refactor(nvim): extract follow engine into dotfiles.follow module

1 files changed, 72 insertions, 0 deletions

diff --git a/plugin/50-notes.lua b/plugin/50-notes.lua
index dee4da3..fec0dd2 100644
--- a/plugin/50-notes.lua
+++ b/plugin/50-notes.lua
@@ -325,3 +325,75 @@ vim.api.nvim_create_user_command("NotesRenameSection", function(opts)
 		end)
 	end
 end, { nargs = "*", desc = "Rename the heading at the cursor and update wiki-links" })
+
+------------------------------------------------------------------------------------------------------------------------
+-- Following notes (`notes://` scheme and `[[wiki-links]]`), wired into the follow engine
+------------------------------------------------------------------------------------------------------------------------
+
+local follow = require("dotfiles.follow")
+
+-- `notes://<path>` resolves to `<path>` relative to the notes dir.
+follow.register_scheme("notes", {
+	resolve = function(uri)
+		return notes_dir .. "/" .. uri
+	end,
+})
+
+-- Returns the inner text of a `[[wiki-link]]` under the cursor, or `nil`.
+local function get_wikilink_target()
+	local line = vim.api.nvim_get_current_line()
+	local col = vim.api.nvim_win_get_cursor(0)[2] + 1
+	local init = 1
+	while true do
+		local s, e, inner = line:find("%[%[(.-)%]%]", init)
+		if s == nil then
+			return nil
+		end
+		if col >= s and col <= e then
+			return inner
+		end
+		init = e + 1
+	end
+end
+
+-- Follow a `[[note]]` / `[[note#Heading]]` / `[[dir/]]` wiki-link relative to the
+-- notes dir, creating parent directories (and the note itself on save) as needed.
+local function follow_wikilink(inner, edit_cmd)
+	local name, heading = inner:match("^(.-)#(.*)$")
+	if name == nil then
+		name = inner
+	end
+	local target = notes_dir .. "/" .. name
+	if name:sub(-1) == "/" then -- directory link: create and open it
+		vim.fn.mkdir(target, "p")
+		vim.cmd(edit_cmd .. " " .. vim.fn.fnameescape(target))
+		return
+	end
+	if not name:match("%.%w+$") then -- default to a Markdown note
+		target = target .. ".md"
+	end
+	vim.fn.mkdir(vim.fs.dirname(target), "p")
+	vim.cmd(edit_cmd .. " " .. vim.fn.fnameescape(target))
+	if heading ~= nil and heading ~= "" then
+		vim.fn.cursor(1, 1)
+		-- `\V` matches the heading literally; `\v` brackets the heading markers.
+		local pat = [[\v^#+\s+\V]] .. vim.fn.escape(heading, [[\]]) .. [[\v\s*$]]
+		if vim.fn.search(pat, "cW") == 0 then
+			vim.notify("No heading '" .. heading .. "' in " .. name, vim.log.levels.WARN)
+		end
+	end
+end
+
+-- Wiki-links take precedence over generic URL/file following, but only on a
+-- `[[...]]` under the cursor in a markdown buffer in normal mode.
+follow.register_handler(function(edit_cmd)
+	if vim.fn.mode() ~= "n" or vim.bo.filetype ~= "markdown" then
+		return false
+	end
+	local inner = get_wikilink_target()
+	if inner == nil then
+		return false
+	end
+	follow_wikilink(inner, edit_cmd)
+	return true
+end)