I am planning to read through this more thoroughly as something I really want is my own personal search engine. Ideally I need it to 1. store data locally for

I am planning to read through this more thoroughly as something I really want is my own personal search engine. Ideally I need it to 1. store data locally for offline retrieval 2. Support indexing big sites including stack overflow, Wikipedia, Reddit, news.ycombinator.com, microsoft.com docs, and a bunch of other domains. 3. Be easy to add a single URL into the index from command line and optionally browser plugin. Only index that page, this would replace my bookmarks. 4. Optionally auto store browser history for a custom period of time, purge when expires. Does anything like that exist?