// Copyright 2017 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package s2

import (
	"testing"

	"github.com/golang/geo/r3"
)

func TestWedgeRelations(t *testing.T) {
	// For simplicity, all of these tests use an origin of (0, 0, 1).
	// This shouldn't matter as long as the lower-level primitives are
	// implemented correctly.
	ab1 := Point{r3.Vector{X: 0, Y: 0, Z: 1}.Normalize()}

	tests := []struct {
		desc           string
		a0, a1, b0, b1 Point
		contains       bool
		intersects     bool
		relation       WedgeRel
	}{
		{
			desc:       "Intersection in one wedge",
			a0:         Point{r3.Vector{X: -1, Y: 0, Z: 10}},
			a1:         Point{r3.Vector{X: 1, Y: 2, Z: 10}},
			b0:         Point{r3.Vector{X: 0, Y: 1, Z: 10}},
			b1:         Point{r3.Vector{X: 1, Y: -2, Z: 10}},
			contains:   false,
			intersects: true,
			relation:   WedgeProperlyOverlaps,
		},
		{
			desc:       "Intersection in two wedges",
			a0:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			a1:         Point{r3.Vector{X: 1, Y: -1, Z: 10}},
			b0:         Point{r3.Vector{X: 1, Y: 0, Z: 10}},
			b1:         Point{r3.Vector{X: -1, Y: 1, Z: 10}},
			contains:   false,
			intersects: true,
			relation:   WedgeProperlyOverlaps,
		},
		{
			desc:       "Normal containment",
			a0:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			a1:         Point{r3.Vector{X: 1, Y: -1, Z: 10}},
			b0:         Point{r3.Vector{X: -1, Y: 0, Z: 10}},
			b1:         Point{r3.Vector{X: 1, Y: 0, Z: 10}},
			contains:   true,
			intersects: true,
			relation:   WedgeProperlyContains,
		},
		{
			desc:       "Containment with equality on one side",
			a0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			a1:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			b0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			b1:         Point{r3.Vector{X: 1, Y: -5, Z: 10}},
			contains:   true,
			intersects: true,
			relation:   WedgeProperlyContains,
		},
		{
			desc:       "Containment with equality on the other side",
			a0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			a1:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			b0:         Point{r3.Vector{X: 1, Y: -2, Z: 10}},
			b1:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			contains:   true,
			intersects: true,
			relation:   WedgeProperlyContains,
		},
		{
			desc:       "Containment with equality on both sides",
			a0:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			a1:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b0:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			b1:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			contains:   true,
			intersects: true,
			relation:   WedgeEquals,
		},
		{
			desc:       "Disjoint with equality on one side",
			a0:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			a1:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b0:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b1:         Point{r3.Vector{X: -2, Y: -3, Z: 10}},
			contains:   false,
			intersects: false,
			relation:   WedgeIsDisjoint,
		},
		{
			desc:       "Disjoint with equality on the other side",
			a0:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			a1:         Point{r3.Vector{X: 0, Y: 5, Z: 10}},
			b0:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b1:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			contains:   false,
			intersects: false,
			relation:   WedgeIsDisjoint,
		},
		{
			desc:       "Disjoint with equality on both sides",
			a0:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			a1:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b0:         Point{r3.Vector{X: 4, Y: -5, Z: 10}},
			b1:         Point{r3.Vector{X: -2, Y: 3, Z: 10}},
			contains:   false,
			intersects: false,
			relation:   WedgeIsDisjoint,
		},
		{
			desc:       "B contains A with equality on one side",
			a0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			a1:         Point{r3.Vector{X: 1, Y: -5, Z: 10}},
			b0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			b1:         Point{r3.Vector{X: -1, Y: -1, Z: 10}},
			contains:   false,
			intersects: true,
			relation:   WedgeIsProperlyContained,
		},

		{
			desc:       "B contains A with equality on the other side",
			a0:         Point{r3.Vector{X: 2, Y: 1, Z: 10}},
			a1:         Point{r3.Vector{X: 1, Y: -5, Z: 10}},
			b0:         Point{r3.Vector{X: -2, Y: 1, Z: 10}},
			b1:         Point{r3.Vector{X: 1, Y: -5, Z: 10}},
			contains:   false,
			intersects: true,
			relation:   WedgeIsProperlyContained,
		},
	}

	for _, test := range tests {
		test.a0 = Point{test.a0.Normalize()}
		test.a1 = Point{test.a1.Normalize()}
		test.b0 = Point{test.b0.Normalize()}
		test.b1 = Point{test.b1.Normalize()}

		if got := WedgeContains(test.a0, ab1, test.a1, test.b0, test.b1); got != test.contains {
			t.Errorf("%s: WedgeContains(%v, %v, %v, %v, %v) = %t, want %t", test.desc, test.a0, ab1, test.a1, test.b0, test.b1, got, test.contains)
		}
		if got := WedgeIntersects(test.a0, ab1, test.a1, test.b0, test.b1); got != test.intersects {
			t.Errorf("%s: WedgeIntersects(%v, %v, %v, %v, %v) = %t, want %t", test.desc, test.a0, ab1, test.a1, test.b0, test.b1, got, test.intersects)
		}
		if got := WedgeRelation(test.a0, ab1, test.a1, test.b0, test.b1); got != test.relation {
			t.Errorf("%s: WedgeRelation(%v, %v, %v, %v, %v) = %v, want %v", test.desc, test.a0, ab1, test.a1, test.b0, test.b1, got, test.relation)
		}
	}
}