codemp-nvim/lua/codemp/workspace.lua

local utils = require('codemp.utils')
local buffers = require('codemp.buffers')
local session = require('codemp.session')

---@class UserHighlight
---@field ns integer namespace to use for this user
---@field hi string color for user to use
---@field pos [integer, integer] cursor start position of this user

---@type table<string, UserHighlight>
local user_hl = {}

local function fetch_workspaces_list()
	local new_list = {}
	local owned = session.client:list_workspaces(true, false):await()
	for _, ws in pairs(owned) do
		table.insert(new_list, {
			name = ws,
			owned = true,
		})
	end
	local invited = session.client:list_workspaces(false, true):await()
	for _, ws in pairs(invited) do
		table.insert(new_list, {
			name = ws,
			owned = false,
		})
	end
	session.available = new_list
	require('codemp.window').update()
end

---@param ws Workspace
local function register_cursor_callback(ws)
	local controller = ws.cursor
	local once = true
	vim.api.nvim_create_autocmd({"CursorMoved", "CursorMovedI", "ModeChanged"}, {
		group = vim.api.nvim_create_augroup("codemp-workspace-" .. ws.name, { clear = true }),
		callback = function (_)
			local cur = utils.cursor.position()
			local buf = vim.api.nvim_get_current_buf()
			if buffers.map[buf] ~= nil then
				once = true
				local _ = controller:send({
					buffer = buffers.map[buf],
					start = cur[1],
					finish = cur[2],
				}) -- no need to await here
			else -- set ourselves "away" only once
				if once then
					local _ = controller:send({
						buffer = "",
						start = { 0, 0 },
						finish = { 0, 0 },
					}) -- no need to await here
				end
				once = false
			end
		end
	})
end

---@param ws Workspace
local function register_cursor_handler(ws)
	local controller = ws.cursor
	local async = vim.loop.new_async(vim.schedule_wrap(function ()
		while true do
			local event = controller:try_recv():await()
			if event == nil then break end
			local user = event.user -- do it on separate line so language server understands that it wont be nil
			if user ~= nil then
				if user_hl[user] == nil then
					user_hl[user] = {
						ns = vim.api.nvim_create_namespace("codemp-cursor-" .. event.user),
						hi = utils.color(event.user),
						pos = { 0, 0 },
					}
				end
				user_hl[user].pos = event.start
				local old_buffer = buffers.users[event.user]
				if old_buffer ~= nil then
					local old_buffer_id = buffers.map_rev[old_buffer]
					if old_buffer_id ~= nil then
						vim.api.nvim_buf_clear_namespace(old_buffer_id, user_hl[event.user].ns, 0, -1)
					end
				end
				buffers.users[event.user] = event.buffer
				local buffer_id = buffers.map_rev[event.buffer]
				if buffer_id ~= nil then
					utils.multiline_highlight(
						buffer_id,
						user_hl[event.user].ns,
						user_hl[event.user].hi,
						event.start,
						event.finish
					)
				end
				if old_buffer ~= event.buffer then
					require('codemp.window').update() -- redraw user positions
				end
			end
		end
	end))
	controller:callback(function (_controller) async:send() end)
end

---@param workspace string workspace name to join
---@return Workspace
---join a workspace and register event handlers
local function join(workspace)
	local ws = session.client:join_workspace(workspace):await()
	print(" >< joined workspace " .. ws.name)
	register_cursor_callback(ws)
	register_cursor_handler(ws)
	utils.poller(
		function() return ws:event() end,
		function(event)
			if event.type == "leave" then
				if buffers.users[event.value] ~= nil then
					vim.schedule(function ()
						local buf_name = buffers.users[event.value]
						vim.api.nvim_buf_clear_namespace(buffers.map_rev[buf_name], user_hl[event.value].ns, 0, -1)
						buffers.users[event.value] = nil
						user_hl[event.value] = nil
					end)
				end
			elseif event.type == "join" then
				buffers.users[event.value] = ""
				user_hl[event.value] = {
					ns = vim.api.nvim_create_namespace("codemp-cursor-" .. event.value),
					hi = utils.color(event.value),
					pos = { 0, 0 },
				}
			end
			vim.schedule(function() require('codemp.window').update() end)
		end
	)

	session.workspace = ws
	require('codemp.window').update()

	return ws
end

local function leave()
	session.client:leave_workspace(session.workspace.name)
	print(" -- left workspace")
	session.workspace = nil
end

return {
	join = join,
	leave = leave,
	map = user_hl,
	list = fetch_workspaces_list,
}