class KPM::Database

def build_insert_statement(table_name, columns_names, values, rows_qty)
  "INSERT INTO #{table_name} ( #{columns_names} ) VALUES #{values}; #{rows_qty == 1 ? LAST_INSERTED_ID : ROWS_UPDATED}"
end

def execute_insert_statement(table_name, query, qty_to_insert, _table_data, record_id = nil)
  query = "set #{record_id[:variable]}=#{record_id[:value]}; #{query}" unless record_id.nil?
  query = "SET sql_mode = ''; SET autocommit=0; #{query} COMMIT; SHOW WARNINGS;"
  File.open(STATEMENT_TMP_FILE, 'w') do |s|
    s.puts query
  end
  response = `#{@mysql_command_line} < "#{STATEMENT_TMP_FILE}" 2>&1`
  if response.include? 'ERROR'
    @logger.error "\e[91;1mTransaction that fails to be executed (first 1,000 chars)\e[0m"
    # Queries can be really big (bulk imports)
    @logger.error "\e[91m#{query[0..1000]}\e[0m"
    if response.include?('Table') && response.include?('doesn\'t exist')
      @logger.warn "Skipping unknown table #{table_name}...."
    else
      raise Interrupt, "Importing table #{table_name}...... \e[91;1m#{response}\e[0m"
    end
  end
  if response.include? 'LAST_INSERT_ID'
    @logger.info "\e[32mImporting table #{table_name}...... Row 1 of #{qty_to_insert} success\e[0m"
    return response.split("\n")[1]
  end
  if response.include? 'ROW_COUNT'
    # Typically, something like: "mysql: [Warning] Using a password on the command line interface can be insecure.\nROW_COUNT()\n3\n"
    # With warning: "mysql: [Warning] Using a password on the command line interface can be insecure.\nROW_COUNT()\n1743\nLevel\tCode\tMessage\nWarning\t1264\tOut of range value for column 'amount' at row 582\n"
    response_msg = response.split("\n")
    idx_row_count_inserted = response_msg.index('ROW_COUNT()') + 1
    row_count_inserted = response_msg[idx_row_count_inserted]
    @logger.info "\e[32mImporting table #{table_name}...... Row #{row_count_inserted || 1} of #{qty_to_insert} success\e[0m"
    if idx_row_count_inserted < response_msg.size - 1
      warning_msg = response_msg[response_msg.size - 1]
      @logger.warn "\e[91m#{warning_msg}\e[0m"
    end
  end
  true
end

def generate_insert_statement(tables)
  statements = []
  @logger.info "\e[32mGenerating statements\e[0m"
  tables.each_key do |table_name|
    table = tables[table_name]
    next unless !table[:rows].nil? && !table[:rows].empty?
    columns_names = table[:col_names].join(',').gsub(/'/, '')
    rows = []
    table[:rows].each do |row|
      rows << row.map do |value|
        case value
        when Symbol
          value.to_s
        when Blob
          value.value
        else
          escaped_value = value.to_s.gsub(/['"]/, "'" => "\\'", '"' => '\\"')
                               .gsub('\N{LINE FEED}', "\n")
                               .gsub('\N{VERTICAL LINE}', '|')
          "'#{escaped_value}'"
        end
      end.join(',')
    end
    # Break the insert statement into small chunks to avoid timeouts
    rows.each_slice(1000).each do |subset_of_rows|
      value_data = subset_of_rows.map { |row| "(#{row})" }.join(',')
      statements << { query: build_insert_statement(table_name, columns_names, value_data, subset_of_rows.size),
                      qty_to_insert: subset_of_rows.size, table_name: table_name, table_data: table }
    end
  end
  statements
end

def initialize(database_name, host, port, username, password, logger)
  @database_name = database_name || DATABASE
  @host = host || HOST
  @port = port || PORT
  @username = username || USERNAME
  @password = password || PASSWORD
  @mysql_command_line = "mysql --max_allowed_packet=128M #{@database_name} --host=#{@host} --port=#{@port} --user=#{@username} --password=#{@password} "
  @logger = logger
end