feat(picker): picker support

lua/cp/config.lua

@@ -52,6 +52,7 @@
 ---@field filename? fun(contest: string, contest_id: string, problem_id?: string, config: cp.Config, language?: string): string
 ---@field run_panel RunPanelConfig
 ---@field diff DiffConfig
+---@field picker "telescope"|"fzf-lua"|nil
 
 ---@class cp.UserConfig
 ---@field contests? table<string, PartialContestConfig>
@@ -62,6 +63,7 @@
 ---@field filename? fun(contest: string, contest_id: string, problem_id?: string, config: cp.Config, language?: string): string
 ---@field run_panel? RunPanelConfig
 ---@field diff? DiffConfig
+---@field picker? "telescope"|"fzf-lua"|nil
 
 local M = {}
 local constants = require('cp.constants')
@@ -110,6 +112,7 @@ M.defaults = {
       args = { 'diff', '--no-index', '--word-diff=plain', '--word-diff-regex=.', '--no-prefix' },
     },
   },
+  picker = nil,
 }
 
 ---@param user_config cp.UserConfig|nil
@@ -129,6 +132,7 @@ function M.setup(user_config)
       filename = { user_config.filename, { 'function', 'nil' }, true },
       run_panel = { user_config.run_panel, { 'table', 'nil' }, true },
       diff = { user_config.diff, { 'table', 'nil' }, true },
+      picker = { user_config.picker, { 'string', 'nil' }, true },
     })
 
     if user_config.contests then
@@ -164,6 +168,12 @@ function M.setup(user_config)
         end
       end
     end
+
+    if user_config.picker then
+      if not vim.tbl_contains({ 'telescope', 'fzf-lua' }, user_config.picker) then
+        error(("Invalid picker '%s'. Must be 'telescope' or 'fzf-lua'"):format(user_config.picker))
+      end
+    end
   end
 
   local config = vim.tbl_deep_extend('force', M.defaults, user_config or {})

lua/cp/constants.lua

@@ -1,7 +1,13 @@
 local M = {}
 
 M.PLATFORMS = { 'atcoder', 'codeforces', 'cses' }
-M.ACTIONS = { 'run', 'next', 'prev' }
+M.ACTIONS = { 'run', 'next', 'prev', 'pick' }
+
+M.PLATFORM_DISPLAY_NAMES = {
+  atcoder = 'AtCoder',
+  codeforces = 'CodeForces',
+  cses = 'CSES',
+}
 
 M.CPP = 'cpp'
 M.PYTHON = 'python'

lua/cp/init.lua

@@ -698,6 +698,48 @@ local function navigate_problem(delta, language)
   setup_problem(state.contest_id, new_problem.id, language)
 end
 
+local function handle_pick_action()
+  if not config.picker then
+    logger.log(
+      'No picker configured. Set picker = "telescope" or picker = "fzf-lua" in config',
+      vim.log.levels.ERROR
+    )
+    return
+  end
+
+  if config.picker == 'telescope' then
+    local ok, telescope = pcall(require, 'telescope')
+    if not ok then
+      logger.log(
+        'Telescope not available. Install telescope.nvim or change picker config',
+        vim.log.levels.ERROR
+      )
+      return
+    end
+    local ok_cp, telescope_cp = pcall(require, 'cp.pickers.telescope')
+    if not ok_cp then
+      logger.log('Failed to load telescope integration', vim.log.levels.ERROR)
+      return
+    end
+    telescope_cp.platform_picker()
+  elseif config.picker == 'fzf-lua' then
+    local ok, _ = pcall(require, 'fzf-lua')
+    if not ok then
+      logger.log(
+        'fzf-lua not available. Install fzf-lua or change picker config',
+        vim.log.levels.ERROR
+      )
+      return
+    end
+    local ok_cp, fzf_cp = pcall(require, 'cp.pickers.fzf_lua')
+    if not ok_cp then
+      logger.log('Failed to load fzf-lua integration', vim.log.levels.ERROR)
+      return
+    end
+    fzf_cp.platform_picker()
+  end
+end
+
 local function restore_from_current_file()
   local current_file = vim.fn.expand('%:p')
   if current_file == '' then
@@ -837,6 +879,8 @@ function M.handle_command(opts)
       navigate_problem(1, cmd.language)
     elseif cmd.action == 'prev' then
       navigate_problem(-1, cmd.language)
+    elseif cmd.action == 'pick' then
+      handle_pick_action()
     end
     return
   end

lua/cp/pickers/fzf_lua.lua

@@ -0,0 +1,123 @@
+local picker_utils = require('cp.pickers')
+
+local function problem_picker(platform, contest_id)
+  local constants = require('cp.constants')
+  local platform_display_name = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
+  local fzf = require('fzf-lua')
+  local problems = picker_utils.get_problems_for_contest(platform, contest_id)
+
+  if #problems == 0 then
+    vim.notify(
+      ('No problems found for contest: %s %s'):format(platform_display_name, contest_id),
+      vim.log.levels.WARN
+    )
+    return
+  end
+
+  local entries = vim.tbl_map(function(problem)
+    return problem.display_name
+  end, problems)
+
+  return fzf.fzf_exec(entries, {
+    prompt = ('Select Problem (%s %s)> '):format(platform_display_name, contest_id),
+    actions = {
+      ['default'] = function(selected)
+        if not selected or #selected == 0 then
+          return
+        end
+
+        local selected_name = selected[1]
+        local problem = nil
+        for _, p in ipairs(problems) do
+          if p.display_name == selected_name then
+            problem = p
+            break
+          end
+        end
+
+        if problem then
+          picker_utils.setup_problem(platform, contest_id, problem.id)
+        end
+      end,
+    },
+  })
+end
+
+local function contest_picker(platform)
+  local constants = require('cp.constants')
+  local platform_display_name = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
+  local fzf = require('fzf-lua')
+  local contests = picker_utils.get_contests_for_platform(platform)
+
+  if #contests == 0 then
+    vim.notify(
+      ('No contests found for platform: %s'):format(platform_display_name),
+      vim.log.levels.WARN
+    )
+    return
+  end
+
+  local entries = vim.tbl_map(function(contest)
+    return contest.display_name
+  end, contests)
+
+  return fzf.fzf_exec(entries, {
+    prompt = ('Select Contest (%s)> '):format(platform_display_name),
+    actions = {
+      ['default'] = function(selected)
+        if not selected or #selected == 0 then
+          return
+        end
+
+        local selected_name = selected[1]
+        local contest = nil
+        for _, c in ipairs(contests) do
+          if c.display_name == selected_name then
+            contest = c
+            break
+          end
+        end
+
+        if contest then
+          problem_picker(platform, contest.id)
+        end
+      end,
+    },
+  })
+end
+
+local function platform_picker()
+  local fzf = require('fzf-lua')
+  local platforms = picker_utils.get_platforms()
+  local entries = vim.tbl_map(function(platform)
+    return platform.display_name
+  end, platforms)
+
+  return fzf.fzf_exec(entries, {
+    prompt = 'Select Platform> ',
+    actions = {
+      ['default'] = function(selected)
+        if not selected or #selected == 0 then
+          return
+        end
+
+        local selected_name = selected[1]
+        local platform = nil
+        for _, p in ipairs(platforms) do
+          if p.display_name == selected_name then
+            platform = p
+            break
+          end
+        end
+
+        if platform then
+          contest_picker(platform.id)
+        end
+      end,
+    },
+  })
+end
+
+return {
+  platform_picker = platform_picker,
+}

lua/cp/pickers/init.lua

@@ -0,0 +1,145 @@
+local M = {}
+
+local cache = require('cp.cache')
+local logger = require('cp.log')
+local scrape = require('cp.scrape')
+
+---@class cp.PlatformItem
+---@field id string Platform identifier (e.g. "codeforces", "atcoder", "cses")
+---@field display_name string Human-readable platform name (e.g. "Codeforces", "AtCoder", "CSES")
+
+---@class cp.ContestItem
+---@field id string Contest identifier (e.g. "1951", "abc324", "sorting")
+---@field name string Full contest name (e.g. "Educational Codeforces Round 168")
+---@field display_name string Formatted display name for picker
+
+---@class cp.ProblemItem
+---@field id string Problem identifier (e.g. "a", "b", "c")
+---@field name string Problem name (e.g. "Two Permutations", "Painting Walls")
+---@field display_name string Formatted display name for picker
+
+---Get list of available competitive programming platforms
+---@return cp.PlatformItem[]
+local function get_platforms()
+  local constants = require('cp.constants')
+  return vim.tbl_map(function(platform)
+    return {
+      id = platform,
+      display_name = constants.PLATFORM_DISPLAY_NAMES[platform] or platform,
+    }
+  end, constants.PLATFORMS)
+end
+
+---Get list of contests for a specific platform
+---@param platform string Platform identifier (e.g. "codeforces", "atcoder")
+---@return cp.ContestItem[]
+local function get_contests_for_platform(platform)
+  local contests = {}
+
+  local function get_plugin_path()
+    local plugin_path = debug.getinfo(1, 'S').source:sub(2)
+    return vim.fn.fnamemodify(plugin_path, ':h:h:h')
+  end
+
+  local plugin_path = get_plugin_path()
+  local cmd = {
+    'uv',
+    'run',
+    '--directory',
+    plugin_path,
+    '-m',
+    'scrapers.' .. platform,
+    'contests',
+  }
+  local result = vim
+    .system(cmd, {
+      cwd = plugin_path,
+      text = true,
+      timeout = 30000,
+    })
+    :wait()
+
+  if result.code ~= 0 then
+    logger.log(
+      ('Failed to get contests for %s: %s'):format(platform, result.stderr or 'unknown error'),
+      vim.log.levels.ERROR
+    )
+    return contests
+  end
+
+  local ok, data = pcall(vim.json.decode, result.stdout)
+  if not ok or not data.success then
+    logger.log(('Failed to parse contest data for %s'):format(platform), vim.log.levels.ERROR)
+    return contests
+  end
+
+  for _, contest in ipairs(data.contests or {}) do
+    table.insert(contests, {
+      id = contest.id,
+      name = contest.name,
+      display_name = contest.display_name,
+    })
+  end
+
+  return contests
+end
+
+---Get list of problems for a specific contest
+---@param platform string Platform identifier
+---@param contest_id string Contest identifier
+---@return cp.ProblemItem[]
+local function get_problems_for_contest(platform, contest_id)
+  local problems = {}
+
+  cache.load()
+  local contest_data = cache.get_contest_data(platform, contest_id)
+  if contest_data and contest_data.problems then
+    for _, problem in ipairs(contest_data.problems) do
+      table.insert(problems, {
+        id = problem.id,
+        name = problem.name,
+        display_name = problem.name,
+      })
+    end
+    return problems
+  end
+
+  local metadata_result = scrape.scrape_contest_metadata(platform, contest_id)
+  if not metadata_result.success then
+    logger.log(
+      ('Failed to get problems for %s %s: %s'):format(
+        platform,
+        contest_id,
+        metadata_result.error or 'unknown error'
+      ),
+      vim.log.levels.ERROR
+    )
+    return problems
+  end
+
+  for _, problem in ipairs(metadata_result.problems or {}) do
+    table.insert(problems, {
+      id = problem.id,
+      name = problem.name,
+      display_name = problem.name,
+    })
+  end
+
+  return problems
+end
+
+---Set up a specific problem by calling the main CP handler
+---@param platform string Platform identifier
+---@param contest_id string Contest identifier
+---@param problem_id string Problem identifier
+local function setup_problem(platform, contest_id, problem_id)
+  local cp = require('cp')
+  cp.handle_command({ fargs = { platform, contest_id, problem_id } })
+end
+
+M.get_platforms = get_platforms
+M.get_contests_for_platform = get_contests_for_platform
+M.get_problems_for_contest = get_problems_for_contest
+M.setup_problem = setup_problem
+
+return M

lua/cp/pickers/telescope.lua

@@ -0,0 +1,130 @@
+local finders = require('telescope.finders')
+local pickers = require('telescope.pickers')
+local telescope = require('telescope')
+local conf = require('telescope.config').values
+local action_state = require('telescope.actions.state')
+local actions = require('telescope.actions')
+
+local picker_utils = require('cp.pickers')
+
+local function platform_picker(opts)
+  opts = opts or {}
+
+  local platforms = picker_utils.get_platforms()
+
+  pickers
+    .new(opts, {
+      prompt_title = 'Select Platform',
+      finder = finders.new_table({
+        results = platforms,
+        entry_maker = function(entry)
+          return {
+            value = entry,
+            display = entry.display_name,
+            ordinal = entry.display_name,
+          }
+        end,
+      }),
+      sorter = conf.generic_sorter(opts),
+      attach_mappings = function(prompt_bufnr, map)
+        actions.select_default:replace(function()
+          local selection = action_state.get_selected_entry()
+          actions.close(prompt_bufnr)
+
+          if selection then
+            contest_picker(opts, selection.value.id)
+          end
+        end)
+        return true
+      end,
+    })
+    :find()
+end
+
+local function contest_picker(opts, platform)
+  local constants = require('cp.constants')
+  local platform_display_name = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
+  local contests = picker_utils.get_contests_for_platform(platform)
+
+  if #contests == 0 then
+    vim.notify(
+      ('No contests found for platform: %s'):format(platform_display_name),
+      vim.log.levels.WARN
+    )
+    return
+  end
+
+  pickers
+    .new(opts, {
+      prompt_title = ('Select Contest (%s)'):format(platform_display_name),
+      finder = finders.new_table({
+        results = contests,
+        entry_maker = function(entry)
+          return {
+            value = entry,
+            display = entry.display_name,
+            ordinal = entry.display_name,
+          }
+        end,
+      }),
+      sorter = conf.generic_sorter(opts),
+      attach_mappings = function(prompt_bufnr, map)
+        actions.select_default:replace(function()
+          local selection = action_state.get_selected_entry()
+          actions.close(prompt_bufnr)
+
+          if selection then
+            problem_picker(opts, platform, selection.value.id)
+          end
+        end)
+        return true
+      end,
+    })
+    :find()
+end
+
+local function problem_picker(opts, platform, contest_id)
+  local constants = require('cp.constants')
+  local platform_display_name = constants.PLATFORM_DISPLAY_NAMES[platform] or platform
+  local problems = picker_utils.get_problems_for_contest(platform, contest_id)
+
+  if #problems == 0 then
+    vim.notify(
+      ('No problems found for contest: %s %s'):format(platform_display_name, contest_id),
+      vim.log.levels.WARN
+    )
+    return
+  end
+
+  pickers
+    .new(opts, {
+      prompt_title = ('Select Problem (%s %s)'):format(platform_display_name, contest_id),
+      finder = finders.new_table({
+        results = problems,
+        entry_maker = function(entry)
+          return {
+            value = entry,
+            display = entry.display_name,
+            ordinal = entry.display_name,
+          }
+        end,
+      }),
+      sorter = conf.generic_sorter(opts),
+      attach_mappings = function(prompt_bufnr, map)
+        actions.select_default:replace(function()
+          local selection = action_state.get_selected_entry()
+          actions.close(prompt_bufnr)
+
+          if selection then
+            picker_utils.setup_problem(platform, contest_id, selection.value.id)
+          end
+        end)
+        return true
+      end,
+    })
+    :find()
+end
+
+return {
+  platform_picker = platform_picker,
+}