From 596749f91980cda2088d95fd0ec7d8bd70b11e85 Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Sun, 6 Sep 2020 00:01:52 +0100
Subject: [PATCH 1/6] Started simple browser.

---
 browse/main.go | 478 +++++++++++++++++++++++++++++++++++++++++++++++++
 go.mod         |   2 +
 go.sum         |  21 +++
 3 files changed, 501 insertions(+)
 create mode 100644 browse/main.go
 create mode 100644 go.sum

diff --git a/browse/main.go b/browse/main.go
new file mode 100644
index 0000000..36539d3
--- /dev/null
+++ b/browse/main.go
@@ -0,0 +1,478 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"os"
+	"strings"
+	"unicode"
+
+	"github.com/a-h/gemini"
+	"github.com/gdamore/tcell"
+	"github.com/mattn/go-runewidth"
+)
+
+func main() {
+	// Create a screen.
+	tcell.SetEncodingFallback(tcell.EncodingFallbackASCII)
+	s, err := tcell.NewScreen()
+	if err != nil {
+		fmt.Println("Error creating screen:", err)
+		os.Exit(1)
+	}
+	err = s.Init()
+	if err != nil {
+		fmt.Println("Error initializing screen:", err)
+		os.Exit(1)
+	}
+	defer s.Fini()
+
+	// Set default colours.
+	s.SetStyle(tcell.StyleDefault.
+		Foreground(tcell.ColorWhite).
+		Background(tcell.ColorBlack))
+	s.Clear()
+	s.Show()
+
+	// Parse the input.
+	urlString := strings.Join(os.Args[1:], "")
+	if urlString == "" {
+		//TODO: Load up a home page.
+		urlString = "gemini://localhost"
+	}
+	for {
+		// Grab the URL input.
+		urlString, ok := NewInput(s, 0, 0, tcell.StyleDefault, "Location:", urlString).Focus()
+		if !ok {
+			break
+		}
+
+		// Check the URL.
+		u, err := url.Parse(urlString)
+		if err != nil {
+			NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Failed to parse address: %q: %v", urlString, err), "OK").Focus()
+			continue
+		}
+
+		// Connect.
+		client := gemini.NewClient()
+		var resp *gemini.Response
+		var certificates []string
+		var redirectCount int
+	out:
+		for {
+			//TODO: Add cert store etc. to the client.
+			resp, certificates, _, ok, err = client.RequestURL(u)
+			if err != nil {
+				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Request error: %v", err), "Retry", "Cancel").Focus() {
+				case "Retry":
+					continue
+				case "Cancel":
+					break out
+				}
+
+			}
+			if !ok {
+				//TOFU check required.
+				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Accept client certificate?\n\n  %v", certificates[0]), "Accept", "Reject").Focus() {
+				case "Accept":
+					client.AddAlllowedCertificateForHost(u.Host, certificates[0])
+					continue
+				case "Reject":
+					break out
+				}
+			}
+			break
+		}
+		if !ok || resp == nil {
+			continue
+		}
+		if resp.Header.Code == gemini.CodeClientCertificateRequired {
+			switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("The server is requested a certificate."), "Create temporary", "Cancel").Focus() {
+			case "Create temporary":
+				//TODO: Add a certificate to the store.
+				break
+			case "Cancel":
+				break
+			}
+		}
+		//if resp.Header.Code == gemini.CodeInput {
+		//text, ok := NewInput(s, 0, 0, tcell.StyleDefault, resp.Header.Meta, "").Focus()
+		////TODO: Post the input back.
+		//continue
+		//}
+		if strings.HasPrefix(string(resp.Header.Code), "3") {
+			//TODO: Handle redirect.
+			redirectCount++
+		}
+		if strings.HasPrefix(string(resp.Header.Code), "2") {
+			NewBrowser(s, u, resp).Focus()
+			continue
+		}
+		NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Unknown code: %v %s", resp.Header.Code, resp.Header.Meta), "OK").Focus()
+	}
+}
+
+// flow breaks up text to its maximum width.
+func flow(s string, maxWidth int) []string {
+	var ss []string
+	flowProcessor(s, maxWidth, func(line string) {
+		ss = append(ss, line)
+	})
+	return ss
+}
+
+func flowProcessor(s string, maxWidth int, out func(string)) {
+	var buf strings.Builder
+	var col int
+	var lastSpace int
+	for _, r := range s {
+		if r == '\r' {
+			continue
+		}
+		if r == '\n' {
+			out(buf.String())
+			buf.Reset()
+			col = 0
+			lastSpace = 0
+			continue
+		}
+		buf.WriteRune(r)
+		if unicode.IsSpace(r) {
+			lastSpace = col
+		}
+		if col == maxWidth {
+			// If the word is greater than the width, then break the word down.
+			end := lastSpace
+			if end == 0 {
+				end = col
+			}
+			out(strings.TrimSpace(buf.String()[:end]))
+			prefix := strings.TrimSpace(buf.String()[end:])
+			buf.Reset()
+			lastSpace = 0
+			buf.WriteString(prefix)
+			col = len(prefix)
+			continue
+		}
+		col++
+	}
+	out(buf.String())
+}
+
+func NewText(s tcell.Screen, x, y int, st tcell.Style, text string) Text {
+	return Text{
+		Screen: s,
+		X:      x,
+		Y:      y,
+		Style:  st,
+		Text:   text,
+	}
+}
+
+type Text struct {
+	Screen tcell.Screen
+	X      int
+	Y      int
+	Style  tcell.Style
+	Text   string
+}
+
+func (t Text) Draw() (x, y int) {
+	maxX, maxY := t.Screen.Size()
+	flowed := flow(t.Text, maxX)
+	for lineIndex := 0; lineIndex < len(flowed); lineIndex++ {
+		y := t.Y + lineIndex
+		if y > maxY {
+			break
+		}
+		x = t.X
+		for _, c := range flowed[lineIndex] {
+			var comb []rune
+			w := runewidth.RuneWidth(c)
+			if w == 0 {
+				comb = []rune{c}
+				c = ' '
+				w = 1
+			}
+			t.Screen.SetContent(x, y, c, comb, t.Style)
+			x += w
+		}
+	}
+	return x, y
+}
+
+func NewOptions(s tcell.Screen, x, y int, st tcell.Style, msg string, opts ...string) *Options {
+	return &Options{
+		Screen:  s,
+		X:       x,
+		Y:       y,
+		Style:   st,
+		Message: msg,
+		Options: opts,
+	}
+}
+
+type Options struct {
+	Screen      tcell.Screen
+	X           int
+	Y           int
+	Style       tcell.Style
+	Message     string
+	Options     []string
+	ActiveIndex int
+}
+
+func (o *Options) Draw() {
+	o.Screen.Clear()
+	t := NewText(o.Screen, 0, 0, tcell.StyleDefault, o.Message)
+	_, y := t.Draw()
+	for i, oo := range o.Options {
+		style := tcell.StyleDefault
+		if i == o.ActiveIndex {
+			style = tcell.StyleDefault.Background(tcell.ColorLightGray)
+		}
+		t := NewText(o.Screen, 1, i+y+2, style, fmt.Sprintf("[ %s ]", oo))
+		t.Draw()
+	}
+}
+
+func (o *Options) Up() {
+	if o.ActiveIndex == 0 {
+		return
+	}
+	o.ActiveIndex--
+}
+
+func (o *Options) Down() {
+	if o.ActiveIndex == len(o.Options)-1 {
+		return
+	}
+	o.ActiveIndex++
+}
+
+func (o *Options) Focus() string {
+	o.Draw()
+	o.Screen.Show()
+	for {
+		switch ev := o.Screen.PollEvent().(type) {
+		case *tcell.EventResize:
+			o.Screen.Sync()
+		case *tcell.EventKey:
+			switch ev.Key() {
+			case tcell.KeyUp:
+				o.Up()
+			case tcell.KeyDown:
+				o.Down()
+			case tcell.KeyEnter:
+				return o.Options[o.ActiveIndex]
+			}
+		}
+		o.Draw()
+		o.Screen.Show()
+	}
+}
+
+func NewBrowser(s tcell.Screen, u *url.URL, resp *gemini.Response) *Browser {
+	return &Browser{
+		Screen:   s,
+		URL:      u,
+		Response: resp,
+	}
+}
+
+type Browser struct {
+	Screen   tcell.Screen
+	URL      *url.URL
+	Response *gemini.Response
+}
+
+func (b Browser) Draw() {
+	b.Screen.Clear()
+	//TODO: Handle error reading.
+	body, _ := ioutil.ReadAll(b.Response.Body)
+	//TODO: Render the lines properly.
+	NewText(b.Screen, 0, 0, tcell.StyleDefault, string(body)).Draw()
+}
+
+func (b Browser) Focus() {
+	b.Draw()
+	b.Screen.Show()
+	for {
+		switch ev := b.Screen.PollEvent().(type) {
+		case *tcell.EventResize:
+			b.Screen.Sync()
+			b.Draw()
+			b.Screen.Show()
+		case *tcell.EventKey:
+			if ev.Key() == tcell.KeyEscape {
+				return
+			}
+		}
+	}
+}
+
+func NewInput(s tcell.Screen, x, y int, st tcell.Style, msg, text string) *Input {
+	return &Input{
+		Screen:      s,
+		X:           x,
+		Y:           y,
+		Style:       st,
+		Message:     msg,
+		Text:        text,
+		CursorIndex: len(text),
+	}
+}
+
+type Input struct {
+	Screen      tcell.Screen
+	X           int
+	Y           int
+	Style       tcell.Style
+	Message     string
+	Text        string
+	CursorIndex int
+	ActiveIndex int
+}
+
+func (o *Input) Draw() {
+	o.Screen.Clear()
+	t := NewText(o.Screen, o.X, o.Y, o.Style, o.Message)
+	_, y := t.Draw()
+
+	defaultStyle := tcell.StyleDefault
+	activeStyle := tcell.StyleDefault.Background(tcell.ColorLightGray)
+
+	textStyle := defaultStyle
+	if o.ActiveIndex == 0 {
+		textStyle = defaultStyle.Underline(true)
+		// Show that the input is active.
+		NewText(o.Screen, o.X, o.Y+y+2, defaultStyle, ">").Draw()
+	}
+	NewText(o.Screen, o.X+2, o.Y+y+2, textStyle, o.Text).Draw()
+	if o.ActiveIndex == 0 {
+		o.Screen.ShowCursor(o.X+2+o.CursorIndex, o.Y+y+2)
+	} else {
+		o.Screen.HideCursor()
+	}
+
+	okStyle := defaultStyle
+	if o.ActiveIndex == 1 {
+		okStyle = activeStyle
+	}
+	NewText(o.Screen, 1, o.Y+y+4, okStyle, "[ OK ]").Draw()
+	cancelStyle := defaultStyle
+	if o.ActiveIndex == 2 {
+		cancelStyle = activeStyle
+	}
+	NewText(o.Screen, 1, o.Y+y+5, cancelStyle, "[ Cancel ]").Draw()
+}
+
+func (o *Input) Up() {
+	if o.ActiveIndex == 0 {
+		return
+	}
+	o.ActiveIndex--
+}
+
+func (o *Input) Down() {
+	if o.ActiveIndex == 2 {
+		return
+	}
+	o.ActiveIndex++
+}
+
+type InputResult string
+
+func (o *Input) Focus() (text string, ok bool) {
+	o.Draw()
+	o.Screen.Show()
+	for {
+		if o.ActiveIndex == 0 {
+			// Handle textbox keys.
+			switch ev := o.Screen.PollEvent().(type) {
+			case *tcell.EventResize:
+				o.Screen.Sync()
+			case *tcell.EventKey:
+				switch ev.Key() {
+				case tcell.KeyBackspace:
+					if tl := len(o.Text); tl > 0 {
+						o.CursorIndex--
+						o.Text = o.Text[0 : tl-1]
+					}
+				case tcell.KeyLeft:
+					if o.CursorIndex > 0 {
+						o.CursorIndex--
+					}
+				case tcell.KeyRight:
+					if o.CursorIndex < len(o.Text) {
+						o.CursorIndex++
+					}
+				case tcell.KeyDelete:
+					o.Text = cut(o.Text, o.CursorIndex)
+				case tcell.KeyHome:
+					o.CursorIndex = 0
+				case tcell.KeyEnd:
+					o.CursorIndex = len(o.Text)
+				case tcell.KeyRune:
+					o.Text = insert(o.Text, o.CursorIndex, ev.Rune())
+					o.CursorIndex++
+				case tcell.KeyDown:
+					o.Down()
+				case tcell.KeyEnter:
+					o.Down()
+				}
+			}
+			o.Draw()
+			o.Screen.Show()
+			continue
+		}
+		switch ev := o.Screen.PollEvent().(type) {
+		case *tcell.EventResize:
+			o.Screen.Sync()
+		case *tcell.EventKey:
+			switch ev.Key() {
+			case tcell.KeyUp:
+				o.Up()
+			case tcell.KeyDown:
+				o.Down()
+			case tcell.KeyEnter:
+				switch o.ActiveIndex {
+				case 0:
+					o.ActiveIndex = 1
+					break
+				case 1:
+					return o.Text, true
+				case 2:
+					return o.Text, false
+				}
+			}
+		}
+		o.Draw()
+		o.Screen.Show()
+	}
+}
+
+func cut(s string, at int) string {
+	prefix, suffix := split(s, at)
+	if len(suffix) > 0 {
+		suffix = suffix[1:]
+	}
+	return prefix + suffix
+}
+
+func split(s string, at int) (prefix, suffix string) {
+	if at > len(s) {
+		prefix = s
+		return
+	}
+	prefix = string([]rune(s)[:at])
+	suffix = string([]rune(s)[at:])
+	return
+}
+
+func insert(s string, at int, r rune) string {
+	prefix, suffix := split(s, at)
+	return prefix + string(r) + suffix
+}
diff --git a/go.mod b/go.mod
index 73272a1..87f8a0c 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module github.com/a-h/gemini
 
 go 1.14
+
+require github.com/rivo/tview v0.0.0-20200818120338-53d50e499bf9 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..3844182
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,21 @@
+github.com/DATA-DOG/go-sqlmock v1.3.3/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
+github.com/gdamore/encoding v1.0.0 h1:+7OoQ1Bc6eTm5niUzBa0Ctsh6JbMW6Ra+YNuAtDBdko=
+github.com/gdamore/encoding v1.0.0/go.mod h1:alR0ol34c49FCSBLjhosxzcPHQbf2trDkoo5dl+VrEg=
+github.com/gdamore/tcell v1.3.0 h1:r35w0JBADPZCVQijYebl6YMWWtHRqVEGt7kL2eBADRM=
+github.com/gdamore/tcell v1.3.0/go.mod h1:Hjvr+Ofd+gLglo7RYKxxnzCBmev3BzsS67MebKS4zMM=
+github.com/lucasb-eyer/go-colorful v1.0.2/go.mod h1:0MS4r+7BZKSJ5mw4/S5MPN+qHFF1fYclkSPilDOKW0s=
+github.com/lucasb-eyer/go-colorful v1.0.3 h1:QIbQXiugsb+q10B+MI+7DI1oQLdmnep86tWFlaaUAac=
+github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
+github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
+github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/rivo/tview v0.0.0-20200818120338-53d50e499bf9 h1:csnip7QsoiE2Ee0RkELN1YggwejK2EFfcjU6tXOT0Q8=
+github.com/rivo/tview v0.0.0-20200818120338-53d50e499bf9/go.mod h1:xV4Aw4WIX8cmhg71U7MUHBdpIQ7zSEXdRruGHLaEAOc=
+github.com/rivo/uniseg v0.1.0 h1:+2KBaVoUmb9XzDsrx/Ct0W/EYOSFf/nWTauy++DprtY=
+github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+golang.org/x/sys v0.0.0-20190626150813-e07cf5db2756/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200817155316-9781c653f443/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

From da5d5e5b3c423db5eac22bdc6740b435b81fde36 Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Sun, 6 Sep 2020 17:12:19 +0100
Subject: [PATCH 2/6] client: fix missing meta from server repsponses.

---
 browse/main.go | 316 ++++++++++++++++++++++++++++++++++++++++++++-----
 client.go      |   2 +-
 2 files changed, 285 insertions(+), 33 deletions(-)

diff --git a/browse/main.go b/browse/main.go
index 36539d3..4e514ee 100644
--- a/browse/main.go
+++ b/browse/main.go
@@ -1,8 +1,9 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/url"
 	"os"
 	"strings"
@@ -41,12 +42,17 @@ func main() {
 		//TODO: Load up a home page.
 		urlString = "gemini://localhost"
 	}
+	var askForURL, ok bool
+	askForURL = true
 	for {
 		// Grab the URL input.
-		urlString, ok := NewInput(s, 0, 0, tcell.StyleDefault, "Location:", urlString).Focus()
-		if !ok {
-			break
+		if askForURL {
+			urlString, ok = NewInput(s, 0, 0, tcell.StyleDefault, "Location:", urlString).Focus()
+			if !ok {
+				break
+			}
 		}
+		askForURL = !askForURL
 
 		// Check the URL.
 		u, err := url.Parse(urlString)
@@ -75,8 +81,9 @@ func main() {
 			}
 			if !ok {
 				//TOFU check required.
-				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Accept client certificate?\n\n  %v", certificates[0]), "Accept", "Reject").Focus() {
+				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Accept client certificate?\n  %v", certificates[0]), "Accept", "Reject").Focus() {
 				case "Accept":
+					//TODO: Save this in a persistent store.
 					client.AddAlllowedCertificateForHost(u.Host, certificates[0])
 					continue
 				case "Reject":
@@ -97,17 +104,37 @@ func main() {
 				break
 			}
 		}
-		//if resp.Header.Code == gemini.CodeInput {
-		//text, ok := NewInput(s, 0, 0, tcell.StyleDefault, resp.Header.Meta, "").Focus()
-		////TODO: Post the input back.
-		//continue
-		//}
+		if resp.Header.Code == gemini.CodeInput {
+			text, ok := NewInput(s, 0, 0, tcell.StyleDefault, resp.Header.Meta, "").Focus()
+			if !ok {
+				continue
+			}
+			// Post the input back.
+			askForURL = false
+			u.RawQuery = url.QueryEscape(text)
+			urlString = u.String()
+			continue
+		}
 		if strings.HasPrefix(string(resp.Header.Code), "3") {
 			//TODO: Handle redirect.
 			redirectCount++
 		}
 		if strings.HasPrefix(string(resp.Header.Code), "2") {
-			NewBrowser(s, u, resp).Focus()
+			b, err := NewBrowser(s, u, resp)
+			if err != nil {
+				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Error displaying server response:\n\n%v", err), "OK").Focus()
+				continue
+			}
+			next, err := b.Focus()
+			if err != nil {
+				//TODO: The link was garbage, show the error.
+				continue
+			}
+			if next != nil {
+				askForURL = false
+				urlString = next.String()
+				continue
+			}
 			continue
 		}
 		NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Unknown code: %v %s", resp.Header.Code, resp.Header.Meta), "OK").Focus()
@@ -181,14 +208,20 @@ type Text struct {
 
 func (t Text) Draw() (x, y int) {
 	maxX, maxY := t.Screen.Size()
-	flowed := flow(t.Text, maxX)
-	for lineIndex := 0; lineIndex < len(flowed); lineIndex++ {
-		y := t.Y + lineIndex
+	maxWidth := maxX - t.X
+	if maxWidth < 0 {
+		// It's off screen, so there's nothing to display.
+		return
+	}
+	lines := flow(t.Text, maxWidth)
+	var requiredMaxWidth int
+	for lineIndex := 0; lineIndex < len(lines); lineIndex++ {
+		y = t.Y + lineIndex
 		if y > maxY {
 			break
 		}
 		x = t.X
-		for _, c := range flowed[lineIndex] {
+		for _, c := range lines[lineIndex] {
 			var comb []rune
 			w := runewidth.RuneWidth(c)
 			if w == 0 {
@@ -198,9 +231,12 @@ func (t Text) Draw() (x, y int) {
 			}
 			t.Screen.SetContent(x, y, c, comb, t.Style)
 			x += w
+			if x > requiredMaxWidth {
+				requiredMaxWidth = x
+			}
 		}
 	}
-	return x, y
+	return requiredMaxWidth, y
 }
 
 func NewOptions(s tcell.Screen, x, y int, st tcell.Style, msg string, opts ...string) *Options {
@@ -274,42 +310,255 @@ func (o *Options) Focus() string {
 	}
 }
 
-func NewBrowser(s tcell.Screen, u *url.URL, resp *gemini.Response) *Browser {
-	return &Browser{
-		Screen:   s,
-		URL:      u,
+func NewLineConverter(resp *gemini.Response) *LineConverter {
+	return &LineConverter{
 		Response: resp,
 	}
 }
 
+type LineConverter struct {
+	Response     *gemini.Response
+	preFormatted bool
+}
+
+func (lc *LineConverter) process(s string) (l Line, isVisualLine bool) {
+	if strings.HasPrefix(s, "```") {
+		lc.preFormatted = !lc.preFormatted
+		return l, false
+	}
+	if lc.preFormatted {
+		return PreformattedTextLine{Text: s}, true
+	}
+	if strings.HasPrefix(s, "=>") {
+		return LinkLine{Text: s}, true
+	}
+	if strings.HasPrefix(s, "#") {
+		return HeadingLine{Text: s}, true
+	}
+	if strings.HasPrefix(s, "* ") {
+		return UnorderedListItemLine{Text: s}, true
+	}
+	if strings.HasPrefix(s, ">") {
+		return QuoteLine{Text: s}, true
+	}
+	return TextLine{Text: s}, true
+}
+
+func (lc *LineConverter) Lines() (lines []Line, err error) {
+	reader := bufio.NewReader(lc.Response.Body)
+	var s string
+	for {
+		s, err = reader.ReadString('\n')
+		line, isVisual := lc.process(strings.TrimRight(s, "\n"))
+		if isVisual {
+			lines = append(lines, line)
+		}
+		if err != nil {
+			break
+		}
+	}
+	if err == io.EOF {
+		err = nil
+	}
+	return
+}
+
+type Line interface {
+	Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int)
+}
+
+type TextLine struct {
+	Text string
+}
+
+func (l TextLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	return NewText(to, atX, atY, tcell.StyleDefault, l.Text).Draw()
+}
+
+type PreformattedTextLine struct {
+	Text string
+}
+
+func (l PreformattedTextLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	return NewText(to, atX, atY, tcell.StyleDefault, l.Text).Draw()
+}
+
+type LinkLine struct {
+	Text string
+}
+
+func (l LinkLine) URL(relativeTo *url.URL) (u *url.URL, err error) {
+	urlString := strings.TrimPrefix(l.Text, "=>")
+	urlString = strings.TrimSpace(urlString)
+	urlString = strings.SplitN(urlString, " ", 2)[0]
+	u, err = url.Parse(urlString)
+	if err != nil {
+		return
+	}
+	if u.IsAbs() || relativeTo == nil {
+		return
+	}
+	return relativeTo.ResolveReference(u), nil
+}
+
+func (l LinkLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	ls := tcell.StyleDefault.Foreground(tcell.ColorBlue)
+	if highlighted {
+		ls = ls.Underline(true)
+	}
+	return NewText(to, atX+2, atY, ls, l.Text).Draw()
+}
+
+type HeadingLine struct {
+	Text string
+}
+
+func (l HeadingLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	return NewText(to, atX, atY, tcell.StyleDefault.Foreground(tcell.ColorGreen), l.Text).Draw()
+}
+
+type UnorderedListItemLine struct {
+	Text string
+}
+
+func (l UnorderedListItemLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	return NewText(to, atX+2, atY, tcell.StyleDefault, l.Text).Draw()
+}
+
+type QuoteLine struct {
+	Text string
+}
+
+func (l QuoteLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
+	return NewText(to, atX+2, atY, tcell.StyleDefault.Foreground(tcell.ColorLightGrey), l.Text).Draw()
+}
+
+func NewBrowser(s tcell.Screen, u *url.URL, resp *gemini.Response) (b *Browser, err error) {
+	b = &Browser{
+		Screen:          s,
+		URL:             u,
+		ResponseHeader:  resp.Header,
+		ActiveLineIndex: -1,
+	}
+	b.Lines, err = NewLineConverter(resp).Lines()
+	return
+}
+
 type Browser struct {
-	Screen   tcell.Screen
-	URL      *url.URL
-	Response *gemini.Response
+	Screen          tcell.Screen
+	URL             *url.URL
+	ResponseHeader  *gemini.Header
+	Lines           []Line
+	ActiveLineIndex int
+}
+
+func (b *Browser) Links() (indices []int) {
+	for i := 0; i < len(b.Lines); i++ {
+		if _, ok := b.Lines[i].(LinkLine); ok {
+			indices = append(indices, i)
+		}
+	}
+	return indices
+}
+
+func (b *Browser) CurrentLink() (u *url.URL, err error) {
+	for i := 0; i < len(b.Lines); i++ {
+		if i == b.ActiveLineIndex {
+			if ll, ok := b.Lines[b.ActiveLineIndex].(LinkLine); ok {
+				return ll.URL(b.URL)
+			}
+		}
+	}
+	return nil, nil
+}
+
+func (b *Browser) PreviousLink() {
+	ll := b.Links()
+	if len(ll) == 0 {
+		return
+	}
+	if b.ActiveLineIndex < 0 {
+		b.ActiveLineIndex = ll[len(ll)-1]
+		return
+	}
+	var curIndex, li int
+	for curIndex, li = range ll {
+		if li == b.ActiveLineIndex {
+			break
+		}
+	}
+	if curIndex == 0 {
+		b.ActiveLineIndex = ll[len(ll)-1]
+		return
+	}
+	b.ActiveLineIndex = ll[curIndex-1]
+}
+
+func (b *Browser) NextLink() {
+	ll := b.Links()
+	if len(ll) == 0 {
+		return
+	}
+	if b.ActiveLineIndex < 0 {
+		b.ActiveLineIndex = ll[0]
+		return
+	}
+	var curIndex, li int
+	for curIndex, li = range ll {
+		if li == b.ActiveLineIndex {
+			break
+		}
+	}
+	if curIndex == len(ll)-1 {
+		b.ActiveLineIndex = ll[0]
+		return
+	}
+	b.ActiveLineIndex = ll[curIndex+1]
 }
 
 func (b Browser) Draw() {
 	b.Screen.Clear()
-	//TODO: Handle error reading.
-	body, _ := ioutil.ReadAll(b.Response.Body)
-	//TODO: Render the lines properly.
-	NewText(b.Screen, 0, 0, tcell.StyleDefault, string(body)).Draw()
+	//TODO: Handle scrolling.
+	var y int
+	for lineIndex, line := range b.Lines {
+		highlighted := lineIndex == b.ActiveLineIndex
+		_, yy := line.Draw(b.Screen, 0, y, highlighted)
+		y = yy + 1
+	}
 }
 
-func (b Browser) Focus() {
+func (b Browser) Focus() (next *url.URL, err error) {
 	b.Draw()
 	b.Screen.Show()
 	for {
 		switch ev := b.Screen.PollEvent().(type) {
 		case *tcell.EventResize:
 			b.Screen.Sync()
-			b.Draw()
-			b.Screen.Show()
 		case *tcell.EventKey:
-			if ev.Key() == tcell.KeyEscape {
+			switch ev.Key() {
+			case tcell.KeyEscape:
 				return
+			case tcell.KeyBacktab:
+				b.PreviousLink()
+			case tcell.KeyTAB:
+				b.NextLink()
+			case tcell.KeyCtrlO:
+				b.PreviousLink()
+			case tcell.KeyEnter:
+				return b.CurrentLink()
+			case tcell.KeyRune:
+				switch ev.Rune() {
+				case 'j':
+					//TODO: Scroll down.
+				case 'k':
+					//TODO: Scroll up.
+				case 'n':
+					b.NextLink()
+				}
 			}
 		}
+		b.Draw()
+		b.Screen.Show()
 	}
 }
 
@@ -347,7 +596,6 @@ func (o *Input) Draw() {
 	textStyle := defaultStyle
 	if o.ActiveIndex == 0 {
 		textStyle = defaultStyle.Underline(true)
-		// Show that the input is active.
 		NewText(o.Screen, o.X, o.Y+y+2, defaultStyle, ">").Draw()
 	}
 	NewText(o.Screen, o.X+2, o.Y+y+2, textStyle, o.Text).Draw()
@@ -418,6 +666,10 @@ func (o *Input) Focus() (text string, ok bool) {
 				case tcell.KeyRune:
 					o.Text = insert(o.Text, o.CursorIndex, ev.Rune())
 					o.CursorIndex++
+				case tcell.KeyBacktab:
+					o.Up()
+				case tcell.KeyTab:
+					o.Down()
 				case tcell.KeyDown:
 					o.Down()
 				case tcell.KeyEnter:
diff --git a/client.go b/client.go
index 5d2161b..2bc865d 100644
--- a/client.go
+++ b/client.go
@@ -69,7 +69,7 @@ func readHeader(r io.Reader) (h Header, err error) {
 		err = ErrInvalidCode
 		return
 	}
-	if len(h.Meta) > 1 {
+	if len(parts) > 1 {
 		h.Meta = parts[1]
 		if !isValidMeta(h.Meta) {
 			err = ErrInvalidMeta

From bc84b2896cb5df4d31686071976af9053dca40cc Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Sun, 6 Sep 2020 17:17:17 +0100
Subject: [PATCH 3/6] Added ability to press escape to quit input boxes.

---
 browse/main.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/browse/main.go b/browse/main.go
index 4e514ee..8d6b8c4 100644
--- a/browse/main.go
+++ b/browse/main.go
@@ -595,7 +595,6 @@ func (o *Input) Draw() {
 
 	textStyle := defaultStyle
 	if o.ActiveIndex == 0 {
-		textStyle = defaultStyle.Underline(true)
 		NewText(o.Screen, o.X, o.Y+y+2, defaultStyle, ">").Draw()
 	}
 	NewText(o.Screen, o.X+2, o.Y+y+2, textStyle, o.Text).Draw()
@@ -685,6 +684,10 @@ func (o *Input) Focus() (text string, ok bool) {
 			o.Screen.Sync()
 		case *tcell.EventKey:
 			switch ev.Key() {
+			case tcell.KeyBacktab:
+				o.Up()
+			case tcell.KeyTab:
+				o.Down()
 			case tcell.KeyUp:
 				o.Up()
 			case tcell.KeyDown:
@@ -699,6 +702,8 @@ func (o *Input) Focus() (text string, ok bool) {
 				case 2:
 					return o.Text, false
 				}
+			case tcell.KeyEscape:
+				return o.Text, false
 			}
 		}
 		o.Draw()

From ffca608d27c7ff8a6570727eee29c05996dc7931 Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Sun, 6 Sep 2020 17:23:32 +0100
Subject: [PATCH 4/6] Precalulate all links to remove wasted processing.

---
 browse/main.go | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/browse/main.go b/browse/main.go
index 8d6b8c4..6745469 100644
--- a/browse/main.go
+++ b/browse/main.go
@@ -441,6 +441,7 @@ func NewBrowser(s tcell.Screen, u *url.URL, resp *gemini.Response) (b *Browser,
 		ActiveLineIndex: -1,
 	}
 	b.Lines, err = NewLineConverter(resp).Lines()
+	b.calculateLinkIndices()
 	return
 }
 
@@ -449,16 +450,16 @@ type Browser struct {
 	URL             *url.URL
 	ResponseHeader  *gemini.Header
 	Lines           []Line
+	LinkLineIndices []int
 	ActiveLineIndex int
 }
 
-func (b *Browser) Links() (indices []int) {
+func (b *Browser) calculateLinkIndices() {
 	for i := 0; i < len(b.Lines); i++ {
 		if _, ok := b.Lines[i].(LinkLine); ok {
-			indices = append(indices, i)
+			b.LinkLineIndices = append(b.LinkLineIndices, i)
 		}
 	}
-	return indices
 }
 
 func (b *Browser) CurrentLink() (u *url.URL, err error) {
@@ -473,47 +474,45 @@ func (b *Browser) CurrentLink() (u *url.URL, err error) {
 }
 
 func (b *Browser) PreviousLink() {
-	ll := b.Links()
-	if len(ll) == 0 {
+	if len(b.LinkLineIndices) == 0 {
 		return
 	}
 	if b.ActiveLineIndex < 0 {
-		b.ActiveLineIndex = ll[len(ll)-1]
+		b.ActiveLineIndex = b.LinkLineIndices[len(b.LinkLineIndices)-1]
 		return
 	}
 	var curIndex, li int
-	for curIndex, li = range ll {
+	for curIndex, li = range b.LinkLineIndices {
 		if li == b.ActiveLineIndex {
 			break
 		}
 	}
 	if curIndex == 0 {
-		b.ActiveLineIndex = ll[len(ll)-1]
+		b.ActiveLineIndex = b.LinkLineIndices[len(b.LinkLineIndices)-1]
 		return
 	}
-	b.ActiveLineIndex = ll[curIndex-1]
+	b.ActiveLineIndex = b.LinkLineIndices[curIndex-1]
 }
 
 func (b *Browser) NextLink() {
-	ll := b.Links()
-	if len(ll) == 0 {
+	if len(b.LinkLineIndices) == 0 {
 		return
 	}
 	if b.ActiveLineIndex < 0 {
-		b.ActiveLineIndex = ll[0]
+		b.ActiveLineIndex = b.LinkLineIndices[0]
 		return
 	}
 	var curIndex, li int
-	for curIndex, li = range ll {
+	for curIndex, li = range b.LinkLineIndices {
 		if li == b.ActiveLineIndex {
 			break
 		}
 	}
-	if curIndex == len(ll)-1 {
-		b.ActiveLineIndex = ll[0]
+	if curIndex == len(b.LinkLineIndices)-1 {
+		b.ActiveLineIndex = b.LinkLineIndices[0]
 		return
 	}
-	b.ActiveLineIndex = ll[curIndex+1]
+	b.ActiveLineIndex = b.LinkLineIndices[curIndex+1]
 }
 
 func (b Browser) Draw() {

From 091fadb330cdbbc5152ffb377b2cd24bb1c29a33 Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Sun, 6 Sep 2020 18:02:03 +0100
Subject: [PATCH 5/6] Added ability to escape from dialogs, also ensured asking
 for URLs.

---
 browse/main.go | 100 ++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 74 insertions(+), 26 deletions(-)

diff --git a/browse/main.go b/browse/main.go
index 6745469..01c330b 100644
--- a/browse/main.go
+++ b/browse/main.go
@@ -36,12 +36,17 @@ func main() {
 	s.Clear()
 	s.Show()
 
-	// Parse the input.
+	// Parse the command-line URL, if provided.
 	urlString := strings.Join(os.Args[1:], "")
 	if urlString == "" {
-		//TODO: Load up a home page.
+		//TODO: Load up a home page based on configuration.
 		urlString = "gemini://localhost"
 	}
+
+	// Create required top-level variables.
+	client := gemini.NewClient()
+	var redirectCount int
+
 	var askForURL, ok bool
 	askForURL = true
 	for {
@@ -52,20 +57,18 @@ func main() {
 				break
 			}
 		}
-		askForURL = !askForURL
 
 		// Check the URL.
 		u, err := url.Parse(urlString)
 		if err != nil {
 			NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Failed to parse address: %q: %v", urlString, err), "OK").Focus()
+			askForURL = true
 			continue
 		}
 
 		// Connect.
-		client := gemini.NewClient()
 		var resp *gemini.Response
 		var certificates []string
-		var redirectCount int
 	out:
 		for {
 			//TODO: Add cert store etc. to the client.
@@ -73,11 +76,11 @@ func main() {
 			if err != nil {
 				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Request error: %v", err), "Retry", "Cancel").Focus() {
 				case "Retry":
+					askForURL = false
 					continue
 				case "Cancel":
 					break out
 				}
-
 			}
 			if !ok {
 				//TOFU check required.
@@ -85,6 +88,7 @@ func main() {
 				case "Accept":
 					//TODO: Save this in a persistent store.
 					client.AddAlllowedCertificateForHost(u.Host, certificates[0])
+					askForURL = false
 					continue
 				case "Reject":
 					break out
@@ -93,51 +97,76 @@ func main() {
 			break
 		}
 		if !ok || resp == nil {
+			askForURL = true
 			continue
 		}
-		if resp.Header.Code == gemini.CodeClientCertificateRequired {
-			switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("The server is requested a certificate."), "Create temporary", "Cancel").Focus() {
+		if strings.HasPrefix(string(resp.Header.Code), "3") {
+			redirectCount++
+			if redirectCount >= 5 {
+				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Server issued 5 or more redirects, cancelling request."), "OK").Focus()
+				askForURL = true
+				continue
+			}
+			redirectTo, err := url.Parse(resp.Header.Meta)
+			if err != nil {
+				//TODO: Add the ability to go back, once history has been added.
+				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Server returned invalid redirect: code %s, meta: %q", resp.Header.Code, resp.Header.Meta), "OK").Focus()
+				askForURL = true
+				continue
+			}
+			//TODO: Check with the user if the redirect is to another domain or protocol.
+			urlString = u.ResolveReference(redirectTo).String()
+			askForURL = false
+			continue
+		}
+		redirectCount = 0
+		if strings.HasPrefix(string(resp.Header.Code), "6") {
+			switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("The server has requested a certificate: code %s, meta: %q", resp.Header.Code, resp.Header.Meta), "Create temporary", "Cancel").Focus() {
 			case "Create temporary":
 				//TODO: Add a certificate to the store.
-				break
+				askForURL = false
+				continue
 			case "Cancel":
-				break
+				askForURL = true
+				continue
 			}
 		}
-		if resp.Header.Code == gemini.CodeInput {
+		if strings.HasPrefix(string(resp.Header.Code), "1") {
 			text, ok := NewInput(s, 0, 0, tcell.StyleDefault, resp.Header.Meta, "").Focus()
 			if !ok {
 				continue
 			}
 			// Post the input back.
-			askForURL = false
 			u.RawQuery = url.QueryEscape(text)
 			urlString = u.String()
+			askForURL = false
 			continue
 		}
-		if strings.HasPrefix(string(resp.Header.Code), "3") {
-			//TODO: Handle redirect.
-			redirectCount++
-		}
 		if strings.HasPrefix(string(resp.Header.Code), "2") {
 			b, err := NewBrowser(s, u, resp)
 			if err != nil {
 				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Error displaying server response:\n\n%v", err), "OK").Focus()
+				askForURL = true
 				continue
 			}
 			next, err := b.Focus()
 			if err != nil {
 				//TODO: The link was garbage, show the error.
+				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Invalid link: %q\n", err), "OK").Focus()
+				askForURL = true
 				continue
 			}
 			if next != nil {
-				askForURL = false
+				//TODO: Ask the user whether they want to follow it, if it's a non-Gemini link.
 				urlString = next.String()
+				askForURL = false
 				continue
 			}
+			askForURL = true
 			continue
 		}
 		NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Unknown code: %v %s", resp.Header.Code, resp.Header.Meta), "OK").Focus()
+		askForURL = true
 	}
 }
 
@@ -240,13 +269,21 @@ func (t Text) Draw() (x, y int) {
 }
 
 func NewOptions(s tcell.Screen, x, y int, st tcell.Style, msg string, opts ...string) *Options {
+	cancelIndex := -1
+	for i, o := range opts {
+		if o == "Cancel" {
+			cancelIndex = i
+			break
+		}
+	}
 	return &Options{
-		Screen:  s,
-		X:       x,
-		Y:       y,
-		Style:   st,
-		Message: msg,
-		Options: opts,
+		Screen:      s,
+		X:           x,
+		Y:           y,
+		Style:       st,
+		Message:     msg,
+		Options:     opts,
+		CancelIndex: cancelIndex,
 	}
 }
 
@@ -258,6 +295,7 @@ type Options struct {
 	Message     string
 	Options     []string
 	ActiveIndex int
+	CancelIndex int
 }
 
 func (o *Options) Draw() {
@@ -276,14 +314,14 @@ func (o *Options) Draw() {
 
 func (o *Options) Up() {
 	if o.ActiveIndex == 0 {
-		return
+		o.ActiveIndex = len(o.Options) - 1
 	}
 	o.ActiveIndex--
 }
 
 func (o *Options) Down() {
 	if o.ActiveIndex == len(o.Options)-1 {
-		return
+		o.ActiveIndex = 0
 	}
 	o.ActiveIndex++
 }
@@ -297,10 +335,18 @@ func (o *Options) Focus() string {
 			o.Screen.Sync()
 		case *tcell.EventKey:
 			switch ev.Key() {
+			case tcell.KeyBacktab:
+				o.Up()
+			case tcell.KeyTab:
+				o.Down()
 			case tcell.KeyUp:
 				o.Up()
 			case tcell.KeyDown:
 				o.Down()
+			case tcell.KeyEscape:
+				if o.CancelIndex > -1 {
+					return o.Options[o.CancelIndex]
+				}
 			case tcell.KeyEnter:
 				return o.Options[o.ActiveIndex]
 			}
@@ -395,7 +441,7 @@ func (l LinkLine) URL(relativeTo *url.URL) (u *url.URL, err error) {
 	if err != nil {
 		return
 	}
-	if u.IsAbs() || relativeTo == nil {
+	if relativeTo == nil {
 		return
 	}
 	return relativeTo.ResolveReference(u), nil
@@ -617,6 +663,7 @@ func (o *Input) Draw() {
 
 func (o *Input) Up() {
 	if o.ActiveIndex == 0 {
+		o.ActiveIndex = 2
 		return
 	}
 	o.ActiveIndex--
@@ -624,6 +671,7 @@ func (o *Input) Up() {
 
 func (o *Input) Down() {
 	if o.ActiveIndex == 2 {
+		o.ActiveIndex = 0
 		return
 	}
 	o.ActiveIndex++

From 4cefa05c982b542c570307cb0dcb275fdc9b536a Mon Sep 17 00:00:00 2001
From: Adrian Hesketh <adrianhesketh@hushmail.com>
Date: Mon, 7 Sep 2020 18:15:20 +0100
Subject: [PATCH 6/6] Minor tidy up.

---
 browse/main.go | 106 +++++++++++++++++++++++++++++--------------------
 1 file changed, 63 insertions(+), 43 deletions(-)

diff --git a/browse/main.go b/browse/main.go
index 01c330b..6f231c9 100644
--- a/browse/main.go
+++ b/browse/main.go
@@ -52,7 +52,7 @@ func main() {
 	for {
 		// Grab the URL input.
 		if askForURL {
-			urlString, ok = NewInput(s, 0, 0, tcell.StyleDefault, "Location:", urlString).Focus()
+			urlString, ok = NewInput(s, "Location:", urlString).Focus()
 			if !ok {
 				break
 			}
@@ -61,7 +61,7 @@ func main() {
 		// Check the URL.
 		u, err := url.Parse(urlString)
 		if err != nil {
-			NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Failed to parse address: %q: %v", urlString, err), "OK").Focus()
+			NewOptions(s, fmt.Sprintf("Failed to parse address: %q: %v", urlString, err), "OK").Focus()
 			askForURL = true
 			continue
 		}
@@ -74,7 +74,7 @@ func main() {
 			//TODO: Add cert store etc. to the client.
 			resp, certificates, _, ok, err = client.RequestURL(u)
 			if err != nil {
-				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Request error: %v", err), "Retry", "Cancel").Focus() {
+				switch NewOptions(s, fmt.Sprintf("Request error: %v", err), "Retry", "Cancel").Focus() {
 				case "Retry":
 					askForURL = false
 					continue
@@ -84,12 +84,16 @@ func main() {
 			}
 			if !ok {
 				//TOFU check required.
-				switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Accept client certificate?\n  %v", certificates[0]), "Accept", "Reject").Focus() {
-				case "Accept":
+				switch NewOptions(s, fmt.Sprintf("Accept client certificate?\n  %v", certificates[0]), "Accept (Permanent)", "Accept (Temporary)", "Reject").Focus() {
+				case "Accept (Permanent)":
 					//TODO: Save this in a persistent store.
 					client.AddAlllowedCertificateForHost(u.Host, certificates[0])
 					askForURL = false
 					continue
+				case "Accept (Temporary)":
+					client.AddAlllowedCertificateForHost(u.Host, certificates[0])
+					askForURL = false
+					continue
 				case "Reject":
 					break out
 				}
@@ -103,14 +107,14 @@ func main() {
 		if strings.HasPrefix(string(resp.Header.Code), "3") {
 			redirectCount++
 			if redirectCount >= 5 {
-				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Server issued 5 or more redirects, cancelling request."), "OK").Focus()
+				NewOptions(s, fmt.Sprintf("Server issued 5 or more redirects, cancelling request."), "OK").Focus()
 				askForURL = true
 				continue
 			}
 			redirectTo, err := url.Parse(resp.Header.Meta)
 			if err != nil {
 				//TODO: Add the ability to go back, once history has been added.
-				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Server returned invalid redirect: code %s, meta: %q", resp.Header.Code, resp.Header.Meta), "OK").Focus()
+				NewOptions(s, fmt.Sprintf("Server returned invalid redirect: code %s, meta: %q", resp.Header.Code, resp.Header.Meta), "OK").Focus()
 				askForURL = true
 				continue
 			}
@@ -121,9 +125,14 @@ func main() {
 		}
 		redirectCount = 0
 		if strings.HasPrefix(string(resp.Header.Code), "6") {
-			switch NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("The server has requested a certificate: code %s, meta: %q", resp.Header.Code, resp.Header.Meta), "Create temporary", "Cancel").Focus() {
-			case "Create temporary":
-				//TODO: Add a certificate to the store.
+			msg := fmt.Sprintf("The server has requested a certificate: code %s, meta: %q", resp.Header.Code, resp.Header.Meta)
+			switch NewOptions(s, msg, "Create (Permanent)", "Create (Temporary)", "Cancel").Focus() {
+			case "Create (Permanent)":
+				//TODO: Add a certificate to the permanent store.
+				askForURL = false
+				continue
+			case "Create (Temporary)":
+				//TODO: Add a certificate to the client.
 				askForURL = false
 				continue
 			case "Cancel":
@@ -132,7 +141,7 @@ func main() {
 			}
 		}
 		if strings.HasPrefix(string(resp.Header.Code), "1") {
-			text, ok := NewInput(s, 0, 0, tcell.StyleDefault, resp.Header.Meta, "").Focus()
+			text, ok := NewInput(s, resp.Header.Meta, "").Focus()
 			if !ok {
 				continue
 			}
@@ -145,19 +154,19 @@ func main() {
 		if strings.HasPrefix(string(resp.Header.Code), "2") {
 			b, err := NewBrowser(s, u, resp)
 			if err != nil {
-				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Error displaying server response:\n\n%v", err), "OK").Focus()
+				NewOptions(s, fmt.Sprintf("Error displaying server response:\n\n%v", err), "OK").Focus()
 				askForURL = true
 				continue
 			}
 			next, err := b.Focus()
 			if err != nil {
 				//TODO: The link was garbage, show the error.
-				NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Invalid link: %q\n", err), "OK").Focus()
+				NewOptions(s, fmt.Sprintf("Invalid link: %v\n", err), "OK").Focus()
 				askForURL = true
 				continue
 			}
 			if next != nil {
-				//TODO: Ask the user whether they want to follow it, if it's a non-Gemini link.
+				//TODO: Ask the user whether they want to follow it, if it's a non-Gemini link, or goes to a different domain.
 				urlString = next.String()
 				askForURL = false
 				continue
@@ -165,7 +174,7 @@ func main() {
 			askForURL = true
 			continue
 		}
-		NewOptions(s, 0, 0, tcell.StyleDefault, fmt.Sprintf("Unknown code: %v %s", resp.Header.Code, resp.Header.Meta), "OK").Focus()
+		NewOptions(s, fmt.Sprintf("Unknown code: %v %s", resp.Header.Code, resp.Header.Meta), "OK").Focus()
 		askForURL = true
 	}
 }
@@ -217,12 +226,12 @@ func flowProcessor(s string, maxWidth int, out func(string)) {
 	out(buf.String())
 }
 
-func NewText(s tcell.Screen, x, y int, st tcell.Style, text string) Text {
-	return Text{
+func NewText(s tcell.Screen, text string) *Text {
+	return &Text{
 		Screen: s,
-		X:      x,
-		Y:      y,
-		Style:  st,
+		X:      0,
+		Y:      0,
+		Style:  tcell.StyleDefault,
 		Text:   text,
 	}
 }
@@ -235,6 +244,17 @@ type Text struct {
 	Text   string
 }
 
+func (t *Text) WithOffset(x, y int) *Text {
+	t.X = x
+	t.Y = y
+	return t
+}
+
+func (t *Text) WithStyle(st tcell.Style) *Text {
+	t.Style = st
+	return t
+}
+
 func (t Text) Draw() (x, y int) {
 	maxX, maxY := t.Screen.Size()
 	maxWidth := maxX - t.X
@@ -268,7 +288,7 @@ func (t Text) Draw() (x, y int) {
 	return requiredMaxWidth, y
 }
 
-func NewOptions(s tcell.Screen, x, y int, st tcell.Style, msg string, opts ...string) *Options {
+func NewOptions(s tcell.Screen, msg string, opts ...string) *Options {
 	cancelIndex := -1
 	for i, o := range opts {
 		if o == "Cancel" {
@@ -278,9 +298,9 @@ func NewOptions(s tcell.Screen, x, y int, st tcell.Style, msg string, opts ...st
 	}
 	return &Options{
 		Screen:      s,
-		X:           x,
-		Y:           y,
-		Style:       st,
+		X:           0,
+		Y:           0,
+		Style:       tcell.StyleDefault,
 		Message:     msg,
 		Options:     opts,
 		CancelIndex: cancelIndex,
@@ -300,21 +320,21 @@ type Options struct {
 
 func (o *Options) Draw() {
 	o.Screen.Clear()
-	t := NewText(o.Screen, 0, 0, tcell.StyleDefault, o.Message)
+	t := NewText(o.Screen, o.Message)
 	_, y := t.Draw()
 	for i, oo := range o.Options {
 		style := tcell.StyleDefault
 		if i == o.ActiveIndex {
 			style = tcell.StyleDefault.Background(tcell.ColorLightGray)
 		}
-		t := NewText(o.Screen, 1, i+y+2, style, fmt.Sprintf("[ %s ]", oo))
-		t.Draw()
+		NewText(o.Screen, fmt.Sprintf("[ %s ]", oo)).WithOffset(1, i+y+2).WithStyle(style).Draw()
 	}
 }
 
 func (o *Options) Up() {
 	if o.ActiveIndex == 0 {
 		o.ActiveIndex = len(o.Options) - 1
+		return
 	}
 	o.ActiveIndex--
 }
@@ -322,6 +342,7 @@ func (o *Options) Up() {
 func (o *Options) Down() {
 	if o.ActiveIndex == len(o.Options)-1 {
 		o.ActiveIndex = 0
+		return
 	}
 	o.ActiveIndex++
 }
@@ -418,7 +439,7 @@ type TextLine struct {
 }
 
 func (l TextLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
-	return NewText(to, atX, atY, tcell.StyleDefault, l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX, atY).Draw()
 }
 
 type PreformattedTextLine struct {
@@ -426,7 +447,7 @@ type PreformattedTextLine struct {
 }
 
 func (l PreformattedTextLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
-	return NewText(to, atX, atY, tcell.StyleDefault, l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX, atY).Draw()
 }
 
 type LinkLine struct {
@@ -452,7 +473,7 @@ func (l LinkLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y in
 	if highlighted {
 		ls = ls.Underline(true)
 	}
-	return NewText(to, atX+2, atY, ls, l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX+2, atY).WithStyle(ls).Draw()
 }
 
 type HeadingLine struct {
@@ -460,7 +481,7 @@ type HeadingLine struct {
 }
 
 func (l HeadingLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
-	return NewText(to, atX, atY, tcell.StyleDefault.Foreground(tcell.ColorGreen), l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX, atY).WithStyle(tcell.StyleDefault.Foreground(tcell.ColorGreen)).Draw()
 }
 
 type UnorderedListItemLine struct {
@@ -468,7 +489,7 @@ type UnorderedListItemLine struct {
 }
 
 func (l UnorderedListItemLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
-	return NewText(to, atX+2, atY, tcell.StyleDefault, l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX+2, atY).Draw()
 }
 
 type QuoteLine struct {
@@ -476,7 +497,7 @@ type QuoteLine struct {
 }
 
 func (l QuoteLine) Draw(to tcell.Screen, atX, atY int, highlighted bool) (x, y int) {
-	return NewText(to, atX+2, atY, tcell.StyleDefault.Foreground(tcell.ColorLightGrey), l.Text).Draw()
+	return NewText(to, l.Text).WithOffset(atX+2, atY).WithStyle(tcell.StyleDefault.Foreground(tcell.ColorLightGrey)).Draw()
 }
 
 func NewBrowser(s tcell.Screen, u *url.URL, resp *gemini.Response) (b *Browser, err error) {
@@ -607,12 +628,12 @@ func (b Browser) Focus() (next *url.URL, err error) {
 	}
 }
 
-func NewInput(s tcell.Screen, x, y int, st tcell.Style, msg, text string) *Input {
+func NewInput(s tcell.Screen, msg, text string) *Input {
 	return &Input{
 		Screen:      s,
-		X:           x,
-		Y:           y,
-		Style:       st,
+		X:           0,
+		Y:           0,
+		Style:       tcell.StyleDefault,
 		Message:     msg,
 		Text:        text,
 		CursorIndex: len(text),
@@ -632,17 +653,16 @@ type Input struct {
 
 func (o *Input) Draw() {
 	o.Screen.Clear()
-	t := NewText(o.Screen, o.X, o.Y, o.Style, o.Message)
-	_, y := t.Draw()
+	_, y := NewText(o.Screen, o.Message).WithOffset(o.X, o.Y).WithStyle(o.Style).Draw()
 
 	defaultStyle := tcell.StyleDefault
 	activeStyle := tcell.StyleDefault.Background(tcell.ColorLightGray)
 
 	textStyle := defaultStyle
 	if o.ActiveIndex == 0 {
-		NewText(o.Screen, o.X, o.Y+y+2, defaultStyle, ">").Draw()
+		NewText(o.Screen, ">").WithOffset(o.X, o.Y+y+2).WithStyle(defaultStyle).Draw()
 	}
-	NewText(o.Screen, o.X+2, o.Y+y+2, textStyle, o.Text).Draw()
+	NewText(o.Screen, o.Text).WithOffset(o.X+2, o.Y+y+2).WithStyle(textStyle).Draw()
 	if o.ActiveIndex == 0 {
 		o.Screen.ShowCursor(o.X+2+o.CursorIndex, o.Y+y+2)
 	} else {
@@ -653,12 +673,12 @@ func (o *Input) Draw() {
 	if o.ActiveIndex == 1 {
 		okStyle = activeStyle
 	}
-	NewText(o.Screen, 1, o.Y+y+4, okStyle, "[ OK ]").Draw()
+	NewText(o.Screen, "[ OK ]").WithOffset(1, o.Y+y+4).WithStyle(okStyle).Draw()
 	cancelStyle := defaultStyle
 	if o.ActiveIndex == 2 {
 		cancelStyle = activeStyle
 	}
-	NewText(o.Screen, 1, o.Y+y+5, cancelStyle, "[ Cancel ]").Draw()
+	NewText(o.Screen, "[ Cancel ]").WithOffset(1, o.Y+y+5).WithStyle(cancelStyle).Draw()
 }
 
 func (o *Input) Up() {