-- Simple SQL Authentication module for Prosody IM

-- Copyright (C) 2011 Tomasz Sterna <tomek@xiaoka.com>

-- Copyright (C) 2011 Waqas Hussain <waqas20@gmail.com>

--

local log = require "util.logger".init("auth_sql");

local new_sasl = require "util.sasl".new;

local DBI = require "DBI"

local connection;

local params = module:get_option("auth_sql", module:get_option("sql"));

local resolve_relative_path = require "core.configmanager".resolve_relative_path;

local function test_connection()

	if not connection then return nil; end

	if connection:ping() then

		return true;

	else

		module:log("debug", "Database connection closed");

		connection = nil;

	end

end

local function connect()

	if not test_connection() then

		prosody.unlock_globals();

		local dbh, err = DBI.Connect(

			params.driver, params.database,

			params.username, params.password,

			params.host, params.port

		);

		prosody.lock_globals();

		if not dbh then

			module:log("debug", "Database connection failed: %s", tostring(err));

			return nil, err;

		end

		module:log("debug", "Successfully connected to database");

		dbh:autocommit(true); -- don't run in transaction

		connection = dbh;

		return connection;

	end

end

do -- process options to get a db connection

	params = params or { driver = "SQLite3" };

	if params.driver == "SQLite3" then

		params.database = resolve_relative_path(prosody.paths.data or ".", params.database or "prosody.sqlite");

	end

	assert(params.driver and params.database, "Both the SQL driver and the database need to be specified");

	assert(connect());

end

local function getsql(sql, ...)

	if params.driver == "PostgreSQL" then

		sql = sql:gsub("`", "\"");

	end

	if not test_connection() then connect(); end

	-- do prepared statement stuff

	local stmt, err = connection:prepare(sql);

	if not stmt and not test_connection() then error("connection failed"); end

	if not stmt then module:log("error", "QUERY FAILED: %s %s", err, debug.traceback()); return nil, err; end

	-- run query

	local ok, err = stmt:execute(...);

	if not ok and not test_connection() then error("connection failed"); end

	if not ok then return nil, err; end

	return stmt;

end

local function get_password(username)

	local stmt, err = getsql("SELECT `password` FROM `authreg` WHERE `username`=? AND `realm`=?", username, module.host);

	if stmt then

		for row in stmt:rows(true) do

			return row.password;

		end

	end

end

provider = {};

function provider.test_password(username, password)

	return password and get_password(username) == password;

end

function provider.get_password(username)

	return get_password(username);

end

function provider.set_password(username, password)

	return nil, "Setting password is not supported.";

end

function provider.user_exists(username)

	return get_password(username) and true;

end

function provider.create_user(username, password)

	return nil, "Account creation/modification not supported.";

end

function provider.get_sasl_handler()

	local profile = {

		plain = function(sasl, username, realm)

			local password = get_password(username);

			if not password then return "", nil; end

			return password, true;

		end

	};

	return new_sasl(module.host, profile);

end

function provider.users()

	local stmt, err = getsql("SELECT `username` FROM `authreg` WHERE `realm`=?", module.host);

	if stmt then

		local next, state = stmt:rows(true)

		return function()

			for row in next, state do

				return row.username;

			end

		end

	end

	return stmt, err;

end

module:provides("auth", provider);