package vector_test

import (
	"math"
	"testing"

	"git.wtrh.nl/patterns/gopatterns/pkg/vector"
	"github.com/stretchr/testify/assert"
)

func TestVector_Abs(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: -1,
		Y: 1,
	}.Abs()
	exp := vector.Vector{
		X: 1,
		Y: 1,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Abs2(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 0,
		Y: -2,
	}.Abs()
	exp := vector.Vector{
		X: 0,
		Y: 2,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Subtract(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4,
	}
	v2 := vector.Vector{
		X: 7,
		Y: -3,
	}
	act := v1.Subtract(v2)
	exp := vector.Vector{
		X: 5.5,
		Y: 7,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Add(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4,
	}
	v2 := vector.Vector{
		X: 7,
		Y: -3,
	}
	act := v1.Add(v2)
	exp := vector.Vector{
		X: 19.5,
		Y: 1,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Multiply(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4,
	}
	act := v1.Multiply(7)
	exp := vector.Vector{
		X: 87.5,
		Y: 28,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Divide(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 15,
		Y: 3,
	}
	act := v1.Divide(3)
	exp := vector.Vector{
		X: 5,
		Y: 1,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Divide2(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: -15,
		Y: 3,
	}
	act := v1.Divide(0)
	exp := vector.Vector{
		X: math.Inf(-1),
		Y: math.Inf(1),
	}

	assert.Equal(t, exp, act)
}

func TestVector_Round(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4.3,
	}
	act := v1.Round()
	exp := vector.Vector{
		X: 13,
		Y: 4,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Floor(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.9,
		Y: 4.3,
	}
	act := v1.Floor()
	exp := vector.Vector{
		X: 12,
		Y: 4,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Ciel(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.9,
		Y: 4.3,
	}
	act := v1.Ceil()
	exp := vector.Vector{
		X: 13,
		Y: 5,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Scale(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4,
	}
	v2 := vector.Vector{
		X: 7,
		Y: -3,
	}
	act := v1.Scale(v2)
	exp := vector.Vector{
		X: 87.5,
		Y: -12,
	}

	assert.Equal(t, exp, act)
}

func TestVector_ScaleDown(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: 4,
	}
	v2 := vector.Vector{
		X: 5,
		Y: -2,
	}
	act := v1.ScaleDown(v2)
	exp := vector.Vector{
		X: 2.5,
		Y: -2,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Max(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: -4,
	}
	v2 := vector.Vector{
		X: 5,
		Y: 2,
	}
	act := v1.Max(v2)
	exp := vector.Vector{
		X: 12.5,
		Y: 2,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Min(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 12.5,
		Y: -4,
	}
	v2 := vector.Vector{
		X: 5,
		Y: 2,
	}
	act := v1.Min(v2)
	exp := vector.Vector{
		X: 5,
		Y: -4,
	}

	assert.Equal(t, exp, act)
}

func TestVector_String(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 12.5,
		Y: 4,
	}.String()
	exp := "12.5,4"

	assert.Equal(t, exp, act)
}

func TestVector_Magnitude(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 3,
		Y: 4,
	}.Magnitude()
	exp := 5.0

	assert.InDelta(t, exp, act, 1e-15)
}

func TestVector_Unit_Panic(t *testing.T) {
	t.Parallel()

	emptyVector := vector.Vector{}

	assert.Panics(t, func() { emptyVector.Unit() })
}

func TestVector_Unit(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 3,
		Y: 4,
	}.Unit()
	exp := vector.Vector{
		X: 0.6,
		Y: 0.8,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Rotate(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 2,
		Y: 0,
	}.Rotate(math.Pi / 2)
	exp := vector.Vector{
		X: 0,
		Y: 2,
	}

	assert.InDelta(t, exp.X, act.X, math.Pow10(-15))
	assert.InDelta(t, exp.Y, act.Y, math.Pow10(-15))
}

func TestVector_Rotate2(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 2,
		Y: 0,
	}.Rotate(math.Pi)
	exp := vector.Vector{
		X: -2,
		Y: 0,
	}

	assert.InDelta(t, exp.X, act.X, math.Pow10(-15))
	assert.InDelta(t, exp.Y, act.Y, math.Pow10(-15))
}

func TestVector_Rotate3(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 0,
		Y: 2,
	}.Rotate(math.Pi / 2)
	exp := vector.Vector{
		X: -2,
		Y: 0,
	}

	assert.InDelta(t, exp.X, act.X, math.Pow10(-15))
	assert.InDelta(t, exp.Y, act.Y, math.Pow10(-15))
}

func TestVector_Rotate4(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 0,
		Y: 2,
	}.Rotate(math.Pi)
	exp := vector.Vector{
		X: 0,
		Y: -2,
	}

	assert.InDelta(t, exp.X, act.X, math.Pow10(-15))
	assert.InDelta(t, exp.Y, act.Y, math.Pow10(-15))
}

func TestVector_Chord(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 2,
		Y: 0,
	}.Span(math.Pi / 2)
	exp := vector.Vector{
		X: 2,
		Y: -2,
	}

	assert.InDelta(t, exp.X, act.X, math.Pow10(-15))
	assert.InDelta(t, exp.Y, act.Y, math.Pow10(-15))
}

func TestVector_Distance(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: 3,
		Y: 0,
	}
	v2 := vector.Vector{
		X: 0,
		Y: 4,
	}

	act := v1.Distance(v2)
	exp := 5.0
	assert.InDelta(t, exp, act, 1e-15)
}

func TestVector_Angle(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: 3,
		Y: 3,
	}.Angle()
	exp := math.Pi / 4

	assert.InDelta(t, exp, act, 1e-15)
}

func TestVector_Angle2(t *testing.T) {
	t.Parallel()

	act := vector.Vector{
		X: -3,
		Y: 3,
	}.Angle()
	exp := 3 * math.Pi / 4

	assert.InDelta(t, exp, act, 1e-15)
}

func TestVector_AngleBetween(t *testing.T) {
	t.Parallel()

	v1 := vector.Vector{
		X: -1,
		Y: 3,
	}
	v2 := vector.Vector{
		X: 2,
		Y: 6,
	}
	act := v1.AngleBetween(v2)
	exp := math.Pi / 4
	assert.InDelta(t, exp, act, 1e-15)
}

func TestVector_Above(t *testing.T) {
	t.Parallel()

	act := vector.Vector{}.Above(1)
	exp := vector.Vector{
		X: 0,
		Y: 1,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Below(t *testing.T) {
	t.Parallel()

	act := vector.Vector{}.Below(1)
	exp := vector.Vector{
		X: 0,
		Y: -1,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Right(t *testing.T) {
	t.Parallel()

	act := vector.Vector{}.Right(1)
	exp := vector.Vector{
		X: 1,
		Y: 0,
	}

	assert.Equal(t, exp, act)
}

func TestVector_Left(t *testing.T) {
	t.Parallel()

	act := vector.Vector{}.Left(1)
	exp := vector.Vector{
		X: -1,
		Y: 0,
	}

	assert.Equal(t, exp, act)
}