89 lines
2.3 KiB
Go
89 lines
2.3 KiB
Go
package gemini
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import (
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"fmt"
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"net/url"
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"regexp"
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"gemini-grc/common"
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"gemini-grc/logging"
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"gemini-grc/util"
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)
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func GetPageLinks(currentURL common.URL, gemtext string) common.LinkList {
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linkLines := util.GetLinesMatchingRegex(gemtext, `(?m)^=>[ \t]+.*`)
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if len(linkLines) == 0 {
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return nil
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}
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var linkURLs common.LinkList
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// Normalize URLs in links
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for _, line := range linkLines {
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linkUrl, err := ParseGeminiLinkLine(line, currentURL.String())
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if err != nil {
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logging.LogDebug("%s: %s", common.ErrGeminiLinkLineParse, err)
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continue
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}
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linkURLs = append(linkURLs, *linkUrl)
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}
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return linkURLs
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}
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// ParseGeminiLinkLine takes a single link line and the current URL,
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// return the URL converted to an absolute URL
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// and its description.
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func ParseGeminiLinkLine(linkLine string, currentURL string) (*common.URL, error) {
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// Check: currentURL is parseable
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baseURL, err := url.Parse(currentURL)
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if err != nil {
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return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
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}
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// Extract the actual URL and the description
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re := regexp.MustCompile(`^=>[ \t]+(\S+)([ \t]+.*)?`)
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matches := re.FindStringSubmatch(linkLine)
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if len(matches) == 0 {
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// If the line doesn't match the expected format, return it unchanged
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return nil, fmt.Errorf("%w could not parse gemini link %s", common.ErrGeminiLinkLineParse, linkLine)
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}
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originalURLStr := matches[1]
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// Check: Unescape the URL if escaped
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_, err = url.QueryUnescape(originalURLStr)
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if err != nil {
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return nil, fmt.Errorf("%w: %w", common.ErrURLDecode, err)
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}
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description := ""
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if len(matches) > 2 {
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description = matches[2]
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}
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// Parse the URL from the link line
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parsedURL, err := url.Parse(originalURLStr)
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if err != nil {
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// If URL parsing fails, return an error
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return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
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}
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// If link URL is relative, resolve full URL
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if !parsedURL.IsAbs() {
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parsedURL = baseURL.ResolveReference(parsedURL)
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}
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// Remove usual first space from URL description:
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// => URL description
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// ^^^^^^^^^^^^
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if len(description) > 0 && description[0] == ' ' {
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description = description[1:]
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}
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finalURL, err := common.ParseURL(parsedURL.String(), description, true)
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if err != nil {
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// If URL parsing fails, return an error
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return nil, fmt.Errorf("%w: %w", common.ErrURLParse, err)
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}
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return finalURL, nil
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}
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