package render import ( "bufio" "fmt" "io" urlPkg "net/url" "strconv" "strings" "github.com/makeworld-the-better-one/amfora/config" "github.com/spf13/viper" "gitlab.com/tslocum/cview" ) // Renderer for gemtext. Other Renderers are in renderer.go. type GemtextRenderer struct { // Buffers and I/O r *io.PipeReader w *io.PipeWriter links chan string // Configurable options // width is the number of columns to wrap to. width int // proxied is whether the request is through the gemini:// scheme. proxied bool ansiEnabled bool colorEnabled bool // State // pre indicates whether the renderer is currently in a preformatted block // or not. pre bool // numLinks is the number of links that exist so far. numLinks int } // NewGemtextRenderer. // // width is the number of columns to wrap to. // // proxied is whether the request is through the gemini:// scheme. // If it's not a gemini:// page, set this to true. func NewGemtextRenderer(width int, proxied bool) *GemtextRenderer { pr, pw := io.Pipe() links := make(chan string, 10) ansiEnabled := false if viper.GetBool("a-general.color") && viper.GetBool("a-general.ansi") { ansiEnabled = true } colorEnabled := false if viper.GetBool("a-general.color") { colorEnabled = true } return &GemtextRenderer{ r: pr, w: pw, links: links, width: width, proxied: proxied, ansiEnabled: ansiEnabled, colorEnabled: colorEnabled, } } // renderLine handles all lines except preformatted markings. The input line // should not end with any line delimiters, but the output line does. func (r *GemtextRenderer) renderLine(line string) string { if r.pre { if r.ansiEnabled { line = cview.TranslateANSI(line) // The TranslateANSI function injects tags like [-:-:-] // but this will reset the background to use the user's terminal color. // These tags need to be replaced with resets that use the theme color. line = strings.ReplaceAll(line, "[-:-:-]", fmt.Sprintf("[%s:%s:-]", config.GetColorString("preformatted_text"), config.GetColorString("bg")), ) // Set color at beginning and end of line to prevent background glitches // where the terminal background color slips through. This only happens on // preformatted blocks with ANSI characters. line = fmt.Sprintf("[%s]", config.GetColorString("preformatted_text")) + line + fmt.Sprintf("[%s:%s:-]", config.GetColorString("regular_text"), config.GetColorString("bg")) } else { line = ansiRegex.ReplaceAllString(line, "") } return line + "\n" } // Not preformatted, regular lines wrappedLines := make([]string, 0) // Final result // ANSI not allowed in regular text - see #59 line = ansiRegex.ReplaceAllString(line, "") if strings.HasPrefix(line, "#") { // Headings var tag string if viper.GetBool("a-general.color") { if strings.HasPrefix(line, "###") { tag = fmt.Sprintf("[%s::b]", config.GetColorString("hdg_3")) } else if strings.HasPrefix(line, "##") { tag = fmt.Sprintf("[%s::b]", config.GetColorString("hdg_2")) } else if strings.HasPrefix(line, "#") { tag = fmt.Sprintf("[%s::b]", config.GetColorString("hdg_1")) } wrappedLines = append(wrappedLines, wrapLine(line, r.width, tag, "[-::-]", true)...) } else { // Just bold, no colors wrappedLines = append(wrappedLines, wrapLine(line, r.width, "[::b]", "[-::-]", true)...) } // Links } else if strings.HasPrefix(line, "=>") && len([]rune(line)) >= 3 { // Trim whitespace and separate link from link text line = strings.Trim(line[2:], " \t") // Remove `=>` part too delim := strings.IndexAny(line, " \t") // Whitespace between link and link text var url string var linkText string if delim == -1 { // No link text url = line linkText = url } else { // There is link text url = line[:delim] linkText = strings.Trim(line[delim:], " \t") if viper.GetBool("a-general.show_link") { linkText += " (" + url + ")" } } if strings.TrimSpace(line) == "" || strings.TrimSpace(url) == "" { // Link was just whitespace, return it return "=>\n" } r.links <- url r.numLinks++ num := r.numLinks // Visible link number, one-indexed var indent int if num > 99 { // Indent link text by 3 or more spaces indent = len(strconv.Itoa(num)) + 4 // +4 indent for spaces and brackets } else { // One digit and two digit links have the same spacing - see #60 indent = 5 // +4 indent for spaces and brackets, and 1 for link number } // Spacing after link number: 1 or 2 spaces? var spacing string if num > 9 { // One space to keep it in line with other links - see #60 spacing = " " } else { // One digit numbers use two spaces spacing = " " } // Wrap and add link text // Wrap the link text, but add some spaces to indent the wrapped lines past the link number // Set the style tags // Add them to the first line var wrappedLink []string if viper.GetBool("a-general.color") { pU, err := urlPkg.Parse(url) if !r.proxied && err == nil && (pU.Scheme == "" || pU.Scheme == "gemini" || pU.Scheme == "about") { // A gemini link // Add the link text in blue (in a region), and a gray link number to the left of it // Those are the default colors, anyway wrappedLink = wrapLine(linkText, r.width, strings.Repeat(" ", indent)+ `["`+strconv.Itoa(num-1)+`"][`+config.GetColorString("amfora_link")+`]`, `[-][""]`, false, // Don't indent the first line, it's the one with link number ) // Add special stuff to first line, like the link number wrappedLink[0] = fmt.Sprintf(`[%s::b][`, config.GetColorString("link_number")) + strconv.Itoa(num) + "[]" + "[-::-]" + spacing + `["` + strconv.Itoa(num-1) + `"][` + config.GetColorString("amfora_link") + `]` + wrappedLink[0] + `[-][""]` } else { // Not a gemini link wrappedLink = wrapLine(linkText, r.width, strings.Repeat(" ", indent)+ `["`+strconv.Itoa(num-1)+`"][`+config.GetColorString("foreign_link")+`]`, `[-][""]`, false, // Don't indent the first line, it's the one with link number ) wrappedLink[0] = fmt.Sprintf(`[%s::b][`, config.GetColorString("link_number")) + strconv.Itoa(num) + "[]" + "[-::-]" + spacing + `["` + strconv.Itoa(num-1) + `"][` + config.GetColorString("foreign_link") + `]` + wrappedLink[0] + `[-][""]` } } else { // No colors allowed wrappedLink = wrapLine(linkText, r.width, strings.Repeat(" ", len(strconv.Itoa(num))+4)+ // +4 for spaces and brackets `["`+strconv.Itoa(num-1)+`"]`, `[""]`, false, // Don't indent the first line, it's the one with link number ) wrappedLink[0] = `[::b][` + strconv.Itoa(num) + "[][::-] " + `["` + strconv.Itoa(num-1) + `"]` + wrappedLink[0] + `[""]` } wrappedLines = append(wrappedLines, wrappedLink...) // Lists } else if strings.HasPrefix(line, "* ") { if viper.GetBool("a-general.bullets") { // Wrap list item, and indent wrapped lines past the bullet wrappedItem := wrapLine(line[1:], r.width, fmt.Sprintf(" [%s]", config.GetColorString("list_text")), "[-]", false) // Add bullet wrappedItem[0] = fmt.Sprintf(" [%s]\u2022", config.GetColorString("list_text")) + wrappedItem[0] + "[-]" wrappedLines = append(wrappedLines, wrappedItem...) } // Optionally list lines could be colored here too, if color is enabled } else if strings.HasPrefix(line, ">") { // It's a quote line, add extra quote symbols and italics to the start of each wrapped line if len(line) == 1 { // Just an empty quote line wrappedLines = append(wrappedLines, fmt.Sprintf("[%s::i]>[-::-]", config.GetColorString("quote_text"))) } else { // Remove beginning quote and maybe space line = strings.TrimPrefix(line, ">") line = strings.TrimPrefix(line, " ") wrappedLines = append(wrappedLines, wrapLine(line, r.width, fmt.Sprintf("[%s::i]> ", config.GetColorString("quote_text")), "[-::-]", true)..., ) } } else if strings.TrimSpace(line) == "" { // Just add empty line without processing wrappedLines = append(wrappedLines, "") } else { // Regular line, just wrap it wrappedLines = append(wrappedLines, wrapLine(line, r.width, fmt.Sprintf("[%s]", config.GetColorString("regular_text")), "[-]", true)...) } return strings.Join(wrappedLines, "\n") + "\n" } func (ren *GemtextRenderer) ReadFrom(r io.Reader) (int64, error) { // Go through lines, render, and write each line // TODO: Should writes be buffered? var n int64 scanner := bufio.NewScanner(r) scanner.Split(ScanLines) for scanner.Scan() { n += int64(len(scanner.Bytes())) line := scanner.Text() if strings.HasPrefix(line, "```") { ren.pre = !ren.pre continue } // Render line and write it //nolint:errcheck ren.w.Write([]byte( ren.renderLine(strings.TrimRight(line, "\r\n")), )) } return n, scanner.Err() } // Write will panic, use ReadFrom instead. func (r *GemtextRenderer) Write(p []byte) (n int, err error) { // This renderer is line based, and so it can't process arbitrary bytes. // One solution would be to handle rendering on the other end of the pipe, // the Read call, but it's simpler to just implement ReadFrom. panic("func Write not allowed for GemtextRenderer") } func (r *GemtextRenderer) Read(p []byte) (n int, err error) { return r.r.Read(p) } func (r *GemtextRenderer) Links() <-chan string { return r.links }