local csexp = require"csexp"
local sqlite = require"lsqlite3"

local function sqlite_ok(errcode)
	return errcode == sqlite.OK or errcode == sqlite.DONE
end

local function quote_name(name)
	return [["]]..string.gsub(name, [["]], [[""]])..[["]]
end

local function setup(db)
	db:create_function("parse_node_name", 1, function(ctx, table_name)
		local ok, obj = pcall(csexp.parse, table_name)
		if not ok then
			ctx:result_null()
			return
		end
		if type(obj) ~= "table" or obj[1] ~= "node" then
			ctx:result_null()
			return
		end
		local node_name = obj[2]
		if not node_name then
			ctx:result_null()
			return
		end
		ctx:result_text(node_name)
	end)
end

local function new_node_type(db, name)
	local table_name = csexp.serialize{"node", name}
	local quoted_name = quote_name(table_name)
	local query = string.format([[
		CREATE TABLE %s (
			id INTEGER PRIMARY KEY
		);
	]], quoted_name)
	-- for _ in db:rows(query) do end
	db:exec(query)

	if not sqlite_ok(db:errcode()) then
		error(db:errmsg())
	end
end

local function get_node_types(db)
	local query = [[
		SELECT parse_node_name(name)
		FROM sqlite_schema
		WHERE parse_node_name(name) IS NOT NULL
		ORDER BY parse_node_name(name) ASC;
	]]
	return db:urows(query)
end

return {
	setup = setup,
	quote_name = quote_name,
	new_node_type = new_node_type,
	get_node_types = get_node_types,
}