statsd_exporter/vendor/gopkg.in/alecthomas/kingpin.v2/cmd.go
2017-08-30 17:48:19 +02:00

274 lines
6.4 KiB
Go

package kingpin
import (
"fmt"
"strings"
)
type cmdMixin struct {
*flagGroup
*argGroup
*cmdGroup
actionMixin
}
// CmdCompletion returns completion options for arguments, if that's where
// parsing left off, or commands if there aren't any unsatisfied args.
func (c *cmdMixin) CmdCompletion(context *ParseContext) []string {
var options []string
// Count args already satisfied - we won't complete those, and add any
// default commands' alternatives, since they weren't listed explicitly
// and the user may want to explicitly list something else.
argsSatisfied := 0
for _, el := range context.Elements {
switch clause := el.Clause.(type) {
case *ArgClause:
if el.Value != nil && *el.Value != "" {
argsSatisfied++
}
case *CmdClause:
options = append(options, clause.completionAlts...)
default:
}
}
if argsSatisfied < len(c.argGroup.args) {
// Since not all args have been satisfied, show options for the current one
options = append(options, c.argGroup.args[argsSatisfied].resolveCompletions()...)
} else {
// If all args are satisfied, then go back to completing commands
for _, cmd := range c.cmdGroup.commandOrder {
if !cmd.hidden {
options = append(options, cmd.name)
}
}
}
return options
}
func (c *cmdMixin) FlagCompletion(flagName string, flagValue string) (choices []string, flagMatch bool, optionMatch bool) {
// Check if flagName matches a known flag.
// If it does, show the options for the flag
// Otherwise, show all flags
options := []string{}
for _, flag := range c.flagGroup.flagOrder {
// Loop through each flag and determine if a match exists
if flag.name == flagName {
// User typed entire flag. Need to look for flag options.
options = flag.resolveCompletions()
if len(options) == 0 {
// No Options to Choose From, Assume Match.
return options, true, true
}
// Loop options to find if the user specified value matches
isPrefix := false
matched := false
for _, opt := range options {
if flagValue == opt {
matched = true
} else if strings.HasPrefix(opt, flagValue) {
isPrefix = true
}
}
// Matched Flag Directly
// Flag Value Not Prefixed, and Matched Directly
return options, true, !isPrefix && matched
}
if !flag.hidden {
options = append(options, "--"+flag.name)
}
}
// No Flag directly matched.
return options, false, false
}
type cmdGroup struct {
app *Application
parent *CmdClause
commands map[string]*CmdClause
commandOrder []*CmdClause
}
func (c *cmdGroup) defaultSubcommand() *CmdClause {
for _, cmd := range c.commandOrder {
if cmd.isDefault {
return cmd
}
}
return nil
}
func (c *cmdGroup) cmdNames() []string {
names := make([]string, 0, len(c.commandOrder))
for _, cmd := range c.commandOrder {
names = append(names, cmd.name)
}
return names
}
// GetArg gets a command definition.
//
// This allows existing commands to be modified after definition but before parsing. Useful for
// modular applications.
func (c *cmdGroup) GetCommand(name string) *CmdClause {
return c.commands[name]
}
func newCmdGroup(app *Application) *cmdGroup {
return &cmdGroup{
app: app,
commands: make(map[string]*CmdClause),
}
}
func (c *cmdGroup) flattenedCommands() (out []*CmdClause) {
for _, cmd := range c.commandOrder {
if len(cmd.commands) == 0 {
out = append(out, cmd)
}
out = append(out, cmd.flattenedCommands()...)
}
return
}
func (c *cmdGroup) addCommand(name, help string) *CmdClause {
cmd := newCommand(c.app, name, help)
c.commands[name] = cmd
c.commandOrder = append(c.commandOrder, cmd)
return cmd
}
func (c *cmdGroup) init() error {
seen := map[string]bool{}
if c.defaultSubcommand() != nil && !c.have() {
return fmt.Errorf("default subcommand %q provided but no subcommands defined", c.defaultSubcommand().name)
}
defaults := []string{}
for _, cmd := range c.commandOrder {
if cmd.isDefault {
defaults = append(defaults, cmd.name)
}
if seen[cmd.name] {
return fmt.Errorf("duplicate command %q", cmd.name)
}
seen[cmd.name] = true
for _, alias := range cmd.aliases {
if seen[alias] {
return fmt.Errorf("alias duplicates existing command %q", alias)
}
c.commands[alias] = cmd
}
if err := cmd.init(); err != nil {
return err
}
}
if len(defaults) > 1 {
return fmt.Errorf("more than one default subcommand exists: %s", strings.Join(defaults, ", "))
}
return nil
}
func (c *cmdGroup) have() bool {
return len(c.commands) > 0
}
type CmdClauseValidator func(*CmdClause) error
// A CmdClause is a single top-level command. It encapsulates a set of flags
// and either subcommands or positional arguments.
type CmdClause struct {
cmdMixin
app *Application
name string
aliases []string
help string
isDefault bool
validator CmdClauseValidator
hidden bool
completionAlts []string
}
func newCommand(app *Application, name, help string) *CmdClause {
c := &CmdClause{
app: app,
name: name,
help: help,
}
c.flagGroup = newFlagGroup()
c.argGroup = newArgGroup()
c.cmdGroup = newCmdGroup(app)
return c
}
// Add an Alias for this command.
func (c *CmdClause) Alias(name string) *CmdClause {
c.aliases = append(c.aliases, name)
return c
}
// Validate sets a validation function to run when parsing.
func (c *CmdClause) Validate(validator CmdClauseValidator) *CmdClause {
c.validator = validator
return c
}
func (c *CmdClause) FullCommand() string {
out := []string{c.name}
for p := c.parent; p != nil; p = p.parent {
out = append([]string{p.name}, out...)
}
return strings.Join(out, " ")
}
// Command adds a new sub-command.
func (c *CmdClause) Command(name, help string) *CmdClause {
cmd := c.addCommand(name, help)
cmd.parent = c
return cmd
}
// Default makes this command the default if commands don't match.
func (c *CmdClause) Default() *CmdClause {
c.isDefault = true
return c
}
func (c *CmdClause) Action(action Action) *CmdClause {
c.addAction(action)
return c
}
func (c *CmdClause) PreAction(action Action) *CmdClause {
c.addPreAction(action)
return c
}
func (c *CmdClause) init() error {
if err := c.flagGroup.init(c.app.defaultEnvarPrefix()); err != nil {
return err
}
if c.argGroup.have() && c.cmdGroup.have() {
return fmt.Errorf("can't mix Arg()s with Command()s")
}
if err := c.argGroup.init(); err != nil {
return err
}
if err := c.cmdGroup.init(); err != nil {
return err
}
return nil
}
func (c *CmdClause) Hidden() *CmdClause {
c.hidden = true
return c
}