-- changelog-ids Soupault Plugin
-- SPDX-FileCopyrightText: 2026 toastal <https://toast.al/contact>
-- SPDX-License-Identifier: MPL-2.0
--
-- Gives each CHANGELOG version entry a shareable fragment id: h2s whose
-- text starts with X.Y.Z (e.g. “2.1.0 (2026-10-02)”) get id="X.Y.Z".
-- Docutils only emits meaningless section-1/section-2 ids, which are left
-- alone. Runs on /changelog/ only; non-version h2s are untouched, and
-- h2s that already carry an id keep it.
Plugin.require_version("5.0.0")

function url_path()
	local url = page_url
	url = Regex.replace(url, "^[a-z]+://[^/]+", "")
	if url == "" then
		url = "/"
	elseif not String.starts_with(url, "/") then
		url = "/" .. url
	end
	return url
end

path = url_path()

if path == "/changelog" or path == "/changelog/" then
	headings = HTML.select(page, "section#Content > section > h2")
	if Table.is_empty(headings) then
		Log.warning(format("No version sections found in “%s”", page_file))
	end
	seen = {}
	local idx = 1
	while headings[idx] do
		local h2 = headings[idx]
		text = String.trim(HTML.strip_tags(h2))
		if not Value.is_nil(Regex.match(text, "^[0-9]+\\.[0-9]+\\.[0-9]+")) then
			chunks = Regex.split(text, " ")
			version = chunks[1]
			if not Value.is_nil(seen[version]) then
				Log.warning(format("Duplicate CHANGELOG version “%s”, keeping first id", version))
			else
				seen[version] = 1
				existing = HTML.get_attribute(h2, "id")
				if Value.is_string(existing) and existing ~= "" then
					Log.warning(format("CHANGELOG h2 already has id “%s”, keeping it", existing))
				else
					HTML.set_attribute(h2, "id", version)
				end
			end
		end
		idx = idx + 1
	end
end