata)
    {
        await LoadConfigByIdAsync(configMetadata.Id);
    }
    
    /// <summary>
    /// Clear error message
    /// </summary>
    public void ClearError()
    {
        ErrorMessage = null;
        NotifyStateChanged();
    }

    /// <summary>
    /// Clear selection
    /// </summary>
    public void ClearSelection()
    {
        SelectedConfig = null;
        NotifyStateChanged();
    }
    
    /// <summary>
    /// Tạo config mới
    /// </summary>
    public async Task<ConfigFileModel> CreateConfigAsync(string configType, List<ConfigVariableModel> variables, string? description = null)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                var config = await _apiService.CreateConfigAsync(configType, variables, description);
                await ReloadConfigsInternalAsync();
                SelectedConfig = config;
                NotifyStateChanged();
                return config;
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Cập nhật config
    /// </summary>
    public async Task UpdateConfigAsync(List<ConfigVariableModel>? variables = null, string? description = null)
    {
        if (SelectedConfig == null)
        {
            throw new InvalidOperationException("No config selected");
        }

        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.UpdateConfigAsync(SelectedConfig.Id, variables, description);
                await ReloadConfigsInternalAsync();
                NotifyStateChanged();
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Xóa config
    /// </summary>
    public async Task DeleteConfigAsync(Guid id)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                await _apiService.DeleteConfigAsync(id);
                await ReloadConfigsInternalAsync();

                // Clear selection if deleted
                if (SelectedConfig?.Id == id)
                {
                    SelectedConfig = null;
                    NotifyStateChanged();
                }
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Import config từ file
    /// </summary>
    public async Task<ConfigFileModel> ImportConfigAsync(Stream fileStream, string fileName, string configType, string? description = null)
    {
        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                var config = await _apiService.ImportConfigAsync(fileStream, fileName, configType, description);
                await ReloadConfigsInternalAsync();
                SelectedConfig = config;
                NotifyStateChanged();
                return config;
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Export config ra file
    /// </summary>
    public async Task<Stream> ExportConfigAsync(Guid id)
    {
        try
        {
            return await _apiService.ExportConfigAsync(id);
        }
        catch (Exception ex)
        {
            ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
            throw;
        }
    }
    
    /// <summary>
    /// Cập nhật variable value
    /// </summary>
    public async Task UpdateVariableAsync(string variableName, object? value)
    {
        if (SelectedConfig == null)
        {
            throw new InvalidOperationException("No config selected");
        }

        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.UpdateVariableAsync(SelectedConfig.Id, variableName, value);
                NotifyStateChanged();
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Thêm variable
    /// </summary>
    public async Task AddVariableAsync(ConfigVariableModel variable)
    {
        if (SelectedConfig == null)
        {
            throw new InvalidOperationException("No config selected");
        }

        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.AddVariableAsync(SelectedConfig.Id, variable);
                NotifyStateChanged();
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Xóa variable
    /// </summary>
    public async Task RemoveVariableAsync(string variableName)
    {
        if (SelectedConfig == null)
        {
            throw new InvalidOperationException("No config selected");
        }

        await _stateLock.WaitAsync();
        try
        {
            IsSaving = true;
            ErrorMessage = null;
            NotifyStateChanged();

            try
            {
                SelectedConfig = await _apiService.RemoveVariableAsync(SelectedConfig.Id, variableName);
                NotifyStateChanged();
            }
            catch (Exception ex)
            {
                ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
                throw;
            }
            finally
            {
                IsSaving = false;
                NotifyStateChanged();
            }
        }
        finally
        {
            _stateLock.Release();
        }
    }
    
    /// <summary>
    /// Kiểm tra ConfigType có tồn tại không
    /// </summary>
    public async Task<bool> ConfigTypeExistsAsync(string configType)
    {
        try
        {
            return await _apiService.ConfigTypeExistsAsync(configType);
        }
        catch (HttpRequestException)
        {
            return false;
        }
    }
    
    // ==========================================
    // ROLE-BASED PERMISSION CHECKS
    // ==========================================
    
    /// <summary>
    /// Kiểm tra user hiện tại có quyền chỉnh sửa config không
    /// </summary>
    public async Task<bool> CanEditConfigAsync()
    {
        // Nếu EditorRole rỗng, mọi thứ hoạt động bình thường
        if (string.IsNullOrWhiteSpace(EditorRole))
        {
            return true;
        }
        
        // Kiểm tra role của user hiện tại
        var userRoles = await GetCurrentUserRolesAsync();
        return userRoles.Contains(EditorRole, StringComparer.OrdinalIgnoreCase);
    }
    
    /// <summary>
    /// Kiểm tra user hiện tại có quyền chỉnh sửa variable không
    /// </summary>
    public async Task<bool> CanEditVariableAsync(ConfigVariableModel variable)
    {
        // Nếu EditorRole rỗng, mọi thứ hoạt động bình thường
        if (string.IsNullOrWhiteSpace(EditorRole))
        {
            return true;
        }
        
        var userRoles = await GetCurrentUserRolesAsync();

        // Kiểm tra nếu user có role = EditorRole
        if (userRoles.Contains(EditorRole, StringComparer.OrdinalIgnoreCase))
        {
            return true;
        }
        
        // Kiểm tra nếu role của user nằm trong Roles của variable
        if (!string.IsNullOrWhiteSpace(variable.Roles))
        {
            var variableRoles = variable.Roles.Split(',', StringSplitOptions.RemoveEmptyEntries)
                .Select(r => r.Trim())
                .Where(r => !string.IsNullOrWhiteSpace(r));
            
            return variableRoles.Any(role => userRoles.Contains(role, StringComparer.OrdinalIgnoreCase));
        }
        
        return false;
    }
    
    /// <summary>
    /// Lấy danh sách roles của user hiện tại
    /// </summary>
    private async Task<List<string>> GetCurrentUserRolesAsync()
    {
        if (_authStateProvider == null)
        {
            return [];
        }
        
        try
        {
            var authState = await _authStateProvider.GetAuthenticationStateAsync();
            var user = authState?.User;
            
            if (user == null || user.Identity?.IsAuthenticated != true)
            {
                return [];
            }
            
            // Lấy roles từ claims
            var roles = user.Claims
                .Where(c => c.Type == ClaimTypes.Role)
                .Select(c => c.Value)
                .ToList();
            
            return roles;
        }
        catch (Exception ex) when (ex is InvalidOperationException or NullReferenceException)
        {
            return [];
        }
    }
    
    // ==========================================
    // PRIVATE METHODS
    // ==========================================
    
    /// <summary>
    /// Reload configs without acquiring the lock (for use inside locked methods)
    /// </summary>
    private async Task ReloadConfigsInternalAsync()
    {
        try
        {
            Configs = await _apiService.GetAllConfigsAsync(SearchQuery);
        }
        catch (Exception ex)
        {
            ErrorMessage = HttpErrorHelper.GetErrorMessage(ex);
            Configs = [];
        }
    }

    private void NotifyStateChanged()
    {
        OnStateChanged?.Invoke();
    }
}