package ring_test

import (
	"runtime"
	"testing"

	"github.com/bloeys/nterm/ring"
)

func TestRing(t *testing.T) {

	// Basics
	b := ring.NewBuffer[rune](4)
	b.Write('a', 'b', 'c', 'd')
	CheckArr(t, []rune{'a', 'b', 'c', 'd'}, b.Data)

	v1, v2 := b.Views()
	CheckArr(t, []rune{'a', 'b', 'c', 'd'}, v1)
	CheckArr(t, nil, v2)
	Check(t, 0, b.Start)
	Check(t, 4, b.Len)

	b.Write('e', 'f')
	Check(t, 2, b.Start)
	CheckArr(t, []rune{'e', 'f', 'c', 'd'}, b.Data)

	v1, v2 = b.Views()
	CheckArr(t, []rune{'c', 'd'}, v1)
	CheckArr(t, []rune{'e', 'f'}, v2)

	b.Write('g')
	Check(t, 3, b.Start)

	v1, v2 = b.Views()
	CheckArr(t, []rune{'e', 'f', 'g', 'd'}, b.Data)
	CheckArr(t, []rune{'d'}, v1)
	CheckArr(t, []rune{'e', 'f', 'g'}, v2)

	b = ring.NewBuffer[rune](4)
	b.Write('a', 'b', 'c', 'd', 'e')
	Check(t, 1, b.Start)

	// Input over 2x bigger than buffer
	b = ring.NewBuffer[rune](4)
	b.Write('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i')
	CheckArr(t, []rune{'i', 'f', 'g', 'h'}, b.Data)

	// Input starting in the middle and having to loop back and WrittenElements
	b2 := ring.NewBuffer[int](4)
	Check(t, 0, b2.WrittenElements)

	b2.Write(1, 2, 3)
	Check(t, 3, b2.WrittenElements)

	b2.Write(4, 5)
	Check(t, 5, b2.WrittenElements)
	CheckArr(t, []int{5, 2, 3, 4}, b2.Data)

	b2.Write(6)
	Check(t, 6, b2.WrittenElements)
	CheckArr(t, []int{5, 6, 3, 4}, b2.Data)

	b2.Write(7)
	Check(t, 7, b2.WrittenElements)
	CheckArr(t, []int{5, 6, 7, 4}, b2.Data)

	b2.Write(8)
	Check(t, 8, b2.WrittenElements)
	CheckArr(t, []int{5, 6, 7, 8}, b2.Data)

	// ViewsFromTo
	b2 = ring.NewBuffer[int](4)

	v11, v22 := b2.ViewsFromToRelIndex(0, 0)
	Check(t, 0, len(v11))
	Check(t, 0, len(v22))

	b2.Write(1, 2, 3, 4)

	v11, v22 = b2.ViewsFromToRelIndex(5, 0)
	Check(t, 0, len(v11))
	Check(t, 0, len(v22))

	v11, v22 = b2.ViewsFromToRelIndex(0, 0)
	Check(t, 1, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{1}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(0, 1)
	Check(t, 2, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{1, 2}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(0, 3)
	Check(t, 4, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{1, 2, 3, 4}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(0, 4)
	Check(t, 4, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{1, 2, 3, 4}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(0, 40)
	Check(t, 4, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{1, 2, 3, 4}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(3, 40)
	Check(t, 1, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{4}, v11)

	b2.Write(5, 6)

	v11, v22 = b2.ViewsFromToRelIndex(3, 40)
	Check(t, 0, len(v11))
	Check(t, 1, len(v22))
	CheckArr(t, []int{6}, v22)

	v11, v22 = b2.ViewsFromToRelIndex(1, 2)
	Check(t, 1, len(v11))
	Check(t, 1, len(v22))
	CheckArr(t, []int{4}, v11)
	CheckArr(t, []int{5}, v22)

	v11, v22 = b2.ViewsFromToRelIndex(0, 1)
	Check(t, 2, len(v11))
	Check(t, 0, len(v22))
	CheckArr(t, []int{3, 4}, v11)

	v11, v22 = b2.ViewsFromToRelIndex(0, 2)
	Check(t, 2, len(v11))
	Check(t, 1, len(v22))
	CheckArr(t, []int{3, 4}, v11)
	CheckArr(t, []int{5}, v22)

	v11, v22 = b2.ViewsFromToRelIndex(0, 3)
	Check(t, 2, len(v11))
	Check(t, 2, len(v22))
	CheckArr(t, []int{3, 4}, v11)
	CheckArr(t, []int{5, 6}, v22)

	v11, v22 = b2.ViewsFromToRelIndex(2, 3)
	Check(t, 0, len(v11))
	Check(t, 2, len(v22))
	CheckArr(t, []int{5, 6}, v22)
}

func TestIterator(t *testing.T) {

	// Only v1 set
	b := ring.NewBuffer[int](4)
	b.Write(1, 2)

	got := []int{}
	ans := []int{1, 2}
	it := b.Iterator()
	for v, done := it.Next(); !done; v, done = it.Next() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{2, 1}
	for v, done := it.Prev(); !done; v, done = it.Prev() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{1, 2}
	it.GotoStart()
	for v, done := it.Next(); !done; v, done = it.Next() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	// V1 and v2 set
	b.Write(3, 4, 5, 6)
	got = []int{}
	ans = []int{3, 4, 5, 6}
	it = b.Iterator()
	for v, done := it.Next(); !done; v, done = it.Next() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	it.GotoEnd()
	got = []int{}
	ans = []int{6, 5, 4, 3}
	for v, done := it.Prev(); !done; v, done = it.Prev() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	// GotoIndex
	got = []int{}
	ans = []int{5, 6}
	it.GotoIndex(2)
	for v, done := it.Next(); !done; v, done = it.Next() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{4, 3}
	it.GotoIndex(2)
	for v, done := it.Prev(); !done; v, done = it.Prev() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{}
	it.GotoIndex(-100)
	for v, done := it.Prev(); !done; v, done = it.Prev() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{6, 5, 4, 3}
	it.GotoIndex(100)
	for v, done := it.Prev(); !done; v, done = it.Prev() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	got = []int{}
	ans = []int{}
	it.GotoIndex(100)
	for v, done := it.Next(); !done; v, done = it.Next() {
		got = append(got, v)
	}
	CheckArr(t, ans, got)

	// NextN
	got = make([]int, 2)
	ans = []int{3, 4}
	it.GotoStart()
	it.NextN(got, 2)
	CheckArr(t, ans, got)

	ans = []int{5, 6}
	it.NextN(got, 2)
	CheckArr(t, ans, got)

	// PrevN
	got = make([]int, 2)
	ans = []int{6, 5}
	it.GotoEnd()
	it.PrevN(got, 2)
	CheckArr(t, ans, got)

	ans = []int{4, 3}
	it.PrevN(got, 2)
	CheckArr(t, ans, got)

	// Empty buffer
	b = ring.NewBuffer[int](4)

	it = b.Iterator()
	Check(t, 0, len(it.V1))
	Check(t, 0, len(it.V2))
	Check(t, false, it.InV1)

	it.GotoStart()
	Check(t, false, it.InV1)

	it.GotoIndex(1)
	Check(t, false, it.InV1)

	_, done := it.Next()
	Check(t, true, done)
}

func Check[T comparable](t *testing.T, expected, got T) {
	if got != expected {
		_, _, line, _ := runtime.Caller(1)
		t.Fatalf("Expected %v but got %v by test at line %d\n", expected, got, line)
	}
}

func CheckArr[T comparable](t *testing.T, expected, got []T) {

	_, _, line, _ := runtime.Caller(1)
	if len(expected) != len(got) {
		t.Fatalf("Expected %v but got %v by test at line %d\n", expected, got, line)
		return
	}

	for i := 0; i < len(expected); i++ {

		if expected[i] != got[i] {
			t.Fatalf("Expected %v but got %v by test at line %d\n", expected, got, line)
			return
		}
	}
}