/*
  Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.

  This program is also distributed with certain software (including
  but not limited to OpenSSL) that is licensed under separate terms,
  as designated in a particular file or component or in included license
  documentation.  The authors of MySQL hereby grant you an additional
  permission to link the program and your derivative works with the
  separately licensed software that they have included with MySQL.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License, version 2.0, for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#include "client/dump/mysql_crawler.h"

#include <stdlib.h>
#include <functional>
#include <string>
#include <vector>

#include "client/base/mysql_query_runner.h"
#include "client/dump/column_statistic.h"
#include "client/dump/event_scheduler_event.h"
#include "client/dump/mysql_function.h"
#include "client/dump/mysqldump_tool_chain_maker_options.h"
#include "client/dump/privilege.h"
#include "client/dump/stored_procedure.h"
#include "client/dump/table_deferred_indexes_dump_task.h"
#include "client/dump/table_definition_dump_task.h"
#include "client/dump/table_rows_dump_task.h"
#include "client/dump/trigger.h"
#include "client/dump/view.h"

using std::string;
using std::vector;

using namespace Mysql::Tools::Dump;

Mysql_crawler::Mysql_crawler(
    I_connection_provider *connection_provider,
    std::function<bool(const Mysql::Tools::Base::Message_data &)>
        *message_handler,
    Simple_id_generator *object_id_generator,
    Mysql_chain_element_options *options,
    Mysql::Tools::Base::Abstract_program *program)
    : Abstract_crawler(message_handler, object_id_generator, program),
      Abstract_mysql_chain_element_extension(connection_provider,
                                             message_handler, options) {}

void Mysql_crawler::enumerate_objects() {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> gtid_mode;
  std::string gtid_value("OFF");
  /* Check if the server is GTID enabled */
  runner->run_query_store("SELECT @@global.gtid_mode", &gtid_mode);
  if (gtid_mode.size()) {
    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator
        mode_it = gtid_mode.begin();
    const Mysql::Tools::Base::Mysql_query_runner::Row &gtid_data = **mode_it;
    gtid_value = gtid_data[0];
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&gtid_mode);

  /* get the GTID_EXECUTED value */
  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>
      gtid_executed;
  runner->run_query_store("SELECT @@GLOBAL.GTID_EXECUTED", &gtid_executed);

  std::string gtid_output_val;
  if (gtid_executed.size()) {
    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator
        gtid_executed_iter = gtid_executed.begin();
    const Mysql::Tools::Base::Mysql_query_runner::Row &gtid_executed_val =
        **gtid_executed_iter;
    gtid_output_val = gtid_executed_val[0];
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&gtid_executed);

  m_dump_start_task = new Dump_start_dump_task(gtid_value, gtid_output_val);
  m_dump_end_task = new Dump_end_dump_task();
  m_tables_definition_ready_dump_task = new Tables_definition_ready_dump_task();

  this->process_dump_task(m_dump_start_task);

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> databases;
  runner->run_query_store("SHOW DATABASES", &databases);

  std::vector<Database *> db_list;
  std::vector<Database_end_dump_task *> db_end_task_list;
  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           databases.begin();
       it != databases.end(); ++it) {
    std::string db_name = (**it)[0];

    Database *database =
        new Database(this->generate_new_object_id(), db_name,
                     this->get_create_statement(runner, "", db_name,
                                                "DATABASE IF NOT EXISTS")
                         .value());

    db_list.push_back(database);
    m_current_database_start_dump_task = new Database_start_dump_task(database);
    m_current_database_end_dump_task = new Database_end_dump_task(database);
    db_end_task_list.push_back(m_current_database_end_dump_task);

    m_current_database_start_dump_task->add_dependency(m_dump_start_task);
    m_dump_end_task->add_dependency(m_current_database_end_dump_task);

    this->process_dump_task(m_current_database_start_dump_task);
    this->enumerate_database_objects(*database);
    m_current_database_start_dump_task = NULL;
  }

  m_dump_end_task->add_dependency(m_tables_definition_ready_dump_task);
  this->process_dump_task(m_tables_definition_ready_dump_task);

  /* SHOW CREATE USER is introduced in 5.7.6 */
  if (use_show_create_user) this->enumerate_users();

  std::vector<Database *>::iterator it;
  std::vector<Database_end_dump_task *>::iterator it_end;
  for (it = db_list.begin(), it_end = db_end_task_list.begin();
       ((it != db_list.end()) && (it_end != db_end_task_list.end()));
       ++it, ++it_end) {
    m_current_database_end_dump_task = *it_end;
    this->enumerate_views(**it);
    this->process_dump_task(m_current_database_end_dump_task);
    m_current_database_end_dump_task = NULL;
  }

  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&databases);

  this->process_dump_task(m_dump_end_task);

  this->report_crawler_completed(this);

  this->wait_for_tasks_completion();
  delete runner;
}

void Mysql_crawler::enumerate_database_objects(const Database &db) {
  this->enumerate_tables(db);
  this->enumerate_functions<Mysql_function>(db, "FUNCTION");
  this->enumerate_functions<Stored_procedure>(db, "PROCEDURE");
  this->enumerate_event_scheduler_events(db);
}

static std::vector<std::string> ignored_tables = {
    /*
      @TODO: MYSQL_DUMP contains more exceptions,
      investigate which one needs to be ported to MYSQL_PUMP.
    */
    {"mysql.innodb_ddl_log"},
    {"mysql.innodb_dynamic_metadata"},
    {"mysql.gtid_executed"}};

static bool is_ignored_table(const std::string &qualified_name) {
  for (std::vector<std::string>::iterator it = ignored_tables.begin();
       it != ignored_tables.end(); ++it) {
    if (*it == qualified_name) {
      return true;
    }
  }

  return false;
}

void Mysql_crawler::enumerate_tables(const Database &db) {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;
  /*
    Get statistics from SE by setting information_schema_stats_expiry=0.
    This makes the queries IS queries retrieve latest
    statistics and avoids getting outdated statistics.
  */
  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> t;
  runner->run_query_store(
      "/*!80000 SET SESSION information_schema_stats_expiry=0 */", &t);

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> tables;

  runner->run_query_store(
      "SHOW TABLE STATUS FROM " + this->quote_name(db.get_name()), &tables);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           tables.begin();
       it != tables.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &table_data = **it;

    std::string table_name = table_data[0];  // "Name"

    std::string qualified_name = db.get_name() + "." + table_name;
    if (is_ignored_table(qualified_name)) {
      continue;
    }

    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>
        fields_data;
    runner->run_query_store("SHOW COLUMNS IN " + this->quote_name(table_name) +
                                " FROM " + this->quote_name(db.get_name()),
                            &fields_data);
    std::vector<Field> fields;
    for (std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row
                         *>::iterator field_it = fields_data.begin();
         field_it != fields_data.end(); ++field_it) {
      fields.push_back(Field((**field_it)[0], (**field_it)[1]));
    }
    Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&fields_data);
    /*
      For views create a dummy view so that dependent objects are
      resolved when actually dumping views.
    */

    if (table_data.is_value_null(1)) {
      std::string fake_view_ddl =
          "CREATE VIEW " +
          this->get_quoted_object_full_name(db.get_name(), table_name) +
          " AS SELECT\n";

      for (std::vector<Field>::iterator field_iterator = fields.begin();
           field_iterator != fields.end(); ++field_iterator) {
        fake_view_ddl +=
            " 1 AS " + this->quote_name(field_iterator->get_name());
        if (field_iterator + 1 != fields.end()) fake_view_ddl += ",\n";
      }

      View *fake_view = new View(this->generate_new_object_id(), table_name,
                                 db.get_name(), fake_view_ddl);

      fake_view->add_dependency(m_current_database_start_dump_task);
      m_current_database_end_dump_task->add_dependency(fake_view);
      m_tables_definition_ready_dump_task->add_dependency(fake_view);
      this->process_dump_task(fake_view);
      continue;
    }

    uint64 rows = table_data.is_value_null(4)
                      ? 0
                      : atoll(table_data[4].c_str());  // "Rows"
    bool isInnoDB = table_data[1] == "InnoDB";         // "Engine"
    Table *table = new Table(
        this->generate_new_object_id(), table_name, db.get_name(),
        this->get_create_statement(runner, db.get_name(), table_name, "TABLE")
            .value(),
        fields, table_data[1], rows, (uint64)(rows * (isInnoDB ? 1.5 : 1)),
        atoll(table_data[6].c_str())  // "Data_length"
    );

    Table_definition_dump_task *ddl_task =
        new Table_definition_dump_task(table);
    Table_rows_dump_task *rows_task = new Table_rows_dump_task(table);
    Table_deferred_indexes_dump_task *indexes_task =
        new Table_deferred_indexes_dump_task(table);

    ddl_task->add_dependency(m_current_database_start_dump_task);
    rows_task->add_dependency(ddl_task);
    indexes_task->add_dependency(rows_task);
    m_current_database_end_dump_task->add_dependency(indexes_task);
    m_tables_definition_ready_dump_task->add_dependency(ddl_task);

    this->process_dump_task(ddl_task);
    this->process_dump_task(rows_task);

    this->enumerate_table_triggers(*table, rows_task);

    this->enumerate_column_statistics(*table, rows_task);

    this->process_dump_task(indexes_task);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&tables);
  runner->run_query_store(
      "/*!80000 SET SESSION information_schema_stats_expiry=default */", &t);
  delete runner;
}

void Mysql_crawler::enumerate_views(const Database &db) {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();
  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> tables;

  runner->run_query_store("SHOW TABLES FROM " + this->quote_name(db.get_name()),
                          &tables);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           tables.begin();
       it != tables.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &table_data = **it;

    std::string table_name = table_data[0];  // "View Name"
    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> check_view;
    runner->run_query_store(
        "SELECT COUNT(*) FROM " +
            this->get_quoted_object_full_name("INFORMATION_SCHEMA", "VIEWS") +
            " WHERE TABLE_NAME= '" + runner->escape_string(table_name) +
            "' AND TABLE_SCHEMA= '" + runner->escape_string(db.get_name()) +
            "'",
        &check_view);

    for (std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row
                         *>::iterator view_it = check_view.begin();
         view_it != check_view.end(); ++view_it) {
      const Mysql::Tools::Base::Mysql_query_runner::Row &is_view = **view_it;
      if (is_view[0] == "1") {
        /* Check if view dependent objects exists */
        if (runner->run_query(
                std::string("LOCK TABLES ") +
                this->get_quoted_object_full_name(db.get_name(), table_name) +
                " READ") != 0)
          return;
        else
          runner->run_query(std::string("UNLOCK TABLES"));
        View *view =
            new View(this->generate_new_object_id(), table_name, db.get_name(),
                     this->get_create_statement(runner, db.get_name(),
                                                table_name, "TABLE")
                         .value());
        m_current_database_end_dump_task->add_dependency(view);
        view->add_dependency(m_tables_definition_ready_dump_task);
        this->process_dump_task(view);
      }
    }
    Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&check_view);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&tables);
  delete runner;
}

template <typename TObject>
void Mysql_crawler::enumerate_functions(const Database &db, std::string type) {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> functions;
  runner->run_query_store("SHOW " + type + " STATUS WHERE db = '" +
                              runner->escape_string(db.get_name()) + '\'',
                          &functions);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           functions.begin();
       it != functions.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &function_row = **it;

    TObject *function = new TObject(
        this->generate_new_object_id(), function_row[1], db.get_name(),
        "DELIMITER //\n" +
            this->get_create_statement(runner, db.get_name(), function_row[1],
                                       type, 2)
                .value() +
            "//\n" + "DELIMITER ;\n");

    function->add_dependency(m_current_database_start_dump_task);
    m_current_database_end_dump_task->add_dependency(function);

    this->process_dump_task(function);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&functions);
  delete runner;
}

void Mysql_crawler::enumerate_event_scheduler_events(const Database &db) {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  // Workaround for "access denied" error fixed in 5.7.6.
  if (this->get_server_version() < 50706 &&
      this->compare_no_case_latin_with_db_string("performance_schema",
                                                 db.get_name()) == 0) {
    return;
  }

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> events;
  runner->run_query_store(
      "SHOW EVENTS FROM " + this->get_quoted_object_full_name(&db), &events);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           events.begin();
       it != events.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &event_row = **it;

    Event_scheduler_event *event = new Event_scheduler_event(
        this->generate_new_object_id(), event_row[1], db.get_name(),
        "DELIMITER //\n" +
            this->get_create_statement(runner, db.get_name(), event_row[1],
                                       "EVENT", 3)
                .value() +
            "//\n" + "DELIMITER ;\n");

    event->add_dependency(m_current_database_start_dump_task);
    m_current_database_end_dump_task->add_dependency(event);

    this->process_dump_task(event);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&events);
  delete runner;
}

void Mysql_crawler::enumerate_users() {
  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> users;
  runner->run_query_store(
      "SELECT CONCAT(QUOTE(user),'@',QUOTE(host)) FROM mysql.user", &users);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           users.begin();
       it != users.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &user_row = **it;

    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>
        create_user;
    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>
        user_grants;
    if (runner->run_query_store("SHOW CREATE USER " + user_row[0],
                                &create_user))
      return;
    if (runner->run_query_store("SHOW GRANTS FOR " + user_row[0], &user_grants))
      return;

    Abstract_dump_task *previous_grant = m_dump_start_task;

    std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator
        it1 = create_user.begin();
    const Mysql::Tools::Base::Mysql_query_runner::Row &create_row = **it1;

    std::string user = create_row[0];
    for (std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row
                         *>::iterator it2 = user_grants.begin();
         it2 != user_grants.end(); ++it2) {
      const Mysql::Tools::Base::Mysql_query_runner::Row &grant_row = **it2;
      user += std::string(";\n" + grant_row[0]);
    }
    Privilege *grant =
        new Privilege(this->generate_new_object_id(), user_row[0], user);

    grant->add_dependency(previous_grant);
    m_dump_end_task->add_dependency(grant);
    this->process_dump_task(grant);
    previous_grant = grant;

    Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&create_user);
    Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&user_grants);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&users);
  delete runner;
}

void Mysql_crawler::enumerate_table_triggers(const Table &table,
                                             Abstract_dump_task *dependency) {
  // Triggers were supported since 5.0.9
  if (this->get_server_version() < 50009) return;

  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *> triggers;
  runner->run_query_store("SHOW TRIGGERS FROM " +
                              this->quote_name(table.get_schema()) + " LIKE '" +
                              runner->escape_string(table.get_name()) + '\'',
                          &triggers);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           triggers.begin();
       it != triggers.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &trigger_row = **it;
    Trigger *trigger = new Trigger(
        this->generate_new_object_id(), trigger_row[0], table.get_schema(),
        "DELIMITER //\n" +
            this->get_version_specific_statement(
                this->get_create_statement(runner, table.get_schema(),
                                           trigger_row[0], "TRIGGER", 2)
                    .value(),
                "TRIGGER", "50017", "50003") +
            "\n//\n" + "DELIMITER ;\n",
        &table);

    trigger->add_dependency(dependency);
    m_current_database_end_dump_task->add_dependency(trigger);

    this->process_dump_task(trigger);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&triggers);
  delete runner;
}

void Mysql_crawler::enumerate_column_statistics(
    const Table &table, Abstract_dump_task *dependency) {
  // Column statistics were supported since 8.0.2
  if (this->get_server_version() < 80002) return;

  Mysql::Tools::Base::Mysql_query_runner *runner = this->get_runner();

  if (!runner) return;

  std::vector<const Mysql::Tools::Base::Mysql_query_runner::Row *>
      column_statistics;
  runner->run_query_store(
      "SELECT COLUMN_NAME, \
          JSON_EXTRACT(HISTOGRAM, '$.\"number-of-buckets-specified\"') \
   FROM information_schema.column_statistics \
   WHERE SCHEMA_NAME = '" +
          runner->escape_string(table.get_schema()) +
          "' \
     AND TABLE_NAME = '" +
          runner->escape_string(table.get_name()) + "';",
      &column_statistics);

  for (std::vector<
           const Mysql::Tools::Base::Mysql_query_runner::Row *>::iterator it =
           column_statistics.begin();
       it != column_statistics.end(); ++it) {
    const Mysql::Tools::Base::Mysql_query_runner::Row &column_row = **it;

    std::string definition;
    definition.append("/*!80002 ANALYZE TABLE ");
    definition.append(this->quote_name(table.get_schema()));
    definition.append(".");
    definition.append(this->quote_name(table.get_name()));
    definition.append(" UPDATE HISTOGRAM ON ");
    definition.append(this->quote_name(column_row[0]));
    definition.append(" WITH ");
    definition.append(column_row[1]);
    definition.append(" BUCKETS */");

    Column_statistic *column_statistic = new Column_statistic(
        this->generate_new_object_id(), table.get_schema(), definition, &table);

    column_statistic->add_dependency(dependency);
    m_current_database_end_dump_task->add_dependency(column_statistic);

    this->process_dump_task(column_statistic);
  }
  Mysql::Tools::Base::Mysql_query_runner::cleanup_result(&column_statistics);
  delete runner;
}

std::string Mysql_crawler::get_version_specific_statement(
    std::string create_string, const std::string &keyword,
    std::string main_version, std::string definer_version) {
  size_t keyword_pos = create_string.find(" " + keyword);
  size_t definer_pos = create_string.find(" DEFINER");
  if (keyword_pos != std::string::npos && definer_pos != std::string::npos &&
      definer_pos < keyword_pos) {
    create_string.insert(keyword_pos, "*/ /*!" + main_version);
    create_string.insert(definer_pos, "*/ /*!" + definer_version);
  }
  return "/*!" + main_version + ' ' + create_string + " */";
}