using Insight.Database;
using System.Data;

namespace Database.Identity
{
	public class DbInfrastructureSetup
	{
		private readonly IDbConnection _db;
		string _schema;

		public DbInfrastructureSetup(IDbConnection db)
		{
			_db = db;
		}

		public async Task CreateDatabaseWithSchema(string schema)
		{
			_schema = schema;

			if (_db.State != ConnectionState.Open)
				_db.Open();

			using var transaction = _db.BeginTransaction();
			try
			{
				await CreateUserTable();
				await CreateTenantTable();
				await CreateUserTenantTable();
				await SetupRLS();

				transaction.Commit();
			}
			catch
			{
				transaction.Rollback();
				throw;
			}
		}

		private async Task CreateUserTable()
		{
			await _db.ExecuteSqlAsync(@$"
           CREATE TABLE IF NOT EXISTS {_schema}.users (
               id SERIAL PRIMARY KEY,
               email VARCHAR(256) NOT NULL UNIQUE,
               password_hash VARCHAR(256) NOT NULL,
               security_stamp VARCHAR(36) NOT NULL,
               email_confirmed BOOLEAN NOT NULL DEFAULT FALSE,
               created_date TIMESTAMP NOT NULL,
               last_login_date TIMESTAMP NULL
           );");
		}

		private async Task CreateTenantTable()
		{
			await _db.ExecuteSqlAsync(@$"
           CREATE TABLE IF NOT EXISTS {_schema}.tenants (
               id SERIAL PRIMARY KEY,
               connection_string VARCHAR(500) NOT NULL,
               created_date TIMESTAMP NOT NULL,
               created_by INTEGER REFERENCES {_schema}.users(id),
               is_active BOOLEAN DEFAULT true
           );");
		}

		private async Task CreateUserTenantTable()
		{
			await _db.ExecuteSqlAsync(@$"
           CREATE TABLE IF NOT EXISTS {_schema}.user_tenants (
               user_id INTEGER REFERENCES {_schema}.users(id),
               tenant_id INTEGER REFERENCES {_schema}.tenants(id),
               created_date TIMESTAMP NOT NULL,
               PRIMARY KEY (user_id, tenant_id)
           );");
		}

		private async Task SetupRLS()
		{
			await _db.ExecuteSqlAsync(@$"
           ALTER TABLE {_schema}.tenants ENABLE ROW LEVEL SECURITY;
           ALTER TABLE {_schema}.user_tenants ENABLE ROW LEVEL SECURITY;

           DROP POLICY IF EXISTS tenant_access ON {_schema}.tenants;
           CREATE POLICY tenant_access ON {_schema}.tenants
               USING (id IN (
                   SELECT tenant_id 
                   FROM {_schema}.user_tenants 
                   WHERE user_id = current_setting('app.user_id', TRUE)::INTEGER
               ));

           DROP POLICY IF EXISTS user_tenant_access ON {_schema}.user_tenants;
           CREATE POLICY user_tenant_access ON {_schema}.user_tenants
               USING (user_id = current_setting('app.user_id', TRUE)::INTEGER);");
		}
	}
}