package erasureencode

import (
	"fmt"
	"testing"
)

// example uses a tiny shard size for testing
// ex: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h] ShardSize(2) RS(3,2)
// c0: [01, 67, cd] [s0, s3, s6]
// c1: [23, 89, ef] [s1, s4, s7]
// c2: [45, ab, gh] [s2, s5, s8]
// read(7, 7)
// desired plan 0,3,1; 1,2,2; 2,2,2; 0,4,2 -> 7; 89; ab; cd

func TestPlan_EvenStride_Full(t *testing.T) {
	params := Params{
		Size:   18,
		Stride: 2,
		Shards: 3,
		Parity: 2,
	}

	expected := []ChunkShardMeta{
		ChunkShardMeta{Chunk: 0, ChunkOffset: 3, GlobalOffset: 7, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 2, GlobalOffset: 8, Size: 2},
		ChunkShardMeta{Chunk: 2, ChunkOffset: 2, GlobalOffset: 10, Size: 2},
		ChunkShardMeta{Chunk: 0, ChunkOffset: 4, GlobalOffset: 12, Size: 2},
	}
	actual := params.Plan(7, 7)

	if len(actual) != len(expected) {
		t.Errorf(`Expected output to have length of %x, got %x`, len(expected), len(actual))
	}

	for i, actualItem := range actual {
		if fmt.Sprintf("%#v", actualItem) != fmt.Sprintf("%#v", expected[i]) {
			t.Errorf(`Expected %#v to equal %#v at %d`, actualItem, expected[i], i)
		} else {
			// fmt.Printf("ok: %#v\n", actualItem)
		}
	}
}

// example uses a tiny shard size for testing
// ex: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f] ShardSize(2) RS(3,2)
// c0: [01, 67, cd] [s0, s3, s6]
// c1: [23, 89, ef] [s1, s4, s7]
// c2: [45, ab, !!] [s2, s5, s8]
// read(7, 7)
// desired plan 0,3,1; 1,2,2; 2,2,2; 0,4,2 -> 7; 89; ab; cd

func TestPlan_EvenStride_Short2(t *testing.T) {
	params := Params{
		Size:   16,
		Stride: 2,
		Shards: 3,
		Parity: 2,
	}

	expected := []ChunkShardMeta{
		ChunkShardMeta{Chunk: 0, ChunkOffset: 3, GlobalOffset: 7, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 2, GlobalOffset: 8, Size: 2},
		ChunkShardMeta{Chunk: 2, ChunkOffset: 2, GlobalOffset: 10, Size: 2},
		ChunkShardMeta{Chunk: 0, ChunkOffset: 4, GlobalOffset: 12, Size: 2},
	}
	actual := params.Plan(7, 7)

	if len(actual) != len(expected) {
		t.Errorf(`Expected output to have length of %x, got %x`, len(expected), len(actual))
	}

	for i, actualItem := range actual {
		if fmt.Sprintf("%#v", actualItem) != fmt.Sprintf("%#v", expected[i]) {
			t.Errorf(`Expected %#v to equal %#v at %d`, actualItem, expected[i], i)
		} else {
			// fmt.Printf("ok: %#v\n", actualItem)
		}
	}
}

// example uses a tiny shard size for testing
// ex: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g] ShardSize(2) RS(3,2)
// c0: [01, 67, cd] [s0, s3, s6]
// c1: [23, 89, ef] [s1, s4, s7]
// c2: [45, ab, g!] [s2, s5, s8]
// read(7, 7)
// desired plan 0,3,1; 1,2,2; 2,2,2; 0,4,2 -> 7; 89; ab; cd

func TestPlan_EvenStride_Short1(t *testing.T) {
	params := Params{
		Size:   17,
		Stride: 2,
		Shards: 3,
		Parity: 2,
	}

	expected := []ChunkShardMeta{
		ChunkShardMeta{Chunk: 0, ChunkOffset: 3, GlobalOffset: 7, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 2, GlobalOffset: 8, Size: 2},
		ChunkShardMeta{Chunk: 2, ChunkOffset: 2, GlobalOffset: 10, Size: 2},
		ChunkShardMeta{Chunk: 0, ChunkOffset: 4, GlobalOffset: 12, Size: 2},
	}
	actual := params.Plan(7, 7)

	if len(actual) != len(expected) {
		t.Errorf(`Expected output to have length of %x, got %x`, len(expected), len(actual))
	}

	for i, actualItem := range actual {
		if fmt.Sprintf("%#v", actualItem) != fmt.Sprintf("%#v", expected[i]) {
			t.Errorf(`Expected %#v to equal %#v at %d`, actualItem, expected[i], i)
		} else {
			// fmt.Printf("ok: %#v\n", actualItem)
		}
	}
}

// example uses a tiny shard size for testing
// ex: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d] ShardSize(2) RS(3,2)
// c0: [01, 67, c] [s0, s3, s6]
// c1: [23, 89, d] [s1, s4, s7]
// c2: [45, ab, !] [s2, s5, s8]
// read(7, 7)
// desired plan 0,3,1; 1,2,2; 2,2,2; 0,4,1; 1,4,1 -> 7; 89; ab; c; d

func TestPlan_OddStride_Short1(t *testing.T) {
	params := Params{
		Size:   13,
		Stride: 2,
		Shards: 3,
		Parity: 2,
	}

	expected := []ChunkShardMeta{
		ChunkShardMeta{Chunk: 0, ChunkOffset: 3, GlobalOffset: 7, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 2, GlobalOffset: 8, Size: 2},
		ChunkShardMeta{Chunk: 2, ChunkOffset: 2, GlobalOffset: 10, Size: 2},
		ChunkShardMeta{Chunk: 0, ChunkOffset: 4, GlobalOffset: 12, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 4, GlobalOffset: 13, Size: 1},
	}
	actual := params.Plan(7, 7)

	if len(actual) != len(expected) {
		t.Errorf(`Expected output to have length of %x, got %x`, len(expected), len(actual))
	}

	for i, actualItem := range actual {
		if fmt.Sprintf("%#v", actualItem) != fmt.Sprintf("%#v", expected[i]) {
			t.Errorf(`Expected %#v to equal %#v at %d`, actualItem, expected[i], i)
		} else {
			// fmt.Printf("ok: %#v\n", actualItem)
		}
	}
}

func TestPlan_OddStride_Full(t *testing.T) {
	params := Params{
		Size:   14,
		Stride: 2,
		Shards: 3,
		Parity: 2,
	}

	expected := []ChunkShardMeta{
		ChunkShardMeta{Chunk: 0, ChunkOffset: 3, GlobalOffset: 7, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 2, GlobalOffset: 8, Size: 2},
		ChunkShardMeta{Chunk: 2, ChunkOffset: 2, GlobalOffset: 10, Size: 2},
		ChunkShardMeta{Chunk: 0, ChunkOffset: 4, GlobalOffset: 12, Size: 1},
		ChunkShardMeta{Chunk: 1, ChunkOffset: 4, GlobalOffset: 13, Size: 1},
	}
	actual := params.Plan(7, 7)

	if len(actual) != len(expected) {
		t.Errorf(`Expected output to have length of %x, got %x`, len(expected), len(actual))
	}

	for i, actualItem := range actual {
		if fmt.Sprintf("%#v", actualItem) != fmt.Sprintf("%#v", expected[i]) {
			t.Errorf(`Expected %#v to equal %#v at %d`, actualItem, expected[i], i)
		} else {
			// fmt.Printf("ok: %#v\n", actualItem)
		}
	}
}