## Problem
On CSES, Kattis, and USACO, `:CP <platform> login` always prompted
for credentials and ran a full web login even when a valid session was
already cached. Submit also had weak stale-session detection.
## Solution
`credentials.lua` now tries cached credentials first before prompting,
delegating fast-path detection to each scraper. CSES `login()` checks
the cached API token and returns immediately if valid. USACO `login()`
and `submit()` call `_check_usaco_login()` upfront. Kattis `submit()`
emits `checking_login` consistently and also triggers re-auth on HTTP
400/403, not just on the `"Request validation failed"` text match.
The premature `Submitting...` log emitted by Lua before the scraper
started is removed — Python's own status events are sufficient.
## Problem
CodeChef had no working login, submit, or contest list. The browser
selectors were wrong, the contest list was missing present/past
contests,
and problem/contest URLs were unset.
## Solution
Fix login and submit selectors for the Drupal-based site. Paginate
`/api/list/contests/past` to collect all 228 Starters, then expand each
parent contest into individual division entries (e.g. `START228 (Div.
4)`).
Add language IDs, correct `url`/`contest_url`/`standings_url` in
metadata,
and make `:CP <platform>` open the contest picker directly.
## Problem
`:CP <platform> login` blindly caches username/password without
server-side
validation. Bad credentials are only discovered at submit time, which is
confusing and wastes a browser session.
## Solution
Wire `:CP <platform> login` through the scraper pipeline so each
platform
actually authenticates before persisting credentials. On failure, the
user
sees an error and nothing is cached.
- CSES: reuses `_check_token` (fast path) and `_web_login`; returns API
token
in `LoginResult.credentials` so subsequent submits skip re-auth.
- AtCoder/Codeforces: new `_login_headless` functions open a
StealthySession,
solve Turnstile/Cloudflare, fill the login form, and validate success by
checking for the logout link. Cookies only persist on confirmed login.
- CodeChef/Kattis/USACO: return "not yet implemented" errors.
- `scraper.lua`: generalizes submit-only guards (`needs_browser` flag)
to
cover both `submit` and `login` subcommands.
- `credentials.lua`: prompts for username/password, passes cached token
for
CSES fast path, shows ndjson status notifications, only caches on
success.
## Problem
After the initial submit hardening, two issues remained: source code was
read in Lua and piped as stdin to the scraper (unnecessary roundtrip
since
the file exists on disk), and CF's `page.fill()` timed out on the hidden
`textarea[name="source"]` because CodeMirror owns the editor state.
## Solution
Pass the source file path as a CLI arg instead — AtCoder calls
`page.set_input_files(file_path)` directly, CF reads it with
`Path(file_path).read_text()`. Fix CF source injection via
`page.evaluate()`
into the CodeMirror instance. Extract `BROWSER_SUBMIT_NAV_TIMEOUT` as a
per-platform `defaultdict` (CF defaults to 2× nav timeout). Save the
buffer
with `vim.cmd.update()` before submitting.
## Problem
`:CP credentials login/logout/clear` is verbose and inconsistent with
other
actions that are all top-level (`:CP run`, `:CP submit`, etc.). The
clear-all
subcommand is also unnecessary since re-logging in overwrites existing
credentials.
## Solution
Replace `:CP credentials {login,logout,clear}` with `:CP login
[platform]`
and `:CP logout [platform]`. Remove the clear-all command and the
credentials
subcommand dispatch — login/logout are now regular actions routed
through the
standard action dispatcher.
## Problem
The `set` and `clear` subcommands don't clearly convey their intent —
`set`
reads like a generic setter rather than an auth action, and `clear`
overloads
single-platform and all-platform semantics in one subcommand.
## Solution
Rename `set` to `login`, split `clear` into `logout` (per-platform,
defaults
to active) and `clear` (all platforms).
New API:
- `:CP credentials login [platform]` — prompt and save credentials
- `:CP credentials logout [platform]` — remove credentials for one
platform
- `:CP credentials clear` — remove all stored credentials
Problem: :CP login was a poor API — no way to clear credentials without
raw Lua, and the single command didn't scale to multiple operations.
Solution: replace login with a :CP credentials subcommand following the
same pattern as :CP cache. :CP credentials set [platform] prompts and
saves; :CP credentials clear [platform] removes one or all platforms.
Add cache.clear_credentials(), rename login.lua to credentials.lua,
update parse/dispatch/tab-complete, and rewrite vimdoc accordingly.