#nullable enable

using System.Transactions;

using Abp.Dependency;
using Abp.Domain.Uow;
using Abp.EntityFrameworkCore;
using Abp.Extensions;

using Microsoft.EntityFrameworkCore;

using VberZero.BaseSystem.MultiTenancy;
using VberZero.Data;
using VberZero.MultiTenancy;

namespace VberZero.EntityFramework;

public abstract class VzDbMigrator<TDbContext> : IVzDbMigrator, ITransientDependency
    where TDbContext : DbContext
{
    private readonly IUnitOfWorkManager _unitOfWorkManager;
    private readonly IDbPerTenantConnectionStringResolver _connectionStringResolver;
    private readonly IDbContextResolver _dbContextResolver;

    protected VzDbMigrator(
        IUnitOfWorkManager unitOfWorkManager,
        IDbPerTenantConnectionStringResolver connectionStringResolver,
        IDbContextResolver dbContextResolver)
    {
        _unitOfWorkManager = unitOfWorkManager;
        _connectionStringResolver = connectionStringResolver;
        _dbContextResolver = dbContextResolver;
    }

    public virtual void CreateOrMigrateForHost()
    {
        CreateOrMigrateForHost(null);
    }

    public virtual void CreateOrMigrateForHost(Action<TDbContext>? seedAction)
    {
        CreateOrMigrate(null, seedAction);
    }

    public virtual void CreateOrMigrateForTenant(Tenant tenant)
    {
        CreateOrMigrateForTenant(tenant, null);
    }

    public virtual void CreateOrMigrateForTenant(Tenant? tenant, Action<TDbContext>? seedAction)
    {
        if (tenant != null && tenant.ConnectionString.IsNullOrEmpty())
        {
            return;
        }

        CreateOrMigrate(tenant, seedAction);
    }

    protected virtual void CreateOrMigrate(Tenant? tenant, Action<TDbContext>? seedAction)
    {
        var args = new DbPerTenantConnectionStringResolveArgs(
            tenant?.Id,
            tenant == null ? Abp.MultiTenancy.MultiTenancySides.Host : Abp.MultiTenancy.MultiTenancySides.Tenant
        )
        {
            ["DbContextType"] = typeof(TDbContext),
            ["DbContextConcreteType"] = typeof(TDbContext)
        };

        var nameOrConnectionString = ConnectionStringHelper.GetConnectionString(
            _connectionStringResolver.GetNameOrConnectionString(args)
        );

        using var uow = _unitOfWorkManager.Begin(TransactionScopeOption.Suppress);
        using var dbContext = _dbContextResolver.Resolve<TDbContext>(nameOrConnectionString, null);
        dbContext.Database.Migrate();
        seedAction?.Invoke(dbContext);
        _unitOfWorkManager.Current.SaveChanges();
        uow.Complete();
    }
}