fix: remove bad file

Problem: CF and AtCoder always did a full browser login on every
`login` invocation, even with valid cookies. AtCoder submit never
persisted cookies, re-logging in on every submit. CF's cookie guard
used `X-User-Handle` (no longer set by CF — now `X-User-Sha1`),
so cookies were never saved. CF `login_action` was missing
`wait_for_selector` for the form that appears after the Cloudflare
gate reloads. AtCoder submit injected source via CodeMirror which
doesn't exist on AtCoder (it uses ACE editor).

Solution: Added cookie fast paths to CF and AtCoder login — emit
`checking_login` and return early if the existing session is valid.
`checking_login` is only emitted when cookies actually exist; fresh
starts go straight to `logging_in`. Fixed CF cookie guard to
`X-User-Sha1` and added `wait_for_selector` for the login form.
Rewrote AtCoder submit to use `set_input_files` on the real source
file path, with `wait_for_function` on `#plain-textarea` to confirm
the ACE editor populated before clicking submit.

lua/cp/constants.lua

@@ -219,4 +219,6 @@ M.LANGUAGE_VERSIONS = {
 
 M.DEFAULT_VERSIONS = { cpp = 'c++20', python = 'python3' }
 
+M.COOKIE_FILE = vim.fn.expand('~/.cache/cp-nvim/cookies.json')
+
 return M

lua/cp/credentials.lua

@@ -38,6 +38,7 @@ local function prompt_and_login(platform, display)
     end, function(result)
       vim.schedule(function()
         if result.success then
+          cache.set_credentials(platform, credentials)
           logger.log(
             display .. ' login successful',
             { level = vim.log.levels.INFO, override = true }
@@ -105,6 +106,14 @@ function M.logout(platform)
   local display = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
   cache.load()
   cache.clear_credentials(platform)
+  local cookie_file = constants.COOKIE_FILE
+  if vim.fn.filereadable(cookie_file) == 1 then
+    local ok, data = pcall(vim.fn.json_decode, vim.fn.readfile(cookie_file, 'b'))
+    if ok and type(data) == 'table' then
+      data[platform] = nil
+      vim.fn.writefile({ vim.fn.json_encode(data) }, cookie_file)
+    end
+  end
   logger.log(display .. ' credentials cleared', { level = vim.log.levels.INFO, override = true })
 end
 

scrapers/atcoder.py

@@ -6,7 +6,6 @@ import os
 import re
 import subprocess
 import time
-from pathlib import Path
 from typing import Any
 
 import backoff
@@ -16,7 +15,13 @@ from bs4 import BeautifulSoup, Tag
 from requests.adapters import HTTPAdapter
 from urllib3.util.retry import Retry
 
-from .base import BaseScraper, extract_precision
+from .base import (
+    BaseScraper,
+    clear_platform_cookies,
+    extract_precision,
+    load_platform_cookies,
+    save_platform_cookies,
+)
 from .models import (
     ContestListResult,
     ContestSummary,
@@ -379,26 +384,15 @@ def _ensure_browser() -> None:
             break
 
 
-def _login_headless(credentials: dict[str, str]) -> LoginResult:
-    try:
-        from scrapling.fetchers import StealthySession  # type: ignore[import-untyped,unresolved-import]
-    except ImportError:
-        return LoginResult(
-            success=False,
-            error="scrapling is required for AtCoder login. Install it: uv add 'scrapling[fetchers]>=0.4'",
-        )
+def _at_check_logged_in(page) -> bool:
+    return page.evaluate(
+        "() => Array.from(document.querySelectorAll('a')).some(a => a.textContent.trim() === 'Sign Out')"
+    )
 
-    _ensure_browser()
 
-    logged_in = False
+def _at_login_action(credentials: dict[str, str]):
     login_error: str | None = None
 
-    def check_login(page):
-        nonlocal logged_in
-        logged_in = page.evaluate(
-            "() => Array.from(document.querySelectorAll('a')).some(a => a.textContent.trim() === 'Sign Out')"
-        )
-
     def login_action(page):
         nonlocal login_error
         try:
@@ -412,6 +406,47 @@ def _login_headless(credentials: dict[str, str]) -> LoginResult:
         except Exception as e:
             login_error = str(e)
 
+    return login_action, lambda: login_error
+
+
+def _login_headless(credentials: dict[str, str]) -> LoginResult:
+    try:
+        from scrapling.fetchers import StealthySession  # type: ignore[import-untyped,unresolved-import]
+    except ImportError:
+        return LoginResult(
+            success=False,
+            error="scrapling is required for AtCoder login. Install it: uv add 'scrapling[fetchers]>=0.4'",
+        )
+
+    _ensure_browser()
+
+    saved_cookies = load_platform_cookies("atcoder") or []
+
+    if saved_cookies:
+        print(json.dumps({"status": "checking_login"}), flush=True)
+        logged_in = False
+
+        def check_action(page):
+            nonlocal logged_in
+            logged_in = _at_check_logged_in(page)
+
+        try:
+            with StealthySession(
+                headless=True,
+                timeout=BROWSER_SESSION_TIMEOUT,
+                google_search=False,
+                cookies=saved_cookies,
+            ) as session:
+                session.fetch(
+                    f"{BASE_URL}/home", page_action=check_action, network_idle=True
+                )
+            if logged_in:
+                return LoginResult(success=True, error="")
+        except Exception:
+            pass
+
+    login_action, get_error = _at_login_action(credentials)
+
     try:
         with StealthySession(
             headless=True,
@@ -424,17 +459,31 @@ def _login_headless(credentials: dict[str, str]) -> LoginResult:
                 page_action=login_action,
                 solve_cloudflare=True,
             )
+            login_error = get_error()
             if login_error:
                 return LoginResult(success=False, error=f"Login failed: {login_error}")
 
+            logged_in = False
+
+            def verify_action(page):
+                nonlocal logged_in
+                logged_in = _at_check_logged_in(page)
+
             session.fetch(
-                f"{BASE_URL}/home", page_action=check_login, network_idle=True
+                f"{BASE_URL}/home", page_action=verify_action, network_idle=True
             )
             if not logged_in:
                 return LoginResult(
                     success=False, error="Login failed (bad credentials?)"
                 )
 
+            try:
+                browser_cookies = session.context.cookies()
+                if browser_cookies:
+                    save_platform_cookies("atcoder", browser_cookies)
+            except Exception:
+                pass
+
         return LoginResult(success=True, error="")
     except Exception as e:
         return LoginResult(success=False, error=str(e))
@@ -446,6 +495,7 @@ def _submit_headless(
     file_path: str,
     language_id: str,
     credentials: dict[str, str],
+    _retried: bool = False,
 ) -> "SubmitResult":
     try:
         from scrapling.fetchers import StealthySession  # type: ignore[import-untyped,unresolved-import]
@@ -457,26 +507,24 @@ def _submit_headless(
 
     _ensure_browser()
 
-    login_error: str | None = None
-    submit_error: str | None = None
+    saved_cookies: list[dict[str, Any]] = []
+    if not _retried:
+        saved_cookies = load_platform_cookies("atcoder") or []
 
-    def login_action(page):
-        nonlocal login_error
-        try:
-            _solve_turnstile(page)
-            page.fill('input[name="username"]', credentials.get("username", ""))
-            page.fill('input[name="password"]', credentials.get("password", ""))
-            page.click("#submit")
-            page.wait_for_url(
-                lambda url: "/login" not in url, timeout=BROWSER_NAV_TIMEOUT
-            )
-        except Exception as e:
-            login_error = str(e)
+    logged_in = bool(saved_cookies)
+    submit_error: str | None = None
+    needs_relogin = False
+
+    def check_login(page):
+        nonlocal logged_in
+        logged_in = _at_check_logged_in(page)
+
+    login_action, get_login_error = _at_login_action(credentials)
 
     def submit_action(page):
-        nonlocal submit_error
+        nonlocal submit_error, needs_relogin
         if "/login" in page.url:
-            submit_error = "Not logged in after login step"
+            needs_relogin = True
             return
         try:
             _solve_turnstile(page)
@@ -488,18 +536,12 @@ def _submit_headless(
                 f'select[name="data.LanguageId"] option[value="{language_id}"]'
             ).wait_for(state="attached", timeout=BROWSER_ELEMENT_WAIT)
             page.select_option('select[name="data.LanguageId"]', language_id)
-            ext = _LANGUAGE_ID_EXTENSION.get(
-                language_id, Path(file_path).suffix.lstrip(".") or "txt"
+            page.set_input_files("#input-open-file", file_path)
+            page.wait_for_function(
+                "() => { const ta = document.getElementById('plain-textarea'); return ta && ta.value.length > 0; }",
+                timeout=BROWSER_ELEMENT_WAIT,
             )
-            page.set_input_files(
-                "#input-open-file",
-                {
-                    "name": f"solution.{ext}",
-                    "mimeType": "text/plain",
-                    "buffer": Path(file_path).read_bytes(),
-                },
-            )
-            page.locator('button[type="submit"]').click(no_wait_after=True)
+            page.evaluate("document.getElementById('submit').click()")
             page.wait_for_url(
                 lambda url: "/submissions/me" in url,
                 timeout=BROWSER_SUBMIT_NAV_TIMEOUT["atcoder"],
@@ -512,15 +554,33 @@ def _submit_headless(
             headless=True,
             timeout=BROWSER_SESSION_TIMEOUT,
             google_search=False,
+            cookies=saved_cookies if saved_cookies else [],
         ) as session:
-            print(json.dumps({"status": "logging_in"}), flush=True)
-            session.fetch(
-                f"{BASE_URL}/login",
-                page_action=login_action,
-                solve_cloudflare=True,
-            )
-            if login_error:
-                return SubmitResult(success=False, error=f"Login failed: {login_error}")
+            if not _retried and saved_cookies:
+                print(json.dumps({"status": "checking_login"}), flush=True)
+                session.fetch(
+                    f"{BASE_URL}/home", page_action=check_login, network_idle=True
+                )
+
+            if not logged_in:
+                print(json.dumps({"status": "logging_in"}), flush=True)
+                session.fetch(
+                    f"{BASE_URL}/login",
+                    page_action=login_action,
+                    solve_cloudflare=True,
+                )
+                login_error = get_login_error()
+                if login_error:
+                    return SubmitResult(
+                        success=False, error=f"Login failed: {login_error}"
+                    )
+                logged_in = True
+                try:
+                    browser_cookies = session.context.cookies()
+                    if browser_cookies:
+                        save_platform_cookies("atcoder", browser_cookies)
+                except Exception:
+                    pass
 
             print(json.dumps({"status": "submitting"}), flush=True)
             session.fetch(
@@ -529,6 +589,17 @@ def _submit_headless(
                 solve_cloudflare=True,
             )
 
+        if needs_relogin and not _retried:
+            clear_platform_cookies("atcoder")
+            return _submit_headless(
+                contest_id,
+                problem_id,
+                file_path,
+                language_id,
+                credentials,
+                _retried=True,
+            )
+
         if submit_error:
             return SubmitResult(success=False, error=submit_error)
 

scrapers/base.py

@@ -4,6 +4,8 @@ import os
 import re
 import sys
 from abc import ABC, abstractmethod
+from pathlib import Path
+from typing import Any
 
 from .language_ids import get_language_id
 from .models import (
@@ -15,6 +17,36 @@ from .models import (
     TestsResult,
 )
 
+_COOKIE_FILE = Path.home() / ".cache" / "cp-nvim" / "cookies.json"
+
+
+def load_platform_cookies(platform: str) -> Any | None:
+    try:
+        data = json.loads(_COOKIE_FILE.read_text())
+        return data.get(platform)
+    except Exception:
+        return None
+
+
+def save_platform_cookies(platform: str, data: Any) -> None:
+    _COOKIE_FILE.parent.mkdir(parents=True, exist_ok=True)
+    try:
+        existing = json.loads(_COOKIE_FILE.read_text())
+    except Exception:
+        existing = {}
+    existing[platform] = data
+    _COOKIE_FILE.write_text(json.dumps(existing))
+
+
+def clear_platform_cookies(platform: str) -> None:
+    try:
+        existing = json.loads(_COOKIE_FILE.read_text())
+        existing.pop(platform, None)
+        _COOKIE_FILE.write_text(json.dumps(existing))
+    except Exception:
+        pass
+
+
 _PRECISION_ABS_REL_RE = re.compile(
     r"(?:absolute|relative)\s+error[^.]*?10\s*[\^{]\s*\{?\s*[-\u2212]\s*(\d+)\s*\}?",
     re.IGNORECASE,

scrapers/codechef.py

@@ -9,8 +9,18 @@ from typing import Any
 
 import httpx
 
-from .base import BaseScraper
-from .timeouts import BROWSER_SESSION_TIMEOUT, HTTP_TIMEOUT
+from .base import (
+    BaseScraper,
+    clear_platform_cookies,
+    load_platform_cookies,
+    save_platform_cookies,
+)
+from .timeouts import (
+    BROWSER_ELEMENT_WAIT,
+    BROWSER_NAV_TIMEOUT,
+    BROWSER_SESSION_TIMEOUT,
+    HTTP_TIMEOUT,
+)
 from .models import (
     ContestListResult,
     ContestSummary,
@@ -31,7 +41,6 @@ HEADERS = {
 }
 CONNECTIONS = 8
 
-_COOKIE_PATH = Path.home() / ".cache" / "cp-nvim" / "codechef-cookies.json"
 
 _CC_CHECK_LOGIN_JS = "() => !!document.querySelector('a[href*=\"/users/\"]')"
 
@@ -54,6 +63,29 @@ async def fetch_json(client: httpx.AsyncClient, path: str) -> dict[str, Any]:
     return r.json()
 
 
+def _cc_check_logged_in(page) -> bool:
+    return "dashboard" in page.url or page.evaluate(_CC_CHECK_LOGIN_JS)
+
+
+def _cc_login_action(credentials: dict[str, str]):
+    login_error: str | None = None
+
+    def login_action(page):
+        nonlocal login_error
+        try:
+            page.locator('input[name="name"]').fill(credentials.get("username", ""))
+            page.locator('input[name="pass"]').fill(credentials.get("password", ""))
+            page.locator("input.cc-login-btn").click()
+            page.wait_for_function(
+                "() => !window.location.pathname.includes('/login')",
+                timeout=BROWSER_NAV_TIMEOUT,
+            )
+        except Exception as e:
+            login_error = str(e)
+
+    return login_action, lambda: login_error
+
+
 def _login_headless_codechef(credentials: dict[str, str]) -> LoginResult:
     try:
         from scrapling.fetchers import StealthySession  # type: ignore[import-untyped,unresolved-import]
@@ -67,28 +99,32 @@ def _login_headless_codechef(credentials: dict[str, str]) -> LoginResult:
 
     _ensure_browser()
 
-    _COOKIE_PATH.parent.mkdir(parents=True, exist_ok=True)
+    saved_cookies = load_platform_cookies("codechef") or []
 
-    logged_in = False
-    login_error: str | None = None
+    if saved_cookies:
+        print(json.dumps({"status": "checking_login"}), flush=True)
+        logged_in = False
 
-    def check_login(page):
-        nonlocal logged_in
-        logged_in = "dashboard" in page.url or page.evaluate(_CC_CHECK_LOGIN_JS)
+        def check_action(page):
+            nonlocal logged_in
+            logged_in = _cc_check_logged_in(page)
 
-    def login_action(page):
-        nonlocal login_error
         try:
-            page.locator('input[name="name"]').fill(credentials.get("username", ""))
-            page.locator('input[name="pass"]').fill(credentials.get("password", ""))
-            page.locator("input.cc-login-btn").click()
-            try:
-                page.wait_for_url(lambda url: "/login" not in url, timeout=3000)
-            except Exception:
-                login_error = "Login failed (bad credentials?)"
-                return
-        except Exception as e:
-            login_error = str(e)
+            with StealthySession(
+                headless=True,
+                timeout=BROWSER_SESSION_TIMEOUT,
+                google_search=False,
+                cookies=saved_cookies,
+            ) as session:
+                session.fetch(
+                    f"{BASE_URL}/", page_action=check_action, network_idle=True
+                )
+            if logged_in:
+                return LoginResult(success=True, error="")
+        except Exception:
+            pass
+
+    login_action, get_error = _cc_login_action(credentials)
 
     try:
         with StealthySession(
@@ -97,11 +133,20 @@ def _login_headless_codechef(credentials: dict[str, str]) -> LoginResult:
             google_search=False,
         ) as session:
             print(json.dumps({"status": "logging_in"}), flush=True)
-            session.fetch(f"{BASE_URL}/login", page_action=login_action)
+            session.fetch(
+                f"{BASE_URL}/login", page_action=login_action, network_idle=True
+            )
+            login_error = get_error()
             if login_error:
                 return LoginResult(success=False, error=f"Login failed: {login_error}")
 
-            session.fetch(f"{BASE_URL}/", page_action=check_login, network_idle=True)
+            logged_in = False
+
+            def verify_action(page):
+                nonlocal logged_in
+                logged_in = _cc_check_logged_in(page)
+
+            session.fetch(f"{BASE_URL}/", page_action=verify_action, network_idle=True)
             if not logged_in:
                 return LoginResult(
                     success=False, error="Login failed (bad credentials?)"
@@ -109,8 +154,8 @@ def _login_headless_codechef(credentials: dict[str, str]) -> LoginResult:
 
             try:
                 browser_cookies = session.context.cookies()
-                if browser_cookies:
-                    _COOKIE_PATH.write_text(json.dumps(browser_cookies))
+                if any(c.get("name") == "userkey" for c in browser_cookies):
+                    save_platform_cookies("codechef", browser_cookies)
             except Exception:
                 pass
 
@@ -126,6 +171,7 @@ def _submit_headless_codechef(
     language_id: str,
     credentials: dict[str, str],
     _retried: bool = False,
+    _practice: bool = False,
 ) -> SubmitResult:
     source_code = Path(file_path).read_text()
 
@@ -141,36 +187,19 @@ def _submit_headless_codechef(
 
     _ensure_browser()
 
-    _COOKIE_PATH.parent.mkdir(parents=True, exist_ok=True)
     saved_cookies: list[dict[str, Any]] = []
-    if _COOKIE_PATH.exists() and not _retried:
-        try:
-            saved_cookies = json.loads(_COOKIE_PATH.read_text())
-        except Exception:
-            pass
+    if not _retried:
+        saved_cookies = load_platform_cookies("codechef") or []
 
-    logged_in = bool(saved_cookies) and not _retried
-    login_error: str | None = None
+    logged_in = bool(saved_cookies)
     submit_error: str | None = None
     needs_relogin = False
 
     def check_login(page):
         nonlocal logged_in
-        logged_in = "dashboard" in page.url or page.evaluate(_CC_CHECK_LOGIN_JS)
+        logged_in = _cc_check_logged_in(page)
 
-    def login_action(page):
-        nonlocal login_error
-        try:
-            page.locator('input[name="name"]').fill(credentials.get("username", ""))
-            page.locator('input[name="pass"]').fill(credentials.get("password", ""))
-            page.locator("input.cc-login-btn").click()
-            try:
-                page.wait_for_url(lambda url: "/login" not in url, timeout=3000)
-            except Exception:
-                login_error = "Login failed (bad credentials?)"
-                return
-        except Exception as e:
-            login_error = str(e)
+    _login_action, _get_login_error = _cc_login_action(credentials)
 
     def submit_action(page):
         nonlocal submit_error, needs_relogin
@@ -178,12 +207,13 @@ def _submit_headless_codechef(
             needs_relogin = True
             return
         try:
-            page.wait_for_selector('[aria-haspopup="listbox"]', timeout=10000)
+            page.wait_for_selector(
+                '[aria-haspopup="listbox"]', timeout=BROWSER_ELEMENT_WAIT
+            )
 
             page.locator('[aria-haspopup="listbox"]').click()
-            page.wait_for_selector('[role="option"]', timeout=5000)
+            page.wait_for_selector('[role="option"]', timeout=BROWSER_ELEMENT_WAIT)
             page.locator(f'[role="option"][data-value="{language_id}"]').click()
-            page.wait_for_timeout(250)
 
             page.locator(".ace_editor").click()
             page.keyboard.press("Control+a")
@@ -198,7 +228,6 @@ def _submit_headless_codechef(
                 }""",
                 source_code,
             )
-            page.wait_for_timeout(125)
 
             page.evaluate(
                 "() => document.getElementById('submit_btn').scrollIntoView({block:'center'})"
@@ -213,7 +242,9 @@ def _submit_headless_codechef(
                 const d = document.querySelector('[role="dialog"], .swal2-popup');
                 return d ? d.textContent.trim() : null;
             }""")
-            if dialog_text and (
+            if dialog_text and "login" in dialog_text.lower():
+                needs_relogin = True
+            elif dialog_text and (
                 "not available for accepting solutions" in dialog_text
                 or "not available for submission" in dialog_text
             ):
@@ -228,9 +259,9 @@ def _submit_headless_codechef(
             headless=True,
             timeout=BROWSER_SESSION_TIMEOUT,
             google_search=False,
-            cookies=saved_cookies if (saved_cookies and not _retried) else [],
+            cookies=saved_cookies if saved_cookies else [],
         ) as session:
-            if not logged_in:
+            if not _retried and not _practice and saved_cookies:
                 print(json.dumps({"status": "checking_login"}), flush=True)
                 session.fetch(
                     f"{BASE_URL}/", page_action=check_login, network_idle=True
@@ -238,13 +269,18 @@ def _submit_headless_codechef(
 
             if not logged_in:
                 print(json.dumps({"status": "logging_in"}), flush=True)
-                session.fetch(f"{BASE_URL}/login", page_action=login_action)
+                session.fetch(
+                    f"{BASE_URL}/login", page_action=_login_action, network_idle=True
+                )
+                login_error = _get_login_error()
                 if login_error:
                     return SubmitResult(
                         success=False, error=f"Login failed: {login_error}"
                     )
+                logged_in = True
 
-            print(json.dumps({"status": "submitting"}), flush=True)
+            if not _practice:
+                print(json.dumps({"status": "submitting"}), flush=True)
             submit_url = (
                 f"{BASE_URL}/submit/{problem_id}"
                 if contest_id == "PRACTICE"
@@ -254,13 +290,13 @@ def _submit_headless_codechef(
 
             try:
                 browser_cookies = session.context.cookies()
-                if browser_cookies and logged_in:
-                    _COOKIE_PATH.write_text(json.dumps(browser_cookies))
+                if any(c.get("name") == "userkey" for c in browser_cookies):
+                    save_platform_cookies("codechef", browser_cookies)
             except Exception:
                 pass
 
         if needs_relogin and not _retried:
-            _COOKIE_PATH.unlink(missing_ok=True)
+            clear_platform_cookies("codechef")
             return _submit_headless_codechef(
                 contest_id,
                 problem_id,
@@ -270,14 +306,14 @@ def _submit_headless_codechef(
                 _retried=True,
             )
 
-        if submit_error == "PRACTICE_FALLBACK" and not _retried:
+        if submit_error == "PRACTICE_FALLBACK" and not _practice:
             return _submit_headless_codechef(
                 "PRACTICE",
                 problem_id,
                 file_path,
                 language_id,
                 credentials,
-                _retried=True,
+                _practice=True,
             )
 
         if submit_error:

scrapers/codeforces.py

@@ -8,7 +8,13 @@ from typing import Any
 import requests
 from bs4 import BeautifulSoup, Tag
 
-from .base import BaseScraper, extract_precision
+from .base import (
+    BaseScraper,
+    clear_platform_cookies,
+    extract_precision,
+    load_platform_cookies,
+    save_platform_cookies,
+)
 from .models import (
     ContestListResult,
     ContestSummary,
@@ -331,9 +337,33 @@ class CodeforcesScraper(BaseScraper):
         return await asyncio.to_thread(_login_headless_cf, credentials)
 
 
-def _login_headless_cf(credentials: dict[str, str]) -> LoginResult:
-    from pathlib import Path
+def _cf_check_logged_in(page) -> bool:
+    return page.evaluate(
+        "() => Array.from(document.querySelectorAll('a'))"
+        ".some(a => a.textContent.includes('Logout'))"
+    )
 
+
+def _cf_login_action(credentials: dict[str, str]):
+    login_error: str | None = None
+
+    def login_action(page):
+        nonlocal login_error
+        try:
+            page.wait_for_selector('input[name="handleOrEmail"]', timeout=60000)
+            page.fill('input[name="handleOrEmail"]', credentials.get("username", ""))
+            page.fill('input[name="password"]', credentials.get("password", ""))
+            page.locator('#enterForm input[type="submit"]').click()
+            page.wait_for_url(
+                lambda url: "/enter" not in url, timeout=BROWSER_NAV_TIMEOUT
+            )
+        except Exception as e:
+            login_error = str(e)
+
+    return login_action, lambda: login_error
+
+
+def _login_headless_cf(credentials: dict[str, str]) -> LoginResult:
     try:
         from scrapling.fetchers import StealthySession  # type: ignore[import-untyped,unresolved-import]
     except ImportError:
@@ -346,36 +376,32 @@ def _login_headless_cf(credentials: dict[str, str]) -> LoginResult:
 
     _ensure_browser()
 
-    cookie_cache = Path.home() / ".cache" / "cp-nvim" / "codeforces-cookies.json"
-    cookie_cache.parent.mkdir(parents=True, exist_ok=True)
+    saved_cookies = load_platform_cookies("codeforces") or []
 
-    logged_in = False
-    login_error: str | None = None
+    if saved_cookies:
+        print(json.dumps({"status": "checking_login"}), flush=True)
+        logged_in = False
 
-    def check_login(page):
-        nonlocal logged_in
-        logged_in = page.evaluate(
-            "() => Array.from(document.querySelectorAll('a'))"
-            ".some(a => a.textContent.includes('Logout'))"
-        )
+        def check_action(page):
+            nonlocal logged_in
+            logged_in = _cf_check_logged_in(page)
 
-    def login_action(page):
-        nonlocal login_error
         try:
-            page.fill(
-                'input[name="handleOrEmail"]',
-                credentials.get("username", ""),
-            )
-            page.fill(
-                'input[name="password"]',
-                credentials.get("password", ""),
-            )
-            page.locator('#enterForm input[type="submit"]').click()
-            page.wait_for_url(
-                lambda url: "/enter" not in url, timeout=BROWSER_NAV_TIMEOUT
-            )
-        except Exception as e:
-            login_error = str(e)
+            with StealthySession(
+                headless=True,
+                timeout=BROWSER_SESSION_TIMEOUT,
+                google_search=False,
+                cookies=saved_cookies,
+            ) as session:
+                session.fetch(
+                    f"{BASE_URL}/", page_action=check_action, solve_cloudflare=True
+                )
+            if logged_in:
+                return LoginResult(success=True, error="")
+        except Exception:
+            pass
+
+    login_action, get_error = _cf_login_action(credentials)
 
     try:
         with StealthySession(
@@ -389,14 +415,17 @@ def _login_headless_cf(credentials: dict[str, str]) -> LoginResult:
                 page_action=login_action,
                 solve_cloudflare=True,
             )
+            login_error = get_error()
             if login_error:
                 return LoginResult(success=False, error=f"Login failed: {login_error}")
 
-            session.fetch(
-                f"{BASE_URL}/",
-                page_action=check_login,
-                network_idle=True,
-            )
+            logged_in = False
+
+            def verify_action(page):
+                nonlocal logged_in
+                logged_in = _cf_check_logged_in(page)
+
+            session.fetch(f"{BASE_URL}/", page_action=verify_action, network_idle=True)
             if not logged_in:
                 return LoginResult(
                     success=False, error="Login failed (bad credentials?)"
@@ -404,8 +433,8 @@ def _login_headless_cf(credentials: dict[str, str]) -> LoginResult:
 
             try:
                 browser_cookies = session.context.cookies()
-                if any(c.get("name") == "X-User-Handle" for c in browser_cookies):
-                    cookie_cache.write_text(json.dumps(browser_cookies))
+                if any(c.get("name") == "X-User-Sha1" for c in browser_cookies):
+                    save_platform_cookies("codeforces", browser_cookies)
             except Exception:
                 pass
 
@@ -438,44 +467,19 @@ def _submit_headless(
 
     _ensure_browser()
 
-    cookie_cache = Path.home() / ".cache" / "cp-nvim" / "codeforces-cookies.json"
-    cookie_cache.parent.mkdir(parents=True, exist_ok=True)
     saved_cookies: list[dict[str, Any]] = []
-    if cookie_cache.exists():
-        try:
-            saved_cookies = json.loads(cookie_cache.read_text())
-        except Exception:
-            pass
+    if not _retried:
+        saved_cookies = load_platform_cookies("codeforces") or []
 
-    logged_in = cookie_cache.exists() and not _retried
-    login_error: str | None = None
+    logged_in = bool(saved_cookies)
     submit_error: str | None = None
     needs_relogin = False
 
     def check_login(page):
         nonlocal logged_in
-        logged_in = page.evaluate(
-            "() => Array.from(document.querySelectorAll('a'))"
-            ".some(a => a.textContent.includes('Logout'))"
-        )
+        logged_in = _cf_check_logged_in(page)
 
-    def login_action(page):
-        nonlocal login_error
-        try:
-            page.fill(
-                'input[name="handleOrEmail"]',
-                credentials.get("username", ""),
-            )
-            page.fill(
-                'input[name="password"]',
-                credentials.get("password", ""),
-            )
-            page.locator('#enterForm input[type="submit"]').click()
-            page.wait_for_url(
-                lambda url: "/enter" not in url, timeout=BROWSER_NAV_TIMEOUT
-            )
-        except Exception as e:
-            login_error = str(e)
+    _login_action, _get_login_error = _cf_login_action(credentials)
 
     def submit_action(page):
         nonlocal submit_error, needs_relogin
@@ -520,27 +524,27 @@ def _submit_headless(
             headless=True,
             timeout=BROWSER_SESSION_TIMEOUT,
             google_search=False,
-            cookies=saved_cookies if (cookie_cache.exists() and not _retried) else [],
+            cookies=saved_cookies if saved_cookies else [],
         ) as session:
-            if not (cookie_cache.exists() and not _retried):
+            if not _retried and saved_cookies:
                 print(json.dumps({"status": "checking_login"}), flush=True)
                 session.fetch(
-                    f"{BASE_URL}/",
-                    page_action=check_login,
-                    network_idle=True,
+                    f"{BASE_URL}/", page_action=check_login, solve_cloudflare=True
                 )
 
             if not logged_in:
                 print(json.dumps({"status": "logging_in"}), flush=True)
                 session.fetch(
                     f"{BASE_URL}/enter",
-                    page_action=login_action,
+                    page_action=_login_action,
                     solve_cloudflare=True,
                 )
+                login_error = _get_login_error()
                 if login_error:
                     return SubmitResult(
                         success=False, error=f"Login failed: {login_error}"
                     )
+                logged_in = True
 
             print(json.dumps({"status": "submitting"}), flush=True)
             session.fetch(
@@ -551,13 +555,13 @@ def _submit_headless(
 
             try:
                 browser_cookies = session.context.cookies()
-                if any(c.get("name") == "X-User-Handle" for c in browser_cookies):
-                    cookie_cache.write_text(json.dumps(browser_cookies))
+                if any(c.get("name") == "X-User-Sha1" for c in browser_cookies):
+                    save_platform_cookies("codeforces", browser_cookies)
             except Exception:
                 pass
 
         if needs_relogin and not _retried:
-            cookie_cache.unlink(missing_ok=True)
+            clear_platform_cookies("codeforces")
             return _submit_headless(
                 contest_id,
                 problem_id,

scrapers/kattis.py

@@ -10,7 +10,13 @@ from pathlib import Path
 
 import httpx
 
-from .base import BaseScraper, extract_precision
+from .base import (
+    BaseScraper,
+    clear_platform_cookies,
+    extract_precision,
+    load_platform_cookies,
+    save_platform_cookies,
+)
 from .timeouts import HTTP_TIMEOUT
 from .models import (
     ContestListResult,
@@ -28,8 +34,6 @@ HEADERS = {
 }
 CONNECTIONS = 8
 
-_COOKIE_PATH = Path.home() / ".cache" / "cp-nvim" / "kattis-cookies.json"
-
 TIME_RE = re.compile(
     r"CPU Time limit</span>\s*<span[^>]*>\s*(\d+)\s*seconds?\s*</span>",
     re.DOTALL,
@@ -209,20 +213,24 @@ async def _stream_single_problem(client: httpx.AsyncClient, slug: str) -> None:
 
 
 async def _load_kattis_cookies(client: httpx.AsyncClient) -> None:
-    if not _COOKIE_PATH.exists():
-        return
-    try:
-        for k, v in json.loads(_COOKIE_PATH.read_text()).items():
+    data = load_platform_cookies("kattis")
+    if isinstance(data, dict):
+        for k, v in data.items():
             client.cookies.set(k, v)
-    except Exception:
-        pass
 
 
 async def _save_kattis_cookies(client: httpx.AsyncClient) -> None:
-    cookies = {k: v for k, v in client.cookies.items()}
+    cookies = dict(client.cookies.items())
     if cookies:
-        _COOKIE_PATH.parent.mkdir(parents=True, exist_ok=True)
-        _COOKIE_PATH.write_text(json.dumps(cookies))
+        save_platform_cookies("kattis", cookies)
+
+
+async def _check_kattis_login(client: httpx.AsyncClient) -> bool:
+    try:
+        r = await client.get(BASE_URL, headers=HEADERS, timeout=HTTP_TIMEOUT)
+        return bool(r.headers.get("x-username"))
+    except Exception:
+        return False
 
 
 async def _do_kattis_login(
@@ -329,9 +337,10 @@ class KattisScraper(BaseScraper):
             return self._submit_error("Missing credentials. Use :CP kattis login")
 
         async with httpx.AsyncClient(follow_redirects=True) as client:
-            print(json.dumps({"status": "checking_login"}), flush=True)
             await _load_kattis_cookies(client)
-            if not client.cookies:
+            if client.cookies:
+                print(json.dumps({"status": "checking_login"}), flush=True)
+            else:
                 print(json.dumps({"status": "logging_in"}), flush=True)
                 ok = await _do_kattis_login(client, username, password)
                 if not ok:
@@ -368,7 +377,7 @@ class KattisScraper(BaseScraper):
                 return self._submit_error(f"Submit request failed: {e}")
 
             if r.status_code in (400, 403) or r.text == "Request validation failed":
-                _COOKIE_PATH.unlink(missing_ok=True)
+                clear_platform_cookies("kattis")
                 print(json.dumps({"status": "logging_in"}), flush=True)
                 ok = await _do_kattis_login(client, username, password)
                 if not ok:
@@ -399,6 +408,16 @@ class KattisScraper(BaseScraper):
             return self._login_error("Missing username or password")
 
         async with httpx.AsyncClient(follow_redirects=True) as client:
+            await _load_kattis_cookies(client)
+            if client.cookies:
+                print(json.dumps({"status": "checking_login"}), flush=True)
+                if await _check_kattis_login(client):
+                    return LoginResult(
+                        success=True,
+                        error="",
+                        credentials={"username": username, "password": password},
+                    )
+
             print(json.dumps({"status": "logging_in"}), flush=True)
             ok = await _do_kattis_login(client, username, password)
             if not ok:

scrapers/usaco.py

@@ -8,7 +8,12 @@ from typing import Any, cast
 
 import httpx
 
-from .base import BaseScraper, extract_precision
+from .base import (
+    BaseScraper,
+    extract_precision,
+    load_platform_cookies,
+    save_platform_cookies,
+)
 from .timeouts import HTTP_TIMEOUT
 from .models import (
     ContestListResult,
@@ -27,7 +32,6 @@ HEADERS = {
 }
 CONNECTIONS = 4
 
-_COOKIE_PATH = Path.home() / ".cache" / "cp-nvim" / "usaco-cookies.json"
 _LOGIN_PATH = "/current/tpcm/login-session.php"
 _SUBMIT_PATH = "/current/tpcm/submit-solution.php"
 
@@ -202,20 +206,16 @@ def _parse_submit_form(
 
 
 async def _load_usaco_cookies(client: httpx.AsyncClient) -> None:
-    if not _COOKIE_PATH.exists():
-        return
-    try:
-        for k, v in json.loads(_COOKIE_PATH.read_text()).items():
+    data = load_platform_cookies("usaco")
+    if isinstance(data, dict):
+        for k, v in data.items():
             client.cookies.set(k, v)
-    except Exception:
-        pass
 
 
 async def _save_usaco_cookies(client: httpx.AsyncClient) -> None:
-    cookies = {k: v for k, v in client.cookies.items()}
+    cookies = dict(client.cookies.items())
     if cookies:
-        _COOKIE_PATH.parent.mkdir(parents=True, exist_ok=True)
-        _COOKIE_PATH.write_text(json.dumps(cookies))
+        save_platform_cookies("usaco", cookies)
 
 
 async def _check_usaco_login(client: httpx.AsyncClient, username: str) -> bool: