using CredentialManager.Data;
using CredentialManager.Models;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

namespace CredentialManager.Services;

/// <summary>
/// Servizio per la gestione delle associazioni tra record sorgente e destinazione
/// </summary>
public class RecordAssociationService : IRecordAssociationService
{
    private readonly CredentialDbContext _context;
    private readonly ILogger<RecordAssociationService> _logger;

    public RecordAssociationService(
        CredentialDbContext context,
        ILogger<RecordAssociationService> logger)
    {
        _context = context;
        _logger = logger;
    }

    public async Task<int> SaveAssociationAsync(RecordAssociation association)
    {
        try
        {
            // Controlla se esiste già un'associazione per questa combinazione
            var existing = await _context.RecordAssociations
                .FirstOrDefaultAsync(ra => 
                    ra.SourceName == association.SourceName &&
                    ra.SourceKey == association.SourceKey &&
                    ra.DestinationEntity == association.DestinationEntity &&
                    ra.IsActive);

            if (existing != null)
            {
                // Aggiorna l'associazione esistente
                existing.DestinationId = association.DestinationId;
                existing.RestCredentialName = association.RestCredentialName;
                existing.UpdatedAt = DateTime.UtcNow;
                existing.AdditionalInfo = association.AdditionalInfo;

                _context.RecordAssociations.Update(existing);
                await _context.SaveChangesAsync();

                _logger.LogInformation("Associazione aggiornata: {SourceName}/{SourceKey} -> {DestinationEntity}/{DestinationId}",
                    association.SourceName, association.SourceKey, association.DestinationEntity, association.DestinationId);

                return existing.Id;
            }
            else
            {
                // Crea nuova associazione
                _context.RecordAssociations.Add(association);
                await _context.SaveChangesAsync();

                _logger.LogInformation("Nuova associazione creata: {SourceName}/{SourceKey} -> {DestinationEntity}/{DestinationId}",
                    association.SourceName, association.SourceKey, association.DestinationEntity, association.DestinationId);

                return association.Id;
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nel salvare l'associazione: {SourceName}/{SourceKey} -> {DestinationEntity}",
                association.SourceName, association.SourceKey, association.DestinationEntity);
            throw;
        }
    }

    public async Task<RecordAssociation?> FindAssociationAsync(string sourceName, string sourceKey, string destinationEntity)
    {
        try
        {
            return await _context.RecordAssociations
                .FirstOrDefaultAsync(ra => 
                    ra.SourceName == sourceName &&
                    ra.SourceKey == sourceKey &&
                    ra.DestinationEntity == destinationEntity &&
                    ra.IsActive);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nella ricerca dell'associazione: {SourceName}/{SourceKey} -> {DestinationEntity}",
                sourceName, sourceKey, destinationEntity);
            throw;
        }
    }

    public async Task<List<RecordAssociation>> GetAssociationsBySourceAsync(string sourceName, string sourceType)
    {
        try
        {
            return await _context.RecordAssociations
                .Where(ra => ra.SourceName == sourceName && ra.SourceType == sourceType && ra.IsActive)
                .OrderByDescending(ra => ra.CreatedAt)
                .ToListAsync();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nel recupero delle associazioni per sorgente: {SourceName} ({SourceType})",
                sourceName, sourceType);
            throw;
        }
    }

    public async Task<List<RecordAssociation>> GetAssociationsByDestinationAsync(string destinationEntity, string restCredentialName)
    {
        try
        {
            return await _context.RecordAssociations
                .Where(ra => ra.DestinationEntity == destinationEntity && 
                           ra.RestCredentialName == restCredentialName && 
                           ra.IsActive)
                .OrderByDescending(ra => ra.CreatedAt)
                .ToListAsync();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nel recupero delle associazioni per destinazione: {DestinationEntity} ({RestCredentialName})",
                destinationEntity, restCredentialName);
            throw;
        }
    }

    public async Task<List<RecordAssociation>> GetAllActiveAssociationsAsync()
    {
        try
        {
            return await _context.RecordAssociations
                .Where(ra => ra.IsActive)
                .OrderByDescending(ra => ra.CreatedAt)
                .ToListAsync();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nel recupero di tutte le associazioni attive");
            throw;
        }
    }

    public async Task<bool> UpdateAssociationAsync(RecordAssociation association)
    {
        try
        {
            var existing = await _context.RecordAssociations.FindAsync(association.Id);
            if (existing == null)
            {
                _logger.LogWarning("Associazione con ID {Id} non trovata per l'aggiornamento", association.Id);
                return false;
            }

            existing.DestinationId = association.DestinationId;
            existing.RestCredentialName = association.RestCredentialName;
            existing.UpdatedAt = DateTime.UtcNow;
            existing.AdditionalInfo = association.AdditionalInfo;
            existing.IsActive = association.IsActive;

            _context.RecordAssociations.Update(existing);
            await _context.SaveChangesAsync();

            _logger.LogInformation("Associazione aggiornata: ID {Id}", association.Id);
            return true;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nell'aggiornamento dell'associazione: ID {Id}", association.Id);
            throw;
        }
    }

    public async Task<bool> DeactivateAssociationAsync(int id)
    {
        try
        {
            var association = await _context.RecordAssociations.FindAsync(id);
            if (association == null)
            {
                _logger.LogWarning("Associazione con ID {Id} non trovata per la disattivazione", id);
                return false;
            }

            association.IsActive = false;
            association.UpdatedAt = DateTime.UtcNow;

            _context.RecordAssociations.Update(association);
            await _context.SaveChangesAsync();

            _logger.LogInformation("Associazione disattivata: ID {Id}", id);
            return true;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nella disattivazione dell'associazione: ID {Id}", id);
            throw;
        }
    }

    public async Task<bool> DeleteAssociationAsync(int id)
    {
        try
        {
            var association = await _context.RecordAssociations.FindAsync(id);
            if (association == null)
            {
                _logger.LogWarning("Associazione con ID {Id} non trovata per l'eliminazione", id);
                return false;
            }

            _context.RecordAssociations.Remove(association);
            await _context.SaveChangesAsync();

            _logger.LogInformation("Associazione eliminata: ID {Id}", id);
            return true;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nell'eliminazione dell'associazione: ID {Id}", id);
            throw;
        }
    }

    public async Task<int> CleanupOldAssociationsAsync(TimeSpan olderThan)
    {
        try
        {
            var cutoffDate = DateTime.UtcNow - olderThan;
            var oldAssociations = await _context.RecordAssociations
                .Where(ra => ra.CreatedAt < cutoffDate && !ra.IsActive)
                .ToListAsync();

            if (oldAssociations.Any())
            {
                _context.RecordAssociations.RemoveRange(oldAssociations);
                await _context.SaveChangesAsync();

                _logger.LogInformation("Pulite {Count} associazioni obsolete più vecchie di {Cutoff}",
                    oldAssociations.Count, cutoffDate);
            }

            return oldAssociations.Count;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Errore nella pulizia delle associazioni obsolete");
            throw;
        }
    }
}