module ActiveRecord::ConnectionAdapters::SQLite3::DatabaseStatements

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 18
def explain(arel, binds = [], _options = [])
  sql    = "EXPLAIN QUERY PLAN " + to_sql(arel, binds)
  result = internal_exec_query(sql, "EXPLAIN", [])
  SQLite3::ExplainPrettyPrinter.new.pp(result)
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 49
def high_precision_current_timestamp
  HIGH_PRECISION_CURRENT_TIMESTAMP
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 142
def affected_rows(result)
  result.affected_rows
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 151
def build_truncate_statement(table_name)
  "DELETE FROM #{quote_table_name(table_name)}"
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 136
def cast_result(result)
  # Given that SQLite3 doesn't have a Result type, raw_execute already returns an ActiveRecord::Result
  # so we have nothing to cast here.
  result
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 146
def execute_batch(statements, name = nil, **kwargs)
  sql = combine_multi_statements(statements)
  raw_execute(sql, name, batch: true, **kwargs)
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 73
def internal_begin_transaction(mode, isolation)
  if isolation
    raise TransactionIsolationError, "SQLite3 only supports the `read_uncommitted` transaction isolation level" if isolation != :read_uncommitted
    raise StandardError, "You need to enable the shared-cache mode in SQLite mode before attempting to change the transaction isolation level" unless shared_cache?
  end

  internal_execute("BEGIN #{mode} TRANSACTION", "TRANSACTION", allow_retry: true, materialize_transactions: false)
  if isolation
    @previous_read_uncommitted = query_value("PRAGMA read_uncommitted")
    internal_execute("PRAGMA read_uncommitted=ON", "TRANSACTION", allow_retry: true, materialize_transactions: false)
  end
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 86
def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notification_payload:, batch: false)
  total_changes_before_query = raw_connection.total_changes
  affected_rows = nil

  if batch
    raw_connection.execute_batch2(sql)
  else
    stmt = if prepare
      @statements[sql] ||= raw_connection.prepare(sql)
      @statements[sql].reset!
    else
      # Don't cache statements if they are not prepared.
      raw_connection.prepare(sql)
    end
    begin
      unless binds.nil? || binds.empty?
        stmt.bind_params(type_casted_binds)
      end
      result = if stmt.column_count.zero? # No return
        stmt.step

        affected_rows = if raw_connection.total_changes > total_changes_before_query
          raw_connection.changes
        else
          0
        end

        ActiveRecord::Result.empty(affected_rows: affected_rows)
      else
        rows = stmt.to_a

        affected_rows = if raw_connection.total_changes > total_changes_before_query
          raw_connection.changes
        else
          0
        end

        ActiveRecord::Result.new(stmt.columns, rows, stmt.types.map { |t| type_map.lookup(t) }, affected_rows: affected_rows)
      end
    ensure
      stmt.close unless prepare
    end
  end
  verified!

  notification_payload[:affected_rows] = affected_rows
  notification_payload[:row_count] = result&.length || 0
  result
end

# File lib/active_record/connection_adapters/sqlite3/database_statements.rb, line 155
def returning_column_values(result)
  result.rows.first
end