var ctx = require('../../../context');

var express = require('express');
var router = express.Router();
var path = require('path');
var fs = require('fs');

var cfg = ctx.config;
var storage_cfg = cfg.storage
var response = ctx.getLib('lib/ws/response');
var request = ctx.getLib('lib/ws/request');
var BinStream = ctx.getLib('lib/bss/binarystream_v1_1');
var ObjId = ctx.getLib('lib/bss/objid');
var BSData = ctx.getLib('lib/model/bsdata');
var Tokenizer = ctx.getLib('lib/auth/tokenizer');

const ACL_SERVICE_NAME = "storage";

router.get('/:id',function (req, res) {
    var reqHelper = request.create(req);
    var respHelper = response.create(res);
    var oid = req.params.id;

    var opt = {}

    get_object(reqHelper,respHelper,{'oid':oid,'opt':opt});

});

router.get('/:id/data',function (req, res) {
    var reqHelper = request.create(req);
    var respHelper = response.create(res);
    var query = reqHelper.getQuery();
    var oid = req.params.id;

    var opt = {
      'field' : 'data'
    }
    opt.filetype = (query.filetype)?query.filetype:null
    get_object(reqHelper,respHelper,{'oid':oid,'opt':opt});

});

function oid_parse(oid,caller,cb)
{
  var ret = {'valid':true}
  if(!oid)
  {
    return cb(null,{'valid':false});
  }

  var storage_and_addr = oid.split('$');

  ret.storage_name = storage_and_addr[0];
  if(storage_and_addr.length == 1)
  {
    ret.by = "seq"
    ret.seq = -1;
    return cb(null,ret);
  }else if(storage_and_addr.length==2){
    var str_addr = storage_and_addr[1];
    if(str_addr.startsWith('{') && str_addr.endsWith('}')){
      ret.by = "key";
      ret.key = str_addr.substr(1,str_addr.length-2);
      if(ret.key.length<=0){
        return cb(null,{'valid':false});
      }
      var callreq = {
        'object_type' : 'storage_request',
        'command' : 'idxget',
        'param' : {
          'storage_name' : ret.storage_name,
          'key' : ret.key
        }
      }

      caller.call(callreq,function(err,resp){
        if(!err && resp.status=='OK' && resp.resp.found){
          ret.by = "obj";
          ret.obj_id = resp.resp.object_id;
          ret.seq = (new ObjId(ret.obj_id)).extract().seq;
          cb(null,ret);
        }else{
          cb(null,{'valid':false});
        }
      });

    }else if(str_addr.startsWith('[') && str_addr.endsWith(']')){
      ret.by = "seq";
      var str_num = str_addr.substr(1,str_addr.length-2);
      if(isNaN(str_num) || !Number.isInteger(Number(str_num))){
        ret.valid = false;
      }else{
        ret.seq = Number(str_num);
      }
      return cb(null,ret);
    }else{
      ret.by = "obj";
      ret.obj_id = storage_and_addr[1];

      try{
        var obj_id = new ObjId(ret.obj_id);
        ret.seq = obj_id.extract().seq;
      }catch(err){
        ret.valid=false;
      }
      return cb(null,ret);
    }
  }else{
    ret.valid=false;
    return cb(null,ret);
  }

}



function get_object(reqHelper,respHelper,prm)
{
  prm=prm||{};

  var oid = prm.oid;
  var opt = prm.opt || {};

  var storagecaller = reqHelper.request.context.storagecaller;
  
  oid_parse(oid,storagecaller,(err,oid_result)=>{

    if(!oid_result.valid){
      respHelper.response404();
    }else{
      var acl_validator = reqHelper.request.context.acl_validator;
      var tInfo = Tokenizer.info(reqHelper.request.auth);
      var acp = acl_validator.isAccept(tInfo.acl,{
        "vo":tInfo.vo,"service":ACL_SERVICE_NAME,"resource":oid_result.storage_name,"mode":"r"
      });

      if(!acp){
        respHelper.response403();
      }else{

        var bss_full_path = storage_cfg.repository + "/" + oid_result.storage_name.split('.').join('/') + ".bss";
        
        fs.exists(bss_full_path,function(exists){

          if(exists){
            BinStream.open(bss_full_path,function(err,bss){
              var rd = bss.reader();
              var rec_count = rd.count();
              var seq = (oid_result.seq>=0)?oid_result.seq:rec_count + oid_result.seq + 1;
      
              rd.objectAt(seq,function(err,obj){
                bss.close(function(err){
                  if(obj && (oid_result.by == 'seq' ||  oid_result.obj_id == (new ObjId(obj.header.ID)).toString()) ){
                      output(respHelper,obj,opt);
                  }else{respHelper.response404();}
                });
              });
      
            });
          }else{
            respHelper.response404();
          }
      
        });

      }

    }

  });

}

function output(resp,obj,opt)
{
  if(opt.field=='data')
  {
    data_out(resp,obj,opt);
  }else{
    obj_out(resp,obj,opt);
  }
}

function obj_out(resp,obj,opt)
{
  var ret = {"_id" : (new ObjId(obj.header.ID)).toString(),
              "meta" : obj.meta
            }

  if(obj.header.TY==BinStream.BINARY_TYPE)
  {
    var bs = BSData.create(obj.data);
    ret.data = bs.serialize('object-encoded');
  }else{
    ret.data = obj.data;
  }
  resp.responseOK(ret);
}

function data_out(resp,obj,opt)
{
  var objType = obj.header.TY;

  if(objType == BinStream.BINARY_TYPE){
    if(opt.filetype){
      resp.response.type(opt.filetype);
    }else{

    }

    resp.response.send(obj.data);
  }else if(objType == BinStream.STRING_TYPE){
    resp.response.send(obj.data);
  }else{
    resp.responseOK(obj.data);
  }

}


module.exports = router;
