Add ability to override congestion levels for specific road classes.

[MaximAlien]

Description

This PR implements the ability to override congestion levels for specific road classes.

Implementation

Since implementation is using Mapbox Directions property RouteStep.segmentIndicesByIntersection it depends on branch vk/478-intersection-geometry. Dependency will be updated after dependent branch is merged to main.

Since Android implementation is using road classes from mapbox_streets_v8 there is slight difference between congestion segments. After iOS is done with implementing same functionality current implementation should re-tested and revised once more.

Update: Most recent version was updated and is currently using MapboxStreetsRoadClass which matches Android implementation.

Screenshots or Gifs

Screenshots show congestion consistency comparison between iOS and Android. In this example .unknown congestion level for .motorway road class is replaced to .low (blue color). Currently there is slight shift of color because of gradient which is used on iOS.

[1ec5]

OfflineRoutingTests is failing because of a decoding error that would probably be fixed by mapbox/mapbox-directions-swift#485:

/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:33: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : failed - Unexpected Failure: unknown(underlying: Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "iso_3166_1_alpha3", intValue: nil), Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "routes", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "legs", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "admins", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0)], debugDescription: "No value associated with key CodingKeys(stringValue: \"iso_3166_1_alpha3\", intValue: nil) (\"iso_3166_1_alpha3\").", underlyingError: nil)))
/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:43: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : Asynchronous wait failed: Exceeded timeout of 2 seconds, with unfulfilled expectations: "Calculate route offline".
/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:46: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : failed - No route returned

[MaximAlien]

OfflineRoutingTests is failing because of a decoding error that would probably be fixed by mapbox/mapbox-directions-swift#485:

/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:33: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : failed - Unexpected Failure: unknown(underlying: Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "iso_3166_1_alpha3", intValue: nil), Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "routes", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "legs", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "admins", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0)], debugDescription: "No value associated with key CodingKeys(stringValue: \"iso_3166_1_alpha3\", intValue: nil) (\"iso_3166_1_alpha3\").", underlyingError: nil)))
/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:43: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : Asynchronous wait failed: Exceeded timeout of 2 seconds, with unfulfilled expectations: "Calculate route offline".
/Users/distiller/project/MapboxCoreNavigationTests/OfflineRoutingTests.swift:46: error: -[MapboxCoreNavigationTests.OfflineRoutingTests testOfflineDirections] : failed - No route returned

Yep, I've seen that. Since current PR already depends on vk/478-intersection-geometry we'll have to wait till both mapbox/mapbox-directions-swift#490 and mapbox/mapbox-directions-swift#485 land in Mapbox Directions.

[MaximAlien]

@1ec5, can you please take a look at this PR once more? RoadClasses option set was replaced with MapboxStreetsRoadClass, so iOS implementation is now in par with Android.

[1ec5]

I think RouteLeg.segmentRangesByStep may simplify this computation.

[MaximAlien]

Seems that segmentRangesByStep is not detailed enough, as it stores only lower and upper bounds. segmentIndicesByIntersection is more precise in this case, as it stores segment indices for Intersection.

[1ec5]

At a glance, it seems like this calculation would be simplified by zipping segmentIndices, but it’s hard to be sure. I’m a bit wary of the manual index arithmetic, but I trust you’ve already tested the multi-leg route edge case. I can’t think of any other edge cases at the moment.

[MaximAlien]

Just tried several approaches with zipping and striding, but seems that it doesn't help to make this code more elegant and simple. I propose to move on with landing this PR so that we can start testing and I can follow-up with any better solutions in future PRs.