package lmdb

import (
	"testing"

	"github.com/stretchr/testify/require"
)

func TestQuickselect(t *testing.T) {
	{
		its := iterators{
			{last: 781},
			{last: 900},
			{last: 1},
			{last: 81},
			{last: 325},
			{last: 781},
			{last: 562},
			{last: 81},
			{last: 444},
		}

		its.quickselect(3)
		require.ElementsMatch(t,
			[]uint32{its[0].last, its[1].last, its[2].last},
			[]uint32{900, 781, 781},
		)
	}

	{
		its := iterators{
			{last: 781},
			{last: 781},
			{last: 900},
			{last: 1},
			{last: 87},
			{last: 315},
			{last: 789},
			{last: 500},
			{last: 812},
			{last: 306},
			{last: 612},
			{last: 444},
			{last: 59},
			{last: 441},
			{last: 901},
			{last: 901},
			{last: 2},
			{last: 81},
			{last: 325},
			{last: 781},
			{last: 562},
			{last: 81},
			{last: 326},
			{last: 662},
			{last: 444},
			{last: 81},
			{last: 444},
		}

		its.quickselect(6)
		require.ElementsMatch(t,
			[]uint32{its[0].last, its[1].last, its[2].last, its[3].last, its[4].last, its[5].last},
			[]uint32{901, 900, 901, 781, 812, 789},
		)
	}

	{
		its := iterators{
			{last: 229},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 85},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 121},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 157},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 193},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 329},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 185},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 221},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 257},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 293},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 0},
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			{last: 285},
			{last: 0},
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			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 0},
			{last: 0},
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			{last: 0},
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			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 729},
			{last: 0},
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			{last: 0},
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			{last: 0},
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			{last: 585},
			{last: 0},
			{last: 0},
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			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 0},
			{last: 0},
			{last: 0},
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			{last: 0},
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			{last: 0},
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			{last: 0},
			{last: 693},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
			{last: 0},
		}

		its.quickselect(18)
		require.ElementsMatch(t,
			[]uint32{
				its[0].last, its[1].last, its[2].last, its[3].last, its[4].last, its[5].last,
				its[6].last, its[7].last, its[8].last, its[9].last, its[10].last, its[11].last,
				its[12].last, its[13].last, its[14].last, its[15].last, its[16].last, its[17].last,
			},
			[]uint32{
				729,
				693,
				657,
				629,
				621,
				593,
				585,
				557,
				529,
				521,
				493,
				485,
				457,
				429,
				421,
				393,
				385,
				357,
			},
		)
	}
}