Merge pull request #173 from barrett-ruth/feat/lang

fix language-based problem navigation

lua/cp/runner/run_render.lua

@@ -276,10 +276,13 @@ local function data_row(c, idx, tc, is_current, test_state)
 end
 
 ---@param test_state PanelState
----@return string[], Highlight[] lines and highlight positions
+---@return string[] lines
+---@return Highlight[] highlights
+---@return integer current_test_line
 function M.render_test_list(test_state)
   local lines, highlights = {}, {}
   local c = compute_cols(test_state)
+  local current_test_line = nil
 
   table.insert(lines, top_border(c))
   table.insert(lines, header_line(c))
@@ -289,6 +292,11 @@ function M.render_test_list(test_state)
     local is_current = (i == test_state.current_index)
     local row, hi = data_row(c, i, tc, is_current, test_state)
     table.insert(lines, row)
+
+    if is_current then
+      current_test_line = #lines
+    end
+
     if hi then
       hi.line = #lines - 1
       table.insert(highlights, hi)
@@ -327,7 +335,7 @@ function M.render_test_list(test_state)
     end
   end
 
-  return lines, highlights
+  return lines, highlights, current_test_line or 1
 end
 
 ---@param ran_test_case RanTestCase?

lua/cp/setup.lua

@@ -9,7 +9,7 @@ local scraper = require('cp.scraper')
 local state = require('cp.state')
 
 ---Get the language of the current file from cache
----@return string|nil
+---@return string?
 local function get_current_file_language()
   local current_file = vim.fn.expand('%:p')
   if current_file == '' then
@@ -20,6 +20,34 @@ local function get_current_file_language()
   return file_state and file_state.language or nil
 end
 
+---Check if a problem file exists for any enabled language
+---@param platform string
+---@param contest_id string
+---@param problem_id string
+---@return string?
+local function get_existing_problem_language(platform, contest_id, problem_id)
+  local config = config_module.get_config()
+  local platform_config = config.platforms[platform]
+  if not platform_config then
+    return nil
+  end
+
+  for _, lang_id in ipairs(platform_config.enabled_languages) do
+    local effective = config.runtime.effective[platform][lang_id]
+    if effective and effective.extension then
+      local basename = config.filename
+          and config.filename(platform, contest_id, problem_id, config, lang_id)
+        or config_module.default_filename(contest_id, problem_id)
+      local filepath = basename .. '.' .. effective.extension
+      if vim.fn.filereadable(filepath) == 1 then
+        return lang_id
+      end
+    end
+  end
+
+  return nil
+end
+
 ---@class TestCaseLite
 ---@field input string
 ---@field expected string
@@ -306,21 +334,30 @@ function M.navigate_problem(direction, language)
     require('cp.ui.views').disable()
   end
 
+  local lang = nil
+
   if language then
     local lang_result = config_module.get_language_for_platform(platform, language)
     if not lang_result.valid then
       logger.log(lang_result.error, vim.log.levels.ERROR)
       return
     end
-  end
-
-  local lang = language or get_current_file_language()
-  if lang and not language then
+    lang = language
+  else
+    local existing_lang =
+      get_existing_problem_language(platform, contest_id, problems[new_index].id)
+    if existing_lang then
+      lang = existing_lang
+    else
+      lang = get_current_file_language()
+      if lang then
         local lang_result = config_module.get_language_for_platform(platform, lang)
         if not lang_result.valid then
           lang = nil
         end
       end
+    end
+  end
 
   M.setup_contest(platform, contest_id, problems[new_index].id, lang)
 end

lua/cp/ui/views.lua

@@ -574,7 +574,7 @@ function M.toggle_panel(panel_opts)
     end
     run_render.setup_highlights()
     local test_state = run.get_panel_state()
-    local tab_lines, tab_highlights = run_render.render_test_list(test_state)
+    local tab_lines, tab_highlights, current_line = run_render.render_test_list(test_state)
     utils.update_buffer_content(
       test_buffers.tab_buf,
       tab_lines,
@@ -582,6 +582,17 @@ function M.toggle_panel(panel_opts)
       test_list_namespace
     )
     update_diff_panes()
+
+    if
+      current_line
+      and test_windows.tab_win
+      and vim.api.nvim_win_is_valid(test_windows.tab_win)
+    then
+      vim.api.nvim_win_set_cursor(test_windows.tab_win, { current_line, 0 })
+      vim.api.nvim_win_call(test_windows.tab_win, function()
+        vim.cmd('normal! zz')
+      end)
+    end
   end
 
   local function navigate_test_case(delta)

plugin/cp.lua

@@ -3,8 +3,6 @@ if vim.g.loaded_cp then
 end
 vim.g.loaded_cp = 1
 
-local utils = require('cp.utils')
-
 vim.api.nvim_create_user_command('CP', function(opts)
   local cp = require('cp')
   cp.handle_command(opts)
@@ -69,6 +67,7 @@ end, {
       elseif args[2] == 'cache' then
         return filter_candidates({ 'clear', 'read' })
       elseif args[2] == 'interact' then
+        local utils = require('cp.utils')
         return filter_candidates(utils.cwd_executables())
       elseif args[2] == 'run' or args[2] == 'panel' then
         local state = require('cp.state')