package sort

import (
	"fmt"
	"testing"

	"codeberg.org/snonux/algorithms/ds"
)

// Store here so that Go isn't optimizing the benchmark away.
var benchResult interface{}

const minLength int = 1
const maxLength int = 1000000
const factor int = 100
const maxSlowLength int = 100000

var arrayListCache map[string]ds.ArrayList[int]

type sortAlgorithm[V ds.Number] func(ds.ArrayList[V]) ds.ArrayList[V]
type sortAlgorithmInt func([]int) []int

func TestSleepSort(t *testing.T) {
	a := ds.NewRandomArrayList[int](10, 10)
	a = Sleep(a)
	if !a.Sorted() {
		t.Errorf("Array not sorted: %v", a)
	}
}

func TestSelectionSort(t *testing.T) {
	for i := minLength; i <= maxSlowLength; i *= factor {
		test(Selection[int], i, t)
	}
}

func TestInsertionSort(t *testing.T) {
	for i := minLength; i <= maxSlowLength; i *= factor {
		test(Insertion[int], i, t)
	}
}

func TestShellSort(t *testing.T) {
	for i := minLength; i <= maxLength; i *= factor {
		test(Shell[int], i, t)
	}
}

func TestMergeSort(t *testing.T) {
	for i := minLength; i <= maxLength; i *= factor {
		test(Merge[int], i, t)
	}
}

func TestBottomUpMergeSort(t *testing.T) {
	t.Log("Parallel merge sort")
	for i := minLength; i <= maxLength; i *= factor {
		test(BottomUpMerge[int], i, t)
	}
	test(BottomUpMerge[int], maxLength*2, t)
}

func TestParallelMergeSort(t *testing.T) {
	t.Log("Bottom-up merge sort")
	for i := minLength; i <= maxLength; i *= factor {
		test(ParallelMerge[int], i, t)
	}
}

func TestQuickSort(t *testing.T) {
	for i := minLength; i <= maxLength; i *= factor {
		test(Quick[int], i, t)
	}
}

func TestParallelQuickSort(t *testing.T) {
	for i := minLength; i <= maxLength; i *= factor {
		test(ParallelQuick[int], i, t)
	}
}

func TestQuick3WaySort(t *testing.T) {
	for i := minLength; i <= maxLength; i *= factor {
		test(Quick3Way[int], i, t)
	}
}

func TestShuffleSort(t *testing.T) {
	for i := 10; i <= maxLength; i *= factor {
		testShuffleSort(Shuffle[int], i, t)
	}
}

func BenchmarkInsertionSort(b *testing.B) {
	for i := minLength; i <= maxSlowLength; i *= factor {
		benchmark(Insertion[int], i, b)
	}
}

func BenchmarkSelectionSort(b *testing.B) {
	for i := minLength; i <= maxSlowLength; i *= factor {
		benchmark(Selection[int], i, b)
	}
}

func BenchmarkShellSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(Shell[int], i, b)
	}
}

func BenchmarkMergeSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(Merge[int], i, b)
	}
}

func BenchmarkBottomUpMergeSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(BottomUpMerge[int], i, b)
	}
}

func BenchmarkParallelMergeSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(ParallelMerge[int], i, b)
	}
}

func BenchmarkQuickSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(Quick[int], i, b)
	}
}

func BenchmarkParallelQuickSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(ParallelQuick[int], i, b)
	}
}

func BenchmarkQuick3WaySort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(Quick3Way[int], i, b)
	}
}

/*
func BenchmarkShuffleSort(b *testing.B) {
	for i := minLength; i <= maxLength; i *= factor {
		benchmark(Shuffle[int], i, b)
	}
}
*/

func test[V ds.Number](sort sortAlgorithm[V], l int, t *testing.T) {
	cb := func(t *testing.T) {
		t.Parallel()
		a := ds.NewRandomArrayList[V](l, -1)
		a = sort(a)
		if !a.Sorted() {
			t.Errorf("Array not sorted: %v", a)
		}
	}
	t.Run(fmt.Sprintf("%d", l), cb)
}

func testShuffleSort[V ds.Number](sort sortAlgorithm[V], l int, t *testing.T) {
	cb := func(t *testing.T) {
		t.Parallel()
		a := sort(ds.NewAscendingArrayList[V](l))
		if a.Sorted() {
			t.Errorf("Array sorted: %v", a.FirstN(10))
		}
	}
	t.Run(fmt.Sprintf("%d", l), cb)
}

func benchmark[V ds.Number](sort sortAlgorithm[V], l int, b *testing.B) {
	a := ds.NewRandomArrayList[V](l, -1)
	aux := ds.NewArrayList[V](l)

	b.Run(fmt.Sprintf("random(%d)", l), func(b *testing.B) {
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			copy(aux, a)
			benchResult = sort(aux)
		}
	})

	a = ds.NewAscendingArrayList[V](l)
	b.Run(fmt.Sprintf("ascending(%d)", l), func(b *testing.B) {
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			copy(aux, a)
			benchResult = sort(aux)
		}
	})

	a = ds.NewDescendingArrayList[V](l)
	b.Run(fmt.Sprintf("descending(%d)", l), func(b *testing.B) {
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			copy(aux, a)
			benchResult = sort(aux)
		}
	})
}