wrong data structure is wrong

working with wrong json format

/*
 * data structure:
 * { status: 0, data:{}}
 * { status: 0, data:{}, message: "you did something" }
 * { status: 1, data:{}, message: "you did something" }
 * { status: 1, data:{}}
 * { status: 2, data:{response:{data:{form:{global:'something going wrong'}}}}}
 * { status: 2, data:{response:{data:{form:{global:'error'}}}}, message: "you did something" }
 * { status: 2, data:{response:{data:{form:{global:'error'}}}}, message: "you did something" }
 * { status: 2, data:{response:{data:{form:{global:'error'}}}}, message: "you did something" }
 * { status: 1404, data:{}, message: "you did something" }
 *
 */

var handler = function(response, status, xhr){
    
               var errors = {}, i, l;
               errors['globalErrors'] = []; 
               errors['formErrors'] = []; 
               errors['fieldErrors'] = []; 

                if (that.checkResponse(xhr) === 'json') {
    
                    // even status is 0 may data could not found
                    if(response.status == '0' && response.data.length < 1 ){
                        return;
                    }   

                    // status is not 0 then we have error
                    if(response.status != '0') {
    
                        // status is 1 then we have kind of global logic error 
                        // status is bigger than 1000 then we have http error code
                        if(response.status == 1 || response.status > 1000) {
    
                            that.get('notify').show({
                                type: 'error',
                                content: response.message 
                            }); 

                            return;
                        }   
    
                        // form errors
                        if(response.status == '2' ) { 
                            // I dont know what we'll do this. It is not in the design.
                            if(response.data.form.global !== undefined) {
                                errors.formErrors = response.data.form.global;  // always array
                            }   
    
                            l = response.data.form.fieldset.length;
    
                            // if there are no any field dont use the for
                            if ( l > 0 ) { 
    
                                // if there are any fields
                                for ( i = 0; i < 0; i += 1 ) { 
    
                                    // if there are any field has error
                                    if (response.data.form.fieldset[i].error) {
                                        errors['fieldErrors'].push(response.data.form.fieldset[i].error);
                                    }   

                                }   
    
                            }   

                        }   

                    }   
                        
                    // finally data valid, return it
                    if (response.status == '0' && response.data.length > 0) {
                        return response;
                    }   
                }   

                // it is html response, not json
                else {
                    return response;
                }   
                return response;
            };