/*
 * QQQ - Low-code Application Framework for Engineers.
 * Copyright (C) 2021-2025.  Kingsrook, LLC
 * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
 * contact@kingsrook.com
 * https://github.com/Kingsrook/
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.kingsrook.qbits.documentgeneration;


import java.sql.Connection;
import java.util.List;
import com.kingsrook.qqq.backend.core.exceptions.QException;
import com.kingsrook.qqq.backend.module.rdbms.jdbc.ConnectionManager;
import com.kingsrook.qqq.backend.module.rdbms.model.metadata.RDBMSBackendMetaData;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;


/***************************************************************************
 ** Run the unchanged native authorization/transaction/concurrency suite on a
 ** real PostgreSQL 17 engine, plus PostgreSQL-specific durability and drift cases.
 ***************************************************************************/
class PostgresGenerationQueueTest extends GenerationQueueJdbcTest
{
   private static PostgresGenerationDatabase postgres;

   // The engine the fixture calls of the running test address: the shared pinned one unless that test started its own.
   private PostgresGenerationDatabase current;

   /***********************************************************************
    ** One exact disposable engine per suite; all test cases use new databases.
    ***********************************************************************/
   @BeforeAll
   static void startPostgres()
   {
      postgres = new PostgresGenerationDatabase();
   }

   /***********************************************************************
    ** Remove only the fixture-owned engine after every inherited assertion.
    ***********************************************************************/
   @AfterAll
   static void stopPostgres()
   {
      if(postgres != null)
      {
         postgres.close();
      }
   }

   /***********************************************************************
    ** Native actions receive only the DML identity, never migration authority.
    ***********************************************************************/
   @Override
   protected RDBMSBackendMetaData database(String name, String defaultUrl) throws Exception
   {
      return (engine().database(name));
   }

   /***********************************************************************
    ** Assertion and fault-injection connections remain separate from QQQ.
    ***********************************************************************/
   @Override
   protected Connection connection() throws Exception
   {
      return (engine().connection());
   }

   /***********************************************************************
    ** Execute fixed fixture DDL, with no compatibility/emulation database mode.
    ***********************************************************************/
   @Override
   protected void sql(String source) throws Exception
   {
      engine().sql(source);
   }

   /***********************************************************************
    ** The shared pinned engine, or the unpinned one a single test started.
    ***********************************************************************/
   private PostgresGenerationDatabase engine()
   {
      return (current == null ? postgres : current);
   }

   /***********************************************************************
    ** The shipped migration scripts for this engine.
    ***********************************************************************/
   @Override
   protected String dialect()
   {
      return ("postgres");
   }

   /***********************************************************************
    ** Exercise the shipped native schema without the H2 timestamp rewrite.
    ***********************************************************************/
   @Override
   protected String schema(DocumentGenerationQBitConfig configuration)
   {
      return (DocumentGenerationSchema.postgresScript(configuration));
   }

   /***************************************************************************
    ** Cold server restart preserves committed results and untouched work.
    ***************************************************************************/
   @Test
   void serverRestartPreservesQueueAndIndependentAudit() throws Exception
   {
      int id = enqueue("restart");
      var first = queue.advance(id);
      assertThat(first.state()).isEqualTo("GENERATED");
      postgres.restart();
      assertThat(queue.status(id, -1, 10).items().getFirst()).isEqualTo(first);
      assertThat(queue.advance(id).state()).isEqualTo("GENERATED");
      assertThat(queue.advance(id)).isNull();
      try(var connection = connection(); var statement = connection.createStatement();
          var rows = statement.executeQuery("SELECT COUNT(*) FROM document_generation_event WHERE outcome='GENERATION_RETAINED'"))
      {
         rows.next();
         assertThat(rows.getInt(1)).isEqualTo(2);
      }
   }

   /***************************************************************************
    ** Exact text comparison keeps case and trailing-space keys distinct, and a retry is idempotent.
    ***************************************************************************/
   @Test
   void caseAndTrailingSpaceRemainDistinctIdempotencyKeys() throws Exception
   {
      int upper = enqueue("Case");
      int lower = enqueue("case");
      int spaced = enqueue("Case ");
      assertThat(List.of(upper, lower, spaced)).doesNotHaveDuplicates();
      assertThat(enqueue("Case")).isEqualTo(upper);
   }

   /***************************************************************************
    ** Unlogged tables, nondeterministic collations and missing idempotency keys fail closed before any write.
    ***************************************************************************/
   @Test
   void realSchemaDriftFailsClosed() throws Exception
   {
      sql("ALTER TABLE document_generation_stock SET UNLOGGED");
      assertThatThrownBy(() -> enqueue("unlogged")).isInstanceOf(QException.class).hasMessageContaining("logged");
      assertThatThrownBy(() -> new DocumentDefinitionService(config).createType("must not persist")).isInstanceOf(QException.class).hasMessageContaining("logged");
      sql("ALTER TABLE document_generation_stock SET LOGGED");
      sql("CREATE COLLATION fixture_ci (provider = icu, locale = 'und-u-ks-level2', deterministic = false)");
      sql("ALTER TABLE document_generation_queue ALTER COLUMN request_key TYPE VARCHAR(130) COLLATE fixture_ci");
      assertThatThrownBy(() -> enqueue("collation")).isInstanceOf(QException.class).hasMessageContaining("deterministic");
      sql("ALTER TABLE document_generation_queue ALTER COLUMN request_key TYPE VARCHAR(130) COLLATE \"default\"");
      sql("DROP INDEX uq_document_generation_queue_1");
      assertThatThrownBy(() -> enqueue("index")).isInstanceOf(QException.class).hasMessageContaining("idempotency");
   }

   /***************************************************************************
    ** Role-level settings are observed from the actual server, never assumed from fixture setup.
    ***************************************************************************/
   @Test
   void weakCommitAndUnboundedLockSettingsAreRejectedBeforeWriting() throws Exception
   {
      try
      {
         sql("ALTER ROLE generation_app SET synchronous_commit='off'");
         ConnectionManager.closeConnectionProviders();
         assertThatThrownBy(() -> enqueue("weak-commit")).isInstanceOf(QException.class).hasMessageContaining("synchronous PostgreSQL");
         sql("ALTER ROLE generation_app SET synchronous_commit='on'");
         sql("ALTER ROLE generation_app RESET lock_timeout");
         ConnectionManager.closeConnectionProviders();
         assertThatThrownBy(() -> enqueue("unbounded-lock")).isInstanceOf(QException.class).hasMessageContaining("lock_timeout");
         sql("ALTER ROLE generation_app SET lock_timeout='60s'");
         ConnectionManager.closeConnectionProviders();
         assertThatThrownBy(() -> enqueue("long-lock")).isInstanceOf(QException.class).hasMessageContaining("lock_timeout");
      }
      finally
      {
         sql("ALTER ROLE generation_app SET synchronous_commit='on'");
         sql("ALTER ROLE generation_app SET lock_timeout='5s'");
         ConnectionManager.closeConnectionProviders();
      }
      assertThat(queue.status(enqueue("restored"), -1, 10).items()).hasSize(2);
   }

   /***************************************************************************
    ** Amazon Aurora PostgreSQL always runs with full_page_writes off (its storage
    ** layer does not write torn pages), so that one setting is accepted there and
    ** nowhere else. The engine is a real PostgreSQL 17 whose settings are really
    ** changed. Only Aurora itself is simulated: a function named aurora_version()
    ** is created in the test database, so the same to_regprocedure detection that
    ** is true on Aurora resolves here.
    ***************************************************************************/
   @Test
   void fullPageWritesOffIsAcceptedOnlyOnAuroraAndNothingElseIsRelaxed() throws Exception
   {
      current = new PostgresGenerationDatabase(false);
      try
      {
         // Rebuild the instance, schema and definitions on the unpinned engine (durable defaults, so this qualifies).
         cleanup();
         setup();
         assertThat(queue.advance(enqueue("stock-durable")).state()).isEqualTo("GENERATED");

         // Stock PostgreSQL with full_page_writes off is refused, and the refusal states the rule.
         current.system("full_page_writes", "off");
         assertThatThrownBy(() -> enqueue("stock-torn-pages")).isInstanceOf(QException.class)
            .hasMessageContaining("full-page writes (except on Amazon Aurora PostgreSQL)").hasMessageContaining("not satisfied: synchronous commit");

         // The same server, now resolving aurora_version(), is accepted and work really commits.
         sql("CREATE FUNCTION aurora_version() RETURNS text LANGUAGE sql IMMUTABLE AS $$ SELECT '17.9'::text $$");
         ConnectionManager.closeConnectionProviders();
         assertThat(queue.advance(enqueue("aurora")).state()).isEqualTo("GENERATED");

         // Aurora relaxes nothing else: fsync off is refused.
         current.system("fsync", "off");
         assertThatThrownBy(() -> enqueue("aurora-no-fsync")).isInstanceOf(QException.class).hasMessageContaining("not satisfied: synchronous commit");
         current.system("fsync", "on");

         // Aurora relaxes nothing else: asynchronous commit is refused.
         sql("ALTER ROLE generation_app SET synchronous_commit='off'");
         ConnectionManager.closeConnectionProviders();
         assertThatThrownBy(() -> enqueue("aurora-async-commit")).isInstanceOf(QException.class).hasMessageContaining("not satisfied: synchronous commit");
         sql("ALTER ROLE generation_app SET synchronous_commit='on'");
         ConnectionManager.closeConnectionProviders();
         assertThat(enqueue("aurora-restored")).isNotNull();

         // Without the function the server is stock PostgreSQL again and is refused again.
         sql("DROP FUNCTION aurora_version()");
         ConnectionManager.closeConnectionProviders();
         assertThatThrownBy(() -> enqueue("stock-again")).isInstanceOf(QException.class).hasMessageContaining("not satisfied: synchronous commit");
      }
      finally
      {
         ConnectionManager.closeConnectionProviders();
         current.close();
         current = null;
      }
   }

   /***************************************************************************
    ** The durability decision itself, for the combinations the live case does
    ** not reach: no server and nothing simulated, only the values of one row.
    ***************************************************************************/
   @Test
   void durabilityRuleAcceptsOnlyTheAuroraFullPageWritesException()
   {
      assertThat(GenerationPostgres.durable("on", "on", "on", false)).isTrue();
      assertThat(GenerationPostgres.durable("remote_apply", "on", "on", false)).isTrue();
      assertThat(GenerationPostgres.durable("on", "on", "on", true)).isTrue();
      assertThat(GenerationPostgres.durable("on", "on", "off", true)).isTrue();
      assertThat(GenerationPostgres.durable("remote_apply", "on", "off", true)).isTrue();
      assertThat(GenerationPostgres.durable("on", "on", "off", false)).isFalse();
      assertThat(GenerationPostgres.durable("on", "off", "on", false)).isFalse();
      assertThat(GenerationPostgres.durable("on", "off", "off", true)).isFalse();
      for(String weak : List.of("off", "local", "remote_write"))
      {
         assertThat(GenerationPostgres.durable(weak, "on", "on", false)).isFalse();
         assertThat(GenerationPostgres.durable(weak, "on", "off", true)).isFalse();
      }
      assertThat(GenerationPostgres.durable(null, "on", "on", true)).isFalse();
      assertThat(GenerationPostgres.durable("on", null, "on", true)).isFalse();
      assertThat(GenerationPostgres.durable("on", "on", null, true)).isFalse();
   }

   /***************************************************************************
    ** The native identity must be the postgres module on a real PostgreSQL17 server, not a vendor label.
    ***************************************************************************/
   @Test
   void vendorLabelWithoutPostgresModuleIsRejected() throws Exception
   {
      jdbcBackend.setBackendType("rdbms");
      assertThatThrownBy(() -> enqueue("wrong-module")).isInstanceOf(QException.class).hasMessageContaining("not qualified");
   }
}