lots of fixes and additions:

- add color and color config support
- fix epub parsing
- add variable margin (left and right arrow keys)
- add help screen (hit `?`)
- add config file support

cmd/colors.go

@@ -0,0 +1,63 @@
+package cmd
+
+import (
+	"github.com/charmbracelet/lipgloss"
+)
+
+type ColorSetting struct {
+	Title   string `koanf:"title"`
+	Chapter string `koanf:"chapter"`
+	Body    string `koanf:"body"`
+}
+
+type Colors struct {
+	Title   lipgloss.Style
+	Chapter lipgloss.Style
+	Body    lipgloss.Style
+}
+
+func SetColorconfig(defaultdark, defaultlight ColorSetting, conf *Config) Colors {
+	var defaults, user ColorSetting
+
+	switch conf.Darkmode {
+	case true:
+		defaults = defaultdark
+		user = conf.ColorDark
+	default:
+		defaults = defaultlight
+		user = conf.ColorLight
+	}
+
+	var colors Colors
+	var fg string
+
+	border := lipgloss.RoundedBorder()
+	border.Right = "├"
+	styletitle := lipgloss.NewStyle().BorderStyle(border).Padding(0, 1)
+
+	if user.Title != "" {
+		fg = user.Title
+	} else {
+		fg = defaults.Title
+	}
+
+	colors.Title = styletitle.Foreground(lipgloss.Color(fg))
+
+	if user.Chapter != "" {
+		fg = user.Chapter
+	} else {
+		fg = defaults.Chapter
+	}
+
+	colors.Chapter = lipgloss.NewStyle().Foreground(lipgloss.Color(fg))
+
+	if user.Body != "" {
+		fg = user.Body
+	} else {
+		fg = defaults.Body
+	}
+
+	colors.Body = lipgloss.NewStyle().Foreground(lipgloss.Color(fg))
+
+	return colors
+}

cmd/config.go

@@ -7,20 +7,29 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/alecthomas/repr"
+	"github.com/knadh/koanf/parsers/toml"
+	"github.com/knadh/koanf/providers/file"
 	"github.com/knadh/koanf/providers/posflag"
 	"github.com/knadh/koanf/v2"
 	flag "github.com/spf13/pflag"
 )
 
 const (
-	Version string = `v0.0.1`
+	Version string = `v0.0.2`
 	Usage   string = `epuppy [-vd] <epub file>`
 )
 
 type Config struct {
-	Showversion     bool `koanf:"version"`        // -v
-	Debug           bool `koanf:"debug"`          // -d
-	StoreProgress   bool `koanf:"store-progress"` // -s
+	Showversion   bool         `koanf:"version"`        // -v
+	Debug         bool         `koanf:"debug"`          // -d
+	StoreProgress bool         `koanf:"store-progress"` // -s
+	Darkmode      bool         `koanf:"dark"`           // -D
+	Config        string       `koanf:"config"`         // -c
+	ColorDark     ColorSetting `koanf:"colordark"`      // comes from config file only
+	ColorLight    ColorSetting `koanf:"colorlight"`     // comes from config file only
+
+	Colors          Colors // generated from user config file or internal defaults, respects dark mode
 	Document        string
 	InitialProgress int // lines
 }
@@ -41,12 +50,41 @@ func InitConfig(output io.Writer) (*Config, error) {
 	// parse commandline flags
 	flagset.BoolP("version", "v", false, "show program version")
 	flagset.BoolP("debug", "d", false, "enable debugging")
+	flagset.BoolP("dark", "D", false, "enable dark mode")
 	flagset.BoolP("store-progress", "s", false, "store reading progress")
+	flagset.StringP("config", "c", "", "read config from file")
 
 	if err := flagset.Parse(os.Args[1:]); err != nil {
 		return nil, fmt.Errorf("failed to parse program arguments: %w", err)
 	}
 
+	// generate a  list of config files to try  to load, including the
+	// one provided via -c, if any
+	var configfiles []string
+
+	configfile, _ := flagset.GetString("config")
+	home, _ := os.UserHomeDir()
+
+	if configfile != "" {
+		configfiles = []string{configfile}
+	} else {
+		configfiles = []string{
+			"/etc/epuppy.toml", "/usr/local/etc/epuppy.toml", // unix variants
+			filepath.Join(home, ".config", "epuppy", "config.toml"),
+		}
+	}
+
+	// Load the config file[s]
+	for _, cfgfile := range configfiles {
+		if path, err := os.Stat(cfgfile); !os.IsNotExist(err) {
+			if !path.IsDir() {
+				if err := kloader.Load(file.Provider(cfgfile), toml.Parser()); err != nil {
+					return nil, fmt.Errorf("error loading config file: %w", err)
+				}
+			}
+		} // else: we ignore the file if it doesn't exists
+	}
+
 	// command line setup
 	if err := kloader.Load(posflag.Provider(flagset, ".", kloader), nil); err != nil {
 		return nil, fmt.Errorf("error loading flags: %w", err)
@@ -63,6 +101,24 @@ func InitConfig(output io.Writer) (*Config, error) {
 		conf.Document = flagset.Args()[0]
 	}
 
+	if conf.Debug {
+		repr.Println(conf)
+	}
+
+	// setup color config
+	conf.Colors = SetColorconfig(
+		ColorSetting{ // Dark
+			Title:   "#ff4500",
+			Chapter: "#ff4500",
+			Body:    "#cdb79e",
+		},
+		ColorSetting{ // Light
+			Title:   "#ff0000",
+			Chapter: "#8b0000",
+			Body:    "#696969",
+		},
+		conf)
+
 	return conf, nil
 }
 

cmd/pager.go

@@ -9,6 +9,8 @@ import (
 	"os"
 	"strings"
 
+	"github.com/charmbracelet/bubbles/help"
+	"github.com/charmbracelet/bubbles/key"
 	"github.com/charmbracelet/bubbles/viewport"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
@@ -32,6 +34,11 @@ var (
 	viewstyle = lipgloss.NewStyle()
 )
 
+const (
+	MarginStep = 5
+	MinSize    = 40
+)
+
 type Meta struct {
 	lines           int
 	currentline     int
@@ -39,13 +46,67 @@ type Meta struct {
 	document        string
 }
 
+type keyMap struct {
+	Up    key.Binding
+	Down  key.Binding
+	Left  key.Binding
+	Right key.Binding
+	Help  key.Binding
+	Quit  key.Binding
+}
+
+func (k keyMap) FullHelp() [][]key.Binding {
+	return [][]key.Binding{
+		{k.Up, k.Down, k.Left, k.Right}, // first column
+		{k.Help, k.Quit},                // second column
+	}
+}
+
+func (k keyMap) ShortHelp() []key.Binding {
+	return []key.Binding{k.Help, k.Quit}
+}
+
+var keys = keyMap{
+	Up: key.NewBinding(
+		key.WithKeys("up", "k"),
+		key.WithHelp("↑", "move up"),
+	),
+	Down: key.NewBinding(
+		key.WithKeys("down", "j"),
+		key.WithHelp("↓", "move down"),
+	),
+	Left: key.NewBinding(
+		key.WithKeys("left", "h"),
+		key.WithHelp("←", "decrease text width"),
+	),
+	Right: key.NewBinding(
+		key.WithKeys("right", "l"),
+		key.WithHelp("→", "increase text width"),
+	),
+	Help: key.NewBinding(
+		key.WithKeys("?"),
+		key.WithHelp("?", "toggle help"),
+	),
+	Quit: key.NewBinding(
+		key.WithKeys("q", "esc", "ctrl+c"),
+		key.WithHelp("q", "quit"),
+	),
+}
+
 type Doc struct {
 	content      string
 	title        string
 	ready        bool
 	viewport     viewport.Model
 	initialwidth int
+	lastwidth    int
+	margin       int
+	marginMod    bool
 	meta         *Meta
+	config       *Config
+
+	keys keyMap
+	help help.Model
 }
 
 func (m Doc) Init() tea.Cmd {
@@ -60,8 +121,21 @@ func (m Doc) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 	switch msg := msg.(type) {
 	case tea.KeyMsg:
-		if k := msg.String(); k == "ctrl+c" || k == "q" || k == "esc" {
+		switch {
+		case key.Matches(msg, m.keys.Help):
+			m.help.ShowAll = !m.help.ShowAll
+		case key.Matches(msg, m.keys.Quit):
 			return m, tea.Quit
+		case key.Matches(msg, m.keys.Left):
+			if m.lastwidth-(m.margin*2) >= MinSize {
+				m.margin += MarginStep
+				m.marginMod = true
+			}
+		case key.Matches(msg, m.keys.Right):
+			if m.margin >= MarginStep {
+				m.margin -= MarginStep
+				m.marginMod = true
+			}
 		}
 
 	case tea.WindowSizeMsg:
@@ -85,10 +159,11 @@ func (m Doc) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		} else {
 			m.viewport.Width = msg.Width
 			m.viewport.Height = msg.Height - verticalMarginHeight
-			m.viewport.SetContent(wordwrap.String(m.content, msg.Width))
 		}
 	}
 
+	m.Rewrap()
+
 	// Handle keyboard and mouse events in the viewport
 	m.viewport, cmd = m.viewport.Update(msg)
 	cmds = append(cmds, cmd)
@@ -96,6 +171,17 @@ func (m Doc) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	return m, tea.Batch(cmds...)
 }
 
+// re-calculate word wrapping, also add left margin
+func (m *Doc) Rewrap() {
+	if m.lastwidth != m.viewport.Width || m.marginMod {
+		m.viewport.SetContent(wordwrap.String(m.content, m.viewport.Width-(m.margin*2)))
+		m.lastwidth = m.viewport.Width
+		m.marginMod = false
+
+		m.viewport.Style = viewstyle.MarginLeft(m.margin)
+	}
+}
+
 func (m Doc) View() string {
 	if !m.ready {
 		return "\n  Initializing..."
@@ -105,17 +191,23 @@ func (m Doc) View() string {
 	// FIXME: doesn't work correctly yet
 	m.meta.currentline = int(float64(m.meta.lines) * m.viewport.ScrollPercent())
 
-	return fmt.Sprintf("%s\n%s\n%s", m.headerView(), m.viewport.View(), m.footerView())
+	var helpView string
+	if m.help.ShowAll {
+		helpView = "\n" + m.help.View(m.keys)
+	}
+
+	return fmt.Sprintf("%s\n%s\n%s%s", m.headerView(), m.viewport.View(), m.footerView(), helpView)
 }
 
 func (m Doc) headerView() string {
-	title := titleStyle.Render(m.title)
+	title := m.config.Colors.Title.Render(m.title)
 	line := strings.Repeat("─", max(0, m.viewport.Width-lipgloss.Width(title)))
 	return lipgloss.JoinHorizontal(lipgloss.Center, title, line)
 }
 
 func (m Doc) footerView() string {
 	info := infoStyle.Render(fmt.Sprintf("%3.f%%", m.viewport.ScrollPercent()*100))
+
 	line := strings.Repeat("─", max(0, m.viewport.Width-lipgloss.Width(info)))
 	return lipgloss.JoinHorizontal(lipgloss.Center, line, info)
 }
@@ -148,7 +240,7 @@ func Pager(conf *Config, title, message string) (int, error) {
 	}
 
 	p := tea.NewProgram(
-		Doc{content: message, title: title, initialwidth: width, meta: &meta},
+		Doc{content: message, title: title, initialwidth: width, meta: &meta, config: conf, keys: keys},
 		tea.WithAltScreen(),       // use the full size of the terminal in its "alternate screen buffer"
 		tea.WithMouseCellMotion(), // turn on mouse support so we can track the mouse wheel
 	)

cmd/root.go

@@ -3,11 +3,11 @@ package cmd
 import (
 	"fmt"
 	"io"
-	"log"
+	"os"
 )
 
 func Die(err error) int {
-	log.Fatal("Error: ", err.Error())
+	fmt.Fprintln(os.Stderr, "Error: ", err.Error())
 
 	return 1
 }

cmd/view.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/tlinden/epuppy/pkg/epub"
@@ -28,12 +29,18 @@ func View(conf *Config) (int, error) {
 		head.WriteString(" ")
 	}
 
-	for _, point := range book.Ncx.Points {
-		if len(point.Content.Body) > 0 {
-			buf.WriteString("### " + point.Content.Title)
+	// FIXME:  since the  switch to  book.Files() in  epub.Open() this
+	// returns invalid chapter numbering
+	chapter := 1
+
+	for _, content := range book.Content {
+		if len(content.Body) > 0 {
+			buf.WriteString(conf.Colors.Chapter.
+				Render(fmt.Sprintf("Chapter %d: %s", chapter, content.Title)))
 			buf.WriteString("\r\n\r\n")
-			buf.WriteString(point.Content.Body)
+			buf.WriteString(conf.Colors.Body.Render(content.Body))
 			buf.WriteString("\r\n\r\n\r\n\r\n")
+			chapter++
 		}
 	}