using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using FinlyticSentiment.Database;
using FinlyticSentiment.Entities;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

namespace FinlyticSentiment.Services;

/// <summary>
/// Interface for reading and persisting FinlyticSentiment runtime configuration settings in PostgreSQL.
/// </summary>
public interface ISettingsDbService
{
    /// <summary>
    /// Retrieves current sentiment settings from PostgreSQL database, seeding defaults if empty.
    /// </summary>
    Task<SentimentSettingsEntity> GetSettingsAsync();

    /// <summary>
    /// Persists updated settings entity to PostgreSQL.
    /// </summary>
    Task<SentimentSettingsEntity> SaveSettingsAsync(SentimentSettingsEntity settings);

    /// <summary>
    /// Updates settings from a key-value dictionary received via Admin Panel MQTT events.
    /// </summary>
    Task UpdateSettingsFromDictionaryAsync(Dictionary<string, string> dictionary);
}

/// <summary>
/// EF Core PostgreSQL implementation of <see cref="ISettingsDbService"/>.
/// </summary>
public class SettingsDbService : ISettingsDbService
{
    private readonly SentimentDbContext _context;
    private readonly ILogger<SettingsDbService> _logger;

    /// <summary>
    /// Initializes a new instance of the <see cref="SettingsDbService"/> class.
    /// </summary>
    public SettingsDbService(SentimentDbContext context, ILogger<SettingsDbService> logger)
    {
        _context = context;
        _logger = logger;
    }

    /// <summary>
    /// Retrieves current sentiment settings from PostgreSQL database.
    /// </summary>
    public async Task<SentimentSettingsEntity> GetSettingsAsync()
    {
        var settings = await _context.Settings.AsNoTracking().FirstOrDefaultAsync();
        if (settings == null)
        {
            settings = new SentimentSettingsEntity { Id = Guid.NewGuid() };
            _context.Settings.Add(settings);
            await _context.SaveChangesAsync();
            _context.ChangeTracker.Clear();
        }
        return settings;
    }

    /// <summary>
    /// Persists updated settings entity to PostgreSQL.
    /// </summary>
    public async Task<SentimentSettingsEntity> SaveSettingsAsync(SentimentSettingsEntity settings)
    {
        var existing = await _context.Settings.FirstOrDefaultAsync();
        if (existing == null)
        {
            if (settings.Id == Guid.Empty) settings.Id = Guid.NewGuid();
            _context.Settings.Add(settings);
        }
        else
        {
            existing.MinConfidenceScore = settings.MinConfidenceScore;
            existing.MaxBatchSize = settings.MaxBatchSize;
            existing.SweepIntervalMinutes = settings.SweepIntervalMinutes;
            existing.GermanWebhookUrl = settings.GermanWebhookUrl;
            existing.EnglishWebhookUrl = settings.EnglishWebhookUrl;
            existing.UpdatedAt = settings.UpdatedAt;
            _context.Settings.Update(existing);
        }
        await _context.SaveChangesAsync();
        return settings;
    }

    /// <summary>
    /// Updates settings from a key-value dictionary.
    /// </summary>
    public async Task UpdateSettingsFromDictionaryAsync(Dictionary<string, string> dictionary)
    {
        var settings = await GetSettingsAsync();

        foreach (var (key, value) in dictionary)
        {
            if (string.Equals(key, "MinConfidenceScore", StringComparison.OrdinalIgnoreCase) && double.TryParse(value, out var mcs))
                settings.MinConfidenceScore = mcs;
            else if (string.Equals(key, "MaxBatchSize", StringComparison.OrdinalIgnoreCase) && int.TryParse(value, out var mbs))
                settings.MaxBatchSize = mbs;
            else if (string.Equals(key, "SweepIntervalMinutes", StringComparison.OrdinalIgnoreCase) && int.TryParse(value, out var sim))
                settings.SweepIntervalMinutes = sim;
            else if (string.Equals(key, "GermanWebhookUrl", StringComparison.OrdinalIgnoreCase) && !string.IsNullOrWhiteSpace(value))
                settings.GermanWebhookUrl = value.Trim();
            else if (string.Equals(key, "EnglishWebhookUrl", StringComparison.OrdinalIgnoreCase) && !string.IsNullOrWhiteSpace(value))
                settings.EnglishWebhookUrl = value.Trim();
        }

        settings.UpdatedAt = DateTime.UtcNow;
        await SaveSettingsAsync(settings);
        _logger.LogInformation("[{Channel}] Successfully updated {Count} sentiment settings in PostgreSQL database.", "SentimentChannel", dictionary.Count);
    }
}