package rags_test

import (
	"flag"
	"fmt"
	"os"
	"strconv"
	"strings"

	"edge-infra.dev/pkg/lib/cli/rags"
)

// Person is a struct we want to bind to a flag as a [flag.Getter].
type Person struct {
	age  int
	name string
}

// String implements [flag.Value]
func (p *Person) String() string {
	if p.age == 0 || p.name == "" {
		return ""
	}
	return fmt.Sprintf("%s is %d years old", p.name, p.age)
}

// Set implements [flag.Value]
func (p *Person) Set(s string) error {
	v := strings.Split(s, ":")
	age, err := strconv.Atoi(v[1])
	if err != nil {
		return err
	}
	*p = Person{
		name: v[0],
		age:  age,
	}
	return nil
}

// Get implements [flag.Getter]
func (p *Person) Get() any { return p }

// Type implements [rags.TypedValue] and exposes the descriptor for our custom
// flag value.
func (p *Person) Type() string {
	return "person"
}

func Example_valueImplementation() {
	p := &Person{100, "tom"}

	rs := rags.New("example-custom-value", flag.ContinueOnError)
	// Equivalent to flag.FlagSet.Var(...)
	rs.Var(p, "person", "describe person in the format 'name:age'")
	rs.SetOutput(os.Stdout)
	rs.Usage()
}

func Example_valueImplementationDeclarative() {
	var dst Person

	rs := rags.New("example-custom-value-declarative", flag.ContinueOnError)
	rs.Add(&rags.Rag{
		Name:  "person",
		Usage: "describe person in the format 'name:age'",
		Value: &rags.Value[Person]{
			Var:     &dst,
			Default: Person{100, "tom"},
			Parse: func(s string) (Person, error) {
				v := strings.Split(s, ":")
				age, err := strconv.Atoi(v[1])
				if err != nil {
					return Person{}, err
				}
				return Person{name: v[0], age: age}, nil
			},
		},
	})

	rs.SetOutput(os.Stdout)
	rs.Usage()
}

func Example_declarativeValue() {
	var dst bool
	rs := rags.New("example-built-in-value-declarative", flag.ContinueOnError)
	// Create a flag bound to a built-in value type declaratively
	rs.Add(&rags.Rag{
		Name:  "enabled",
		Value: &rags.Bool{Var: &dst},
	})

	rs.SetOutput(os.Stdout)
	rs.Usage()
}

func Example_imperativeValue() {
	var dst bool
	rs := rags.New("example-built-in-value-helpers", flag.ContinueOnError)
	// Create a flag bound to a built-in value type using the generic helper
	// function that supports all primitives supported by this package.
	rs.Add(&rags.Rag{
		Name:  "enabled",
		Value: rags.NewValue(&dst),
	})

	rs.SetOutput(os.Stdout)
	rs.Usage()
}

func Example_collectionValues() {
	var (
		targets  []string
		platform string
	)
	rs := rags.New("example-built-in-collection-values", flag.ContinueOnError)
	rs.Add(
		&rags.Rag{
			Name:  "targets",
			Usage: "clusters to target for operations",
			Value: &rags.StringSet{Var: &targets},
		},
		&rags.Rag{
			Name:  "platform",
			Usage: "platform for targeted clusters",
			Value: &rags.StringEnum{Var: &platform, Valid: []string{"gke", "aws"}},
		})

	rs.SetOutput(os.Stdout)
	rs.Usage()
}