using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using Mizuki.Database.Models;

namespace Mizuki.Database;

/// <summary>
/// The DB context for Mizuki.
/// </summary>
public class MizukiDbContext : DbContext
{
    /// <summary>
    /// The users.
    /// </summary>
    public virtual DbSet<User> Users { get; set; } = null!;

    /// <summary>
    /// The files.
    /// </summary>
    public virtual DbSet<Upload> Uploads { get; set; } = null!;
    
    /// <inheritdoc />
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<User>();
        modelBuilder.Entity<Upload>();
        
        if (Database.ProviderName == "Microsoft.EntityFrameworkCore.Sqlite")
        {
            // SQLite does not have proper support for DateTimeOffset via Entity Framework Core, see the limitations
            // here: https://docs.microsoft.com/en-us/ef/core/providers/sqlite/limitations#query-limitations
            // To work around this, when the Sqlite database provider is used, all model properties of type DateTimeOffset
            // use the DateTimeOffsetToBinaryConverter
            // Based on: https://github.com/aspnet/EntityFrameworkCore/issues/10784#issuecomment-415769754
            // This only supports millisecond precision, but should be sufficient for most use cases.
            foreach (var entityType in modelBuilder.Model.GetEntityTypes())
            {
                var properties = entityType.ClrType.GetProperties().Where(p => p.PropertyType == typeof(DateTimeOffset)
                                                                               || p.PropertyType == typeof(DateTimeOffset?));
                foreach (var property in properties)
                {
                    modelBuilder
                        .Entity(entityType.Name)
                        .Property(property.Name)
                        .HasConversion(new DateTimeOffsetToBinaryConverter());
                }
            }
        }
    }
    
    /// <inheritdoc />
    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlite($"Data Source=mizuki.db");
}