# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import requests
import json
import secrets
import yaml

class ResDBORM:
    def __init__(self, config_path='config.yaml'):
        with open(config_path, 'r') as config_file:
            self.config = yaml.safe_load(config_file)
        self.db_root_url = self.config['database']['db_root_url']

    def generate_token(self, length=64):
        """Generate a secure random hexadecimal token."""
        return secrets.token_hex(length // 2)

    def create(self, data):
        """Create a new record in the DB."""
        token = self.generate_token()
        payload = {"id":token, "data":data}
        headers = {'Content-Type': 'application/json'}
        response = requests.post(f'{self.db_root_url}/v1/transactions/commit',
                             data=json.dumps(payload), headers=headers)

        
        # Check if response is successful and handle empty response content
        if response.status_code == 201:
            if response.content:
                decoded_content = response.content.decode('utf-8')
                id_value = decoded_content.split(': ')[1].strip()
                return id_value
            else:
                return {"status": "create unsuccessful, no content in response"}
    
    def read_all(self):
        """Read all records from the DB."""
        response = requests.get(f'{self.db_root_url}/v1/transactions')
        return response.json()

    def read(self, key):
        """Read a specific record by key from the DB."""
        response = requests.get(f'{self.db_root_url}/v1/transactions/{key}')
        return response.json()

    def delete(self, key):
        """Delete a specific record by key in the DB."""
        payload = {"id": key}
        headers = {'Content-Type': 'application/json'}
        response = requests.post(f'{self.db_root_url}/v1/transactions/commit', 
                     data=json.dumps(payload), headers=headers)
    
        # Check if response is successful and handle empty response content
        if response.status_code == 201:
            if response.content:
                return {"status": "delete successful"} 
            else:
                return {"status": "delete unsuccessful, no content in response"}
    
    def update(self, key, new_data):
        """Update a specific record by key in the DB."""
        # Delete the existing record first
        delete_response = self.delete(key)
    
        # Handle the response accordingly
        if "status" in delete_response and "no content in response" in delete_response["status"]:
            print("Warning: Delete operation returned no content.")
    
        # Update by creating a new entry with the same key
        payload = {"id": key, "data": new_data}
        headers = {'Content-Type': 'application/json'}
        response = requests.post(f'{self.db_root_url}/v1/transactions/commit', 
                             data=json.dumps(payload), headers=headers)
    
        # Check if response is successful and handle empty response content
        if response.status_code == 201:
            if response.content:
                return {"status": "update successful"}
            else:
                return {"status": "update unsuccessful, no content in response"}