Add contests, register and unregister commands

cf.go

@@ -41,6 +41,9 @@ Usage:
   cf race [<specifier>...]
   cf pull [ac] [<specifier>...]
   cf clone [ac] [<handle>]
+  cf contests
+  cf register [<specifier>...]
+  cf unregister [<specifier>...]
   cf upgrade
 
 Options:
@@ -107,6 +110,9 @@ Examples:
   cf pull              Pull the latest codes of current problem into current
                        path.
   cf clone xalanq      Clone all codes of xalanq.
+  cf contests          List upcoming contests
+  cf register 1270     Register for contest "Good Bye 2019"
+  cf unregister 1270   Unregister from a contest "Good Bye 2019"
   cf upgrade           Upgrade the "cf" to the latest version from GitHub.
 
 File:

client/contests.go

@@ -0,0 +1,119 @@
+package client
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+
+	"github.com/PuerkitoBio/goquery"
+)
+
+// ContestInfo contests information
+type ContestInfo struct {
+	ID           string
+	Name         string
+	Start        string
+	Length       string
+	State        string
+	Registration string
+	Registered   bool
+}
+
+func getRegistrationStatus(cell *goquery.Selection) (string, bool) {
+	participants := cell.Find(".contestParticipantCountLinkMargin")
+	participantCount := participants.Text()
+	participants.Remove()
+	if cell.Find(".welldone").Length() != 0 {
+		text := cleanText(cell.Text())
+		return text + "\n" + participantCount, true
+	}
+	countdown := cell.Find(".countdown")
+	text := ""
+	if strings.Contains(cell.Text(), "»") {
+		text = "Registering"
+		parent := countdown.Parent()
+		countdownText := countdown.Text()
+		countdown.Remove()
+		note := cleanText(parent.Text())
+		if strings.Contains(cell.Text(), "*") {
+			countdownText += "*"
+		}
+		return fmt.Sprintf("%s %s\n%s %s", text, participantCount, note, countdownText), false
+	}
+	return cleanText(cell.Text()), false
+}
+
+func getState(cell *goquery.Selection) string {
+	cell.Find("a").Remove()
+	countdown := cell.Find(".countdown").Text()
+	cell.Find(".countdown").Remove()
+	text := cleanText(cell.Text())
+
+	return text + "\n" + countdown
+}
+
+func findContests(body io.ReadCloser, utcOffset string) ([]ContestInfo, error) {
+	doc, err := goquery.NewDocumentFromReader(body)
+	if err != nil {
+		return nil, err
+	}
+	table := doc.Find(".datatable").First().Find("tbody")
+	rows := table.Find("tr").Slice(1, goquery.ToEnd)
+	contests := []ContestInfo{}
+	rows.Each(func(i int, row *goquery.Selection) {
+		contest := ContestInfo{}
+		contest.ID, _ = row.Attr("data-contestid")
+		row.Find("td").Each(func(j int, cell *goquery.Selection) {
+			switch j {
+			case 0:
+				cell.Find("a").Remove()
+				name := cleanText(cell.Text())
+				contest.Name = strings.Replace(name, " (", "\n(", 1)
+			case 2:
+				contest.Start = parseWhen(cell.Find(".format-time").Text(), utcOffset)
+			case 3:
+				duration := cleanText(cell.Text())
+				if strings.Count(duration, ":") == 2 {
+					duration = strings.TrimSuffix(duration, ":00")
+				}
+				contest.Length = duration
+			case 4:
+				contest.State = getState(cell)
+			case 5:
+				contest.Registration, contest.Registered = getRegistrationStatus(cell)
+			}
+		})
+		contests = append(contests, contest)
+	})
+	if err != nil {
+		return nil, err
+	}
+	return contests, nil
+}
+
+// StatisContest get upcoming contests
+func (c *Client) GetContests() (contests []ContestInfo, err error) {
+	URL := c.host + "/contests?complete=true"
+	resp, err := c.client.Get(URL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("Status code error: %d %s", resp.StatusCode, resp.Status)
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if _, err = findHandle(body); err != nil {
+		return
+	}
+	utcOffset, err := findCfOffset(body)
+	if err != nil {
+		return nil, err
+	}
+	return findContests(ioutil.NopCloser(bytes.NewReader(body)), utcOffset)
+}

client/register.go

@@ -0,0 +1,96 @@
+package client
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"strings"
+
+	"github.com/PuerkitoBio/goquery"
+	"github.com/fatih/color"
+	"github.com/xalanq/cf-tool/util"
+)
+
+// Register for a contest
+func (c *Client) Register(contestID string) error {
+	URL := fmt.Sprintf("%v/contestRegistration/%v", c.host, contestID)
+	resp, err := c.client.Get(URL)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	if _, err = findHandle(body); err != nil {
+		return err
+	}
+	if msg := findCodeforcesMessage(body); msg != "" {
+		return errors.New(msg)
+	}
+	doc, err := goquery.NewDocumentFromReader(ioutil.NopCloser(bytes.NewReader(body)))
+	if err != nil {
+		return err
+	}
+	color.HiCyan(findTitle(doc))
+	if !agreesToTerms(doc) {
+		return errors.New("You cannot participate without agreeing to the terms")
+	}
+	formData, err := getFormData(doc, c)
+	if err != nil {
+		return err
+	}
+	resp, err = c.client.PostForm(URL, formData)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	fmt.Println(findCodeforcesMessage(body))
+	return nil
+}
+
+func findTitle(doc *goquery.Document) string {
+	title := doc.Find("h2").Text()
+	return cleanText(title)
+}
+
+func agreesToTerms(doc *goquery.Document) bool {
+	label := cleanText(doc.Find("label[for=registrationTerms]").Text())
+	terms := cleanText(doc.Find("#registrationTerms").Text())
+	terms = strings.ReplaceAll(terms, "\n*", "\n    *")
+	color.Green(label)
+	fmt.Println(terms)
+	return util.YesOrNo("Do you argree to the terms? (y/n)")
+}
+
+func getFormData(doc *goquery.Document, c *Client) (url.Values, error) {
+	form := doc.Find(".contestRegistration").First()
+	data := url.Values{}
+	var err error
+	form.Find("input").Each(func(i int, input *goquery.Selection) {
+		key, k := input.Attr("name")
+		value, v := input.Attr("value")
+		if key != "" {
+			if !k || !v {
+				err = errors.New("Unable to get form data")
+				return
+			}
+			data.Set(key, value)
+		}
+	})
+	if data.Get("_tta") == "" {
+		tta, err := getTta(c)
+		if err != nil {
+			return data, nil
+		}
+		data.Set("_tta", tta)
+	}
+	return data, err
+}

client/unregister.go

@@ -0,0 +1,104 @@
+package client
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/PuerkitoBio/goquery"
+)
+
+// Unregister from a contest
+func (c *Client) Unregister(contestID string) error {
+	resp, err := getRegistrantsPage(c, contestID, 1)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	if _, err = findHandle(body); err != nil {
+		return err
+	}
+	if msg := findCodeforcesMessage(body); msg != "" {
+		return errors.New(msg)
+	}
+	doc, err := goquery.NewDocumentFromReader(ioutil.NopCloser(bytes.NewReader(body)))
+	if err != nil {
+		return err
+	}
+	formData, err := getUnregisterFormData(doc, c, contestID)
+	if err != nil {
+		return err
+	}
+	URL := fmt.Sprintf("%v/data/contestRegistration/%v", c.host, contestID)
+	resp, err = c.client.PostForm(URL, formData)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	if strings.Contains(string(body), `{"success":"true"}`) {
+		fmt.Println("Succesfully unregistered from the contest")
+	} else {
+		return errors.New("Can't unregister. Possible reason: you made at least one action in the contest")
+	}
+	return err
+}
+
+func getUnregisterFormData(doc *goquery.Document, c *Client, contestID string) (url.Values, error) {
+	pageCount := getPageCount(doc)
+	for page := 1; page <= pageCount; page++ {
+		if page != 1 {
+			resp, err := getRegistrantsPage(c, contestID, page)
+			if err != nil {
+				return nil, err
+			}
+			defer resp.Body.Close()
+			doc, err = goquery.NewDocumentFromReader(resp.Body)
+			if err != nil {
+				return nil, err
+			}
+		}
+		user := doc.Find(".deleteParty").First()
+		participantID, ok := user.Attr("participantid")
+		if !ok {
+			continue
+		}
+		data := url.Values{}
+		token := getCsrfToken(doc)
+		data.Add("participantId", participantID)
+		data.Add("action", "deleteParty")
+		data.Add("csrf_token", token)
+		return data, nil
+	}
+	return nil, errors.New("You are not registered in this contest")
+}
+
+func getRegistrantsPage(c *Client, contestID string, page int) (r *http.Response, err error) {
+	URL := fmt.Sprintf("%v/contestRegistrants/%v/friends/true/page/%d", c.host, contestID, page)
+	resp, err := c.client.Get(URL)
+	if err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
+func getPageCount(doc *goquery.Document) int {
+	count, ok := doc.Find(".page-index").Last().Attr("pageindex")
+	if ok {
+		c, _ := strconv.Atoi(count)
+		return c
+	}
+	return 1
+}