wand/help.go

package wand

import (
	"code.squareroundforest.org/arpio/bind"
	"code.squareroundforest.org/arpio/docreflect"
	. "code.squareroundforest.org/arpio/textfmt"
	"fmt"
	"github.com/iancoleman/strcase"
	"golang.org/x/term"
	"io"
	"os"
	"reflect"
	"regexp"
	"sort"
	"strings"
	"time"
)

const (
	defaultHelpWidth  = 72
	minPrintWidth     = 42
	maxPrintWidth     = 360
	markdownWrapWidth = 112
)

const (
	noOptionHints = iota
	commandSpecificHints
	allRelevantHints
)

var sentenceDelimiter = regexp.MustCompile("[.?!]")

func help(cmd Cmd) Cmd {
	h := Cmd{
		name:       "help",
		helpFor:    &cmd,
		shortForms: cmd.shortForms,
	}

	cmd.subcommands = append(cmd.subcommands, h)
	return cmd
}

func insertHelp(cmd Cmd) Cmd {
	var hasHelpCmd bool
	for i, sc := range cmd.subcommands {
		if sc.name == "help" {
			hasHelpCmd = true
			continue
		}

		cmd.subcommands[i] = insertHelp(sc)
	}

	if hasHelpCmd || cmd.version != "" {
		return cmd
	}

	return help(cmd)
}

func hasHelpSubcommand(cmd Cmd) bool {
	for _, sc := range cmd.subcommands {
		if sc.helpFor != nil {
			return true
		}
	}

	return false
}

func hasCustomHelpOption(cmd Cmd) bool {
	if cmd.impl == nil {
		return false
	}

	mf := mapFields(cmd.impl)
	_, has := mf["help"]
	return has
}

func suggestHelp(out io.Writer, cmd Cmd, fullCommand []string) {
	if hasHelpSubcommand(cmd) {
		fmt.Fprintf(out, "Show help:\n%s help\n", strings.Join(fullCommand, " "))
		return
	}

	if !hasCustomHelpOption(cmd) {
		fmt.Fprintf(out, "Show help:\n%s --help\n", strings.Join(fullCommand, " "))
		return
	}
}

func allNonHelpOptions(cmd Cmd) []bind.Field {
	var options []bind.Field
	if cmd.impl != nil {
		f := fields(cmd.impl)
		for _, fi := range f {
			options = append(options, fi)
		}
	}

	for _, sc := range cmd.subcommands {
		options = append(options, allNonHelpOptions(sc)...)
	}

	return options
}

func allConfigFiles(conf Config) []Config {
	if conf.file != nil || conf.fromOption {
		return []Config{conf}
	}

	var files []Config
	for _, c := range conf.merge {
		files = append(files, allConfigFiles(c)...)
	}

	return files
}

func functionParams(v any, indices []int) ([]string, []string) {
	var names []string
	r := reflect.ValueOf(v)
	allNames := docreflect.FunctionParams(r)
	if len(allNames) == r.Type().NumIn() {
		for _, i := range indices {
			names = append(names, allNames[i])
		}
	} else {
		names = make([]string, len(indices))
	}

	for i := range names {
		names[i] = strings.TrimSpace(names[i])
		if names[i] == "" {
			names[i] = fmt.Sprintf("arg%d", i+1)
		}
	}

	var types []string
	for _, i := range indices {
		t := r.Type().In(i)
		types = append(types, scalarTypeStringOf(t))
	}

	return names, types
}

func paragraphs(text string) []string {
	l := strings.Split(text, "\n")
	for i := range l {
		l[i] = strings.TrimSpace(l[i])
	}

	var (
		pl []string
		p  []string
	)

	for _, li := range l {
		if li == "" && len(pl) > 0 {
			p = append(p, strings.Join(pl, " "))
			pl = nil
			continue
		}

		if li == "" {
			continue
		}

		pl = append(pl, li)
	}

	if len(pl) > 0 {
		p = append(p, strings.Join(pl, " "))
	}

	return p
}

func firstSentence(text string) string {
	s := sentenceDelimiter.Split(text, 2)
	s[0] = strings.TrimSpace(s[0])
	return s[0]
}

func wrapWidth() int {
	width := defaultHelpWidth
	fd := int(os.Stdin.Fd())
	if !term.IsTerminal(fd) {
		return width
	}

	w, _, err := term.GetSize(fd)
	if err != nil {
		return width
	}

	width = w - 8
	if width < minPrintWidth {
		width = minPrintWidth
	}

	if width > maxPrintWidth {
		width = maxPrintWidth
	}

	return width
}

func implementationCommand(cmd Cmd) Cmd {
	if cmd.impl != nil {
		return cmd
	}

	for _, subCmd := range cmd.subcommands {
		if subCmd.isDefault {
			return subCmd
		}
	}

	return cmd
}

func docCommandNameText(cmd Cmd, fullCommand []string) []string {
	command := strings.Join(fullCommand, " ")
	fdoc := docreflect.Function(reflect.ValueOf(cmd.impl))
	fdoc = strings.TrimSpace(fdoc)
	fdocp := paragraphs(fdoc)
	if len(fdocp) == 0 {
		return []string{command}
	}

	return []string{command, "-", firstSentence(fdocp[0])}
}

func docCommandName(cmd Cmd, fullCommand []string) Entry {
	s := docCommandNameText(cmd, fullCommand)
	txt := make([]Txt, len(s))
	for i := range s {
		txt[i] = Text(s[i])
	}

	return Paragraph(Cat(txt...))
}

func docSynopsis(cmd Cmd, fullCommand []string, titleLevel, wrapWidth int) []Entry {
	implCmd := implementationCommand(cmd)
	command := strings.Join(fullCommand, " ")
	synopsisTitle := Title(titleLevel, "Synopsis:")
	if implCmd.impl == nil {
		synopsis := Syntax(Choice(Sequence(Symbol(command), Required(Symbol("subcommand")))))
		return []Entry{synopsisTitle, Indent(synopsis, 4, 0)}
	}

	pi := positionalIndices(implCmd.impl)
	names, types := functionParams(implCmd.impl, pi)
	if len(names) == 0 {
		synopsis := Syntax(
			Choice(
				Sequence(Symbol(command), ZeroOrMore(Symbol("options"))),
				Sequence(Symbol(command), Required(Symbol("subcommand"))),
			),
		)

		return []Entry{synopsisTitle, Indent(synopsis, 4, 0)}
	}

	var args []SyntaxItem
	_, variadic := positional(implCmd.impl)
	for i := range names[:len(names)-1] {
		args = append(args, Required(Sequence(Symbol(names[i]), Symbol(types[i]))))
	}

	lastArity := Required
	switch {
	case variadic && implCmd.minPositional >= len(pi):
		lastArity = OneOrMore
	case variadic:
		lastArity = ZeroOrMore
	}

	last := len(names) - 1
	args = append(args, lastArity(Sequence(Symbol(names[last]), Symbol(types[last]))))

	var argCountHint Entry
	needsArgCountHint := implCmd.impl != nil && (implCmd.minPositional > 0 || implCmd.maxPositional > 0)
	if needsArgCountHint {
		var hint string
		switch {
		case implCmd.minPositional > 0 && implCmd.maxPositional > 0:
			hint = fmt.Sprintf(
				"Expecting min %d and max %d total number of arguments.",
				implCmd.minPositional,
				implCmd.maxPositional,
			)
		case implCmd.minPositional > 0:
			hint = fmt.Sprintf(
				"Expecting min %d total number of arguments.",
				implCmd.minPositional,
			)
		case implCmd.maxPositional > 0:
			hint = fmt.Sprintf(
				"Expecting max %d total number of arguments.",
				implCmd.maxPositional,
			)
		}

		argCountHint = Paragraph(Text(hint))
	}

	if len(args) > 0 {
		args = append([]SyntaxItem{Optional(Symbol("--"))}, args...)
	}

	synopsis := Syntax(
		Choice(
			Sequence(append([]SyntaxItem{Symbol(command), ZeroOrMore(Symbol("options"))}, args...)...),
			Sequence(Symbol(command), Required(Symbol("subcommand"))),
		),
	)

	if !needsArgCountHint {
		return []Entry{synopsisTitle, Indent(synopsis, 4, 0)}
	}

	return []Entry{synopsisTitle, Indent(synopsis, 4, 0), Wrap(argCountHint, wrapWidth)}
}

func docs(cmd Cmd) []Entry {
	implCmd := implementationCommand(cmd)
	if implCmd.impl == nil {
		return nil
	}

	fdoc := docreflect.Function(reflect.ValueOf(implCmd.impl))
	fdoc = strings.TrimSpace(fdoc)
	fdocp := paragraphs(fdoc)
	if len(fdocp) == 0 {
		return nil
	}

	var e []Entry
	for _, p := range fdocp {
		e = append(e, Paragraph(Text(p)))
	}

	return e
}

func docOptions(cmd Cmd, conf Config, titleLevel, wrapWidth, hintStyle int) []Entry {
	implCmd := implementationCommand(cmd)
	optionsTitle := Title(titleLevel, "Options:")
	fields := make(map[string][]bind.Field)
	docs := make(map[string]string)
	structs := structParameters(implCmd.impl)
	for _, s := range structs {
		f := structFields(s)
		for _, fi := range f {
			fields[fi.Name()] = append(fields[fi.Name()], fi)
			if d := docs[fi.Name()]; d == "" {
				docs[fi.Name()] = docreflect.Field(s, fi.Path()...)
			}
		}
	}

	if len(fields) == 0 {
		var optionItems []DefinitionItem
		if _, ok := fields["config"]; !ok && hasConfigFromOption(conf) {
			optionItems = append(
				optionItems,
				Definition(Text("--config"), Text("Configuration file."), NoBullet()),
			)
		}

		optionItems = append(
			optionItems,
			Definition(
				Text("--help"),
				Text("Show help."),
				NoBullet(),
			),
		)

		return []Entry{
			optionsTitle,
			Wrap(Indent(DefinitionList(optionItems...), 4, 0), wrapWidth),
		}
	}

	var (
		names                                           []string
		optionItems                                     []DefinitionItem
		hasAcceptsMultiple, hasBoolOptions, hasGrouping bool
	)

	for n := range fields {
		names = append(names, n)
	}

	sort.Strings(names)
	s2l := shortFormsToLong(implCmd.shortForms)
	l2s := longFormsToShort(implCmd.shortForms)
	for _, name := range names {
		var def string
		f := fields[name]
		sf := l2s[name]
		if len(sf) == 0 {
			def = fmt.Sprintf("--%s %s", name, scalarTypeString(f[0].Type()))
		} else {
			sfs := make([]string, len(sf))
			copy(sfs, sf)
			for i := range sfs {
				sfs[i] = fmt.Sprintf("-%s", sfs[i])
			}

			def = fmt.Sprintf(
				"--%s, %s %s",
				name,
				strings.Join(sfs, ", "),
				scalarTypeString(f[0].Type()),
			)
		}

		for _, fi := range f {
			if fi.List() {
				def = fmt.Sprintf("%s [*]", def)
				hasAcceptsMultiple = true
			}
		}

		if f[0].Type() == bind.Bool {
			hasBoolOptions = true
			if len(s2l) > 1 && len(sf) > 0 {
				hasGrouping = true
			}
		}

		optionItems = append(
			optionItems,
			Definition(Text(def), Text(docs[name]), NoBullet()),
		)
	}

	if _, ok := fields["config"]; !ok && hasConfigFromOption(conf) {
		optionItems = append(
			optionItems,
			Definition(Text("--config"), Text("Configuration file."), NoBullet()),
		)
	}

	var (
		helpShortForms       []string
		helpShortFormsString string
	)

	_, hasHelpOption := fields["help"]
	if !hasHelpOption {
		hsf := make([]string, len(l2s["help"]))
		copy(hsf, l2s["help"])
		sort.Strings(hsf)
		helpShortForms = append(helpShortForms, hsf...)
	}

	if len(helpShortForms) > 0 {
		for i := range helpShortForms {
			helpShortForms[i] = fmt.Sprintf("-%s", helpShortForms[i])
		}

		helpShortFormsString = strings.Join(helpShortForms, ", ")
	}

	if helpShortFormsString != "" {
		optionItems = append(
			optionItems,
			Definition(
				Text(fmt.Sprintf("--help, %s", helpShortFormsString)),
				Text("Show help."), NoBullet(),
			),
		)
	} else if !hasHelpOption {
		optionItems = append(
			optionItems,
			Definition(Text("--help"), Text("Show help."), NoBullet()),
		)
	}

	if hintStyle == noOptionHints {
		return []Entry{
			optionsTitle,
			Wrap(Indent(DefinitionList(optionItems...), 4, 0), wrapWidth),
		}
	}

	switch hintStyle {
	case allRelevantHints:
		var numShortForm int
		allOptions := allNonHelpOptions(cmd)
		for _, o := range allOptions {
			hasAcceptsMultiple = hasAcceptsMultiple || o.List()
			hasBoolOptions = hasBoolOptions || o.Type() == bind.Bool
			if _, hasShortForm := l2s[o.Name()]; hasShortForm {
				numShortForm++
			}

			hasGrouping = hasGrouping || o.Type() == bind.Bool && numShortForm > 1
		}
	}

	var hints []string
	if hasAcceptsMultiple {
		hints = append(hints, docListOptions)
	}

	if hasBoolOptions {
		hints = append(hints, docBoolOptions)
	}

	if hasGrouping {
		hints = append(hints, docOptionGrouping)
	}

	hints = append(hints, docOptionValues)

	if len(hints) == 1 {
		return []Entry{
			optionsTitle,
			Wrap(Indent(DefinitionList(optionItems...), 4, 0), wrapWidth),
			Wrap(Paragraph(Text(hints[0])), wrapWidth),
		}
	}

	items := make([]ListItem, len(hints))
	for i := range hints {
		items[i] = Item(Text(hints[i]))
	}

	return []Entry{
		optionsTitle,
		Wrap(Indent(DefinitionList(optionItems...), 4, 0), wrapWidth),
		Wrap(Paragraph(Text("Hints:")), wrapWidth),
		Wrap(List(items...), wrapWidth),
	}
}

func docListSubcommands(cmd Cmd, fullCommand []string, level, wrapWidth int) []Entry {
	subcommandsTitle := Title(level+1, "Subcommands:")

	var (
		items      []DefinitionItem
		hasNonHelp bool
	)

	scs := make([]Cmd, len(cmd.subcommands))
	copy(scs, cmd.subcommands)
	sort.Slice(scs, func(i, j int) bool {
		return scs[i].name < scs[j].name
	})

	for _, sc := range scs {
		var description string
		name := sc.name
		if sc.helpFor != nil {
			description = "Show help."
		} else if sc.version != "" {
			description = "Show version information."
		} else {
			if sc.isDefault {
				name = fmt.Sprintf("%s (default)", name)
			}

			hasNonHelp = true
			description = docreflect.Function(reflect.ValueOf(sc.impl))
			description = strings.TrimSpace(description)
			descriptionP := paragraphs(description)
			if len(descriptionP) > 0 {
				description = firstSentence(descriptionP[0])
			}
		}

		items = append(items, Definition(Text(name), Text(description), NoBullet()))
	}

	if hasNonHelp {
		command := strings.Join(fullCommand, " ")
		hint := Paragraph(Text(fmt.Sprintf(docSubcommandHelpFmt, command, command)))
		return []Entry{
			subcommandsTitle,
			Wrap(Indent(DefinitionList(items...), 4, 0), wrapWidth),
			Wrap(hint, wrapWidth),
		}
	}

	return []Entry{
		subcommandsTitle,
		Wrap(Indent(DefinitionList(items...), 4, 0), wrapWidth),
	}
}

func docFullSubcommands(cmd Cmd, conf Config, level int) []Entry {
	var e []Entry
	e = append(
		e,
		Title(level+1, "Subcommands:"),
		Paragraph(Text(docSubcommandHint)),
	)

	type subcommandDef struct {
		fullCommand []string
		command     Cmd
	}

	var (
		allSubcommands     []subcommandDef
		collectSubcommands func(cmd Cmd) []subcommandDef
	)

	collectSubcommands = func(cmd Cmd) []subcommandDef {
		var defs []subcommandDef
		for _, sc := range cmd.subcommands {
			if sc.impl != nil || sc.version != "" {
				defs = append(defs, subcommandDef{fullCommand: []string{cmd.name, sc.name}, command: sc})
			}

			scDefs := collectSubcommands(sc)
			for i := range scDefs {
				scDefs[i].fullCommand = append([]string{cmd.name}, scDefs[i].fullCommand...)
			}

			defs = append(defs, scDefs...)
		}

		return defs
	}

	allSubcommands = collectSubcommands(cmd)
	for _, sc := range allSubcommands {
		command := strings.Join(sc.fullCommand, " ")
		if sc.command.isDefault {
			command = fmt.Sprintf("%s (default)", command)
		}

		e = append(e, Indent(Title(level+2, command), 2, 0))
		if sc.command.version != "" {
			e = append(e, Indent(Paragraph(Text("Show version.")), 4, 0))
			continue
		}

		synopsis := docSynopsis(sc.command, sc.fullCommand, 3, 0)
		for i := range synopsis {
			synopsis[i] = Indent(synopsis[i], 4, 0)
		}

		e = append(e, synopsis...)
		if docs := docs(sc.command); len(docs) > 0 {
			e = append(e, Indent(Title(level+3, "Description:"), 4, 0))
			for i := range docs {
				docs[i] = Indent(docs[i], 4, 0)
			}

			e = append(e, docs...)
		}

		options := docOptions(sc.command, conf, 3, 0, noOptionHints)
		for i := range options {
			options[i] = Indent(options[i], 4, 0)
		}

		e = append(e, options...)
	}

	return e
}

func docEnv(cmd Cmd, level int) []Entry {
	// env will not work if the app has a non-standard name:
	if !commandNameExpression.MatchString(cmd.name) {
		return nil
	}

	options := allNonHelpOptions(cmd)
	if len(options) == 0 {
		return nil
	}

	e := []Entry{Title(level+1, "Environment variables:")}
	p := paragraphs(envDocs)
	for _, pi := range p {
		e = append(e, Indent(Paragraph(Text(pi)), 4, 0))
	}

	e = append(e, Indent(Title(level+2, "Example environment variable:"), 4, 0))
	option := options[0]
	name := strcase.ToScreamingSnake(fmt.Sprintf("%s-%s", cmd.name, option.Name()))
	value := "42"
	if option.Type() == bind.Bool {
		value = "true"
	}

	e = append(e, Indent(CodeBlock(fmt.Sprintf("%s=%s", name, value)), 4, 0))
	return e
}

func docConfig(cmd Cmd, conf Config, level int) []Entry {
	options := allNonHelpOptions(cmd)
	if len(options) == 0 {
		return nil
	}

	configFiles := allConfigFiles(conf)
	if len(configFiles) == 0 {
		return nil
	}

	e := []Entry{Title(level+1, "Configuration:")}
	p := paragraphs(configDocs)
	for _, pi := range p {
		e = append(e, Indent(Paragraph(Text(pi)), 4, 0))
	}

	var items []ListItem
	for _, cf := range configFiles {
		if cf.fromOption {
			items = append(
				items,
				Item(Text("zero or more configuration files defined by the --config option")),
			)

			continue
		}

		text := cf.file(cmd).filename
		if cf.optional {
			text = fmt.Sprintf("%s (optional)", text)
		}

		items = append(items, Item(Text(text)))
	}

	e = append(
		e,
		Indent(Title(level+2, "Configuration files:"), 4, 0),
		Indent(List(items...), 8, 0),
	)

	option := options[0]
	name := option.Name()
	value := "42"
	if option.Type() == bind.Bool {
		value = "true"
	}

	exampleCode := fmt.Sprintf(
		"# Default value for --%s:\n%s = %s",
		name,
		strcase.ToSnake(name),
		value,
	)

	e = append(
		e,
		Indent(Title(level+2, "Example configuration entry:"), 4, 0),
		Indent(CodeBlock(exampleCode), 4, 0),
	)

	discardExample := fmt.Sprintf(
		"# Discarding an inherited entry:\n%s",
		strcase.ToSnake(name),
	)

	e = append(
		e,
		Indent(Title(level+2, "Example for discarding an inherited entry:"), 4, 0),
		Indent(CodeBlock(discardExample), 4, 0),
	)

	return e
}

func helpCommandName(cmd Cmd, fullCommand []string) []Entry {
	return []Entry{docCommandName(cmd, fullCommand)}
}

func helpSynopsis(cmd Cmd, fullCommand []string, width int) []Entry {
	return docSynopsis(cmd, fullCommand, 1, width)
}

func helpDocs(cmd Cmd, width int) []Entry {
	paragraphs := docs(cmd)
	for i := range paragraphs {
		paragraphs[i] = Wrap(paragraphs[i], width)
	}

	return paragraphs
}

func helpOptions(cmd Cmd, conf Config, width int) []Entry {
	return docOptions(cmd, conf, 1, width, commandSpecificHints)
}

func helpSubcommands(cmd Cmd, fullCommand []string, width int) []Entry {
	return docListSubcommands(cmd, fullCommand, 0, width)
}

func manTitle(cmd Cmd, date time.Time, version string) []Entry {
	if version == "" {
		for _, sc := range cmd.subcommands {
			if sc.version != "" {
				version = sc.version
				break
			}
		}
	}

	return []Entry{
		Title(
			0,
			cmd.name,
			ManCategory("User Commands"),
			ManSection(1),
			ReleaseDate(date),
			ReleaseVersion(version),
		),
	}
}

func manCommandName(cmd Cmd) []Entry {
	title := Title(1, "Name:")
	name := docCommandName(cmd, []string{cmd.name})
	name = Indent(name, 4, 0)
	return []Entry{title, name}
}

func manSynopsis(cmd Cmd) []Entry {
	return docSynopsis(cmd, []string{cmd.name}, 1, 0)
}

func manDocs(cmd Cmd) []Entry {
	paragraphs := docs(cmd)
	if len(paragraphs) == 0 {
		return nil
	}

	for i := range paragraphs {
		paragraphs[i] = Indent(paragraphs[i], 4, 0)
	}

	return append([]Entry{Title(1, "Description:")}, paragraphs...)
}

func manOptions(cmd Cmd, conf Config) []Entry {
	e := docOptions(cmd, conf, 1, 0, allRelevantHints)
	for i := 1; i < len(e); i++ {
		e[i] = Indent(e[i], 4, 0)
	}

	return e
}

func manSubcommands(cmd Cmd, conf Config) []Entry {
	var hasSubcommands bool
	for _, sc := range cmd.subcommands {
		if sc.helpFor != nil || sc.version != "" {
			continue
		}

		hasSubcommands = true
		break
	}

	if hasSubcommands {
		return docFullSubcommands(cmd, conf, 0)
	}

	return docListSubcommands(cmd, []string{cmd.name}, 0, 0)
}

func manEnv(cmd Cmd) []Entry {
	return docEnv(cmd, 0)
}

func manConfig(cmd Cmd, conf Config) []Entry {
	return docConfig(cmd, conf, 0)
}

func markdownTitle(cmd Cmd, level int) []Entry {
	txt := docCommandNameText(cmd, []string{cmd.name})
	return []Entry{Title(level, strings.Join(txt, " "))}
}

func markdownSynopsis(cmd Cmd, level int) []Entry {
	return docSynopsis(cmd, []string{cmd.name}, level+1, markdownWrapWidth)
}

func markdownDocs(cmd Cmd, level int) []Entry {
	paragraphs := docs(cmd)
	if len(paragraphs) == 0 {
		return nil
	}

	for i := range paragraphs {
		paragraphs[i] = Wrap(paragraphs[i], markdownWrapWidth)
	}

	return append([]Entry{Title(level+1, "Description:")}, paragraphs...)
}

func markdownOptions(cmd Cmd, conf Config, level int) []Entry {
	e := docOptions(cmd, conf, level+1, 0, allRelevantHints)
	for i := 1; i < len(e); i++ {
		e[i] = Wrap(e[i], markdownWrapWidth)
	}

	return e
}

func markdownSubcommands(cmd Cmd, conf Config, level int) []Entry {
	var hasSubcommands bool
	for _, sc := range cmd.subcommands {
		if sc.helpFor != nil || sc.version != "" {
			continue
		}

		hasSubcommands = true
		break
	}

	var e []Entry
	if hasSubcommands {
		e = docFullSubcommands(cmd, conf, level)
	} else {
		e = docListSubcommands(cmd, []string{cmd.name}, level, 0)
	}

	for i := range e {
		e[i] = Wrap(e[i], markdownWrapWidth)
	}

	return e
}

func markdownEnv(cmd Cmd, level int) []Entry {
	e := docEnv(cmd, level)
	for i := range e {
		e[i] = Wrap(e[i], markdownWrapWidth)
	}

	return e
}

func markdownConfig(cmd Cmd, conf Config, level int) []Entry {
	e := docConfig(cmd, conf, level)
	for i := range e {
		e[i] = Wrap(e[i], markdownWrapWidth)
	}

	return e
}

func showHelp(out io.Writer, cmd Cmd, conf Config, fullCommand []string) error {
	var e []Entry
	width := wrapWidth()
	e = append(e, helpCommandName(cmd, fullCommand)...)
	e = append(e, helpSynopsis(cmd, fullCommand, width)...)
	e = append(e, helpDocs(cmd, width)...)
	e = append(e, helpOptions(cmd, conf, width)...)
	e = append(e, helpSubcommands(cmd, fullCommand, width)...)
	return Teletype(out, Doc(e...))
}

func generateMan(out io.Writer, cmd Cmd, conf Config, date time.Time, version string) error {
	var e []Entry
	e = append(e, manTitle(cmd, date, version)...)
	e = append(e, manCommandName(cmd)...)
	e = append(e, manSynopsis(cmd)...)
	e = append(e, manDocs(cmd)...)
	e = append(e, manOptions(cmd, conf)...)
	e = append(e, manSubcommands(cmd, conf)...)
	e = append(e, manEnv(cmd)...)
	e = append(e, manConfig(cmd, conf)...)
	return Runoff(out, Doc(e...))
}

func generateMarkdown(out io.Writer, cmd Cmd, conf Config, level int) error {
	var e []Entry
	e = append(e, markdownTitle(cmd, level)...)
	e = append(e, markdownSynopsis(cmd, level)...)
	e = append(e, markdownDocs(cmd, level)...)
	e = append(e, markdownOptions(cmd, conf, level)...)
	e = append(e, markdownSubcommands(cmd, conf, level)...)
	e = append(e, markdownEnv(cmd, level)...)
	e = append(e, markdownConfig(cmd, conf, level)...)
	return Markdown(out, Doc(e...))
}

func showVersion(out io.Writer, cmd Cmd) error {
	_, err := fmt.Fprintln(out, cmd.version)
	return err
}