module.exports = function(RED) {
    var https = require('https');
    var http = require('http');
    var url = require('url');

    var OPERATIONS = {
        'oauth:authorize': { method:'GET',  path:'/index.php/apps/oauth2/authorize', query:['client_id','state','response_type','redirect_uri'] },
        'oauth:token':     { method:'POST', path:'/index.php/apps/oauth2/api/v1/token', body:['grant_type','code','refresh_token','client_id','client_secret'] }
    };

    function OAuth2Node(config) {
        RED.nodes.createNode(this, config);
        var node = this;
        this.configNode = RED.nodes.getNode(config.nextcloud);
        this.operation = config.operation || 'oauth:token';

        if (!this.configNode) { node.error("No NC config node"); return; }

        node.on('input', function(msg) {
            var op = OPERATIONS[msg.operation || node.operation];
            if (!op) { node.error("Unknown: "+(msg.operation||node.operation), msg); return; }

            var baseUrl = (node.configNode.baseUrl||'').replace(/\/+$/,'');
            var uname = node.configNode.credentials.username;
            var pw = node.configNode.credentials.password;
            var path = op.path;

            var qp = [];
            if (op.query) op.query.forEach(function(q) {
                var v = msg[q]!==undefined ? msg[q] : '';
                if (v!==undefined&&v!=='') qp.push(encodeURIComponent(q)+'='+encodeURIComponent(v));
            });
            var fu = baseUrl+path+(qp.length?'?'+qp.join('&'):'');
            var pu = url.parse(fu);

            var h = {'Accept':'application/json',
                'Authorization':'Basic '+Buffer.from(uname+':'+pw).toString('base64')};

            var bo={};
            if (op.body) op.body.forEach(function(b){
                var v=msg[b]!==undefined?msg[b]:'';
                if(v!==undefined&&v!=='') bo[b]=v;
            });
            var bs=null;
            if (Object.keys(bo).length>0) {h['Content-Type']='application/json'; bs=JSON.stringify(bo);}

            var o = {hostname:pu.hostname,port:pu.port||(pu.protocol==='https:'?443:80),
                path:pu.path,method:op.method,headers:h,rejectUnauthorized:false};
            node.log(op.method+' '+fu);
            var t = pu.protocol==='https:'?https:http;
            var r = t.request(o,function(res){
                var b='';res.on('data',function(c){b+=c;});
                res.on('end',function(){msg.statusCode=res.statusCode;msg.operation=msg.operation||node.operation;
                    try{msg.payload=JSON.parse(b);}catch(e){msg.payload=b;}node.send(msg);});
            });
            r.on('error',function(e){msg.error=e.message;node.error(op.method+' '+fu+' - '+e.message,msg);});
            if(bs) r.write(bs);
            r.end();
        });
    }
    RED.nodes.registerType("oauth2", OAuth2Node);
};