package cobra

import (
	"context"
	"fmt"
	"io"
	"testing"
)

func BenchmarkPerformanceParse(b *testing.B) {
	wide := performanceFlatTree(128)
	wideArgs := []string{"wide127"}
	deep, deepArgs := performanceNestedTree(24)
	options := ParseOptions{Context: context.Background(), Out: io.Discard, Err: io.Discard}

	for _, benchmark := range []struct {
		name string
		root *Command
		args []string
	}{
		{name: "shallow_wide", root: wide, args: wideArgs},
		{name: "deep", root: deep, args: deepArgs},
	} {
		b.Run(benchmark.name, func(b *testing.B) {
			result := Parse(benchmark.root, benchmark.args, options)
			if result.Failure != nil {
				b.Fatalf("fixture parse failed: %s", result.Failure.Message)
			}
			b.ReportAllocs()
			b.ResetTimer()
			for i := 0; i < b.N; i++ {
				result := Parse(benchmark.root, benchmark.args, options)
				if result.Failure != nil {
					b.Fatalf("parse failed: %s", result.Failure.Message)
				}
			}
		})
	}
}

func BenchmarkPerformanceSessionParseAndHelp(b *testing.B) {
	root := performanceFlatTree(8)
	args := []string{"wide007"}
	session := Prepare(root, ParseOptions{Context: context.Background(), Out: io.Discard, Err: io.Discard})
	result := session.Parse(args)
	if result.Failure != nil {
		b.Fatalf("fixture parse failed: %s", result.Failure.Message)
	}
	if help, failure := session.RenderHelp(result.Path); failure != nil || help == "" {
		b.Fatalf("fixture help failed: %q %v", help, failure)
	}
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		result := session.Parse(args)
		if result.Failure != nil {
			b.Fatalf("parse failed: %s", result.Failure.Message)
		}
		if help, failure := session.RenderHelp(result.Path); failure != nil || help == "" {
			b.Fatalf("help failed: %q %v", help, failure)
		}
	}
}

func performanceFlatTree(count int) *Command {
	root := &Command{Name: "app", Children: make([]*Command, count)}
	for index := range root.Children {
		root.Children[index] = &Command{Name: fmt.Sprintf("wide%03d", index), Runnable: true}
	}
	return root
}

func performanceNestedTree(depth int) (*Command, []string) {
	path := make([]string, depth)
	for index := range path {
		path[index] = fmt.Sprintf("level%02d", index)
	}
	current := &Command{Name: path[depth-1], Runnable: true}
	for index := depth - 2; index >= 0; index-- {
		current = &Command{Name: path[index], Children: []*Command{
			current,
			{Name: fmt.Sprintf("sibling%02d", index), Runnable: true},
		}}
	}
	return &Command{Name: "app", Children: []*Command{current}}, path
}