Ubisam-MobileGit/tasks/028-issues-prs-numbered-pagination.md

# TASK-028: Numbered, jump-to-page pagination for the Issues/PR list

Status: implemented; all required checks pass; live device verification pending (no repository
with existing issues/PRs was found this session — see Known limitations)
Owner: Claude
Reviewer: Codex

## Outcome

The Issues/PR list now shows up to 5 numbered page buttons (tap to jump directly) plus previous/
next, and a `[ page / total ]`-style input field to type an exact page number and jump straight
there — replacing the plain previous/next-only footer, on this screen only. Per the earlier
AskUserQuestion resolution in this session ("이 기능은 전체 커밋/이슈 수를 알 수 있는 화면에만
적용"), every other paginated list in the app (repositories, history, notifications) keeps plain
previous/next, since Gitea's endpoints for those don't report a total count — Issues/PRs do.

## Scope

- Included: `domain/model/RepositoryModels.kt` (`Page.totalCount: Int? = null`),
  `data/workitems/GiteaWorkItemsApi.kt` (`X-Total-Count` header parsing; `listIssues` now sends
  `type=issues` so both the returned items and that header exclude pull requests server-side),
  `feature/workitems/WorkItemsViewModel.kt` (`totalPages` on `IssueList`/`PullRequestList`,
  `goToPage`), `feature/workitems/WorkItemsScreen.kt` (`NumberedPageFooter`, page-window logic,
  the `[ input / total ]` jump field), `MainActivity.kt` (`onGoToPage` wiring).
- Excluded: No change to repository/history/notification pagination (deliberately kept as plain
  previous/next — see Outcome). No change to how issue/PR *detail* screens work, only the list.

## Design notes

- **`type=issues` is a real, documented Gitea query parameter, not a guess**: verified directly
  against Gitea's own source (`routers/api/v1/repo/issue.go`'s `ListIssues` swagger doc comment
  lists `type` with `enum: [issues, pulls]`) before relying on it — this project's established
  convention for anything not obviously provable from the client alone. The class-level doc
  comment on `GiteaWorkItemsApi` previously explained *not* using this parameter as a deliberate
  choice against "a guessed, unverified" one; that reasoning no longer applies now that it's
  verified, so the comment was rewritten rather than left stale. The existing client-side
  `pullRequest == null` filter is kept anyway, as defense in depth.
- **Why `type=issues` specifically matters for this task**: without it, Gitea's issue-list endpoint
  returns issues *and* pull requests mixed together (a PR is internally an issue with a non-null
  `pull_request` field), and its `X-Total-Count` header would count both — producing a total-page
  count that overstates how many pages of genuine issues actually exist. Sending `type=issues`
  makes the count (and the returned items) issues-only at the source.
- **`Page<T>.totalCount` is optional and defaulted** (`totalCount: Int? = null` on both the class
  and `Page.of(...)`), specifically so none of the other 9+ existing `Page.of(...)` call sites
  (repositories, branches, tags, commits, notifications, comments, reviews — none of which have a
  total count available) needed to change.
- **The numbered-pagination UI falls back to the plain previous/next footer whenever `totalPages`
  is null** (e.g. a hypothetical Gitea instance old enough to not send the header) — a defensive
  fallback, not the expected path, but one that avoids ever showing a broken or missing page count
  instead of just quietly degrading to what every other list already does.
- **The 5-button page window slides, centered on the current page**, clamped to stay within
  `[1, totalPages]` — page 1 of a large list shows pages 1–5 (matching "1페이지에선 5까지
  보여줌" exactly), and the window keeps recentering as the user navigates rather than freezing
  once it nears either end.
- **No icon library dependency was added** for the "🔍"-style jump control asked for — this
  project has never used `androidx.compose.material.icons` (every other screen uses plain text
  labels, e.g. "다시 시도" instead of a retry icon), so the jump button uses a plain text label
  ("이동") consistent with that, rather than pulling in `material-icons-core` for one button.

## Acceptance criteria

- [x] The Issues list and the PR list each show up to 5 numbered page buttons, previous/next, and
      a page-jump input field, when the server reports a total count.
- [x] Tapping a numbered page button jumps directly to that page.
- [x] Typing a page number and submitting (IME "Go" or the "이동" button) jumps to that page,
      clamped to `[1, totalPages]`.
- [x] `X-Total-Count` is correctly excluded of pull requests for the Issues list (via `type=issues`)
      and reflects genuine issue count.
- [x] A fractional last page rounds up (45 items at page size 20 is 3 pages, not 2).
- [x] Every other paginated list (repositories, history, notifications) is unchanged — still plain
      previous/next.
- [x] Build, unit tests, and lint pass.
- [ ] Live device confirmation against a repository with enough real issues/PRs to see the numbered
      UI populated — not yet possible this session; see Known limitations.

## Required checks

```text
./gradlew assembleDebug
./gradlew testDebugUnitTest
./gradlew lintDebug
```

## Evidence

- `RepositoryModels.kt`: `Page<T>` gained `totalCount: Int? = null`; `Page.of(...)` validates it's
  non-negative when present.
- `GiteaWorkItemsApi.kt`: `listIssues` now requests `type=issues`; `toPage` parses `X-Total-Count`
  (case-insensitive header lookup, matching the existing `X-HasMore` pattern) into `Page.totalCount`.
- `WorkItemsViewModel.kt`: `IssueList`/`PullRequestList` gained `totalPages: Int? = null`, computed
  via a new private `Page<T>.totalPages(pageSize)` extension (`ceil(total / pageSize)`, at least
  1); new `goToPage(page: Int)`.
- `WorkItemsScreen.kt`: `PageFooter` now branches on `totalPages` — null falls back to the original
  previous/next row unchanged; non-null renders the new `NumberedPageFooter` (page-window buttons +
  `[ input / total ]` jump row) instead. New private `pageWindow(current, totalPages, windowSize=5)`.
- New tests: `GiteaWorkItemsApiTest.kt` (`type=issues` sent, `X-Total-Count` parsed for both issues
  and pull requests, absent header leaves `totalCount` null), `WorkItemsViewModelTest.kt` (45
  items/page size 20 rounds up to 3 pages, missing total count leaves `totalPages` null, `goToPage`
  jumps directly to the requested page), `RepositoryModelsTest.kt` (`totalCount` defaults to null,
  is exposed when given, rejects a negative value).
- `./gradlew compileDebugKotlin compileDebugUnitTestKotlin`: BUILD SUCCESSFUL.
- `./gradlew testDebugUnitTest`: BUILD SUCCESSFUL, all unit tests passing (including the new ones
  above).
- `./gradlew assembleDebug lintDebug`: BUILD SUCCESSFUL, 0 lint errors.
- Live device: build installed over wireless `adb`. Checked the Issues and Pull Request tabs on
  four of the human product owner's actual repositories; every one had zero issues and zero pull
  requests, so the numbered-pagination UI itself was never actually populated with real data this
  session (see Known limitations) — confirmed instead that the screen doesn't crash and correctly
  shows the existing empty state on all four.

## Known limitations

- **Not yet confirmed against a real repository with enough issues/PRs to populate the numbered UI
  with real data.** Every repository checked live this session had zero issues and zero pull
  requests. The header-parsing, total-page-count, and jump-to-page logic are covered by unit tests
  instead, but the actual rendered page-button row and jump field haven't been seen with real
  multi-page data yet.
- The page-jump text field accepts any positive integer typed, including one exceeding
  `totalPages` — it's clamped before being submitted (`coerceIn(1, totalPages)`), so this can't
  request an out-of-range page, but the field itself doesn't visually reject the keystroke.

## Review findings

None yet — pending Codex/human review.