From 58b68408156400f3cd6589ec7088203a0e771f4b Mon Sep 17 00:00:00 2001
From: Barrett Ruth <62671086+barrettruth@users.noreply.github.com>
Date: Fri, 6 Mar 2026 18:18:21 -0500
Subject: [PATCH] feat: race countdown support and language version selection
 (#346)

## Problem

Two gaps in the plugin: (1) contest pickers have no way to know whether
a contest supports countdown (race), so the UI can't surface that
affordance; (2) `:CP submit` hardcodes a single language ID per platform
with no way to choose C++ standard or override the platform ID.

## Solution

**Race countdown** (`4e709c8`): Add `supports_countdown` boolean to
`ContestListResult` and wire it through CSES/USACO scrapers, cache, race
module, and pickers.

**Language version selection** (`b90ac67`): Add `LANGUAGE_VERSIONS` and
`DEFAULT_VERSIONS` tables in `constants.lua`. Config gains `version` and
`submit_id` fields validated at setup time. `submit.lua` resolves the
effective config to a platform ID (priority: `submit_id` > `version` >
default). Helpdocs add `*cp-submit-language*` section. Tests cover
`LANGUAGE_IDS` completeness.
---
 doc/cp.nvim.txt         | 72 +++++++++++++++++++++++++++++++++++------
 lua/cp/cache.lua        | 26 ++++++++++++++-
 lua/cp/config.lua       | 27 ++++++++++++++++
 lua/cp/constants.lua    | 17 ++++++++++
 lua/cp/pickers/init.lua |  6 ++--
 lua/cp/race.lua         | 65 ++++++++++++++++++++++++-------------
 lua/cp/scraper.lua      |  7 ++--
 lua/cp/submit.lua       | 22 ++++++++++++-
 plugin/cp.lua           | 22 +++++++++++--
 scrapers/cses.py        |  8 +++--
 scrapers/models.py      |  1 +
 scrapers/usaco.py       | 12 +++++--
 tests/test_scrapers.py  | 26 +++++++++++++++
 13 files changed, 265 insertions(+), 46 deletions(-)

diff --git a/doc/cp.nvim.txt b/doc/cp.nvim.txt
index 1db397b..add0bcb 100644
--- a/doc/cp.nvim.txt
+++ b/doc/cp.nvim.txt
@@ -24,15 +24,16 @@ CONTENTS                                                        *cp-contents*
  16. Race .......................................................... |cp-race|
  17. Credentials ............................................ |cp-credentials|
  18. Submit ...................................................... |cp-submit|
- 19. Open ......................................................... |cp-open|
- 20. ANSI Colors ................................................... |cp-ansi|
- 21. Highlight Groups ........................................ |cp-highlights|
- 22. Terminal Colors .................................... |cp-terminal-colors|
- 23. Highlight Customization .......................... |cp-highlight-custom|
- 24. Helpers .................................................... |cp-helpers|
- 25. Statusline Integration .................................. |cp-statusline|
- 26. Panel Keymaps .......................................... |cp-panel-keys|
- 27. File Structure ................................................ |cp-files|
+ 19. Submit Language Versions ......................... |cp-submit-language|
+ 20. Open ......................................................... |cp-open|
+ 21. ANSI Colors ................................................... |cp-ansi|
+ 22. Highlight Groups ........................................ |cp-highlights|
+ 23. Terminal Colors .................................... |cp-terminal-colors|
+ 24. Highlight Customization .......................... |cp-highlight-custom|
+ 25. Helpers .................................................... |cp-helpers|
+ 26. Statusline Integration .................................. |cp-statusline|
+ 27. Panel Keymaps .......................................... |cp-panel-keys|
+ 28. File Structure ................................................ |cp-files|
  28. Health Check ................................................ |cp-health|
 
 ==============================================================================
@@ -1032,7 +1033,58 @@ Submit the current solution to the online judge.
 
         Platform support:
             AtCoder     Fully implemented.
-            Others      Not yet implemented.
+            Codeforces  Fully implemented.
+            CSES        Fully implemented.
+            Kattis      Fully implemented.
+            USACO       Fully implemented.
+            CodeChef    Not yet implemented.
+
+        See |cp-submit-language| for configuring the language version
+        (e.g. C++20 instead of C++17).
+
+==============================================================================
+SUBMIT LANGUAGE VERSIONS                              *cp-submit-language*
+
+When submitting, cp.nvim selects a language version for the platform.
+The default is C++17 for cpp and Python 3 for python.
+
+Configuring a version ~
+
+Set {version} globally or per-platform:
+>lua
+    languages = {
+      cpp = { version = "c++20", ... },
+    },
+    platforms = {
+      atcoder = {
+        overrides = { cpp = { version = "c++23" } },
+      },
+    },
+<
+Available versions per platform ~
+
+  Platform    cpp              python
+  AtCoder     c++23            python3
+  Codeforces  c++17            python3
+  CSES        c++17            python3
+  Kattis      c++17/20/23      python3
+  USACO       c++17/20/23      python3
+  CodeChef    c++17            python3
+
+Using a raw platform ID ~
+
+If your preferred version is not listed, you can bypass version
+lookup by setting {submit_id} to the raw platform language ID:
+>lua
+    platforms = {
+      codeforces = {
+        overrides = { cpp = { submit_id = "91" } },
+      },
+    },
+<
+To find the raw ID, open the platform's submit page in your browser,
+inspect the language dropdown, and copy the <option value="..."> for
+your desired language.
 
 ==============================================================================
 OPEN                                                                 *cp-open*
diff --git a/lua/cp/cache.lua b/lua/cp/cache.lua
index 987caee..b596671 100644
--- a/lua/cp/cache.lua
+++ b/lua/cp/cache.lua
@@ -392,7 +392,8 @@ end
 
 ---@param platform string
 ---@param contests ContestSummary[]
-function M.set_contest_summaries(platform, contests)
+---@param opts? { supports_countdown?: boolean }
+function M.set_contest_summaries(platform, contests, opts)
   cache_data[platform] = cache_data[platform] or {}
   for _, contest in ipairs(contests) do
     cache_data[platform][contest.id] = cache_data[platform][contest.id] or {}
@@ -405,9 +406,22 @@ function M.set_contest_summaries(platform, contests)
     end
   end
 
+  if opts and opts.supports_countdown ~= nil then
+    cache_data[platform].supports_countdown = opts.supports_countdown
+  end
+
   M.save()
 end
 
+---@param platform string
+---@return boolean?
+function M.get_supports_countdown(platform)
+  if not cache_data[platform] then
+    return nil
+  end
+  return cache_data[platform].supports_countdown
+end
+
 ---@param platform string
 ---@param contest_id string
 ---@return integer?
@@ -418,6 +432,16 @@ function M.get_contest_start_time(platform, contest_id)
   return cache_data[platform][contest_id].start_time
 end
 
+---@param platform string
+---@param contest_id string
+---@return string?
+function M.get_contest_display_name(platform, contest_id)
+  if not cache_data[platform] or not cache_data[platform][contest_id] then
+    return nil
+  end
+  return cache_data[platform][contest_id].display_name
+end
+
 ---@param platform string
 ---@return table?
 function M.get_credentials(platform)
diff --git a/lua/cp/config.lua b/lua/cp/config.lua
index 728b85f..835da99 100644
--- a/lua/cp/config.lua
+++ b/lua/cp/config.lua
@@ -8,6 +8,8 @@
 ---@field extension string
 ---@field commands CpLangCommands
 ---@field template? string
+---@field version? string
+---@field submit_id? string
 
 ---@class CpTemplatesConfig
 ---@field cursor_marker? string
@@ -16,6 +18,8 @@
 ---@field extension? string
 ---@field commands? CpLangCommands
 ---@field template? string
+---@field version? string
+---@field submit_id? string
 
 ---@class CpPlatform
 ---@field enabled_languages string[]
@@ -293,6 +297,12 @@ local function merge_lang(base, ov)
   if ov.template then
     out.template = ov.template
   end
+  if ov.version then
+    out.version = ov.version
+  end
+  if ov.submit_id then
+    out.submit_id = ov.submit_id
+  end
   return out
 end
 
@@ -323,6 +333,23 @@ local function build_runtime(cfg)
       validate_language(lid, base)
       local eff = merge_lang(base, p.overrides and p.overrides[lid] or nil)
       validate_language(lid, eff)
+      if eff.version then
+        local normalized = eff.version:lower():gsub('%s+', '')
+        local versions = (constants.LANGUAGE_VERSIONS[plat] or {})[lid]
+        if not versions or not versions[normalized] then
+          local avail = versions and vim.tbl_keys(versions) or {}
+          table.sort(avail)
+          error(
+            ("[cp.nvim] Unknown version '%s' for %s on %s. Available: [%s]. See :help cp-submit-language"):format(
+              eff.version,
+              lid,
+              plat,
+              table.concat(avail, ', ')
+            )
+          )
+        end
+        eff.version = normalized
+      end
       cfg.runtime.effective[plat][lid] = eff
     end
   end
diff --git a/lua/cp/constants.lua b/lua/cp/constants.lua
index 94c28ba..d2d306e 100644
--- a/lua/cp/constants.lua
+++ b/lua/cp/constants.lua
@@ -74,4 +74,21 @@ M.signal_codes = {
   [143] = 'SIGTERM',
 }
 
+M.LANGUAGE_VERSIONS = {
+  atcoder = { cpp = { ['c++23'] = '6017' }, python = { python3 = '6082' } },
+  codeforces = { cpp = { ['c++17'] = '89' }, python = { python3 = '70' } },
+  cses = { cpp = { ['c++17'] = 'C++17' }, python = { python3 = 'Python3' } },
+  kattis = {
+    cpp = { ['c++17'] = 'C++', ['c++20'] = 'C++', ['c++23'] = 'C++' },
+    python = { python3 = 'Python 3' },
+  },
+  usaco = {
+    cpp = { ['c++17'] = 'cpp', ['c++20'] = 'cpp', ['c++23'] = 'cpp' },
+    python = { python3 = 'python' },
+  },
+  codechef = { cpp = { ['c++17'] = 'C++ 17' }, python = { python3 = 'Python 3' } },
+}
+
+M.DEFAULT_VERSIONS = { cpp = 'c++17', python = 'python3' }
+
 return M
diff --git a/lua/cp/pickers/init.lua b/lua/cp/pickers/init.lua
index 562c274..3eb975f 100644
--- a/lua/cp/pickers/init.lua
+++ b/lua/cp/pickers/init.lua
@@ -48,8 +48,10 @@ function M.get_platform_contests(platform, refresh)
       { level = vim.log.levels.INFO, override = true, sync = true }
     )
 
-    local contests = scraper.scrape_contest_list(platform)
-    cache.set_contest_summaries(platform, contests)
+    local result = scraper.scrape_contest_list(platform)
+    local contests = result and result.contests or {}
+    local sc = result and result.supports_countdown
+    cache.set_contest_summaries(platform, contests, { supports_countdown = sc })
     picker_contests = cache.get_contest_summaries(platform)
 
     logger.log(
diff --git a/lua/cp/race.lua b/lua/cp/race.lua
index b44b9ab..5b49fc1 100644
--- a/lua/cp/race.lua
+++ b/lua/cp/race.lua
@@ -9,15 +9,24 @@ local race_state = {
   timer = nil,
   platform = nil,
   contest_id = nil,
+  contest_name = nil,
   language = nil,
   start_time = nil,
 }
 
 local function format_countdown(seconds)
-  local h = math.floor(seconds / 3600)
+  local d = math.floor(seconds / 86400)
+  local h = math.floor((seconds % 86400) / 3600)
   local m = math.floor((seconds % 3600) / 60)
   local s = seconds % 60
-  return string.format('%02d:%02d:%02d', h, m, s)
+  if d > 0 then
+    return string.format('%dd %dh %dm %ds', d, h, m, s)
+  elseif h > 0 then
+    return string.format('%dh %dm %ds', h, m, s)
+  elseif m > 0 then
+    return string.format('%dm %ds', m, s)
+  end
+  return string.format('%ds', s)
 end
 
 function M.start(platform, contest_id, language)
@@ -35,20 +44,42 @@ function M.start(platform, contest_id, language)
   end
 
   cache.load()
+
+  local display = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
+  local cached_countdown = cache.get_supports_countdown(platform)
+  if cached_countdown == false then
+    logger.log(('%s does not support :CP race'):format(display), { level = vim.log.levels.ERROR })
+    return
+  end
+
   local start_time = cache.get_contest_start_time(platform, contest_id)
 
   if not start_time then
-    logger.log('Fetching contest list...', { level = vim.log.levels.INFO, override = true })
-    local contests = scraper.scrape_contest_list(platform)
-    if contests and #contests > 0 then
-      cache.set_contest_summaries(platform, contests)
-      start_time = cache.get_contest_start_time(platform, contest_id)
+    logger.log(
+      'Fetching contest list...',
+      { level = vim.log.levels.INFO, override = true, sync = true }
+    )
+    local result = scraper.scrape_contest_list(platform)
+    if result then
+      local sc = result.supports_countdown
+      if sc == false then
+        cache.set_contest_summaries(platform, result.contests or {}, { supports_countdown = false })
+        logger.log(
+          ('%s does not support :CP race'):format(display),
+          { level = vim.log.levels.ERROR }
+        )
+        return
+      end
+      if result.contests and #result.contests > 0 then
+        cache.set_contest_summaries(platform, result.contests, { supports_countdown = sc })
+        start_time = cache.get_contest_start_time(platform, contest_id)
+      end
     end
   end
 
   if not start_time then
     logger.log(
-      ('No start time found for %s contest %s'):format(
+      ('No start time found for %s contest "%s"'):format(
         constants.PLATFORM_DISPLAY_NAMES[platform] or platform,
         contest_id
       ),
@@ -69,18 +100,10 @@ function M.start(platform, contest_id, language)
 
   race_state.platform = platform
   race_state.contest_id = contest_id
+  race_state.contest_name = cache.get_contest_display_name(platform, contest_id) or contest_id
   race_state.language = language
   race_state.start_time = start_time
 
-  logger.log(
-    ('Race started for %s %s — %s remaining'):format(
-      constants.PLATFORM_DISPLAY_NAMES[platform] or platform,
-      contest_id,
-      format_countdown(remaining)
-    ),
-    { level = vim.log.levels.INFO, override = true }
-  )
-
   local timer = vim.uv.new_timer()
   race_state.timer = timer
   timer:start(
@@ -97,17 +120,14 @@ function M.start(platform, contest_id, language)
         local l = race_state.language
         race_state.platform = nil
         race_state.contest_id = nil
+        race_state.contest_name = nil
         race_state.language = nil
         race_state.start_time = nil
         logger.log('Contest started!', { level = vim.log.levels.INFO, override = true })
         require('cp.setup').setup_contest(p, c, nil, l)
       else
         vim.notify(
-          ('[cp.nvim] %s %s — %s'):format(
-            constants.PLATFORM_DISPLAY_NAMES[race_state.platform] or race_state.platform,
-            race_state.contest_id,
-            format_countdown(r)
-          ),
+          ('[cp.nvim] %s starts in %s'):format(race_state.contest_name, format_countdown(r)),
           vim.log.levels.INFO
         )
       end
@@ -126,6 +146,7 @@ function M.stop()
   race_state.timer = nil
   race_state.platform = nil
   race_state.contest_id = nil
+  race_state.contest_name = nil
   race_state.language = nil
   race_state.start_time = nil
   logger.log('Race cancelled', { level = vim.log.levels.INFO, override = true })
diff --git a/lua/cp/scraper.lua b/lua/cp/scraper.lua
index 28705df..e488cc5 100644
--- a/lua/cp/scraper.lua
+++ b/lua/cp/scraper.lua
@@ -257,9 +257,12 @@ function M.scrape_contest_list(platform)
       ),
       { level = vim.log.levels.ERROR }
     )
-    return {}
+    return nil
   end
-  return result.data.contests
+  return {
+    contests = result.data.contests,
+    supports_countdown = result.data.supports_countdown ~= false,
+  }
 end
 
 ---@param platform string
diff --git a/lua/cp/submit.lua b/lua/cp/submit.lua
index 50d884f..d76fbe2 100644
--- a/lua/cp/submit.lua
+++ b/lua/cp/submit.lua
@@ -1,6 +1,8 @@
 local M = {}
 
 local cache = require('cp.cache')
+local config = require('cp.config')
+local constants = require('cp.constants')
 local logger = require('cp.log')
 local state = require('cp.state')
 
@@ -56,6 +58,24 @@ function M.submit(opts)
   end
   source_file = vim.fn.fnamemodify(source_file, ':p')
 
+  local submit_language = language
+  local cfg = config.get_config()
+  local plat_effective = cfg.runtime and cfg.runtime.effective and cfg.runtime.effective[platform]
+  local eff = plat_effective and plat_effective[language]
+  if eff then
+    if eff.submit_id then
+      submit_language = eff.submit_id
+    else
+      local ver = eff.version or constants.DEFAULT_VERSIONS[language]
+      if ver then
+        local versions = (constants.LANGUAGE_VERSIONS[platform] or {})[language]
+        if versions and versions[ver] then
+          submit_language = versions[ver]
+        end
+      end
+    end
+  end
+
   prompt_credentials(platform, function(creds)
     vim.cmd.update()
     vim.notify('[cp.nvim] Submitting...', vim.log.levels.INFO)
@@ -64,7 +84,7 @@ function M.submit(opts)
       platform,
       contest_id,
       problem_id,
-      language,
+      submit_language,
       source_file,
       creds,
       function(ev)
diff --git a/plugin/cp.lua b/plugin/cp.lua
index 44b9d5c..cc6a367 100644
--- a/plugin/cp.lua
+++ b/plugin/cp.lua
@@ -109,6 +109,9 @@ end, {
         end
         return filter_candidates(candidates)
       elseif args[2] == 'race' then
+        if require('cp.race').status().active then
+          return filter_candidates({ 'stop' })
+        end
         local candidates = { 'stop' }
         vim.list_extend(candidates, platforms)
         return filter_candidates(candidates)
@@ -126,7 +129,11 @@ end, {
       if args[2] == 'stress' then
         local utils = require('cp.utils')
         return filter_candidates(utils.cwd_executables())
-      elseif args[2] == 'race' and vim.tbl_contains(platforms, args[3]) then
+      elseif
+        args[2] == 'race'
+        and not require('cp.race').status().active
+        and vim.tbl_contains(platforms, args[3])
+      then
         local cache = require('cp.cache')
         cache.load()
         local contests = cache.get_cached_contest_ids(args[3])
@@ -153,7 +160,11 @@ end, {
         return filter_candidates(candidates)
       end
     elseif num_args == 5 then
-      if args[2] == 'race' and vim.tbl_contains(platforms, args[3]) then
+      if
+        args[2] == 'race'
+        and not require('cp.race').status().active
+        and vim.tbl_contains(platforms, args[3])
+      then
         return filter_candidates({ '--lang' })
       elseif args[2] == 'cache' and args[3] == 'clear' and vim.tbl_contains(platforms, args[4]) then
         local cache = require('cp.cache')
@@ -168,7 +179,12 @@ end, {
         end
       end
     elseif num_args == 6 then
-      if args[2] == 'race' and vim.tbl_contains(platforms, args[3]) and args[5] == '--lang' then
+      if
+        args[2] == 'race'
+        and not require('cp.race').status().active
+        and vim.tbl_contains(platforms, args[3])
+        and args[5] == '--lang'
+      then
         return filter_candidates(get_enabled_languages(args[3]))
       elseif vim.tbl_contains(platforms, args[2]) and args[5] == '--lang' then
         return filter_candidates(get_enabled_languages(args[2]))
diff --git a/scrapers/cses.py b/scrapers/cses.py
index bf1edbd..d0ff3d8 100644
--- a/scrapers/cses.py
+++ b/scrapers/cses.py
@@ -228,9 +228,13 @@ class CSESScraper(BaseScraper):
         cats = parse_categories(html)
         if not cats:
             return ContestListResult(
-                success=False, error=f"{self.platform_name}: No contests found"
+                success=False,
+                error=f"{self.platform_name}: No contests found",
+                supports_countdown=False,
             )
-        return ContestListResult(success=True, error="", contests=cats)
+        return ContestListResult(
+            success=True, error="", contests=cats, supports_countdown=False
+        )
 
     async def login(self, credentials: dict[str, str]) -> LoginResult:
         username = credentials.get("username", "")
diff --git a/scrapers/models.py b/scrapers/models.py
index 2d579cb..4560c3e 100644
--- a/scrapers/models.py
+++ b/scrapers/models.py
@@ -50,6 +50,7 @@ class MetadataResult(ScrapingResult):
 
 class ContestListResult(ScrapingResult):
     contests: list[ContestSummary] = Field(default_factory=list)
+    supports_countdown: bool = True
 
     model_config = ConfigDict(extra="forbid")
 
diff --git a/scrapers/usaco.py b/scrapers/usaco.py
index 53f92be..b3970db 100644
--- a/scrapers/usaco.py
+++ b/scrapers/usaco.py
@@ -337,10 +337,16 @@ class USACOScraper(BaseScraper):
                     contests.extend(await coro)
 
             if not contests:
-                return self._contests_error("No contests found")
-            return ContestListResult(success=True, error="", contests=contests)
+                return ContestListResult(
+                    success=False, error="No contests found", supports_countdown=False
+                )
+            return ContestListResult(
+                success=True, error="", contests=contests, supports_countdown=False
+            )
         except Exception as e:
-            return self._contests_error(str(e))
+            return ContestListResult(
+                success=False, error=str(e), supports_countdown=False
+            )
 
     async def stream_tests_for_category_async(self, category_id: str) -> None:
         month_year, division = _parse_contest_id(category_id)
diff --git a/tests/test_scrapers.py b/tests/test_scrapers.py
index c4fa6d5..0bf2f15 100644
--- a/tests/test_scrapers.py
+++ b/tests/test_scrapers.py
@@ -1,5 +1,6 @@
 import pytest
 
+from scrapers.language_ids import LANGUAGE_IDS, get_language_id
 from scrapers.models import (
     ContestListResult,
     MetadataResult,
@@ -137,3 +138,28 @@ def test_scraper_metadata_error(run_scraper_offline, scraper, contest_id):
     assert objs
     assert objs[-1].get("success") is False
     assert objs[-1].get("error")
+
+
+EXPECTED_PLATFORMS = {"atcoder", "codeforces", "cses", "usaco", "kattis", "codechef"}
+EXPECTED_LANGUAGES = {"cpp", "python"}
+
+
+def test_language_ids_coverage():
+    assert set(LANGUAGE_IDS.keys()) == EXPECTED_PLATFORMS
+    for platform, langs in LANGUAGE_IDS.items():
+        assert set(langs.keys()) == EXPECTED_LANGUAGES, f"{platform} missing languages"
+        for lang, lid in langs.items():
+            assert isinstance(lid, str) and lid, f"{platform}/{lang} empty ID"
+
+
+@pytest.mark.parametrize("platform", EXPECTED_PLATFORMS)
+@pytest.mark.parametrize("language", EXPECTED_LANGUAGES)
+def test_get_language_id(platform, language):
+    result = get_language_id(platform, language)
+    assert result is not None, f"No ID for {platform}/{language}"
+    assert result == LANGUAGE_IDS[platform][language]
+
+
+def test_get_language_id_unknown():
+    assert get_language_id("nonexistent", "cpp") is None
+    assert get_language_id("codeforces", "rust") is None