package menu

import (
	"bytes"
	"io"
	"reflect"
	"regexp"
	"strings"
	"testing"
)

var sample = []Item{
	{Label: "module build", Desc: "build the .mod", Args: []string{"module", "build"}},
	{Label: "topdata validate-topdata", Desc: "validate topdata", Args: []string{"topdata", "validate-topdata"}},
}

func TestSelectReturnsChosenArgs(t *testing.T) {
	got, err := Select(io.Discard, strings.NewReader("1\n\n"), sample)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if want := []string{"module", "build"}; !reflect.DeepEqual(got, want) {
		t.Fatalf("got %v, want %v", got, want)
	}
}

func TestSelectAppendsExtraArgs(t *testing.T) {
	got, err := Select(io.Discard, strings.NewReader("2\n--dry-run foo\n"), sample)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	want := []string{"topdata", "validate-topdata", "--dry-run", "foo"}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("got %v, want %v", got, want)
	}
}

func TestSelectQuitReturnsNil(t *testing.T) {
	got, err := Select(io.Discard, strings.NewReader("q\n"), sample)
	if err != nil || got != nil {
		t.Fatalf("quit should return (nil,nil); got (%v,%v)", got, err)
	}
}

func TestSelectInvalidErrors(t *testing.T) {
	if _, err := Select(io.Discard, strings.NewReader("99\n"), sample); err == nil {
		t.Fatal("out-of-range selection should error")
	}
}

func TestSelectAlignsDescriptionsAfterLongestLabel(t *testing.T) {
	items := []Item{
		{Label: "hak build", Desc: "build haks", Args: []string{"hak", "build"}},
		{Label: "topdata exceptionally-long-command", Desc: "long command", Args: []string{"topdata", "long"}},
	}
	var out bytes.Buffer
	if _, err := Select(&out, strings.NewReader("q\n"), items); err != nil {
		t.Fatalf("select: %v", err)
	}
	text := stripANSI(out.String())
	var positions []int
	for _, line := range strings.Split(text, "\n") {
		for _, desc := range []string{"build haks", "long command"} {
			if index := strings.Index(line, desc); index >= 0 {
				positions = append(positions, index)
			}
		}
	}
	if len(positions) != 2 {
		t.Fatalf("expected two menu descriptions, got %d:\n%s", len(positions), text)
	}
	if positions[0] != positions[1] {
		t.Fatalf("descriptions are not aligned: columns %v\n%s", positions, text)
	}
}

func TestSelectShowsCommandGuidanceBeforeArgumentsPrompt(t *testing.T) {
	items := []Item{{
		Label:   "topdata build",
		Desc:    "compile topdata",
		Args:    []string{"topdata", "build"},
		Usage:   "crucible topdata build [--force]",
		Options: []string{"--force   rebuild outputs"},
	}}
	var out bytes.Buffer
	if _, err := Select(&out, strings.NewReader("1\n\n"), items); err != nil {
		t.Fatalf("select: %v", err)
	}
	text := stripANSI(out.String())
	for _, want := range []string{
		"usage: crucible topdata build [--force]",
		"options:",
		"--force   rebuild outputs",
		"arguments (press Enter to use defaults):",
	} {
		if !strings.Contains(text, want) {
			t.Errorf("selected command guidance missing %q:\n%s", want, text)
		}
	}
}

func stripANSI(value string) string {
	return regexp.MustCompile(`\x1b\[[0-9;]*m`).ReplaceAllString(value, "")
}