Data model for spend price per building blocks and project settings

[maxceem]

Implementation for #316

Done via 2 challenges:
http://www.topcoder.com/challenge-details/30096338/?type=develop
http://www.topcoder.com/challenge-details/30096337/?type=develop

Implemented:

Models:

• ProjectEstimationItems
• ProjectSettings
• BuildingBlock

Endpoints:

• GET /projects/{id}/estimations/{id}/items
• CRUD for ProjectSettings
• BuildingBlock are returned now as a par of GET /projects/metadata

ProjectEstimationItems calculation

ProjectEstimationItems are calculated when:

• we create a project with estimations and there are buildingBlocks for that estimations. Note, we don't have any logic to recalculate ProjectEstimationItems based buildingBlocks. So ProjectEstimationItems are calculated based on buildingBlocks only during project creation.
• after we create a project we can create ProjectSettings. As soon as we create at least one ProjectSettings which descibes price calculation logic: all existent ProjectEstimationItems are deleted and recreated using ProjectSettings. And later when add/update/delete ProjectSettings about pricing all existent ProjectEstimationItems are delted and recreated.

As a result of the logic above, if we have at least one ProjectSettings about pricing buildingBlocks are not more used to calculate ProjectEstimationItems.

SQL Migrations

To apply this PR two migrations SQL scripts should be applied:

• https://github.com/topcoder-platform/tc-project-service/blob/feature/price-estimation-items/merged/migrations/20190719_project_settings_and_project_estimation_items.sql
• https://github.com/topcoder-platform/tc-project-service/blob/feature/price-estimation-items/merged/migrations/20190720_project_building_block.sql

[vikasrohit]

Thanks @maxceem for the PR, a quick question for you: Do you think if we merge this PR into dev, we can safely move the changes to production, in case we have to do a production release before the 2.5 release?

[maxceem]

I think yes. This PR almost doesn't touch the existent logic. The only place is triggering ProjectEstimationItems calculation on project creation. But I think we have enough time to verify there are no issues in project creation before releasing.

All other logic uses new models and endpoints.

[vikasrohit]

Looks good. Few queries and minor suggestions. @maxceem could you please refer to me our final approach about using settings vs building blocks for determining pricing items? I would like keep that handy for my discussions with the team.

[vikasrohit]

Thanks for the changes @maxceem Seems like we have conflicts now.

[maxceem]

@vikasrohit resolved merge conflicts.

[maxceem]

Looks good. Few queries and minor suggestions. @maxceem could you please refer to me our final approach about using settings vs building blocks for determining pricing items? I would like keep that handy for my discussions with the team.

I've created a wiki page with summarised implementation logic https://github.com/topcoder-platform/tc-project-service/wiki/Logic-for-calculating-ProjectEstimationItems

Let me know if any moment has to be clarified.