78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
package main
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import (
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"errors"
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"fmt"
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"io"
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"log/slog"
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"net/http"
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"github.com/PuerkitoBio/goquery"
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"resty.dev/v3"
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)
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var (
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errArticleContentNotFound = errors.New("无法找到文章内容")
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errArticleContentParseFailed = errors.New("无法解析文章内容")
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)
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// getArticleHTML 优先从缓存读取文章 HTML，缓存未命中时从源站抓取。
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func getArticleHTML(db *DB, client *resty.Client, articleID string) (string, error) {
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html, err := db.GetArticleHtml(articleID)
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if err == nil {
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return html, nil
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}
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cookies, err := getLoginCookies(db, client)
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if err != nil {
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return "", err
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}
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html, err = fetchRemoteArticleHTML(client, articleID, cookies)
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if err != nil {
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return "", err
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}
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if err := db.SetArticleHtml(articleID, html, articleCacheTTL); err != nil {
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slog.Warn("failed to cache article", slog.String("article_id", articleID), slog.String("error", err.Error()))
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}
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return html, nil
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}
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// fetchRemoteArticleHTML 从源站下载文章页面并提取正文 HTML。
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func fetchRemoteArticleHTML(client *resty.Client, articleID string, cookies []*http.Cookie) (string, error) {
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request := client.R()
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if len(cookies) > 0 {
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request.SetCookies(cookies)
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}
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resp, err := request.Get(fmt.Sprintf(articleURLFormat, articleID))
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if err != nil {
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return "", err
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}
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defer func() { _ = resp.Body.Close() }()
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return extractArticleHTML(resp.Body)
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}
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// extractArticleHTML 从源站页面中提取文章正文区域。
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func extractArticleHTML(reader io.Reader) (string, error) {
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doc, err := goquery.NewDocumentFromReader(reader)
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if err != nil {
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return "", err
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}
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selection := doc.Find("div.entry")
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if selection.Length() == 0 {
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return "", errArticleContentNotFound
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}
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html, err := selection.Html()
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if err != nil {
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return "", fmt.Errorf("%w：%v", errArticleContentParseFailed, err)
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}
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return html, nil
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}
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