import json
from flask import Flask
from flask import request, make_response

app = Flask(__name__)

""" storage all users' data
data structure:
    users_dict = {
        'uid1': {
            'name': 'name1',
            'password': 'pwd1'
        },
        'uid2': {
            'name': 'name2',
            'password': 'pwd2'
        }
    }
"""
users_dict = {}

@app.route('/')
def index():
    return "Hello World!"

@app.route('/status_code/<int:status_code>')
def get_response_with_status_code(status_code):
    return "Status Code: %d" % status_code, status_code

@app.route('/response_headers', methods=['POST'])
def get_response_with_headers():
    headers_dict = request.get_json()
    content = "Response headers: %s" % json.dumps(headers_dict)
    response = make_response(content)
    for header_key, header_value in headers_dict.items():
        response.headers[header_key] = header_value
    return response

@app.route('/api/users')
def get_users():
    users_list = [user for uid, user in users_dict.items()]
    users = {
        'success': True,
        'count': len(users_list),
        'items': users_list
    }
    response = make_response(json.dumps(users))
    response.headers["Content-Type"] = "application/json"
    return response

@app.route('/api/users', methods=['DELETE'])
def clear_users():
    users_dict.clear()
    result = {
        'success': True
    }
    response = make_response(json.dumps(result))
    response.headers["Content-Type"] = "application/json"
    return response

@app.route('/api/users/<int:uid>', methods=['POST'])
def create_user(uid):
    user = request.get_json()
    if uid not in users_dict:
        result = {
            'success': True,
            'msg': "user created successfully."
        }
        status_code = 201
        users_dict[uid] = user
    else:
        result = {
            'success': False,
            'msg': "user already existed."
        }
        status_code = 500

    response = make_response(json.dumps(result), status_code)
    response.headers["Content-Type"] = "application/json"
    return response

@app.route('/api/users/<int:uid>')
def get_user(uid):
    user = users_dict.get(uid, {})
    if user:
        result = {
            'success': True,
            'data': user
        }
        status_code = 200
    else:
        result = {
            'success': False,
            'data': user
        }
        status_code = 404

    response = make_response(json.dumps(result), status_code)
    response.headers["Content-Type"] = "application/json"
    return response

@app.route('/api/users/<int:uid>', methods=['PUT'])
def update_user(uid):
    user = users_dict.get(uid, {})
    if user:
        user = request.get_json()
        success = True
        status_code = 200
    else:
        success = False
        status_code = 404

    result = {
        'success': success,
        'data': user
    }
    response = make_response(json.dumps(result), status_code)
    response.headers["Content-Type"] = "application/json"
    return response

@app.route('/api/users/<int:uid>', methods=['DELETE'])
def delete_user(uid):
    user = users_dict.pop(uid, {})
    if user:
        success = True
        status_code = 200
    else:
        success = False
        status_code = 404

    result = {
        'success': success,
        'data': user
    }
    response = make_response(json.dumps(result), status_code)
    response.headers["Content-Type"] = "application/json"
    return response