using System;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Storage;
using Npgsql;

namespace Content.Server.Database
{
    public sealed class PostgresServerDbContext : ServerDbContext
    {
        public PostgresServerDbContext(DbContextOptions<PostgresServerDbContext> options) : base(options)
        {
        }

        protected override void OnConfiguring(DbContextOptionsBuilder options)
        {
            ((IDbContextOptionsBuilderInfrastructure) options).AddOrUpdateExtension(new SnakeCaseExtension());

            options.ConfigureWarnings(x =>
            {
                x.Ignore(CoreEventId.ManyServiceProvidersCreatedWarning);
#if DEBUG
                // for tests
                x.Ignore(CoreEventId.SensitiveDataLoggingEnabledWarning);
#endif
            });

#if DEBUG
            options.EnableSensitiveDataLogging();
#endif
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            // ReSharper disable StringLiteralTypo
            // Enforce that an address cannot be IPv6-mapped IPv4.
            // So that IPv4 addresses are consistent between separate-socket and dual-stack socket modes.
            modelBuilder.Entity<ServerBan>().ToTable(t =>
                t.HasCheckConstraint("AddressNotIPv6MappedIPv4", "NOT inet '::ffff:0.0.0.0/96' >>= address"));

            modelBuilder.Entity<ServerRoleBan>().ToTable( t =>
                t.HasCheckConstraint("AddressNotIPv6MappedIPv4", "NOT inet '::ffff:0.0.0.0/96' >>= address"));

            modelBuilder.Entity<Player>().ToTable(t =>
                t.HasCheckConstraint("LastSeenAddressNotIPv6MappedIPv4",
                    "NOT inet '::ffff:0.0.0.0/96' >>= last_seen_address"));

            modelBuilder.Entity<ConnectionLog>().ToTable(t =>
                t.HasCheckConstraint("AddressNotIPv6MappedIPv4",
                    "NOT inet '::ffff:0.0.0.0/96' >>= address"));

            // ReSharper restore StringLiteralTypo

            modelBuilder.Entity<AdminLog>()
                .HasIndex(l => l.Message)
                .HasMethod("GIN")
                .IsTsVectorExpressionIndex("english");

            foreach(var entity in modelBuilder.Model.GetEntityTypes())
            {
                foreach(var property in entity.GetProperties())
                {
                    if (property.FieldInfo?.FieldType == typeof(DateTime) || property.FieldInfo?.FieldType == typeof(DateTime?))
                        property.SetColumnType("timestamp with time zone");
                }
            }
        }

        public override IQueryable<AdminLog> SearchLogs(IQueryable<AdminLog> query, string searchText)
        {
            return query.Where(log => EF.Functions.ToTsVector("english", log.Message).Matches(searchText));
        }

        public override int CountAdminLogs()
        {
            using var command = new NpgsqlCommand("SELECT reltuples FROM pg_class WHERE relname = 'admin_log';", (NpgsqlConnection?) Database.GetDbConnection());

            Database.GetDbConnection().Open();
            var count = Convert.ToInt32((float) (command.ExecuteScalar() ?? 0));
            Database.GetDbConnection().Close();
            return count;
        }
    }
}