local array = require "util.array";

local datetime = require "util.datetime";

local st = require "util.stanza";

local now = require "util.time".now;

local id = require "util.id".medium;

local archive = {};

driver.archive = { __index = archive };

function archive:append(username, key, value, when, with)

	key = key or id();

	when = when or now();

	if not st.is_stanza(value) then

		return nil, "unsupported-datatype";

	end

	value = st.preserialize(st.clone(value));

	value.key = key;

	value.when = when;

	value.with = with;

	value.attr.stamp = datetime.datetime(when);

	value.attr.stamp_legacy = datetime.legacy(when);

	local ok, err = datamanager.list_append(username, host, self.store, value);

	if not ok then return ok, err; end

	return key;

end

function archive:find(username, query)

	local items, err = datamanager.list_load(username, host, self.store);

	if not items then return items, err; end

	local count = #items;

	local i = 0;

	if query then

		items = array(items);

		if query.with then

			items:filter(function (item)

				return item.with == query.with;

			end);

		end

		if query.start then

			items:filter(function (item)

				return item.when >= query.start;

			end);

		end

		if query["end"] then

			items:filter(function (item)

				return item.when <= query["end"];

			end);

		end

		count = #items;

		if query.reverse then

			items:reverse();

			if query.before then

				for j = 1, count do

					if (items[j].key or tostring(j)) == query.before then

						i = j;

						break;

					end

				end

			end

		elseif query.after then

			for j = 1, count do

				if (items[j].key or tostring(j)) == query.after then

					i = j;

					break;

				end

			end

		end

		if query.limit and #items - i > query.limit then

			items[i+query.limit+1] = nil;

		end

	end

	return function ()

		i = i + 1;

		local item = items[i];

		if not item then return; end

		local key = item.key or tostring(i);

		local when = item.when or datetime.parse(item.attr.stamp);

		local with = item.with;

		item.key, item.when, item.with = nil, nil, nil;

		item.attr.stamp = nil;

		item.attr.stamp_legacy = nil;

		item = st.deserialize(item);

		return key, item, when, with;

	end, count;

end