package controller

import (
	"math"
	"strconv"
	"strings"

	"github.com/tidwall/tile38/controller/glob"
	"github.com/tidwall/tile38/controller/server"
	"github.com/tidwall/tile38/geojson"
)

var tmfmt = "2006-01-02T15:04:05.999999999Z07:00"

// FenceMatch executes a fence match returns back json messages for fence detection.
func FenceMatch(hookName string, sw *scanWriter, fence *liveFenceSwitches, details *commandDetailsT) []string {
	jshookName := jsonString(hookName)
	jstime := jsonString(details.timestamp.Format(tmfmt))
	pattern := fence.glob
	if details.command == "drop" {
		return []string{`{"cmd":"drop","hook":` + jshookName + `,"time":` + jstime + `}`}
	}
	match := true
	if pattern != "" && pattern != "*" {
		match, _ = glob.Match(pattern, details.id)
	}
	if !match {
		return nil
	}

	sw.mu.Lock()
	nofields := sw.nofields
	sw.mu.Unlock()

	if details.obj == nil || !details.obj.IsGeometry() || (details.command == "fset" && nofields) {
		return nil
	}
	match = false

	var roamkeys, roamids []string
	var roammeters []float64
	detect := "outside"
	if fence != nil {
		if fence.roam.on {
			if details.command == "set" {
				// println("roam", fence.roam.key, fence.roam.id, strconv.FormatFloat(fence.roam.meters, 'f', -1, 64))
				roamkeys, roamids, roammeters = fenceMatchRoam(sw.c, fence, details.key, details.id, details.obj)
			}
			if len(roamids) == 0 || len(roamids) != len(roamkeys) {
				return nil
			}
			match = true
			detect = "roam"
		} else {

			// not using roaming
			match1 := fenceMatchObject(fence, details.oldObj)
			match2 := fenceMatchObject(fence, details.obj)
			if match1 && match2 {
				match = true
				detect = "inside"
			} else if match1 && !match2 {
				match = true
				detect = "exit"
			} else if !match1 && match2 {
				match = true
				detect = "enter"
				if details.command == "fset" {
					detect = "inside"
				}
			} else {
				if details.command != "fset" {
					// Maybe the old object and new object create a line that crosses the fence.
					// Must detect for that possibility.
					if details.oldObj != nil {
						ls := geojson.LineString{
							Coordinates: []geojson.Position{
								details.oldObj.CalculatedPoint(),
								details.obj.CalculatedPoint(),
							},
						}
						temp := false
						if fence.cmd == "within" {
							// because we are testing if the line croses the area we need to use
							// "intersects" instead of "within".
							fence.cmd = "intersects"
							temp = true
						}
						if fenceMatchObject(fence, ls) {
							//match = true
							detect = "cross"
						}
						if temp {
							fence.cmd = "within"
						}
					}
				}
			}
		}
	}
	if details.command == "del" {
		return []string{`{"command":"del","hook":` + jshookName + `,"id":` + jsonString(details.id) + `,"time":` + jstime + `}`}
	}
	if details.fmap == nil {
		return nil
	}
	sw.mu.Lock()
	sw.fmap = details.fmap
	sw.fullFields = true
	sw.msg.OutputType = server.JSON
	sw.writeObject(details.id, details.obj, details.fields, true)
	if sw.wr.Len() == 0 {
		sw.mu.Unlock()
		return nil
	}

	res := sw.wr.String()
	resb := make([]byte, len(res))
	copy(resb, res)
	sw.wr.Reset()
	res = string(resb)
	if strings.HasPrefix(res, ",") {
		res = res[1:]
	}
	if sw.output == outputIDs {
		res = `{"id":` + res + `}`
	}
	sw.mu.Unlock()

	if fence.groups == nil {
		fence.groups = make(map[string]string)
	}
	groupkey := details.key + ":" + details.id
	var group string
	var ok bool
	if detect == "enter" {
		group = bsonID()
		fence.groups[groupkey] = group
	} else if detect == "cross" {
		group = bsonID()
		delete(fence.groups, groupkey)
	} else {
		group, ok = fence.groups[groupkey]
		if !ok {
			group = bsonID()
			fence.groups[groupkey] = group
		}
	}

	jskey := jsonString(details.key)

	ores := res
	msgs := make([]string, 0, 2)
	if fence.detect == nil || fence.detect[detect] {
		if strings.HasPrefix(ores, "{") {
			res = `{"command":"` + details.command + `","group":"` + group + `","detect":"` + detect + `","hook":` + jshookName + `,"key":` + jskey + `,"time":` + jstime + `,` + ores[1:]
		}
		msgs = append(msgs, res)
	}
	switch detect {
	case "enter":
		if fence.detect == nil || fence.detect["inside"] {
			msgs = append(msgs, `{"command":"`+details.command+`","group":"`+group+`","detect":"inside","hook":`+jshookName+`,"key":`+jskey+`,"time":`+jstime+`,`+ores[1:])
		}
	case "exit", "cross":
		if fence.detect == nil || fence.detect["outside"] {
			msgs = append(msgs, `{"command":"`+details.command+`","group":"`+group+`","detect":"outside","hook":`+jshookName+`,"key":`+jskey+`,"time":`+jstime+`,`+ores[1:])
		}

	case "roam":
		if len(msgs) > 0 {
			var nmsgs []string
			msg := msgs[0][:len(msgs[0])-1]
			for i, id := range roamids {
				nmsgs = append(nmsgs, msg+`,"nearby":{"key":`+jsonString(roamkeys[i])+`,"id":`+jsonString(id)+`,"meters":`+strconv.FormatFloat(roammeters[i], 'f', -1, 64)+`}}`)
			}
			msgs = nmsgs
		}
	}
	return msgs
}

func fenceMatchObject(fence *liveFenceSwitches, obj geojson.Object) bool {
	if obj == nil {
		return false
	}
	if fence.roam.on {
		// we need to check this object against
		return false
	}
	if fence.cmd == "nearby" {
		return obj.Nearby(geojson.Position{X: fence.lon, Y: fence.lat, Z: 0}, fence.meters)
	} else if fence.cmd == "within" {
		if fence.o != nil {
			return obj.Within(fence.o)
		}
		return obj.WithinBBox(geojson.BBox{
			Min: geojson.Position{X: fence.minLon, Y: fence.minLat, Z: 0},
			Max: geojson.Position{X: fence.maxLon, Y: fence.maxLat, Z: 0},
		})
	} else if fence.cmd == "intersects" {
		if fence.o != nil {
			return obj.Intersects(fence.o)
		}
		return obj.IntersectsBBox(geojson.BBox{
			Min: geojson.Position{X: fence.minLon, Y: fence.minLat, Z: 0},
			Max: geojson.Position{X: fence.maxLon, Y: fence.maxLat, Z: 0},
		})
	}
	return false
}

func fenceMatchRoam(c *Controller, fence *liveFenceSwitches, tkey, tid string, obj geojson.Object) (keys, ids []string, meterss []float64) {
	col := c.getCol(fence.roam.key)
	if col == nil {
		return
	}
	p := obj.CalculatedPoint()
	col.Nearby(0, 0, p.Y, p.X, fence.roam.meters, math.Inf(-1), math.Inf(+1),
		func(id string, obj geojson.Object, fields []float64) bool {
			var match bool
			if id == tid {
				return true // skip self
			}
			if fence.roam.pattern {
				match, _ = glob.Match(fence.roam.id, id)
			} else {
				match = fence.roam.id == id
			}
			if match {
				keys = append(keys, fence.roam.key)
				ids = append(ids, id)
				meterss = append(meterss, obj.CalculatedPoint().DistanceTo(p))
			}
			return true
		},
	)
	return
}