## Problem
There was no way to open a problem, contest, or standings page in the
browser from within the plugin.
## Solution
Add `contest_url` and `standings_url` to `MetadataResult` and persist
them in the cache. Add `cache.get_open_urls` to resolve all three URLs.
Wire up `:CP open [problem|contest|standings]` in `commands/init.lua`
to call `vim.ui.open`, warning when a URL is unavailable (e.g. CSES
has no standings). Closes#315.
## Problem
CSES `_web_login` used bare dict indexing on the API response, raising
an opaque `KeyError` on missing fields. `_check_token` swallowed all
exceptions as `False`, conflating transient network errors with invalid
tokens. CF persisted cookies unconditionally and silently swallowed
`_solve_turnstile` failures in `submit_action`.
## Solution
CSES API fields now use `.get()` with a descriptive `RuntimeError` on
absence. `_check_token` re-raises `httpx` network/timeout exceptions
so callers see real failures. CF cookie writes are guarded by an
`X-User-Handle` check (the CF auth cookie). `_solve_turnstile` errors
propagate to the outer error handler instead of being silenced.
## Problem
The submit path in `codeforces.py` guarded `cookie_cache.write_text` on
the presence of a `JSESSIONID` cookie. Codeforces does not use
`JSESSIONID`, so the cookie file was never written after submit,
breaking the fast-path on subsequent submits.
## Solution
Replace the name-specific guard with a non-empty check (`if
browser_cookies:`), matching the unconditional save already used in the
login path.
Closes#301.
## 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
AtCoder file upload always wrote a `.cpp` temp file regardless of
language. CF submit used `solve_cloudflare=True` on the submit page,
causing a spurious "No Cloudflare challenge found" error;
`_wait_for_gate_reload` in `login_action` was dead code. Stale cookies
caused silent auth failures with no recovery path. The `uv.spawn` ndjson
path for submit had no overall timeout.
## Solution
Replace AtCoder's temp file with `page.set_input_files` using an
in-memory buffer and correct extension via `_LANGUAGE_ID_EXTENSION`.
Replace CF's temp-file/fallback dance with a direct
`textarea[name="source"]` fill and set `solve_cloudflare=False` on the
submit fetch. Add a login fast-path that skips the homepage check when
cookies exist, with automatic stale-cookie recovery via `_retried` flag
on redirect-to-login detection. Remove `_wait_for_gate_reload`. Fix
`_ensure_browser` to propagate install errors. Add a 120s kill timer to
the ndjson `uv.spawn` submit path in `scraper.lua`.
## Problem
Codeforces submit was a stub. CSES submit re-ran the full login flow on
every invocation (~1.5s overhead).
## Solution
**Codeforces**: headless browser submit via StealthySession (same
pattern as AtCoder). Solves Cloudflare Turnstile on login, uploads
source via file input, caches cookies at
`~/.cache/cp-nvim/codeforces-cookies.json` so repeat submits skip login.
**CSES**: persist the API token in credentials via a `credentials`
ndjson event. Subsequent submits validate the cached token with a single
GET before falling back to full login.
Also includes a vimdoc table of contents.
Problem: problem pages contain floating-point precision requirements and
contest start timestamps that were not being extracted or stored. The
submit workflow also needed a foundation in the scraper layer.
Solution: add extract_precision() to base.py and propagate through all
scrapers into cache. Add start_time to ContestSummary and extract it
from AtCoder and Codeforces. Add SubmitResult model, abstract submit()
method, submit CLI case with get_language_id() resolution, stdin/env_extra
support in run_scraper, and a full AtCoder submit implementation; stub
the remaining platforms.
