/* vim set:sw=2 ts=2 et lcs=trail\:.,tab\:>~ : */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "storage_test_harness.h"

#include "mozilla/ReentrantMonitor.h"
#include "nsThreadUtils.h"
#include "mozIStorageStatement.h"

/**
 * This file tests that our implementation around sqlite3_unlock_notify works
 * as expected.
 */

////////////////////////////////////////////////////////////////////////////////
//// Helpers

enum State { STARTING, WRITE_LOCK, READ_LOCK, TEST_DONE };

class DatabaseLocker : public mozilla::Runnable {
 public:
  explicit DatabaseLocker(const char* aSQL, nsIFile* aDBFile = nullptr)
      : mozilla::Runnable("DatabaseLocker"),
        monitor("DatabaseLocker::monitor"),
        mSQL(aSQL),
        mState(STARTING),
        mDBFile(aDBFile) {}

  void RunInBackground() {
    (void)NS_NewNamedThread("DatabaseLocker", getter_AddRefs(mThread));
    do_check_true(mThread);

    do_check_success(mThread->Dispatch(this, NS_DISPATCH_NORMAL));
  }

  void Shutdown() {
    if (mThread) {
      mThread->Shutdown();
    }
  }

  NS_IMETHOD Run() override {
    mozilla::ReentrantMonitorAutoEnter lock(monitor);

    nsCOMPtr<mozIStorageConnection> db(getDatabase(mDBFile));

    nsCString sql(mSQL);
    nsCOMPtr<mozIStorageStatement> stmt;
    do_check_success(db->CreateStatement(sql, getter_AddRefs(stmt)));

    bool hasResult;
    do_check_success(stmt->ExecuteStep(&hasResult));

    Notify(WRITE_LOCK);
    WaitFor(TEST_DONE);

    return NS_OK;
  }

  void WaitFor(State aState) {
    monitor.AssertCurrentThreadIn();
    while (mState != aState) {
      do_check_success(monitor.Wait());
    }
  }

  void Notify(State aState) {
    monitor.AssertCurrentThreadIn();
    mState = aState;
    do_check_success(monitor.Notify());
  }

  mozilla::ReentrantMonitor monitor MOZ_UNANNOTATED;

 protected:
  nsCOMPtr<nsIThread> mThread;
  const char* const mSQL;
  State mState;
  nsCOMPtr<nsIFile> mDBFile;
};

class DatabaseTester : public DatabaseLocker {
 public:
  DatabaseTester(mozIStorageConnection* aConnection, const char* aSQL)
      : DatabaseLocker(aSQL), mConnection(aConnection) {}

  NS_IMETHOD Run() override {
    mozilla::ReentrantMonitorAutoEnter lock(monitor);
    WaitFor(READ_LOCK);

    nsCString sql(mSQL);
    nsCOMPtr<mozIStorageStatement> stmt;
    do_check_success(mConnection->CreateStatement(sql, getter_AddRefs(stmt)));

    bool hasResult;
    nsresult rv = stmt->ExecuteStep(&hasResult);
    do_check_eq(rv, NS_ERROR_FILE_IS_LOCKED);

    // Finalize our statement and null out our connection before notifying to
    // ensure that we close on the proper thread.
    stmt->Finalize();
    mConnection = nullptr;

    Notify(TEST_DONE);

    return NS_OK;
  }

 private:
  nsCOMPtr<mozIStorageConnection> mConnection;
};

////////////////////////////////////////////////////////////////////////////////
//// Test Functions

void setup() {
  nsCOMPtr<mozIStorageConnection> db(getDatabase());

  // Create and populate a dummy table.
  nsresult rv = db->ExecuteSimpleSQL(nsLiteralCString(
      "CREATE TABLE test (id INTEGER PRIMARY KEY, data STRING)"));
  do_check_success(rv);
  rv = db->ExecuteSimpleSQL("INSERT INTO test (data) VALUES ('foo')"_ns);
  do_check_success(rv);
  rv = db->ExecuteSimpleSQL("INSERT INTO test (data) VALUES ('bar')"_ns);
  do_check_success(rv);
  rv =
      db->ExecuteSimpleSQL("CREATE UNIQUE INDEX unique_data ON test (data)"_ns);
  do_check_success(rv);
}

void test_step_locked_does_not_block_main_thread() {
  nsCOMPtr<mozIStorageConnection> db(getDatabase());

  // Need to prepare our statement ahead of time so we make sure to only test
  // step and not prepare.
  nsCOMPtr<mozIStorageStatement> stmt;
  nsresult rv = db->CreateStatement(
      "INSERT INTO test (data) VALUES ('test1')"_ns, getter_AddRefs(stmt));
  do_check_success(rv);

  nsCOMPtr<nsIFile> dbFile;
  db->GetDatabaseFile(getter_AddRefs(dbFile));
  RefPtr<DatabaseLocker> locker(
      new DatabaseLocker("SELECT * FROM test", dbFile));
  do_check_true(locker);
  {
    mozilla::ReentrantMonitorAutoEnter lock(locker->monitor);
    locker->RunInBackground();

    // Wait for the locker to notify us that it has locked the database
    // properly.
    locker->WaitFor(WRITE_LOCK);

    bool hasResult;
    rv = stmt->ExecuteStep(&hasResult);
    do_check_eq(rv, NS_ERROR_FILE_IS_LOCKED);

    locker->Notify(TEST_DONE);
  }
  locker->Shutdown();
}

void test_drop_index_does_not_loop() {
  nsCOMPtr<mozIStorageConnection> db(getDatabase());

  // Need to prepare our statement ahead of time so we make sure to only test
  // step and not prepare.
  nsCOMPtr<mozIStorageStatement> stmt;
  nsresult rv =
      db->CreateStatement("SELECT * FROM test"_ns, getter_AddRefs(stmt));
  do_check_success(rv);

  auto tester =
      mozilla::MakeRefPtr<DatabaseTester>(db, "DROP INDEX unique_data");
  do_check_true(tester);
  {
    mozilla::ReentrantMonitorAutoEnter lock(tester->monitor);
    tester->RunInBackground();

    // Hold a read lock on the database, and then let the tester try to execute.
    bool hasResult;
    rv = stmt->ExecuteStep(&hasResult);
    do_check_success(rv);
    do_check_true(hasResult);
    tester->Notify(READ_LOCK);

    // Make sure the tester finishes its test before we move on.
    tester->WaitFor(TEST_DONE);
  }
  tester->Shutdown();
}

void test_drop_table_does_not_loop() {
  nsCOMPtr<mozIStorageConnection> db(getDatabase());

  // Need to prepare our statement ahead of time so we make sure to only test
  // step and not prepare.
  nsCOMPtr<mozIStorageStatement> stmt;
  nsresult rv =
      db->CreateStatement("SELECT * FROM test"_ns, getter_AddRefs(stmt));
  do_check_success(rv);

  RefPtr<DatabaseTester> tester(new DatabaseTester(db, "DROP TABLE test"));
  do_check_true(tester);
  {
    mozilla::ReentrantMonitorAutoEnter lock(tester->monitor);
    tester->RunInBackground();

    // Hold a read lock on the database, and then let the tester try to execute.
    bool hasResult;
    rv = stmt->ExecuteStep(&hasResult);
    do_check_success(rv);
    do_check_true(hasResult);
    tester->Notify(READ_LOCK);

    // Make sure the tester finishes its test before we move on.
    tester->WaitFor(TEST_DONE);
  }
  tester->Shutdown();
}

TEST(storage_unlock_notify, Test)
{
  // These must execute in order.
  setup();
  test_step_locked_does_not_block_main_thread();
  test_drop_index_does_not_loop();
  test_drop_table_does_not_loop();
}