From 66c69bc84e12dc6e863928d616e61d21fadee965 Mon Sep 17 00:00:00 2001
From: Dhruv Manilawala <dhruvmanila@gmail.com>
Date: Mon, 24 May 2021 14:17:54 +0530
Subject: [PATCH] feat(event): approve workflow run

Conditions:
- Coming from a pull request
- Only if it's required
- Pull request associated for the workflow run is still open
---
 algorithms_keeper/event/__init__.py |  2 ++
 algorithms_keeper/event/workflow.py | 34 +++++++++++++++++++
 algorithms_keeper/utils.py          | 52 +++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 algorithms_keeper/event/workflow.py

diff --git a/algorithms_keeper/event/__init__.py b/algorithms_keeper/event/__init__.py
index b8b1a60..3e06580 100644
--- a/algorithms_keeper/event/__init__.py
+++ b/algorithms_keeper/event/__init__.py
@@ -5,6 +5,7 @@
 from algorithms_keeper.event.installation import installation_router
 from algorithms_keeper.event.issues import issues_router
 from algorithms_keeper.event.pull_request import pull_request_router
+from algorithms_keeper.event.workflow import workflow_router
 
 main_router: Router = Router(
     check_run_router,
@@ -12,6 +13,7 @@
     installation_router,
     issues_router,
     pull_request_router,
+    workflow_router,
 )
 
 __all__ = ["main_router"]
diff --git a/algorithms_keeper/event/workflow.py b/algorithms_keeper/event/workflow.py
new file mode 100644
index 0000000..85957eb
--- /dev/null
+++ b/algorithms_keeper/event/workflow.py
@@ -0,0 +1,34 @@
+import logging
+from typing import Any
+
+from gidgethub import routing
+from gidgethub.sansio import Event
+
+from algorithms_keeper import utils
+from algorithms_keeper.api import GitHubAPI
+
+workflow_router = routing.Router()
+
+logger = logging.getLogger(__package__)
+
+
+@workflow_router.register("workflow_run", action="requested")
+async def approve_workflow_run(
+    event: Event, gh: GitHubAPI, *args: Any, **kwargs: Any
+) -> None:
+    """Approve a workflow run from a first-time contributor."""
+    workflow_run = event.data["workflow_run"]
+
+    if workflow_run["conclusion"] != "action_required":
+        return None
+
+    pull_request = await utils.get_pr_for_workflow_run(gh, workflow_run=workflow_run)
+    if pull_request is None:
+        return None
+
+    logger.info(
+        "Approving the workflow %d (PR #%d)",
+        workflow_run["id"],
+        pull_request["number"],
+    )
+    await utils.approve_workflow_run(gh, workflow_run=workflow_run)
diff --git a/algorithms_keeper/utils.py b/algorithms_keeper/utils.py
index d4c9199..f65d5d7 100644
--- a/algorithms_keeper/utils.py
+++ b/algorithms_keeper/utils.py
@@ -12,6 +12,7 @@
 maintain consistency throughout the module and improve readability in files
 that uses all the given functions.
 """
+import logging
 import urllib.parse
 from base64 import b64decode
 from dataclasses import dataclass
@@ -21,6 +22,8 @@
 from algorithms_keeper.api import GitHubAPI
 from algorithms_keeper.constants import PR_REVIEW_BODY
 
+logger = logging.getLogger(__package__)
+
 
 @dataclass(frozen=True)
 class File:
@@ -271,3 +274,52 @@ async def get_pr_for_issue(gh: GitHubAPI, *, issue: Mapping[str, Any]) -> Any:
 async def update_pr(gh: GitHubAPI, *, pull_request: Mapping[str, Any]) -> Any:
     """Get the updated pull request object for the given pull request."""
     return await gh.getitem(pull_request["url"], oauth_token=await gh.access_token)
+
+
+async def get_pr_for_workflow_run(
+    gh: GitHubAPI, *, workflow_run: Mapping[str, Any]
+) -> Optional[Any]:
+    """Return the pull request object for the given workflow run object.
+
+    If the workflow run is not triggered by a pull request, then return None.
+    If the workflow run contains the pull request information, then return the first
+    pull request object, otherwise make a request to the GitHub API to get the pull
+    request associated with the workflow run.
+    """
+    if workflow_run["event"] != "pull_request":
+        return None
+
+    if workflow_run["pull_requests"]:
+        return await gh.getitem(
+            workflow_run["pull_requests"][0]["url"],
+            oauth_token=await gh.access_token,
+        )
+
+    # Format: "user/organization:branch"
+    head = (
+        workflow_run["head_repository"]["owner"]["login"]
+        + ":"
+        + workflow_run["head_branch"]
+    )
+
+    prs = await gh.getitem(
+        workflow_run["repository"]["pulls_url"]
+        + "?"
+        + urllib.parse.urlencode({"state": "open", "head": head}),
+        oauth_token=await gh.access_token,
+    )
+    if not prs:
+        logger.info("No open pull request found for %r", head)
+        return None
+
+    # There can be only one open pull request for a given branch.
+    return prs[0]
+
+
+async def approve_workflow_run(
+    gh: GitHubAPI, *, workflow_run: Mapping[str, Any]
+) -> None:
+    """Approve the given workflow run."""
+    await gh.post(
+        workflow_run["url"] + "/approve", data={}, oauth_token=await gh.access_token
+    )