Add basic command handling, argument struct, and flag struct

argument.go

@@ -0,0 +1,6 @@
+package cmd
+
+type Argument struct {
+	Name     string
+	Required bool
+}

command.go

@@ -0,0 +1,66 @@
+package cmd
+
+import "go.fifitido.net/cmd/flags"
+
+type Command struct {
+	Name             string
+	ShortDescription string
+	LongDescription  string
+	Aliases          []string
+	Arguments        []*Argument
+	Flags            []flags.Flag
+	Subcommands      []*Command
+	Run              func(args []string)
+	RunE             func(args []string) error
+	isRoot           bool
+}
+
+func NewRoot(options ...Option) *Command {
+	cmd := &Command{isRoot: true}
+	cmd.ApplyOptions(options...)
+	return cmd
+}
+
+func New(name string, options ...Option) *Command {
+	cmd := &Command{Name: name}
+	cmd.ApplyOptions(options...)
+	return cmd
+}
+
+func (c *Command) ApplyOptions(options ...Option) {
+	for _, option := range options {
+		option(c)
+	}
+}
+
+func (c *Command) Execute(args []string) {
+	if len(args) == 0 {
+		return
+	}
+
+	for _, subcommand := range c.Subcommands {
+		if subcommand.Name == args[0] {
+			subcommand.Execute(args[1:])
+			return
+		}
+
+		for _, alias := range subcommand.Aliases {
+			if alias == args[0] {
+				subcommand.Execute(args[1:])
+				return
+			}
+		}
+	}
+
+	if c.Run != nil {
+		c.Run(args)
+		return
+	}
+
+	if c.RunE != nil {
+		if err := c.RunE(args); err != nil {
+			panic(err)
+		}
+		return
+	}
+}

flags/flag.go

@@ -0,0 +1,8 @@
+package flags
+
+type Flag interface {
+	Name() string
+	ShortName() string
+	Description() string
+	Parse(raw string) (any, error)
+}

flags/string.go

@@ -0,0 +1,50 @@
+package flags
+
+type StringFlag struct {
+	name        string
+	shortName   string
+	description string
+	value       string
+}
+
+var _ Flag = (*StringFlag)(nil)
+
+func NewStringFlag(name, shortName, description, defaultValue string) *StringFlag {
+	return &StringFlag{
+		name:        name,
+		shortName:   shortName,
+		description: description,
+		value:       defaultValue,
+	}
+}
+
+// Description implements Flag.
+func (f *StringFlag) Description() string {
+	return f.description
+}
+
+// Name implements Flag.
+func (f *StringFlag) Name() string {
+	return f.name
+}
+
+// ShortName implements Flag.
+func (f *StringFlag) ShortName() string {
+	return f.shortName
+
+}
+
+// Value implements Flag.
+func (f *StringFlag) Parse(raw string) (any, error) {
+	if raw == "" {
+		return f.value, nil
+	}
+
+	f.value = raw
+
+	return raw, nil
+}
+
+func (f *StringFlag) Value() string {
+	return f.value
+}

option.go

@@ -0,0 +1,41 @@
+package cmd
+
+import "go.fifitido.net/cmd/flags"
+
+type Option func(*Command)
+
+func WithArgument(name string, required bool) Option {
+	return func(c *Command) {
+		c.Arguments = append(c.Arguments, &Argument{name, required})
+	}
+}
+
+func WithArguments(args []*Argument) Option {
+	return func(c *Command) {
+		c.Arguments = append(c.Arguments, args...)
+	}
+}
+
+func WithFlag(f flags.Flag) Option {
+	return func(c *Command) {
+		c.Flags = append(c.Flags, f)
+	}
+}
+
+func WithFlags(fs []flags.Flag) Option {
+	return func(c *Command) {
+		c.Flags = append(c.Flags, fs...)
+	}
+}
+
+func WithSubcommand(s *Command) Option {
+	return func(c *Command) {
+		c.Subcommands = append(c.Subcommands, s)
+	}
+}
+
+func WithSubcommands(ss []*Command) Option {
+	return func(c *Command) {
+		c.Subcommands = append(c.Subcommands, ss...)
+	}
+}