What are the visa & residency requirements in Luanda?

"In order to visit Luanda, visitors must obtain a visa prior to arrival. The process of applying for a visa involves submitting an application form, a valid passport, two passport-sized photographs, and a fee. Depending on the type of visa, additional documents may be required. In order to obtain residency in Luanda, Angola, applicants must submit an application form, a valid passport, two passport-sized photographs, a valid residence permit, and a fee. Depending on the type of residency, additional documents may be required. The application process may also involve an interview with the immigration authorities," mentioned another expat when asked about moving to Luanda, Angola.