As an online customer
I want the app to automatically load my latest image feed
So I can always enjoy the newest images of my friends

Given the customer has connectivity
 When the customer requests to see their feed
 Then the app should display the latest feed from remote
  And replace the cache with the new feed

As an offline customer
I want the app to show the latest saved version of my image feed
So I can always enjoy images of my friends

Given the customer doesn't have connectivity
  And there’s a cached version of the feed
  And the cache is less than seven days old
 When the customer requests to see the feed
 Then the app should display the latest feed saved

Given the customer doesn't have connectivity
  And there’s a cached version of the feed
  And the cache is seven days old or more
 When the customer requests to see the feed
 Then the app should display an error message
 
Given the customer doesn't have connectivity
  And the cache is empty
 When the customer requests to see the feed
 Then the app should display an error message

• URL

1. Execute "Load Image Data" command with above data.
2. System downloads data from the URL.
3. System validates downloaded data.
4. System delivers image data.

1. System does not deliver image data nor error.

1. System delivers invalid data error.

1. System delivers connectivity error.

• URL

1. Execute "Load Image Data" command with above data.
2. System downloads data from the URL.
3. System validates downloaded data.
4. System delivers image data.

1. System does not deliver image data nor error.

1. System delivers invalid data error.

1. System delivers connectivity error.

1. Execute "Load Feed Image" command with above data.
2. System retrieves feed data from cache.
3. System validates cache is less than seven days old.
4. System creates feed items from cached data.
5. System delivers feed images.

1. System delivers error.

1. System delivers no feed images.

1. System delivers no feed images.

• URL

1. Execute "Load Image Data" command with above data.
2. System retrieves data from the cache.
3. System delivers cached image data.

1. System does not deliver image data nor error.

1. System delivers error.

1. System delivers not found error.

1. Execute "Validate" command with above data.
2. System retrieves feed data from cache.
3. System validates cache is less than seven days old.

1. System deletes cache

1. System deletes cache.

• Feed items

1. Execute "Save Feed Items" command with above data.
2. System deletes old cache data.
3. System encodes feed items.
4. System timestamps the new cache.
5. System saves new cache data.
6. System delivers success message.

1. System delivers error.

1. System delivers error.

• URL

1. Execute "Load Image Data" command with above data.
2. System retrieves data from the cache.
3. System delivers cached image data.

1. System does not deliver image data nor error.

1. System delivers error.

1. System delivers no image data.

• Model Specs
• Payload Contract
• Model Specs
• App model specs
• UI model specs (viewmodel)
• BDD and Use Cases

Feed Item

GET **url* (TBD)

200 RESPONSE

{
	"items": [
		{
			"id": "a UUID",
			"description": "a description",
			"location": "a location",
			"image": "https://a-image.url",
		},
		{
			"id": "another UUID",
			"description": "another description",
			"image": "https://another-image.url"
		},
		{
			"id": "even another UUID",
			"location": "even another location",
			"image": "https://even-another-image.url"
		},
		{
			"id": "yet another UUID",
			"image": "https://yet-another-image.url"
		}
		...
	]
}

• URL

1. Execute "Load Image Feed" command with above data.
2. System downloads data from the URL.
3. System validates downloaded data.
4. System creates image feed from valid data.
5. System delivers image feed.

1. System delivers invalid data error.

1. System delivers connectivity error.

• URL
• Execute "Load Image Feed" command with above data
• System downloads data from the URL.
• System validates downloaded data.
• System creates image feed from valid data.
• System delivers image feed.