-- mod_migrate

local unpack = table.unpack or unpack; --luacheck: ignore 113/unpack

local sm = require"core.storagemanager";

local um = require"core.usermanager";

local function users(store, host)

	if store.users then

		return store:users();

	else

		return um.users(host);

	end

end

local function stores(host)

	if store.users then

		return store:users();

	else

		return um.users(host);

	end

end

local function migrate_store(host, source_store, store_type, migrate_to, migrate_users)

	local module = module:context(host);

	local storage = module:open_store(source_store, store_type);

	local target = assert(sm.load_driver(host, migrate_to));

	target = assert(target:open(source_store, store_type));

	local function migrate_user(username)

		module:log("info", "Migrating %s data for %s", source_store, username);

		if username == "" then username = nil; end

		local data, err = storage:get(username);

		if not data and err then

			module:log("error", "Could not read data: %s", err);

		else

			local ok, err = target:set(username, data);

			if not ok then

				module:log("error", "Could not write data: %s", err);

			end

		end

	end

	if store_type == "archive" then

		function migrate_user(username)

			module:log("info", "Migrating %s archive items for %s", source_store, username);

			if username == "" then username = nil; end

			local count, errs = 0, 0;

			for id, item, when, with in storage:find(username) do

				local ok, err = target:append(username, id, item, when, with);

				if ok then

					count = count + 1;

				else

					module:log("warn", "Error: %s", err);

					errs = errs + 1;

				end

				if ( count + errs ) % 100 == 0 then

					module:log("info", "%d items migrated, %d errors", count, errs);

				end

			end

			module:log("info", "%d items migrated, %d errors", count, errs);

		end

	end

	if migrate_users then

		for _, username in ipairs(migrate_users) do

			migrate_user(username);

		end

	else

		xpcall(function()

			for username in users(storage, host) do

				migrate_user(username);

			end

		end,

		function (err)

			module:log("error", "Could not list users, you'll have to supply them as arguments");

			module:log("error", "The error was: %s", err);

		end);

	end

end

function module.command(arg)

	local host, source_stores, migrate_to = unpack(arg);

	if not migrate_to then

		return print("Usage: prosodyctl mod_migrate example.com <source-store>[-<store-type>] <target-driver> [users]*");

	end

	if not prosody.hosts[host] then

		return print(("The host %q is not know by Prosody."):format(host));

	end

	sm.initialize_host(host);

	um.initialize_host(host);

	for source_store in source_stores:gmatch("[^,]+") do

		local store_type = source_store:match("%-(%a+)$");

		if store_type then

			source_store = source_store:sub(1, -2-#store_type);

		end

		local migrate_users;

		if arg[4] then

			migrate_users = {};

			for i = 4, #arg do

				migrate_users[i-3] = arg[i];

			end

		end

		if source_store == "pep_data" then

			for store in sm.get_driver(host, source_store):stores(true) do

				if store:match("^pep_") then

					print("Migrating "..store);

					migrate_store(host, store, store_type, migrate_to, migrate_users);

				end

			end

		else

			migrate_store(host, source_store, store_type, migrate_to, migrate_users);

		end

	end

end