From 660a58aa232d250480dce53b64880482837d3160 Mon Sep 17 00:00:00 2001
From: Tim Van Steenburgh <tvansteenburgh@gmail.com>
Date: Fri, 7 Oct 2016 12:52:53 -0400
Subject: [PATCH] Minor cleanups. Added todo list of next work.

---
 README.md              |  7 +++++-
 TODO                   | 28 ++++++++++++++++++++++++
 examples/allwatcher.py | 18 +++++++++++-----
 examples/future.py     | 48 ++++++++++++++++++++++++++++++++++++++++++
 examples/relate.py     |  7 +++++-
 5 files changed, 101 insertions(+), 7 deletions(-)
 create mode 100644 TODO
 create mode 100644 examples/future.py

diff --git a/README.md b/README.md
index 56508fb..37ec461 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,11 @@ See the `examples/` directory for some simple working examples.
 ## Simple bootstrap/deploy
 
 ```python
+"""
+This doesn't work yet! It's an example of what usage might
+look like in the future.
+
+"""
 from juju import Juju
 
 juju = Juju()
@@ -51,7 +56,7 @@ model = controller.get_model('default')
 # We might want an async and blocking version of deploy()?
 model.deploy('mediawiki-single')
 
-mediawiki = model.get_service('mediawiki')
+mediawiki = model.get_application('mediawiki')
 mediawiki.expose()
 
 ```
diff --git a/TODO b/TODO
new file mode 100644
index 0000000..394b228
--- /dev/null
+++ b/TODO
@@ -0,0 +1,28 @@
+TODO
+====
+
+Model as state history of immutable objects
+-------------------------------------------
+
+1. Model gets delta from AllWatcher
+2. Entity type+id in the delta uniquely identifies an entity in the model
+3. The model keeps a history deque for each of these entities
+4. The new delta is appended to the deque for this entity
+5. When a new python object is created for this entitiy, it:
+   a. Registers an observer with the model so it'll get change callbacks
+   b. Gets its state from a pointer back to the last item in the model's
+      history deque for this entity
+   c. Has a previous() method that returns a copy of the object at its previous
+      frame of history (or None if no previous history exists). This object
+      would be disconnected (would not receive live updates from the model).
+
+
+Make model-changing methods (like deploy()) return the appropriate object
+-------------------------------------------------------------------------
+For objects being added (newly created), this will require that the method
+doesn't return until the AllWatcher returns a delta containing an id for
+the newly created thing.
+
+
+Add a LogWatcher coroutine that yields from debug-log api
+---------------------------------------------------------
diff --git a/examples/allwatcher.py b/examples/allwatcher.py
index 3f5ea06..ecd6e82 100644
--- a/examples/allwatcher.py
+++ b/examples/allwatcher.py
@@ -1,15 +1,19 @@
+"""
+This example:
+
+1. Connects to the current model
+2. Starts an AllWatcher
+3. Prints all changes received from the AllWatcher
+4. Runs forever (kill with Ctrl-C)
+
+"""
 import asyncio
 import logging
-logging.basicConfig(level=logging.DEBUG)
 
 from juju.client.connection import Connection
 from juju.client import watcher
 
 
-loop = asyncio.get_event_loop()
-conn = loop.run_until_complete(Connection.connect_current())
-
-
 async def watch():
     allwatcher = watcher.AllWatcher()
     allwatcher.connect(conn)
@@ -18,4 +22,8 @@ async def watch():
         for delta in change.deltas:
             print(delta.deltas)
 
+
+logging.basicConfig(level=logging.DEBUG)
+loop = asyncio.get_event_loop()
+conn = loop.run_until_complete(Connection.connect_current())
 loop.run_until_complete(watch())
diff --git a/examples/future.py b/examples/future.py
new file mode 100644
index 0000000..dd3d04b
--- /dev/null
+++ b/examples/future.py
@@ -0,0 +1,48 @@
+"""
+This example doesn't work - it demonstrates features that don't exist yet.
+
+"""
+import asyncio
+import logging
+
+from juju.model import Model
+
+
+async def run():
+    model = Model()
+    await model.connect_current()
+    await model.reset(force=True)
+
+    goal_state = Model.from_yaml('bundle-like-thing')
+    ubuntu_app = await model.deploy(
+        'ubuntu-0',
+        service_name='ubuntu',
+        series='trusty',
+        channel='stable',
+    )
+    ubuntu_app.on_unit_added(callback=lambda unit: True)
+
+    await model.deploy(
+        'nrpe-11',
+        service_name='nrpe',
+        series='trusty',
+        channel='stable',
+        num_units=0,
+    )
+    await model.add_relation(
+        'ubuntu',
+        'nrpe',
+    )
+
+    result, ok = await model.block_until(
+        lambda: model.matches(goal_state),
+        timeout=600
+    )
+
+
+logging.basicConfig(level=logging.DEBUG)
+ws_logger = logging.getLogger('websockets.protocol')
+ws_logger.setLevel(logging.INFO)
+loop = asyncio.get_event_loop()
+loop.create_task(run())
+loop.run_forever()
diff --git a/examples/relate.py b/examples/relate.py
index a8e39a0..288d58f 100644
--- a/examples/relate.py
+++ b/examples/relate.py
@@ -1,5 +1,10 @@
 """
-Deploy two charms and relate them.
+This example:
+
+1. Connects to the current model
+2. Resets it
+3. Deploys two charms and relates them
+4. Waits for units to be idle, then exits
 
 """
 import asyncio
-- 
2.25.1