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(ns foreclojure.problems
(:require [foreclojure.users :as users]
[noir.session :as session]
[clojure.string :as s]
[ring.util.response :as response]
[cheshire.core :as json]
[clojure.data.xml :refer [element]])
(:import [org.apache.commons.mail EmailException])
(:use [foreclojure.utils :only [from-mongo get-user get-solved login-link flash-msg flash-error row-class approver? can-submit? send-email image-builder if-user with-user as-int maybe-update escape-html]]
[foreclojure.ring-utils :only [*url*]]
[foreclojure.template :only [def-page content-page]]
[foreclojure.social :only [tweet-link]]
[foreclojure.feeds :only [create-feed]]
[foreclojure.users :only [golfer? get-user-id disable-codebox?]]
[foreclojure.solutions :only [save-solution get-solution]]
[clojail.core :exclude [safe-read]]
[clojail.testers :only [secure-tester blanket blacklist-symbols]]
[somnium.congomongo :only [update! fetch-one fetch fetch-and-modify destroy!]]
[hiccup.form :only [form-to text-area hidden-field label text-field drop-down]]
[hiccup.element :only [link-to]]
[hiccup.core :only [html]]
[useful.debug :only [?]]
[compojure.core :only [defroutes GET POST]]))
(def solved-stats (agent {:total 0}))
(defn get-problem [x]
(from-mongo
(fetch-one :problems :where {:_id x})))
(defn get-problem-list
([] (get-problem-list {:approved true}))
([criteria]
(from-mongo
(fetch :problems
:only [:_id :title :difficulty :tags :user]
:where criteria
:sort {:_id 1}))))
(defn next-unsolved-problem [solved-problems just-solved-id]
(when-let [unsolved (seq
(from-mongo
(fetch :problems
:only [:_id :title]
:where {:_id {:$nin solved-problems}, :approved true}
:sort {:_id 1})))]
(let [[skipped not-yet-tried] (split-with #(< (:_id %) just-solved-id)
unsolved)]
(filter identity [(rand-nth (or (seq skipped)
[nil])) ; rand-nth barfs on empty seq
(first not-yet-tried)]))))
(letfn [(problem-link [{id :_id title :title}]
(str "<a href='/problem/" id "#prob-title'>" title "</a>"))]
(defn suggest-problems
([] "You've solved them all! Come back later for more!")
([problem]
(str "Now try " (problem-link problem) "!"))
([skipped not-tried]
(str "Now you can move on to " (problem-link not-tried)
", or go back and try " (problem-link skipped) " again!"))))
(defn next-problem-link [completed-problem-id]
(when-let [{:keys [solved]} (get-user (session/get :user))]
(apply suggest-problems
(next-unsolved-problem solved completed-problem-id))))
(defn get-recent-problems [n]
(map get-problem (map :_id (take-last n (get-problem-list)))))
(defn problem-feed [n]
(reduce (fn [feed v]
(conj feed
(element :item {}
(element :guid {} (str "http://4clojure.com/problem/" (:_id v)))
(element :title {} (:title v))
(element :description {} (:description v)))))
()
(get-recent-problems n)))
(defn mongo-key-from-number
"Turn an integer into a key suitable for fetching from mongodb."
[id]
(keyword (str (int id))))
(defn number-from-mongo-key
"Turn a keyword like :4 into an integer"
[k]
(Integer. (name k)))
(defn trim-code [code]
(when code (.trim code)))
(defn code-length [code]
(count (remove #(or (Character/isWhitespace %)
(= % \,))
code)))
(defn record-golf-score! [user-id problem-id score]
(when-let [{{old-score (keyword (str problem-id))} :scores
user-id :_id :as user}
(from-mongo
(fetch-one :users
:where {:_id user-id}))]
(when (golfer? user)
(session/put! :golf-chart
{:id problem-id
:score score
:best old-score}))
(when (or (not old-score)
(> old-score score))
(update! :users
{:_id user-id}
{:$set {(keyword (str "scores." problem-id)) score}})
(send solved-stats (fn [scores]
(let [inc (fnil inc 0),
dec (fn [x]
(when (and x (> x 1))
(dec x)))]
(maybe-update scores [problem-id]
#(-> %
(maybe-update [score] inc)
(maybe-update [old-score] dec)))))))))
(defn store-completed-state! [username problem-id code]
(let [{user-id :_id} (fetch-one :users
:where {:user username}
:only [:_id])
current-time (java.util.Date.)]
(when (not-any? #{problem-id} (get-solved username))
(update! :users {:_id user-id} {:$addToSet {:solved problem-id}
:$set {:last-solved-date current-time}})
(let [inc (fnil inc 0)]
(send solved-stats
#(-> %
(update-in [:total] inc)
(update-in [:solved-counts problem-id] inc)))))
(record-golf-score! user-id problem-id (code-length code))
(save-solution user-id problem-id code)))
(defn mark-completed [problem code & [user]]
(let [user (or user (session/get :user))
{:keys [_id approved]} problem
paste-link (html [:span.share
[:a.novisited {:href "/share/code"} "share"]
" this solution on github and twitter! "])
message
(cond
(not approved) (str "You've solved the unapproved problem. Now you can approve it!")
user (do
(store-completed-state! user _id code)
(str "Congratulations, you've solved the problem! See the "
"<a href='/problem/solutions/" _id "'>solutions</a>"
" that the users you follow have submitted, or "
paste-link
(next-problem-link _id)))
:else (str "You've solved the problem; "
paste-link
"You need to " (login-link "log in" (str "/problem/" _id)) " in order to save your solutions and track progress."))]
(session/put! :code [_id code])
{:message message, :error "", :url (str "/problem/" _id)}))
(def restricted-list '[use require in-ns future agent send send-off pmap pcalls])
(def base-tester (blanket secure-tester
"foreclojure"
"somnium"
"ring"
"compojure"))
(defn get-tester [restricted]
(apply blacklist-symbols base-tester (concat restricted-list (map symbol restricted))))
(def sb (sandbox*))
(defn read-string-safely [s]
(binding [*read-eval* false]
(with-in-str s
(let [end (Object.)]
(doall (take-while (complement #{end})
(repeatedly #(read *in* false end))))))))
(defn run-code
"Run the specified code-string against the test cases for the problem with the
specified id.
Return a map, {:message, :error, :url, :num-tests-passed}."
[id code]
(try
(let [{:keys [tests restricted] :as problem} (get-problem id)
sb-tester (get-tester restricted)
user-forms (s/join " " (map pr-str (read-string-safely code)))
devnull (java.io.StringWriter.) ;; TODO consider Apache Commons IO
results (if (empty? user-forms)
["Empty input is not allowed."]
(for [test tests]
(try
(when-not (sb (->> user-forms
(s/replace test "__")
read-string-safely
first)
sb-tester
{#'*out* devnull
#'*err* devnull})
"You failed the unit tests")
(catch Throwable t (.getMessage t)))))
[passed [fail-msg]] (split-with nil? results)]
(assoc (if fail-msg
{:message "", :error fail-msg, :url *url*}
(mark-completed problem code))
:num-tests-passed (count passed)))
(catch Throwable t {:message "" :error (.getMessage t), :url *url*
:num-tests-passed 0})))
(defn static-run-code [id code]
(session/flash-put! :code code)
(let [{:keys [message error url num-tests-passed]}
(binding [*url* (str *url* "#prob-desc")]
(run-code id code))]
(session/flash-put! :failing-test num-tests-passed)
(flash-msg url message)
(flash-error url error)))
(let [light-img (image-builder {:red ["red" "test failed"]
:green ["green" "test passed"]
:blue ["blue" "test not run"]}
:src #(str "images/" % "light.png"))]
(defn render-test-cases [tests]
[:table {:class "testcases"}
(let [fail (session/flash-get :failing-test)]
(for [[idx test] (map-indexed list tests)]
[:tr
[:td
(light-img (cond
(or (nil? fail) (> idx fail)) :blue
(= idx fail) :red
:else :green))]
[:td
[:pre {:class "brush: clojure;gutter: false;toolbar: false;light: true"}
test]]]))]))
(defn render-golf-chart []
(let [{:keys [id best score] :as settings}
(session/get :golf-chart)
url (str "/leagues/golf/" id "?best=" best "&curr=" score)]
(session/remove! :golf-chart)
(when settings
[:img {:src url}])))
(defn render-golf-score []
(let [{:keys [id best score] :as settings}
(session/get :golf-chart)]
(when settings
[:div#golf-scores
[:p#golfheader (str "Code Golf Score: " score)]
[:a.graph-class {:href "#"
:onclick "return false"}
[:span#graph-link "View Chart"]]])))
(defn rest-run-code [id raw-code]
(let [{:keys [message error url num-tests-passed]} (run-code id raw-code)]
(json/generate-string {:failingTest num-tests-passed
:message message
:error error
:golfScore (html (render-golf-score))
:golfChart (html (render-golf-chart))})))
(defn wants-no-javascript-codebox? []
(if-user [{:keys [user] :as user-obj}]
(disable-codebox? user-obj)))
(def-page code-box [id]
(let [{:keys [_id title difficulty tags description
restricted tests approved user]}
(get-problem (Integer. id)),
title (str (when-not approved
"Unapproved: ")
title)]
{:title (str _id ". " title)
:content
[:div#prob-container
[:div#prob-number "#" id]
[:div#prob-title title]
(if-user [{:keys [solved]}]
(if (some #{(Integer. id)} solved)
(link-to (str "/problem/solutions/" id)
[:button#solutions-link {:type "submit"} "Solutions"])
[:div {:style "clear: right; margin-bottom: 15px;"} "&nbsp;"])
[:div {:style "clear: right; margin-bottom: 15px;"} "&nbsp;"])
[:hr]
[:table#tags
[:tr [:td "Difficulty:"] [:td (or difficulty "N/A")]]
[:tr [:td "Topics:"] [:td (s/join " " tags)]]]
[:br]
(when-not approved
[:div#submitter "Submitted by: "
(users/mailto user)])
[:br]
[:div#prob-desc
description[:br]
(render-test-cases tests)
(when restricted
[:div#restrictions
[:u "Special Restrictions"] [:br]
(map (partial vector :li) restricted)])]
[:div
[:div.message
[:span#message-text (session/flash-get :message)]
[:span#error-message-text.error (session/flash-get :error)]]
[:div#golfscore
(render-golf-score)]]
(form-to {:id "run-code"} [:post *url*]
[:br]
[:br]
[:p#instruct "Code which fills in the blank: "]
(when (wants-no-javascript-codebox?) [:span#disable-javascript-codebox])
(text-area {:id "code-box"
:name "code"
:spellcheck "false"}
:code (escape-html
(or (session/flash-get :code)
(-> (session/get :user)
(get-user-id)
(get-solution ,,, _id)))))
[:div#golfgraph
(render-golf-chart)]
(hidden-field :id id)
[:br]
[:button.large {:id "run-button" :type "submit"} "Run"]
(when-not approved
[:span [:button.large {:id "reject-button"} "Reject"]
[:button.large {:id "edit-button"} "Edit"]
[:button.large {:id "approve-button"} "Approve"]]))]}))
(defn problem-page [id]
(let [error #(flash-error "/problems" %)
user (delay (session/get :user))]
(if-let [{:keys [approved]} (get-problem id)]
(cond (or approved (approver? (force user))) (code-box id)
(force user) (error "You cannot access this page")
:else (error (str "You must " (login-link)
" to view unapproved problems")))
(error "No such problem!"))))
(def-page show-solutions-page [problem-id]
{:title "4Clojure - Problem Solutions"
:content
(list
[:div.message (session/flash-get :message)]
[:div#problems-error.error (session/flash-get :error)]
[:h3 {:style "margin-top: -20px;"} "Solutions:"]
(with-user [{:keys [_id following]}]
(list
(let [user-code (get-solution :public _id problem-id)]
[:pre {:class "brush: clojure;gutter: false;toolbar: false;light: true; class-name: 'solution-code solution-user-code'"}
(escape-html user-code)])
(if (empty? following)
[:p "You can only see solutions of users whom you follow. Click on any name from the " (link-to "/users" "users") " listing page to see their profile, and click follow from there."]
(if (some (complement nil?) (map #(get-solution :public % problem-id) following))
(interpose [:hr.solution]
(for [f-user-id following
:let [f-user (:user (from-mongo
(fetch-one :users
:where {:_id f-user-id}
:only [:user])))
f-code (get-solution :public
f-user-id problem-id)]
:when f-code]
[:div.follower-solution
[:div.solution-username (str f-user "'s solution:")]
[:pre {:class "brush: clojure;gutter: false;toolbar: false;light: true; class-name: 'solution-code'"}
(escape-html f-code)]]))
[:p "None of the users you follow have solved this problem yet!"])))))})
(defn show-solutions [id]
(let [problem-id (Integer. id)
user (session/get :user)]
(if-user [{:keys [solved]}]
(if (some #{problem-id} solved)
(show-solutions-page problem-id)
(flash-error (str "/problem/" problem-id)
"You must solve this problem before you can see others' solutions!"))
(do
(session/put! :login-to *url*)
(flash-error "/login" "You must log in to see solutions!")))))
(let [checkbox-img (image-builder {true ["images/checkmark.png" "completed"]
false ["images/empty-sq.png" "incomplete"]})]
(def-page problem-list-page []
{:title "4clojure - Problem Listing"
:content
(list
[:div.message (session/flash-get :message)]
[:div#problems-error.error (session/flash-get :error)]
(link-to "/problems/rss" [:div {:class "rss"}])
[:table#problem-table.my-table
[:thead
[:tr
[:th "Title"]
[:th "Difficulty"]
[:th "Topics"]
[:th "Submitted By"]
[:th "Times Solved"]
[:th "Solved?"]]]
(let [solved (get-solved (session/get :user))
problems (get-problem-list)]
(map-indexed
(fn [x {:keys [title difficulty tags user], id :_id}]
[:tr (row-class x)
[:td.titlelink
[:a {:href (str "/problem/" id)}
title]]
[:td.centered difficulty]
[:td.centered
(s/join " " (map #(str "<span class='tag'>" % "</span>")
tags))]
[:td.centered user]
[:td.centered (get-in @solved-stats [:solved-counts id] 0)]
[:td.centered (checkbox-img (contains? solved id))]])
problems))])}))
(defn generate-unapproved-problems-list []
(let [problems (get-problem-list {:approved false})]
(list
[:table#unapproved-problems.my-table
[:thead
[:tr
[:th "Title"]
[:th "Difficulty"]
[:th "Topics"]
[:th "Submitted By"]]]
(map-indexed
(fn [x {:keys [title difficulty tags user], id :_id}]
[:tr (row-class x)
[:td.titlelink
[:a {:href (str "/problem/" id)}
title]]
[:td.centered difficulty]
[:td.centered
(s/join " " (map #(str "<span class='tag'>" % "</span>")
tags))]
[:td.centered user]])
problems)])))
(def-page unapproved-problem-list-page []
{:title "Unapproved problems"
:content
(content-page
{:main (generate-unapproved-problems-list)})})
(defn access-unapproved-problem-list-page []
(let [user (session/get :user)]
(if (approver? user)
(unapproved-problem-list-page)
(flash-error "/problems" "You cannot access this page"))))
(def-page problem-submission-page []
{:title "Submit a problem"
:content
(list
[:div.instructions
[:p "Thanks for choosing to submit a problem. Please make sure that you own the rights to the code you are submitting and that you wouldn't mind having us use the code as a 4clojure problem. Once you've submitted your problem, it won't appear on the site until someone from the 4clojure team has had a chance to review it."]]
(form-to {:id "problem-submission"} [:post "/problems/submit"]
(hidden-field :author (session/flash-get :author))
(hidden-field :prob-id (session/flash-get :prob-id))
(label :title "Problem Title")
(text-field :title (session/flash-get :title))
(label :diffulty "Difficulty")
(drop-down :difficulty ["Elementary" "Easy" "Medium" "Hard"] (session/flash-get :difficulty))
(label :tags "Topics (space separated)")
(text-field :tags (session/flash-get :tags))
(label :restricted "Restricted Functions (space separated)")
(text-field :restricted (session/flash-get :restricted))
(label :description "Problem Description")
(text-area {:id "problem-description"} :description (session/flash-get :description))
[:br]
(label :code-box "Problem test cases. Use two underscores (__) for user input. Individual tests can span multiple lines, but each test should be separated by a totally blank line.")
(text-area {:id "code-box" :spellcheck "false"}
:code (session/flash-get :tests))
[:p
[:button.large {:id "submission-button" :type "submit"} "Submit"]]))})
(defn create-problem
"create a user submitted problem"
[title difficulty tags restricted description code id author]
(let [user (session/get :user)]
(if (or (approver? user)
(and (can-submit? user)
(not id)))
(let [id (or id
(:seq (fetch-and-modify
:seqs
{:_id "problems"}
{:$inc {:seq 1}})))
edit-url (str "https://4clojure.com/problem/"
id)
existing-problem (fetch-one :problems
:where {:_id id}
:only [:approved :times-solved])
approved (true? (:approved existing-problem))]
(when-not existing-problem
(try
(send-email
{:from "team@4clojure.com"
:to ["team@4clojure.com"]
:reply-to [(users/email-address user)]
:subject (str "User submission: " title)
:html (html [:h3 (link-to edit-url title)]
[:div description])
:text (str title ": " edit-url "\n" description)})
;; TODO: dump this in a proper log
(catch EmailException e (println (str "email failed to send on newly submitted problem #" id)))))
(update! :problems
{:_id id}
{:$set
{:title title
:difficulty difficulty
:description description
:tags (re-seq #"\S+" tags)
:restricted (re-seq #"\S+" restricted)
:tests (s/split code #"\r\n\r\n")
:user (if (empty? author) user author)
:approved approved}})
(flash-msg "/problems"
"Thank you for submitting a problem! Be sure to check back to see it posted."))
(flash-error "/problems" "You are not authorized to submit a problem."))))
(defn edit-problem [id]
(if (approver? (session/get :user))
(let [{:keys [title user difficulty tags restricted description tests]} (get-problem id)]
(doseq [[k v] {:prob-id id
:author user
:title title
:difficulty difficulty
:tags (s/join " " tags)
:restricted (s/join " " restricted)
:description description
:tests (s/join "\r\n\r\n" tests)}]
(session/flash-put! k v))
(response/redirect "/problems/submit"))
(flash-error "/problems" "You don't have access to this page")))
(defn approve-problem [id]
"take a user submitted problem and approve it"
(if (approver? (session/get :user))
(let [{:keys [title user]} (from-mongo
(fetch-one :problems
:where {:_id id}
:only [:title :user]))
url (str "/problem/" id)]
(update! :problems
{:_id id}
{:$set {:approved true}})
(try
(send-email
{:from "team@4clojure.com"
:to [(users/email-address user)]
:subject (format "Problem #%d: submission accepted" id)
:html (html (link-to (str "http://www.4clojure.com/" url) title))
:text (str title ": " url)})
;; TODO: dump this in a proper log
(catch EmailException e (println (str "email failed to send on approved problem #" id))))
(flash-msg url (str "Problem " id " has been approved!")))
(flash-error "/problems" "You don't have access to this page")))
(defn reject-problem [id reason]
"reject a user submitted problem by deleting it from the database"
(if (approver? (session/get :user))
(let [{:keys [user title description tags tests]} (get-problem id)
email (:email (get-user user))]
(destroy! :problems
{:_id id})
(send-email
{:from "team@4clojure.com"
:to [email]
:subject "Problem rejected"
:text
(str "A problem you've submitted has been rejected, but don't get discouraged!\n"
"Check out the reason below, and try again.\n\n"
"Title: " title "\n"
"Tags: " tags "\n"
"Description: " description "\n"
"Tests: " tests "\n"
"Rejection Reason: " reason)})
(flash-msg "/problems" (str "Problem " id " was rejected and deleted.")))
(flash-error "/problems" "You do not have permission to access this page")))
(defn total-solved-count []
(html (:total @solved-stats)))
(defroutes problems-routes
(GET "/problems" [] (problem-list-page))
(GET "/problems/solved" [] (total-solved-count))
(GET "/problem/:id" [id]
(if-let [id-int (as-int id)]
(problem-page id-int)
(flash-error "/problems"
(format "'%s' is not a valid problem number." id))))
(GET "/problems/submit" [] (problem-submission-page))
(POST "/problems/submit" [prob-id author title difficulty tags restricted description code]
(create-problem title difficulty tags restricted description code (when (not= "" prob-id) (Integer. prob-id)) author))
(GET "/problems/unapproved" [] (access-unapproved-problem-list-page))
(GET "/problem/:id/edit" [id]
(edit-problem (Integer. id)))
(POST "/problem/edit" [id]
(edit-problem (Integer. id)))
(POST "/problem/approve" [id]
(approve-problem (Integer. id)))
(POST "/problem/reject" [id]
(reject-problem (Integer. id) "We didn't like your problem."))
(GET "/problem/solutions/:id" [id]
(show-solutions id))
(POST "/problem/:id" [id code]
(static-run-code (Integer. id) (trim-code code)))
(POST "/rest/problem/:id" [id code]
{:headers {"Content-Type" "application/json"}}
(rest-run-code (Integer. id) (trim-code code)))
(GET "/problems/rss" [] (create-feed
"4Clojure: Recent Problems"
"http://4clojure.com/problems"
"Recent problems at 4Clojure.com"
"http://4clojure.com/problems/rss"
(problem-feed 20))))
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