transferwise/pipelinewise-target-redshift ? reverse-engineered prompt

Build me a Python command line tool that acts as a Singer target for Amazon Redshift. It should read Singer messages from standard input, stage incoming data in S3, then load it into Redshift using the connection settings from a config file. I want it to support the usual things like host, port, database, user, password, S3 bucket, AWS credentials, a default target schema, and options for batching and parallel loading. It should also handle basic schema mapping and permissions when new tables or schemas are created.

Please make it easy to run from a virtual environment, include sensible defaults, logging, and a few tests so I can trust it works. If you need to check current Singer or Redshift behavior, look up the latest docs online and follow the common patterns.