Separating message handling from information loading

Previously, the functions that would handle the UI updates and
triggering of additional information loading were often the message
handlers. The support workflows where higher level components want to
trigger information loads, we want those operations to be broken out
into functions which don't require message passing to occur.

lazy_github/ui/screens/primary.py

@@ -1,7 +1,7 @@
 from functools import partial
 from typing import NamedTuple
 
-from textual import work
+from textual import on, work
 from textual.app import ComposeResult
 from textual.command import Hit, Hits, Provider
 from textual.containers import Container, Horizontal
@@ -27,7 +27,7 @@
     PullRequestSelected,
     RepoSelected,
 )
-from lazy_github.models.github import Repository
+from lazy_github.models.github import Issue, PartialPullRequest, Repository
 from lazy_github.ui.screens.new_issue import NewIssueModal
 from lazy_github.ui.screens.new_pull_request import NewPullRequestModal
 from lazy_github.ui.screens.notifications import NotificationsModal
@@ -198,6 +198,13 @@ def workflows(self) -> WorkflowsContainer:
 
     @work
     async def fetch_issues_and_pull_requests(self, repo: Repository) -> None:
+        """
+        Fetches the combined issues and pull requests from the Github API and then adds them to the appropriate tables.
+
+        Pull Requests are technically issues in the Github data model, so they are fetched by loading issues and then
+        checking returned attributes to determine if those attributes indicate that an issue can be treated as a pull
+        request instead.
+        """
         state_filter = LazyGithubContext.config.issues.state_filter
         owner_filter = LazyGithubContext.config.issues.owner_filter
         try:
@@ -209,13 +216,16 @@ async def fetch_issues_and_pull_requests(self, repo: Repository) -> None:
             self.pull_requests.post_message(issue_and_pr_message)
             self.issues.post_message(issue_and_pr_message)
 
-    async def on_repo_selected(self, message: RepoSelected) -> None:
-        lg.info(f"Selected repo {message.repo.full_name}")
-        LazyGithubContext.current_repo = message.repo
+    async def load_repository(self, repo: Repository) -> None:
+        """Loads more information about the specified repository, such as the PRs, issues, and workflows"""
         if self.pull_requests.display or self.issues.display:
-            self.fetch_issues_and_pull_requests(message.repo)
+            self.fetch_issues_and_pull_requests(repo)
         if self.workflows.display:
-            self.workflows.load_repo(message.repo)
+            self.workflows.load_repo(repo)
+
+    @on(RepoSelected)
+    async def handle_repo_selection(self, message: RepoSelected) -> None:
+        await self.load_repository(message.repo)
 
 
 class SelectionDetailsPane(Container):
@@ -269,8 +279,11 @@ def selections(self) -> SelectionsPane:
     def details(self) -> SelectionDetailsContainer:
         return self.query_one("#selection_details", SelectionDetailsContainer)
 
-    async def on_pull_request_selected(self, message: PullRequestSelected) -> None:
-        full_pr = await get_full_pull_request(message.pr.repo, message.pr.number)
+    async def load_repository(self, repo: Repository) -> None:
+        await self.selections.load_repository(repo)
+
+    async def load_pull_request(self, pull_request: PartialPullRequest) -> None:
+        full_pr = await get_full_pull_request(pull_request.repo, pull_request.number)
         tabbed_content = self.query_one("#selection_detail_tabs", TabbedContent)
         await tabbed_content.clear_panes()
         await tabbed_content.add_pane(PrOverviewTabPane(full_pr))
@@ -279,13 +292,21 @@ async def on_pull_request_selected(self, message: PullRequestSelected) -> None:
         tabbed_content.children[0].focus()
         self.details.border_title = f"[5] PR #{full_pr.number} Details"
 
-    async def on_issue_selected(self, message: IssueSelected) -> None:
+    async def load_issue(self, issue: Issue) -> None:
         tabbed_content = self.query_one("#selection_detail_tabs", TabbedContent)
         await tabbed_content.clear_panes()
-        await tabbed_content.add_pane(IssueOverviewTabPane(message.issue))
-        await tabbed_content.add_pane(IssueConversationTabPane(message.issue))
+        await tabbed_content.add_pane(IssueOverviewTabPane(issue))
+        await tabbed_content.add_pane(IssueConversationTabPane(issue))
         tabbed_content.children[0].focus()
-        self.details.border_title = f"[5] Issue #{message.issue.number} Details"
+        self.details.border_title = f"[5] Issue #{issue.number} Details"
+
+    @on(PullRequestSelected)
+    async def handle_pull_request_selection(self, message: PullRequestSelected) -> None:
+        await self.load_pull_request(message.pr)
+
+    @on(IssueSelected)
+    async def handle_issue_selection(self, message: IssueSelected) -> None:
+        await self.load_issue(message.issue)
 
 
 class LazyGithubCommand(NamedTuple):
@@ -348,16 +369,27 @@ class LazyGithubMainScreen(Screen):
     def compose(self):
         with Container():
             yield LazyGithubStatusSummary()
-            yield MainViewPane()
+            yield MainViewPane(id="main-view-pane")
             yield LazyGithubFooter()
 
+    @property
+    def main_view_pane(self) -> MainViewPane:
+        return self.query_one("#main-view-pane", MainViewPane)
+
     @work
     async def action_view_notifications(self) -> None:
         notification = await self.app.push_screen_wait(NotificationsModal())
         self.refresh_notification_count()
 
         if notification:
-            lg.info(f"Selected notification: {notification}")
+            self.notify("Opening selected notification")
+            # The thing we'll do most immediately is swap over to the repo associated with the notification
+            await self.main_view_pane.load_repository(notification.repository)
+            self.set_currently_loaded_repo(notification.repository)
+
+            # TODO: Once that's done, we need to determine what the subject of the repo is and how to handle it. For
+            # example, if the subject of the notification is a pull request then we should swap over to viewing that
+            # pull request.
 
     async def on_mount(self) -> None:
         if LazyGithubContext.config.notifications.enabled:
@@ -402,5 +434,11 @@ def handle_settings_update(self) -> None:
                 NOTIFICATION_REFRESH_INTERVAL, self.refresh_notification_count
             )
 
-    def on_repo_selected(self, message: RepoSelected) -> None:
-        self.query_one("#currently_selected_repo", CurrentlySelectedRepo).current_repo_name = message.repo.full_name
+    def set_currently_loaded_repo(self, repo: Repository) -> None:
+        lg.info(f"Selected repo {repo.full_name}")
+        LazyGithubContext.current_repo = repo
+        self.query_one("#currently_selected_repo", CurrentlySelectedRepo).current_repo_name = repo.full_name
+
+    @on(RepoSelected)
+    def handle_repo_selection(self, message: RepoSelected) -> None:
+        self.set_currently_loaded_repo(message.repo)