using Microsoft.Extensions.Caching.Memory;

namespace BpsRwApp.Services;

/// <summary>
/// Base service class yang menyediakan functionality umum untuk semua services
/// Menerapkan prinsip DRY dengan mengekstrak common patterns
/// </summary>
public abstract class BaseService
{
    protected readonly ILogger _logger;
    protected readonly IMemoryCache _cache;
    protected readonly IConfiguration _configuration;

    /// <summary>
    /// Constructor untuk base service
    /// </summary>
    /// <param name="logger">Logger instance</param>
    /// <param name="cache">Memory cache instance</param>
    /// <param name="configuration">Configuration instance</param>
    protected BaseService(ILogger logger, IMemoryCache cache, IConfiguration configuration)
    {
        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
        _cache = cache ?? throw new ArgumentNullException(nameof(cache));
        _configuration = configuration ?? throw new ArgumentNullException(nameof(configuration));
    }

    /// <summary>
    /// Executes a function with comprehensive error handling and logging
    /// </summary>
    /// <typeparam name="T">Return type</typeparam>
    /// <param name="operation">Function to execute</param>
    /// <param name="operationName">Name of the operation for logging</param>
    /// <param name="fallbackValue">Fallback value if operation fails</param>
    /// <returns>Result of operation or fallback value</returns>
    protected async Task<T> ExecuteWithErrorHandlingAsync<T>(
        Func<Task<T>> operation,
        string operationName,
        T? fallbackValue = default)
    {
        try
        {
            _logger.LogInformation("Starting operation: {OperationName}", operationName);

            var result = await operation();

            _logger.LogInformation("Successfully completed operation: {OperationName}", operationName);
            return result;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error in operation: {OperationName}", operationName);

            if (fallbackValue is not null)
            {
                _logger.LogWarning("Returning fallback value for operation: {OperationName}", operationName);
                return fallbackValue;
            }

            throw;
        }
    }

    /// <summary>
    /// Gets or sets cached data with configurable expiration
    /// </summary>
    /// <typeparam name="T">Type of cached data</typeparam>
    /// <param name="cacheKey">Cache key</param>
    /// <param name="dataProvider">Function to get data if not cached</param>
    /// <param name="expiration">Cache expiration time</param>
    /// <param name="priority">Cache priority</param>
    /// <returns>Cached or fresh data</returns>
    protected async Task<T> GetOrSetCacheAsync<T>(
        string cacheKey,
        Func<Task<T>> dataProvider,
        TimeSpan expiration,
        CacheItemPriority priority = CacheItemPriority.Normal)
    {
        if (_cache.TryGetValue(cacheKey, out T? cachedValue))
        {
            _logger.LogDebug("Retrieved data from cache with key: {CacheKey}", cacheKey);
            return cachedValue!;
        }

        _logger.LogDebug("Cache miss for key: {CacheKey}, fetching fresh data", cacheKey);

        var data = await dataProvider();

        var cacheOptions = new MemoryCacheEntryOptions
        {
            AbsoluteExpirationRelativeToNow = expiration,
            Priority = priority
        };

        _cache.Set(cacheKey, data, cacheOptions);

        _logger.LogDebug("Cached data with key: {CacheKey} for {Expiration}", cacheKey, expiration);

        return data;
    }

    /// <summary>
    /// Gets or sets cached data with sliding expiration
    /// </summary>
    /// <typeparam name="T">Type of cached data</typeparam>
    /// <param name="cacheKey">Cache key</param>
    /// <param name="dataProvider">Function to get data if not cached</param>
    /// <param name="slidingExpiration">Sliding expiration time</param>
    /// <param name="absoluteExpiration">Absolute expiration time</param>
    /// <param name="priority">Cache priority</param>
    /// <returns>Cached or fresh data</returns>
    protected async Task<T> GetOrSetCacheWithSlidingAsync<T>(
        string cacheKey,
        Func<Task<T>> dataProvider,
        TimeSpan slidingExpiration,
        TimeSpan absoluteExpiration,
        CacheItemPriority priority = CacheItemPriority.Normal)
    {
        if (_cache.TryGetValue(cacheKey, out T? cachedValue))
        {
            _logger.LogDebug("Retrieved data from cache with key: {CacheKey}", cacheKey);
            return cachedValue!;
        }

        _logger.LogDebug("Cache miss for key: {CacheKey}, fetching fresh data", cacheKey);

        var data = await dataProvider();

        var cacheOptions = new MemoryCacheEntryOptions
        {
            SlidingExpiration = slidingExpiration,
            AbsoluteExpirationRelativeToNow = absoluteExpiration,
            Priority = priority
        };

        _cache.Set(cacheKey, data, cacheOptions);

        _logger.LogDebug("Cached data with key: {CacheKey} with sliding expiration", cacheKey);

        return data;
    }

    /// <summary>
    /// Removes data from cache
    /// </summary>
    /// <param name="cacheKey">Cache key to remove</param>
    protected void RemoveFromCache(string cacheKey)
    {
        _cache.Remove(cacheKey);
        _logger.LogDebug("Removed cache entry with key: {CacheKey}", cacheKey);
    }

    /// <summary>
    /// Gets configuration value with fallback
    /// </summary>
    /// <typeparam name="T">Type of configuration value</typeparam>
    /// <param name="key">Configuration key</param>
    /// <param name="defaultValue">Default value if key not found</param>
    /// <returns>Configuration value or default</returns>
    protected T GetConfigurationValue<T>(string key, T defaultValue)
    {
        return _configuration.GetValue<T>(key) ?? defaultValue;
    }

    /// <summary>
    /// Validates arguments for null values
    /// </summary>
    /// <param name="arguments">Dictionary of argument names and values</param>
    /// <exception cref="ArgumentNullException">Thrown if any argument is null</exception>
    protected static void ValidateArguments(Dictionary<string, object?> arguments)
    {
        foreach (var arg in arguments)
        {
            if (arg.Value == null)
            {
                throw new ArgumentNullException(arg.Key);
            }
        }
    }

    /// <summary>
    /// Creates a logging scope with operation context
    /// </summary>
    /// <param name="operationName">Name of the operation</param>
    /// <param name="additionalContext">Additional context data</param>
    /// <returns>Disposable logging scope</returns>
    protected IDisposable? CreateLogScope(string operationName, Dictionary<string, object>? additionalContext = null)
    {
        var scopeData = new Dictionary<string, object>
        {
            ["Operation"] = operationName,
            ["Service"] = GetType().Name
        };

        if (additionalContext != null)
        {
            foreach (var item in additionalContext)
            {
                scopeData[item.Key] = item.Value;
            }
        }

        return _logger.BeginScope(scopeData);
    }
}