Bitbucket Required Builds

A Bitbucket repository only allows a commit to merge when its required builds have passed. You are given:

• commits: rows [commit_id, repo].
• build_events: rows [commit_id, build_key, state, timestamp], where state is one of "SUCCESSFUL", "FAILED", "STOPPED" or "INPROGRESS". Events may arrive out of order.
• required: a dictionary mapping a repo name to the list of build keys that must pass. A repo missing from required has no required builds.

For each (commit_id, build_key) pair, only the latest event counts: the one with the largest timestamp, and if timestamps are equal, the one that appears later in build_events. Builds that are not required for the commit's repo are ignored.

Classify each commit using its required builds:

• "BLOCKED" if any required build's latest state is "FAILED" or "STOPPED";
• otherwise "MERGEABLE" if every required build's latest state is "SUCCESSFUL" (this includes a repo with no required builds);
• otherwise "PENDING" (some required build is still "INPROGRESS" or has not reported yet).

Return [commit_id, status] for each commit, in the order of commits.