What follows is a dump from my notebook
Existing tools
- Mapbook osm-boundaries in osmium js Unmaintained, not touched in years, depends on old osmium and would need work to port it to the new osmium. Those who were involved in writing it recommend a rewrite.
- Community run admin relation validation tools These are designed for validation, not turning sometimes messy admin boundaries to lines
Scope
Read in the planet and output file with linestrings for each admin line
Maybe: Build polygons
Maybe: Build labeling points
Maybe: Merge linestrings
Per linestring information needed
- Lowest admin level the line participates in
- If it is disputed or not or part of a disputed admin area
- If it is a maratime border
- If it is a closure line
- Name on the left and right foreach admin level
- OSM id of parent, if not merging
Next steps
- Create sample OSM file with possible admin situations. Create with JOSM, then osmium renumber