package rbang

import (
	"fmt"
	"math/rand"
	"os"
	"sort"
	"strconv"
	"strings"
	"testing"
	"time"

	"github.com/tidwall/geoindex"
	"github.com/tidwall/lotsa"
)

func TestBenchInsert2D(t *testing.T) {
	testBenchInsert(t, 100000, 2)
}

func testBenchInsert(t *testing.T, N, D int) {
	rand.Seed(time.Now().UnixNano())
	points := make([]float64, N*D)
	for i := 0; i < N; i++ {
		for j := 0; j < D; j++ {
			points[i*D+j] = rand.Float64()*100 - 50
		}
	}
	var tr RTree
	lotsa.Output = os.Stdout
	fmt.Printf("Insert(%dD): ", D)
	lotsa.Ops(N, 1, func(i, _ int) {
		point := [2]float64{points[i*D+0], points[i*D+1]}
		tr.Insert(point, point, i)
	})
	fmt.Printf("Search(%dD): ", D)
	var count int
	lotsa.Ops(N, 1, func(i, _ int) {
		point := [2]float64{points[i*D+0], points[i*D+1]}
		tr.Search(point, point,
			func(min, max [2]float64, value interface{}) bool {
				count++
				return true
			},
		)
	})
	if count != N {
		t.Fatalf("expected %d, got %d", N, count)
	}
	fmt.Printf("Delete(%dD): ", D)
	lotsa.Ops(N, 1, func(i, _ int) {
		point := [2]float64{points[i*D+0], points[i*D+1]}
		tr.Delete(point, point, i)
	})
	if tr.Len() != 0 {
		t.Fatalf("expected %d, got %d", N, tr.Len())
	}
}

type tItem2 struct {
	point [2]float64
}

func (item *tItem2) Point() (x, y float64) {
	return item.point[0], item.point[1]
}
func (item *tItem2) Rect() (minX, minY, maxX, maxY float64) {
	return item.point[0], item.point[1], item.point[0], item.point[1]
}

const dims = 2

type tBox struct {
	min [dims]float64
	max [dims]float64
}

var boxes []tBox
var points []tBox

func init() {
	seed := time.Now().UnixNano()
	seed = 1532132365683340889
	println("seed:", seed)
	rand.Seed(seed)
}

func randPoints(N int) []tBox {
	boxes := make([]tBox, N)
	for i := 0; i < N; i++ {
		boxes[i].min[0] = rand.Float64()*360 - 180
		boxes[i].min[1] = rand.Float64()*180 - 90
		for j := 2; j < dims; j++ {
			boxes[i].min[j] = rand.Float64()
		}
		boxes[i].max = boxes[i].min
	}
	return boxes
}

func randBoxes(N int) []tBox {
	boxes := make([]tBox, N)
	for i := 0; i < N; i++ {
		boxes[i].min[0] = rand.Float64()*360 - 180
		boxes[i].min[1] = rand.Float64()*180 - 90
		for j := 2; j < dims; j++ {
			boxes[i].min[j] = rand.Float64() * 100
		}
		boxes[i].max[0] = boxes[i].min[0] + rand.Float64()
		boxes[i].max[1] = boxes[i].min[1] + rand.Float64()
		for j := 2; j < dims; j++ {
			boxes[i].max[j] = boxes[i].min[j] + rand.Float64()
		}
		if boxes[i].max[0] > 180 || boxes[i].max[1] > 90 {
			i--
		}
	}
	return boxes
}

func sortBoxes(boxes []tBox) {
	sort.Slice(boxes, func(i, j int) bool {
		for k := 0; k < len(boxes[i].min); k++ {
			if boxes[i].min[k] < boxes[j].min[k] {
				return true
			}
			if boxes[i].min[k] > boxes[j].min[k] {
				return false
			}
			if boxes[i].max[k] < boxes[j].max[k] {
				return true
			}
			if boxes[i].max[k] > boxes[j].max[k] {
				return false
			}
		}
		return i < j
	})
}

func sortBoxesNearby(boxes []tBox, min, max [2]float64) {
	sort.Slice(boxes, func(i, j int) bool {
		return testBoxDist(boxes[i].min, boxes[i].max, min, max) <
			testBoxDist(boxes[j].min, boxes[j].max, min, max)
	})
}

func testBoxDist(amin, amax, bmin, bmax [2]float64) float64 {
	var dist float64
	for i := 0; i < len(amin); i++ {
		var min, max float64
		if amin[i] > bmin[i] {
			min = amin[i]
		} else {
			min = bmin[i]
		}
		if amax[i] < bmax[i] {
			max = amax[i]
		} else {
			max = bmax[i]
		}
		squared := min - max
		if squared > 0 {
			dist += squared * squared
		}
	}
	return dist
}

func testBoxesVarious(t *testing.T, boxes []tBox, label string) {
	N := len(boxes)

	var tr RTree

	// N := 10000
	// boxes := randPoints(N)

	/////////////////////////////////////////
	// insert
	/////////////////////////////////////////
	for i := 0; i < N; i++ {
		tr.Insert(boxes[i].min, boxes[i].max, boxes[i])
	}
	if tr.Len() != N {
		t.Fatalf("expected %d, got %d", N, tr.Len())
	}
	// area := tr.TotalOverlapArea()
	// fmt.Printf("overlap:    %.0f, %.1f/item\n", area, area/float64(N))

	//	ioutil.WriteFile(label+".svg", []byte(rtreetools.SVG(&tr)), 0600)

	/////////////////////////////////////////
	// scan all items and count one-by-one
	/////////////////////////////////////////
	var count int
	tr.Scan(func(min, max [2]float64, value interface{}) bool {
		count++
		return true
	})
	if count != N {
		t.Fatalf("expected %d, got %d", N, count)
	}

	/////////////////////////////////////////
	// check every point for correctness
	/////////////////////////////////////////
	var tboxes1 []tBox
	tr.Scan(func(min, max [2]float64, value interface{}) bool {
		tboxes1 = append(tboxes1, value.(tBox))
		return true
	})
	tboxes2 := make([]tBox, len(boxes))
	copy(tboxes2, boxes)
	sortBoxes(tboxes1)
	sortBoxes(tboxes2)
	for i := 0; i < len(tboxes1); i++ {
		if tboxes1[i] != tboxes2[i] {
			t.Fatalf("expected '%v', got '%v'", tboxes2[i], tboxes1[i])
		}
	}

	/////////////////////////////////////////
	// search for each item one-by-one
	/////////////////////////////////////////
	for i := 0; i < N; i++ {
		var found bool
		tr.Search(boxes[i].min, boxes[i].max,
			func(min, max [2]float64, value interface{}) bool {
				if value == boxes[i] {
					found = true
					return false
				}
				return true
			})
		if !found {
			t.Fatalf("did not find item %d", i)
		}
	}

	centerMin, centerMax := [2]float64{-18, -9}, [2]float64{18, 9}

	/////////////////////////////////////////
	// search for 10% of the items
	/////////////////////////////////////////
	for i := 0; i < N/5; i++ {
		var count int
		tr.Search(centerMin, centerMax,
			func(min, max [2]float64, value interface{}) bool {
				count++
				return true
			},
		)
	}

	/////////////////////////////////////////
	// delete every other item
	/////////////////////////////////////////
	for i := 0; i < N/2; i++ {
		j := i * 2
		tr.Delete(boxes[j].min, boxes[j].max, boxes[j])
	}

	/////////////////////////////////////////
	// count all items. should be half of N
	/////////////////////////////////////////
	count = 0
	tr.Scan(func(min, max [2]float64, value interface{}) bool {
		count++
		return true
	})
	if count != N/2 {
		t.Fatalf("expected %d, got %d", N/2, count)
	}

	///////////////////////////////////////////////////
	// reinsert every other item, but in random order
	///////////////////////////////////////////////////
	var ij []int
	for i := 0; i < N/2; i++ {
		j := i * 2
		ij = append(ij, j)
	}
	rand.Shuffle(len(ij), func(i, j int) {
		ij[i], ij[j] = ij[j], ij[i]
	})
	for i := 0; i < N/2; i++ {
		j := ij[i]
		tr.Insert(boxes[j].min, boxes[j].max, boxes[j])
	}

	//////////////////////////////////////////////////////
	// replace each item with an item that is very close
	//////////////////////////////////////////////////////
	var nboxes = make([]tBox, N)
	for i := 0; i < N; i++ {
		for j := 0; j < len(boxes[i].min); j++ {
			nboxes[i].min[j] = boxes[i].min[j] + (rand.Float64() - 0.5)
			if boxes[i].min == boxes[i].max {
				nboxes[i].max[j] = nboxes[i].min[j]
			} else {
				nboxes[i].max[j] = boxes[i].max[j] + (rand.Float64() - 0.5)
			}
		}

	}
	for i := 0; i < N; i++ {
		tr.Insert(nboxes[i].min, nboxes[i].max, nboxes[i])
		tr.Delete(boxes[i].min, boxes[i].max, boxes[i])
	}
	if tr.Len() != N {
		t.Fatalf("expected %d, got %d", N, tr.Len())
	}
	// area = tr.TotalOverlapArea()
	// fmt.Fprintf(wr, "overlap:    %.0f, %.1f/item\n", area, area/float64(N))

	/////////////////////////////////////////
	// check every point for correctness
	/////////////////////////////////////////
	tboxes1 = nil
	tr.Scan(func(min, max [2]float64, value interface{}) bool {
		tboxes1 = append(tboxes1, value.(tBox))
		return true
	})
	tboxes2 = make([]tBox, len(nboxes))
	copy(tboxes2, nboxes)
	sortBoxes(tboxes1)
	sortBoxes(tboxes2)
	for i := 0; i < len(tboxes1); i++ {
		if tboxes1[i] != tboxes2[i] {
			t.Fatalf("expected '%v', got '%v'", tboxes2[i], tboxes1[i])
		}
	}

	/////////////////////////////////////////
	// search for 10% of the items
	/////////////////////////////////////////
	for i := 0; i < N/5; i++ {
		var count int
		tr.Search(centerMin, centerMax,
			func(min, max [2]float64, value interface{}) bool {
				count++
				return true
			},
		)
	}

	var boxes3 []tBox
	geoindex.Wrap(&tr).Nearby(
		geoindex.SimpleBoxAlgo(centerMin, centerMax),
		func(min, max [2]float64, value interface{}, dist float64) bool {
			boxes3 = append(boxes3, value.(tBox))
			return true
		},
	)

	if len(boxes3) != len(nboxes) {
		t.Fatalf("expected %d, got %d", len(nboxes), len(boxes3))
	}
	if len(boxes3) != tr.Len() {
		t.Fatalf("expected %d, got %d", tr.Len(), len(boxes3))
	}

	var ldist float64
	for i, box := range boxes3 {
		dist := testBoxDist(box.min, box.max, centerMin, centerMax)
		if i > 0 && dist < ldist {
			t.Fatalf("out of order")
		}
		ldist = dist
	}
}

func TestRandomBoxes(t *testing.T) {
	testBoxesVarious(t, randBoxes(10000), "boxes")
}

func TestRandomPoints(t *testing.T) {
	testBoxesVarious(t, randPoints(10000), "points")
}

func (r *rect) boxstr() string {
	var b []byte
	b = append(b, '[', '[')
	for i := 0; i < len(r.min); i++ {
		if i != 0 {
			b = append(b, ' ')
		}
		b = strconv.AppendFloat(b, r.min[i], 'f', -1, 64)
	}
	b = append(b, ']', '[')
	for i := 0; i < len(r.max); i++ {
		if i != 0 {
			b = append(b, ' ')
		}
		b = strconv.AppendFloat(b, r.max[i], 'f', -1, 64)
	}
	b = append(b, ']', ']')
	return string(b)
}

func (r *rect) print(height, indent int) {
	fmt.Printf("%s%s", strings.Repeat("  ", indent), r.boxstr())
	if height == 0 {
		fmt.Printf("\t'%v'\n", r.data)
	} else {
		fmt.Printf("\n")
		for i := 0; i < r.data.(*node).count; i++ {
			r.data.(*node).boxes[i].print(height-1, indent+1)
		}
	}

}

func (tr RTree) print() {
	if tr.root.data == nil {
		println("EMPTY TREE")
		return
	}
	tr.root.print(tr.height+1, 0)
}

func TestZeroPoints(t *testing.T) {
	N := 10000
	var tr RTree
	var pt [2]float64
	for i := 0; i < N; i++ {
		tr.Insert(pt, pt, i)
	}
}

func BenchmarkRandomInsert(b *testing.B) {
	var tr RTree
	boxes := randBoxes(b.N)
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		tr.Insert(boxes[i].min, boxes[i].max, i)
	}
}