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authorFuwn <[email protected]>2021-09-02 02:08:25 +0000
committerFuwn <[email protected]>2021-09-02 02:08:25 +0000
commit9dcf275615184c6c11fb54acf8f32eb04bf4de55 (patch)
treedaa9f79e9cdadc5cc37e898e8daa232e145a8551 /capybara.go
parentfix(main): remove redundant type conversion (diff)
downloadcapybara-9dcf275615184c6c11fb54acf8f32eb04bf4de55.tar.xz
capybara-9dcf275615184c6c11fb54acf8f32eb04bf4de55.zip
refactor(main): main.go -> capybara.go
Diffstat (limited to 'capybara.go')
-rw-r--r--capybara.go666
1 files changed, 666 insertions, 0 deletions
diff --git a/capybara.go b/capybara.go
new file mode 100644
index 0000000..2e6c5be
--- /dev/null
+++ b/capybara.go
@@ -0,0 +1,666 @@
+package main
+
+import (
+ "context"
+ "fmt"
+ "html/template"
+ "io"
+ "io/ioutil"
+ "log"
+ "mime"
+ "net/http"
+ "net/url"
+ "os"
+ "strings"
+ "time"
+
+ "git.sr.ht/~adnano/go-gemini"
+ "git.sr.ht/~sircmpwn/getopt"
+)
+
+var gemtextPage = template.Must(template.
+ New("gemtext").
+ Funcs(template.FuncMap{
+ "heading": func(line gemini.Line) *GemtextHeading {
+ switch l := line.(type) {
+ case gemini.LineHeading1:
+ return &GemtextHeading{1, string(l)}
+ case gemini.LineHeading2:
+ return &GemtextHeading{2, string(l)}
+ case gemini.LineHeading3:
+ return &GemtextHeading{3, string(l)}
+ default:
+ return nil
+ }
+ },
+ "link": func(line gemini.Line) *gemini.LineLink {
+ switch l := line.(type) {
+ case gemini.LineLink:
+ return &l
+ default:
+ return nil
+ }
+ },
+ "li": func(line gemini.Line) *gemini.LineListItem {
+ switch l := line.(type) {
+ case gemini.LineListItem:
+ return &l
+ default:
+ return nil
+ }
+ },
+ "pre_toggle_on": func(ctx *GemtextContext, line gemini.Line) *gemini.LinePreformattingToggle {
+ switch l := line.(type) {
+ case gemini.LinePreformattingToggle:
+ if ctx.Pre%4 == 0 {
+ ctx.Pre += 1
+ return &l
+ }
+ ctx.Pre += 1
+ return nil
+ default:
+ return nil
+ }
+ },
+ "pre_toggle_off": func(ctx *GemtextContext, line gemini.Line) *gemini.LinePreformattingToggle {
+ switch l := line.(type) {
+ case gemini.LinePreformattingToggle:
+ if ctx.Pre%4 == 3 {
+ ctx.Pre += 1
+ return &l
+ }
+ ctx.Pre += 1
+ return nil
+ default:
+ return nil
+ }
+ },
+ "pre": func(line gemini.Line) *gemini.LinePreformattedText {
+ switch l := line.(type) {
+ case gemini.LinePreformattedText:
+ return &l
+ default:
+ return nil
+ }
+ },
+ "quote": func(line gemini.Line) *gemini.LineQuote {
+ switch l := line.(type) {
+ case gemini.LineQuote:
+ return &l
+ default:
+ return nil
+ }
+ },
+ "text": func(line gemini.Line) *gemini.LineText {
+ switch l := line.(type) {
+ case gemini.LineText:
+ return &l
+ default:
+ return nil
+ }
+ },
+ "url": func(ctx *GemtextContext, s string) template.URL {
+ u, err := url.Parse(s)
+ if err != nil {
+ return "error"
+ }
+ u = ctx.URL.ResolveReference(u)
+
+ if u.Scheme == "" || u.Scheme == "gemini" {
+ if u.Host != ctx.Root.Host {
+ u.Path = fmt.Sprintf("/proxy/%s%s", u.Host, u.Path)
+ }
+ u.Scheme = ""
+ u.Host = ""
+ }
+ return template.URL(u.String())
+ },
+ "safeCSS": func(s string) template.CSS {
+ return template.CSS(s)
+ },
+ "safeURL": func(s string) template.URL {
+ return template.URL(s)
+ },
+ }).
+ Parse(`<!doctype html>
+<html>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+{{- if .CSS }}
+{{- if .ExternalCSS }}
+<link rel="stylesheet" type="text/css" href="{{.CSS | safeCSS}}">
+{{- else }}
+<style>
+{{.CSS | safeCSS}}
+</style>
+{{- end }}
+{{- end }}
+<title>{{.Title}}</title>
+<article{{if .Lang}} lang="{{.Lang}}"{{end}}>
+ {{ $ctx := . -}}
+ {{- $isList := false -}}
+ {{- range .Lines -}}
+ {{- if and $isList (not (. | li)) }}
+ </ul>
+ {{- $isList = false -}}
+ {{- end -}}
+
+ {{- with . | heading }}
+ {{- $isList = false -}}
+ <h{{.Level}}>{{.Text}}</h{{.Level}}>
+ {{- end -}}
+
+ {{- with . | link }}
+ {{- $isList = false -}}
+ <p>
+ <a
+ href="{{.URL | url $ctx}}"
+ >{{if .Name}}{{.Name}}{{else}}{{.URL}}{{end}}</a>
+ {{- end -}}
+
+ {{- with . | quote }}
+ {{- $isList = false -}}
+ <blockquote>
+ {{slice .String 1}}
+ </blockquote>
+ {{- end -}}
+
+ {{- with . | pre_toggle_on $ctx }}
+ <div aria-label="{{slice .String 3}}">
+ <pre aria-hidden="true" alt="{{slice .String 3}}">
+ {{- $isList = false -}}
+ {{- end -}}
+ {{- with . | pre -}}
+ {{- $isList = false -}}
+ {{.}}
+{{ end -}}
+ {{- with . | pre_toggle_off $ctx -}}
+ {{- $isList = false -}}
+ </pre>
+ </div>
+ {{- end -}}
+
+ {{- with . | text }}
+ {{- $isList = false }}
+ <p>{{.}}
+ {{- end -}}
+
+ {{- with . | li }}
+ {{- if not $isList }}
+ <ul>
+ {{- end -}}
+
+ {{- $isList = true }}
+ <li>{{slice .String 1}}</li>
+ {{- end -}}
+
+ {{- end }}
+ {{- if $isList }}
+ </ul>
+ {{- end }}
+</article>
+<details>
+ <summary>
+ Proxied content from <a href="{{.URL.String | safeURL}}">{{.URL.String}}</a>
+ {{if .External}}
+ (external content)
+ {{end}}
+ </summary>
+ <p>Gemini request details:
+ <dl>
+ <dt>Original URL</dt>
+ <dd><a href="{{.URL.String | safeURL}}">{{.URL.String}}</a></dd>
+ <dt>Status code</dt>
+ <dd>{{.Resp.Status}}</dd>
+ <dt>Meta</dt>
+ <dd>{{.Resp.Meta}}</dd>
+ <dt>Proxied by</dt>
+ <dd><a href="https://github.com/fuwn/capybara">Capybara</a></dd>
+ </dl>
+ <p>Be advised that no attempt was made to verify the remote SSL certificate.
+</details>
+`))
+
+var inputPage = template.Must(template.
+ New("input").
+ Funcs(template.FuncMap{
+ "safeCSS": func(s string) template.CSS {
+ return template.CSS(s)
+ },
+ }).
+ Parse(`<!doctype html>
+<html>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+{{- if .CSS }}
+{{- if .ExternalCSS }}
+<link rel="stylesheet" type="text/css" href="{{.CSS | safeCSS}}">
+{{- else }}
+<style>
+{{.CSS | safeCSS}}
+</style>
+{{- end }}
+{{- end }}
+<title>{{.Prompt}}</title>
+<form method="POST">
+ <label for="input">{{.Prompt}}</label>
+ {{ if .Secret }}
+ <input type="password" id="input" name="q" />
+ {{ else }}
+ <input type="text" id="input" name="q" />
+ {{ end }}
+</form>
+`))
+
+// TODO: let user customize this
+const defaultCSS = `html {
+ font-family: sans-serif;
+ color: #080808;
+}
+
+body {
+ max-width: 920px;
+ margin: 0 auto;
+ padding: 1rem 2rem;
+}
+
+blockquote {
+ background-color: #eee;
+ border-left: 3px solid #444;
+ margin: 1rem -1rem 1rem calc(-1rem - 3px);
+ padding: 1rem;
+}
+
+ul {
+ margin-left: 0;
+ padding: 0;
+}
+
+li {
+ padding: 0;
+}
+
+li:not(:last-child) {
+ margin-bottom: 0.5rem;
+}
+
+a {
+ position: relative;
+}
+
+a:before {
+ content: '⇒';
+ color: #999;
+ text-decoration: none;
+ font-weight: bold;
+ position: absolute;
+ left: -1.25rem;
+}
+
+pre {
+ background-color: #eee;
+ margin: 0 -1rem;
+ padding: 1rem;
+ overflow-x: auto;
+}
+
+details:not([open]) summary,
+details:not([open]) summary a {
+ color: gray;
+}
+
+details summary a:before {
+ display: none;
+}
+
+dl dt {
+ font-weight: bold;
+}
+
+dl dt:not(:first-child) {
+ margin-top: 0.5rem;
+}
+
+@media(prefers-color-scheme:dark) {
+ html {
+ background-color: #111;
+ color: #eee;
+ }
+
+ blockquote {
+ background-color: #000;
+ }
+
+ pre {
+ background-color: #222;
+ }
+
+ a {
+ color: #0087BD;
+ }
+
+ a:visited {
+ color: #333399;
+ }
+}
+
+label {
+ display: block;
+ font-weight: bold;
+ margin-bottom: 0.5rem;
+}
+
+input {
+ display: block;
+ border: 1px solid #888;
+ padding: .375rem;
+ line-height: 1.25rem;
+ transition: border-color .15s ease-in-out,box-shadow .15s ease-in-out;
+ width: 100%;
+}
+
+input:focus {
+ outline: 0;
+ border-color: #80bdff;
+ box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
+}
+`
+
+type GemtextContext struct {
+ CSS string
+ ExternalCSS bool
+ External bool
+ Lines []gemini.Line
+ Pre int
+ Resp *gemini.Response
+ Title string
+ Lang string
+ URL *url.URL
+ Root *url.URL
+}
+
+type InputContext struct {
+ CSS string
+ ExternalCSS bool
+ Prompt string
+ Secret bool
+ URL *url.URL
+}
+
+type GemtextHeading struct {
+ Level int
+ Text string
+}
+
+func proxyGemini(req gemini.Request, external bool, root *url.URL,
+ w http.ResponseWriter, r *http.Request, css string, externalCSS bool) {
+
+ ctx, cancel := context.WithTimeout(r.Context(), 20*time.Second)
+ defer cancel()
+
+ client := gemini.Client{}
+ resp, err := client.Do(ctx, &req)
+ if err != nil {
+ w.WriteHeader(http.StatusBadGateway)
+ fmt.Fprintf(w, "Gateway error: %v", err)
+ return
+ }
+ defer resp.Body.Close()
+
+ switch resp.Status {
+ case 10, 11:
+ w.Header().Add("Content-Type", "text/html")
+ err = inputPage.Execute(w, &InputContext{
+ CSS: css,
+ ExternalCSS: externalCSS,
+ Prompt: resp.Meta,
+ Secret: resp.Status == 11,
+ URL: req.URL,
+ })
+ if err != nil {
+ w.WriteHeader(http.StatusInternalServerError)
+ w.Write([]byte(fmt.Sprintf("%v", err)))
+ }
+ return
+ case 20:
+ break // OK
+ case 30, 31:
+ to, err := url.Parse(resp.Meta)
+ if err != nil {
+ w.WriteHeader(http.StatusBadGateway)
+ fmt.Fprintf(w, "Gateway error: bad redirect: %v", err)
+ }
+ next := req.URL.ResolveReference(to)
+ if next.Scheme != "gemini" {
+ w.WriteHeader(http.StatusOK)
+ fmt.Fprintf(w, "This page is redirecting you to %s", next)
+ return
+ }
+ if external {
+ next.Path = fmt.Sprintf("/proxy/%s/%s", next.Host, next.Path)
+ }
+ next.Host = r.URL.Host
+ next.Scheme = r.URL.Scheme
+ w.Header().Add("Location", next.String())
+ w.WriteHeader(http.StatusFound)
+ fmt.Fprintf(w, "Redirecting to %s", next)
+ return
+ case 40, 41, 42, 43, 44:
+ w.WriteHeader(http.StatusServiceUnavailable)
+ fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
+ return
+ case 50, 51:
+ w.WriteHeader(http.StatusNotFound)
+ fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
+ return
+ case 52, 53, 59:
+ w.WriteHeader(http.StatusServiceUnavailable)
+ fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
+ return
+ default:
+ w.WriteHeader(http.StatusNotImplemented)
+ fmt.Fprintf(w, "Proxy does not understand Gemini response status %d", resp.Status)
+ return
+ }
+
+ m, params, err := mime.ParseMediaType(resp.Meta)
+ if err != nil {
+ w.WriteHeader(http.StatusBadGateway)
+ fmt.Fprintf(w, "Gateway error: %d %s: %v", resp.Status, resp.Meta, err)
+ return
+ }
+
+ if m != "text/gemini" {
+ w.Header().Add("Content-Type", resp.Meta)
+ io.Copy(w, resp.Body)
+ return
+ }
+
+ if charset, ok := params["charset"]; ok {
+ charset = strings.ToLower(charset)
+ if charset != "utf-8" {
+ w.WriteHeader(http.StatusNotImplemented)
+ fmt.Fprintf(w, "Unsupported charset: %s", charset)
+ return
+ }
+ }
+
+ lang := params["lang"]
+
+ w.Header().Add("Content-Type", "text/html")
+ gemctx := &GemtextContext{
+ CSS: css,
+ ExternalCSS: externalCSS,
+ External: external,
+ Resp: resp,
+ Title: req.URL.Host + " " + req.URL.Path,
+ Lang: lang,
+ URL: req.URL,
+ Root: root,
+ }
+
+ var title bool
+ gemini.ParseLines(resp.Body, func(line gemini.Line) {
+ gemctx.Lines = append(gemctx.Lines, line)
+ if !title {
+ if h, ok := line.(gemini.LineHeading1); ok {
+ gemctx.Title = string(h)
+ title = true
+ }
+ }
+ })
+
+ err = gemtextPage.Execute(w, gemctx)
+ if err != nil {
+ w.WriteHeader(http.StatusInternalServerError)
+ fmt.Fprintf(w, "%v", err)
+ return
+ }
+}
+
+func performIfEnv(key string, do func()) {
+ if len(os.Getenv(key)) != 0 {
+ do()
+ }
+}
+
+func main() {
+ var (
+ bind string = ":8080"
+ css string = defaultCSS
+ external bool = false
+ )
+
+ opts, optind, err := getopt.Getopts(os.Args, "b:c:s:e:")
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ performIfEnv("BIND", func() {
+ bind = os.Getenv("BIND")
+ })
+ performIfEnv("CSS", func() {
+ external = false
+ cssContent, err := ioutil.ReadFile(os.Getenv("CSS"))
+ if err == nil {
+ css = string(cssContent)
+ } else {
+ log.Fatalf("Error opening custom CSS from '%s': %v", os.Getenv("CSS"), err)
+ }
+ })
+ performIfEnv("CSS_EXTERNAL", func() {
+ external = true
+ css = os.Getenv("CSS_EXTERNAL")
+ })
+
+ for _, opt := range opts {
+ switch opt.Option {
+ case 'b':
+ bind = opt.Value
+ case 's':
+ external = false
+ cssContent, err := ioutil.ReadFile(opt.Value)
+ if err == nil {
+ css = string(cssContent)
+ } else {
+ log.Fatalf("Error opening custom CSS from '%s': %v", opt.Value, err)
+ }
+ case 'e':
+ external = true
+ css = opt.Value
+ }
+ }
+
+ args := os.Args[optind:]
+ var (
+ envRoot string
+ root *url.URL
+ )
+ if len(args) != 1 {
+ envRoot = os.Getenv("ROOT")
+ if len(envRoot) == 0 {
+ log.Fatalf("Usage: %s <gemini root>", os.Args[0])
+ }
+ } else {
+ root, err = url.Parse(args[0])
+ }
+ if len(envRoot) != 0 {
+ root, err = url.Parse(envRoot)
+ }
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ http.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ if r.Method == "POST" {
+ r.ParseForm()
+ if q, ok := r.Form["q"]; !ok {
+ w.WriteHeader(http.StatusBadRequest)
+ w.Write([]byte("Bad request"))
+ } else {
+ w.Header().Add("Location", "?"+q[0])
+ w.WriteHeader(http.StatusFound)
+ w.Write([]byte("Redirecting"))
+ }
+ return
+ }
+
+ log.Printf("%s %s", r.Method, r.URL.Path)
+ if r.Method != "GET" {
+ w.WriteHeader(http.StatusMethodNotAllowed)
+ w.Write([]byte("404 Not found"))
+ return
+ }
+
+ if r.URL.Path == "/favicon.ico" {
+ w.WriteHeader(http.StatusNotFound)
+ w.Write([]byte("404 Not found"))
+ return
+ }
+
+ req := gemini.Request{}
+ req.URL = &url.URL{}
+ req.URL.Scheme = root.Scheme
+ req.URL.Host = root.Host
+ req.URL.Path = r.URL.Path
+ req.URL.RawQuery = r.URL.RawQuery
+ proxyGemini(req, false, root, w, r, css, external)
+ }))
+
+ http.Handle("/proxy/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ if r.Method == "POST" {
+ r.ParseForm()
+ if q, ok := r.Form["q"]; !ok {
+ w.WriteHeader(http.StatusBadRequest)
+ w.Write([]byte("Bad request"))
+ } else {
+ w.Header().Add("Location", "?"+q[0])
+ w.WriteHeader(http.StatusFound)
+ w.Write([]byte("Redirecting"))
+ }
+ return
+ }
+
+ if r.Method != "GET" {
+ w.WriteHeader(http.StatusMethodNotAllowed)
+ w.Write([]byte("404 Not found"))
+ return
+ }
+
+ path := strings.SplitN(r.URL.Path, "/", 4)
+ if len(path) != 4 {
+ path = append(path, "")
+ }
+ req := gemini.Request{}
+ req.URL = &url.URL{}
+ req.URL.Scheme = "gemini"
+ req.URL.Host = path[2]
+ req.URL.Path = "/" + path[3]
+ req.URL.RawQuery = r.URL.RawQuery
+ log.Printf("%s (external) %s%s", r.Method, r.URL.Host, r.URL.Path)
+ proxyGemini(req, true, root, w, r, css, external)
+ }))
+
+ log.Printf("HTTP server listening on %s", bind)
+ log.Fatal(http.ListenAndServe(bind, nil))
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-06-06 14:32:20 +0000