Update to new API and refactor

- the previous API calls (/rest/sysutem/config) are deprecated, so it's
  been adjusted to use the new ones (/rest/config/devices and
  /rest/config/devices/*id*)
- the code is simplified to operate just on one devices rather than
  the list of devices, the new API has sufficient functionality to do
  this

library/storage/syncthing/syncthing_device.py

@@ -82,7 +82,7 @@ from xml.etree.ElementTree import parse
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.urls import fetch_url, url_argument_spec
 
-SYNCTHING_API_URI = "/rest/system/config"
+SYNCTHING_API_URI = "/rest/config/devices"
 if platform.system() == 'Windows':
     DEFAULT_ST_CONFIG_LOCATION = '%localappdata%/Syncthing/config.xml'
 elif platform.system() == 'Darwin':
@@ -91,8 +91,11 @@ else:
     DEFAULT_ST_CONFIG_LOCATION = '$HOME/.config/syncthing/config.xml'
 
 
-def make_headers(host, api_key):
-    url = '{}{}'.format(host, SYNCTHING_API_URI)
+def make_headers(host, api_key, device=None):
+    if device:
+        url = '{}{}/{}'.format(host, SYNCTHING_API_URI, device)
+    else:
+        url = '{}{}'.format(host, SYNCTHING_API_URI)
     headers = {'X-Api-Key': api_key }
     return url, headers
 
@@ -112,11 +115,19 @@ def get_key_from_filesystem(module):
                              "the API key manually.")
 
 # Fetch Syncthing configuration
-def get_config(module):
-    url, headers = make_headers(module.params['host'], module.params['api_key'])
+def remote_config(module, method='GET', config=None, result=None, device=None):
+    url, headers = make_headers(module.params['host'], module.params['api_key'],
+                                device)
+    data = config
+    if config:
+        headers['Content-Type'] = 'application/json'
+        data = json.dumps(config)
+    if not result:
+        result = {}
+
     resp, info = fetch_url(
-        module, url, data=None, headers=headers,
-        method='GET', timeout=module.params['timeout'])
+        module, url, data=data, headers=headers,
+        method=method, timeout=module.params['timeout'])
 
     if not info or info['status'] != 200:
         result['response'] = info
@@ -131,19 +142,22 @@ def get_config(module):
 
     return json.loads(content)
 
+
+def get_device(module, device=None):
+    return remote_config(module, device=device)
+def delete_device(module, device, result=None):
+    return remote_config(module, method='DELETE', device=device, result=result)
+
 # Post the new configuration to Syncthing API
-def post_config(module, config, result):
-    url, headers = make_headers(module.params['host'], module.params['api_key'])
-    headers['Content-Type'] = 'application/json'
-
-    result['msg'] = config
-    resp, info = fetch_url(
-        module, url, data=json.dumps(config), headers=headers,
-        method='POST', timeout=module.params['timeout'])
-
-    if not info or info['status'] != 200:
-        result['response'] = str(info)
-        module.fail_json(msg='Error occured while posting new config', **result)
+def post_device(module, config, result=None, device=None):
+    return remote_config(module, method='POST', config=config, result=result,
+                         device=device)
+def put_device(module, config, result=None, device=None):
+    return remote_config(module, method='PUT', config=config, result=result,
+                         device=device)
+def patch_device(module, config, result=None, device=None):
+    return remote_config(module, method='PATCH', config=config, result=result,
+                         device=device)
 
 # Returns an object of a new device
 def create_device(params):
@@ -204,35 +218,26 @@ def run_module():
     if not module.params['api_key']:
         module.params['api_key'] = get_key_from_filesystem(module)
 
-    config = get_config(module)
+    device = get_device(module, module.params['id'])
+    device_exists = False
+    if 'deviceID' in device and device['deviceID'] == module.params['id']:
+        device_exists = True
+    want_pause = module.params['state'] == 'pause'
+
     if module.params['state'] == 'absent':
-        # Remove device from list, if found
-        for idx, device in enumerate(config['devices']):
-            if device['deviceID'] == module.params['id']:
-                config['devices'].pop(idx)
-                result['changed'] = True
-                break
-    else:
-        # Bail-out if device is already added
-        for device in config['devices']:
-            if device['deviceID'] == module.params['id']:
-                want_pause = module.params['state'] == 'pause'
-                if (want_pause and device['paused']) or \
-                        (not want_pause and not device['paused']):
-                    module.exit_json(**result)
-                else:
-                    device['paused'] = want_pause
-                    result['changed'] = True
-                    break
-
-        # Append the new device into configuration
-        if not result['changed']:
-            device = create_device(module.params)
-            config['devices'].append(device)
+        if device_exists:
+            delete_device(module, device=device['deviceID'], result=result)
             result['changed'] = True
-
-    if result['changed']:
-        post_config(module, config, result)
+    elif device_exists:  # exists but maybe needs changing
+        if device['paused'] != want_pause:
+            device['paused'] = want_pause
+            patch_device(module, config=device, result=result,
+                         device=device['deviceID'])
+            result['changed'] = True
+    else:  # Doesn't exist but needs to be added
+        device = create_device(module.params)
+        post_device(module, config=device, result=result)
+        result['changed'] = True
 
     module.exit_json(**result)