feat: flesh out language support

lua/cp/config.lua

@@ -1,13 +1,34 @@
+---@class LanguageConfig
+---@field compile? string[] Compile command template
+---@field run string[] Run command template
+---@field debug? string[] Debug command template
+---@field executable? string Executable name
+---@field version? number Language version
+---@field extension string File extension
+
+---@class ContestConfig
+---@field cpp LanguageConfig
+---@field python LanguageConfig
+---@field default_language string
+---@field timeout_ms number
+
 ---@class cp.Config
----@field contests table
----@field snippets table
+---@field contests table<string, ContestConfig>
+---@field snippets table[]
 ---@field hooks table
 ---@field debug boolean
 ---@field tile? fun(source_buf: number, input_buf: number, output_buf: number)
----@field filename? fun(contest: string, problem_id: string, problem_letter?: string): string
+---@field filename? fun(contest: string, contest_id: string, problem_id?: string, config: cp.Config, language?: string): string
 
 local M = {}
 
+local filetype_to_language = {
+	cc = "cpp",
+	c = "cpp",
+	py = "python",
+	py3 = "python",
+}
+
 ---@type cp.Config
 M.defaults = {
 	contests = {
@@ -37,13 +58,16 @@ M.defaults = {
 				},
 				executable = nil,
 				version = 20,
+				extension = "cc",
 			},
 			python = {
 				compile = nil,
 				run = { "{source}" },
 				debug = { "{source}" },
 				executable = "python3",
+				extension = "py",
 			},
+			default_language = "cpp",
 			timeout_ms = 2000,
 		},
 		atcoder = {
@@ -74,8 +98,8 @@ local function extend_contest_config(base_config, contest_config)
 	return result
 end
 
----@param user_config table|nil
----@return table
+---@param user_config cp.Config|nil
+---@return cp.Config
 function M.setup(user_config)
 	vim.validate({
 		user_config = { user_config, { "table", "nil" }, true },
@@ -97,6 +121,20 @@ function M.setup(user_config)
 				before_debug = { user_config.hooks.before_debug, { "function", "nil" }, true },
 			})
 		end
+
+		if user_config.contests then
+			for contest_name, contest_config in pairs(user_config.contests) do
+				for lang_name, lang_config in pairs(contest_config) do
+					if type(lang_config) == "table" and lang_config.extension then
+						if not vim.tbl_contains(vim.tbl_keys(filetype_to_language), lang_config.extension) then
+							error(("Invalid extension '%s' for language '%s' in contest '%s'. Valid extensions: %s"):format(
+								lang_config.extension, lang_name, contest_name, table.concat(vim.tbl_keys(filetype_to_language), ", ")
+							))
+						end
+					end
+				end
+			end
+		end
 	end
 
 	local config = vim.tbl_deep_extend("force", M.defaults, user_config or {})
@@ -111,14 +149,32 @@ function M.setup(user_config)
 	return config
 end
 
-local function default_filename(contest, contest_id, problem_id)
+---@param contest string
+---@param contest_id string
+---@param problem_id? string
+---@param config cp.Config
+---@param language? string
+---@return string
+local function default_filename(contest, contest_id, problem_id, config, language)
+	vim.validate({
+		contest = { contest, "string" },
+		contest_id = { contest_id, "string" },
+		problem_id = { problem_id, { "string", "nil" }, true },
+		config = { config, "table" },
+		language = { language, { "string", "nil" }, true },
+	})
+
 	local full_problem_id = contest_id:lower()
 	if contest == "atcoder" or contest == "codeforces" then
 		if problem_id then
 			full_problem_id = full_problem_id .. problem_id:lower()
 		end
 	end
-	return full_problem_id .. ".cc"
+
+	local contest_config = config.contests[contest] or config.contests.default
+	local target_language = language or contest_config.default_language
+	local language_config = contest_config[target_language]
+	return full_problem_id .. "." .. language_config.extension
 end
 
 M.default_filename = default_filename