using System.Globalization;
using System.Text;
using System.Text.Json;
using Microsoft.Extensions.Logging;
using DiunaBI.Core.Models;
using DiunaBI.Database.Context;

namespace DiunaBI.Plugins.Morska.Importers;

public class MorskaD3Importer : MorskaBaseImporter
{
    public override string ImporterType => "Morska.Import.D3";
    
    private readonly AppDbContext _db;
    private readonly ILogger<MorskaD3Importer> _logger;

    public MorskaD3Importer(
        AppDbContext db,
        ILogger<MorskaD3Importer> logger)
    {
        _db = db;
        _logger = logger;
    }

    public override void Import(Layer importWorker)
    {
        _logger.LogInformation("MorskaD3: Starting import for {ImportWorkerName} ({ImportWorkerId})", 
            importWorker.Name, importWorker.Id);

        var year = importWorker.Records!.FirstOrDefault(x => x.Code == "ImportYear")?.Desc1;
        if (year == null)
        {
            throw new Exception($"ImportYear not found, {importWorker.Name}");
        }

        var month = importWorker.Records!.FirstOrDefault(x => x.Code == "ImportMonth")?.Desc1;
        if (month == null)
        {
            throw new Exception($"ImportMonth not found, {importWorker.Name}");
        }

        var name = importWorker.Records!.FirstOrDefault(x => x.Code == "ImportName")?.Desc1;
        if (name == null)
        {
            throw new Exception($"ImportName not found, {importWorker.Name}");
        }

        var type = importWorker.Records!.FirstOrDefault(x => x.Code == "ImportType")?.Desc1;
        if (type == null)
        {
            throw new Exception($"ImportType not found, {importWorker.Name}");
        }

        _logger.LogDebug("MorskaD3: Looking for DataInbox with type {Type}", type);

        var dataInbox = _db.DataInbox.OrderByDescending(x => x.CreatedAt).FirstOrDefault(x => x.Name == type);
        if (dataInbox == null)
        {
            throw new Exception($"DataInbox not found, {type}");
        }

        _logger.LogDebug("MorskaD3: Found DataInbox {DataInboxId}, created at {CreatedAt}", 
            dataInbox.Id, dataInbox.CreatedAt);

        try
        {
            var data = Convert.FromBase64String(dataInbox.Data);
            var jsonString = Encoding.UTF8.GetString(data);
            
            _logger.LogDebug("MorskaD3: Decoded {DataSize} bytes from base64", data.Length);

            var records = JsonSerializer.Deserialize<List<Record>>(jsonString);
            if (records == null)
            {
                throw new Exception($"DataInbox.Data is empty, {dataInbox.Name}");
            }

            _logger.LogDebug("MorskaD3: Deserialized {RecordCount} records from JSON", records.Count);

            records = records.Where(x => x.Code!.StartsWith($"{year}{month}")).ToList();
            if (records.Count == 0)
            {
                throw new Exception($"No records found for {year}{month}");
            }

            _logger.LogDebug("MorskaD3: Filtered to {FilteredCount} records for period {Year}{Month}", 
                records.Count, year, month);

            records = records.Select(x =>
            {
                x.Id = Guid.NewGuid();
                x.CreatedAt = DateTime.UtcNow;
                x.ModifiedAt = DateTime.UtcNow;
                return x;
            }).ToList();

            var layer = new Layer
            {
                Id = Guid.NewGuid(), 
                Number = _db.Layers.Count() + 1,
                ParentId = importWorker.Id,
                Type = LayerType.Import,
                CreatedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D"),
                ModifiedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D"),
                CreatedAt = DateTime.UtcNow,
                ModifiedAt = DateTime.UtcNow
            };
            layer.Name = $"L{layer.Number}-I-{name}-{year}/{month}-{DateTime.Now:yyyyMMddHHmm}";

            _db.Layers.Add(layer);
            
            SaveRecords(layer.Id, records);
            _db.SaveChanges();

            _logger.LogInformation("MorskaD3: Successfully imported {RecordCount} records for layer {LayerName} ({LayerId})", 
                records.Count, layer.Name, layer.Id);
        }
        catch (Exception e)
        {
            _logger.LogError(e, "MorskaD3: Error processing DataInbox {DataInboxId}", dataInbox.Id);
            throw;
        }
    }

    private void SaveRecords(Guid layerId, ICollection<Record> records)
    {
        var toDelete = _db.Records.Where(x => x.LayerId == layerId).ToList();
        if (toDelete.Count > 0)
        {
            _db.Records.RemoveRange(toDelete);
        }

        foreach (var record in records)
        {
            record.CreatedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D");
            record.CreatedAt = DateTime.UtcNow;
            record.ModifiedById = Guid.Parse("F392209E-123E-4651-A5A4-0B1D6CF9FF9D");
            record.ModifiedAt = DateTime.UtcNow;
            record.LayerId = layerId;
            _db.Records.Add(record);
        }

        _logger.LogDebug("MorskaD3: Saved {RecordCount} records for layer {LayerId}", records.Count, layerId);
    }
}