using Nop.Core.Domain.Customers;
using Nop.Services.Customers;

namespace Nop.Services.Plugins;

/// <summary>
/// Represents a plugin manager implementation
/// </summary>
/// <typeparam name="TPlugin">Type of plugin</typeparam>
public partial class PluginManager<TPlugin> : IPluginManager<TPlugin> where TPlugin : class, IPlugin
{
    #region Fields

    protected readonly ICustomerService _customerService;
    protected readonly IPluginService _pluginService;

    protected readonly Dictionary<string, IList<TPlugin>> _plugins = new();

    #endregion

    #region Ctor

    public PluginManager(ICustomerService customerService,
        IPluginService pluginService)
    {
        _customerService = customerService;
        _pluginService = pluginService;
    }

    #endregion

    #region Utilities

    /// <summary>
    /// Prepare the dictionary key to store loaded plugins
    /// </summary>
    /// <param name="customer">Customer</param>
    /// <param name="storeId">Store identifier</param>
    /// <param name="systemName">Plugin system name</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the key
    /// </returns>
    protected virtual async Task<string> GetKeyAsync(Customer customer, int storeId, string systemName = null)
    {
        return $"{storeId}-{(customer != null ? string.Join(',', await _customerService.GetCustomerRoleIdsAsync(customer)) : null)}-{systemName}";
    }

    /// <summary>
    /// Load primary active plugin
    /// </summary>
    /// <param name="systemName">System name of primary active plugin</param>
    /// <param name="customer">Filter by customer; pass null to load all plugins</param>
    /// <param name="storeId">Filter by store; pass 0 to load all plugins</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the plugin
    /// </returns>
    protected virtual async Task<TPlugin> LoadPrimaryPluginAsync(string systemName, Customer customer = null, int storeId = 0)
    {
        //try to get a plugin by system name or return the first loaded one (it's necessary to have a primary active plugin)
        var plugin = await LoadPluginBySystemNameAsync(systemName, customer, storeId)
                     ?? (await LoadAllPluginsAsync(customer, storeId)).FirstOrDefault();

        return plugin;
    }

    #endregion

    #region Methods

    /// <summary>
    /// Load all plugins
    /// </summary>
    /// <param name="customer">Filter by customer; pass null to load all plugins</param>
    /// <param name="storeId">Filter by store; pass 0 to load all plugins</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the list of plugins
    /// </returns>
    public virtual async Task<IList<TPlugin>> LoadAllPluginsAsync(Customer customer = null, int storeId = 0)
    {
        //get plugins and put them into the dictionary to avoid further loading
        var key = await GetKeyAsync(customer, storeId);
        if (!_plugins.ContainsKey(key))
            _plugins.Add(key, await _pluginService.GetPluginsAsync<TPlugin>(customer: customer, storeId: storeId));

        return _plugins[key];
    }

    /// <summary>
    /// Load plugin by system name
    /// </summary>
    /// <param name="systemName">System name</param>
    /// <param name="customer">Filter by customer; pass null to load all plugins</param>
    /// <param name="storeId">Filter by store; pass 0 to load all plugins</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the plugin
    /// </returns>
    public virtual async Task<TPlugin> LoadPluginBySystemNameAsync(string systemName, Customer customer = null, int storeId = 0)
    {
        if (string.IsNullOrEmpty(systemName))
            return null;

        //try to get already loaded plugin
        var key = await GetKeyAsync(customer, storeId, systemName);
        if (_plugins.TryGetValue(key, out var value))
            return value.FirstOrDefault();

        //or get it from list of all loaded plugins or load it for the first time
        var pluginBySystemName = _plugins.TryGetValue(await GetKeyAsync(customer, storeId), out var plugins)
                                 && plugins.FirstOrDefault(plugin =>
                                     plugin.PluginDescriptor.SystemName.Equals(systemName, StringComparison.InvariantCultureIgnoreCase)) is TPlugin loadedPlugin
            ? loadedPlugin
            : (await _pluginService.GetPluginDescriptorBySystemNameAsync<TPlugin>(systemName, customer: customer, storeId: storeId))?.Instance<TPlugin>();

        _plugins.Add(key, new List<TPlugin> { pluginBySystemName });

        return pluginBySystemName;
    }

    /// <summary>
    /// Load active plugins
    /// </summary>
    /// <param name="systemNames">System names of active plugins</param>
    /// <param name="customer">Filter by customer; pass null to load all plugins</param>
    /// <param name="storeId">Filter by store; pass 0 to load all plugins</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the list of active plugins
    /// </returns>
    public virtual async Task<IList<TPlugin>> LoadActivePluginsAsync(List<string> systemNames, Customer customer = null, int storeId = 0)
    {
        if (systemNames == null)
            return new List<TPlugin>();

        //get loaded plugins according to passed system names
        return (await LoadAllPluginsAsync(customer, storeId))
            .Where(plugin => systemNames.Contains(plugin.PluginDescriptor.SystemName, StringComparer.InvariantCultureIgnoreCase))
            .ToList();
    }

    /// <summary>
    /// Check whether the passed plugin is active
    /// </summary>
    /// <param name="plugin">Plugin to check</param>
    /// <param name="systemNames">System names of active plugins</param>
    /// <returns>Result</returns>
    public virtual bool IsPluginActive(TPlugin plugin, List<string> systemNames)
    {
        if (plugin == null)
            return false;

        return systemNames
                   ?.Any(systemName => plugin.PluginDescriptor.SystemName.Equals(systemName, StringComparison.InvariantCultureIgnoreCase))
               ?? false;
    }

    /// <summary>
    /// Get plugin logo URL
    /// </summary>
    /// <param name="plugin">Plugin</param>
    /// <returns>
    /// A task that represents the asynchronous operation
    /// The task result contains the logo URL
    /// </returns>
    public virtual async Task<string> GetPluginLogoUrlAsync(TPlugin plugin)
    {
        return await _pluginService.GetPluginLogoUrlAsync(plugin.PluginDescriptor);
    }

    #endregion
}