query.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strings"
)

const ApiUrl = "https://leetcode-cn.com/graphql"
const ContentType = "application/json"

const getItemTmpl = `{"operationName":"GetItem","variables":{"itemId":"%s"},"query":"query GetItem($itemId: String!) {\n  item(id: $itemId) {\n    id\n    title\n    type\n    paidOnly\n    lang\n    question {\n      questionId\n      title\n      titleSlug\n      __typename\n    }\n    article {\n      id\n      title\n      __typename\n    }\n    video {\n      id\n      __typename\n    }\n    htmlArticle {\n      id\n      __typename\n    }\n    webPage {\n      id\n      __typename\n    }\n    __typename\n  }\n  isCurrentUserAuthenticated\n}\n"}`
const getQuestionTmpl = `{"operationName":"GetQuestion","variables":{"titleSlug":"%s"},"query":"query GetQuestion($titleSlug: String!) {\n  question(titleSlug: $titleSlug) {\n    questionId\n    sessionId\n    questionTitle\n    categoryTitle\n    submitUrl\n    interpretUrl\n    codeDefinition\n    sampleTestCase\n    enableTestMode\n    metaData\n    langToValidPlayground\n    enableRunCode\n    enableSubmit\n    judgerAvailable\n    infoVerified\n    envInfo\n    content\n    translatedContent\n    urlManager\n    __typename\n  }\n  isCurrentUserAuthenticated\n}\n"}`
const getCardDetailTmpl = `{"operationName":"GetExtendedCardDetail","variables":{"cardSlug":"%s"},"query":"query GetExtendedCardDetail($cardSlug: String!) {\n  card(cardSlug: $cardSlug) {\n    id\n    title\n    slug\n    description\n    introduction\n    chapters {\n      id\n      __typename\n    }\n    __typename\n  }\n}\n"}`
const getChapterTmpl = `{"operationName":"GetChapter","variables":{"chapterId":"%s","cardSlug":"%s"},"query":"query GetChapter($chapterId: String, $cardSlug: String) {\n  chapter(chapterId: $chapterId, cardSlug: $cardSlug) {\n    ...ExtendedChapterDetail\n    description\n    __typename\n  }\n}\n\nfragment ExtendedChapterDetail on ChapterNode {\n  id\n  title\n  slug\n  items {\n    id\n    title\n    type\n    info\n    paidOnly\n    chapterId\n    prerequisites {\n      id\n      chapterId\n      __typename\n    }\n    __typename\n  }\n  __typename\n}\n"}`

type Item struct {
	Id       string
	Title    string
	Question struct {
		QuestionId string
		Title      string
		TitleSlug  string
	}
}

func getItem(id string) *Item {
	body := fmt.Sprintf(getItemTmpl, id)
	decoder := postRequestWith(body)
	wrapper := struct {
		Data struct {
			Item Item
		}
	}{}
	err := decoder.Decode(&wrapper)
	if err != nil {
		log.Fatal(err)
	}
	return &wrapper.Data.Item
}

type Question struct {
	QuestionId        string
	QuestionTitle     string
	CategoryTitle     string
	CodeDefinition    string
	Content           string
	TranslatedContent string
}

func getQuestion(titleSlug string) *Question {
	body := fmt.Sprintf(getQuestionTmpl, titleSlug)
	decoder := postRequestWith(body)
	wrapper := struct {
		Data struct {
			Question Question
		}
	}{}
	err := decoder.Decode(&wrapper)
	if err != nil {
		log.Fatal(err)
	}
	return &wrapper.Data.Question
}

type Card struct {
	Chapters []struct {
		Id string
	}
}

func getCard(cardSlug string) *Card {
	body := fmt.Sprintf(getCardDetailTmpl, cardSlug)
	decoder := postRequestWith(body)
	wrapper := struct {
		Data struct {
			Card Card
		}
	}{}
	err := decoder.Decode(&wrapper)
	if err != nil {
		log.Fatal(err)
	}
	return &wrapper.Data.Card
}

type Chapter struct {
	Slug  string
	Items []struct {
		Id string
	}
}

func getChapter(chapterId, cardSlug string) *Chapter {
	body := fmt.Sprintf(getChapterTmpl, chapterId, cardSlug)
	decoder := postRequestWith(body)
	wrapper := struct {
		Data struct {
			Chapter Chapter
		}
	}{}
	err := decoder.Decode(&wrapper)
	if err != nil {
		log.Fatal(err)
	}
	return &wrapper.Data.Chapter
}

func postRequestWith(requestBody string) *json.Decoder {
	bodyReader := strings.NewReader(requestBody)
	resp, err := http.Post(ApiUrl, ContentType, bodyReader)
	if err != nil {
		fmt.Printf("error when query: %T:%v\n", err, err)
	}
	return json.NewDecoder(resp.Body)
}