package repository

import (
	"fmt"
	"joylink.club/rtsssimulation/repository/model/proto"
	"joylink.club/rtsssimulation/util"
	"math"
	"strconv"
)

var simId = 1

func BuildSimulation(id string, version string) (*Simulation, error) {
	repository, err := getRepository(id, version)
	if err != nil {
		return nil, err
	}
	simulation := newSimulation(repository)
	//构建link
	err = buildLinks(simulation)
	if err != nil {
		return nil, err
	}
	//构建Slope的Link区间
	err = buildSlopeLinkSegments(simulation)
	if err != nil {
		return nil, err
	}
	//构建SectionalCurvature的Link区间
	err = buildSectionalCurvatureLinkSegments(simulation)
	if err != nil {
		return nil, err
	}
	return simulation, nil
}

func getASimulationId() string {
	id := strconv.Itoa(simId)
	simId++
	return id
}

type Simulation struct {
	id                               string
	idGenerator                      int
	repository                       *Repository
	linkMap                          map[string]*Link
	devicePositionMap                map[string]*DeviceLinkPosition //key为device的id
	linkNodeMap                      map[string]*LinkNode           //LinkNode的id应该没什么意义，所以此处key用LinkNode中Turnout的id
	slopeLinkSegmentMap              map[string]SlopeLinkSegment
	sectionalCurvatureLinkSegmentMap map[string]SectionalCurvatureLinkSegment
}

func newSimulation(repository *Repository) *Simulation {
	return &Simulation{
		id:                               getASimulationId(),
		idGenerator:                      1,
		repository:                       repository,
		linkMap:                          make(map[string]*Link),
		devicePositionMap:                make(map[string]*DeviceLinkPosition),
		linkNodeMap:                      make(map[string]*LinkNode),
		slopeLinkSegmentMap:              make(map[string]SlopeLinkSegment),
		sectionalCurvatureLinkSegmentMap: make(map[string]SectionalCurvatureLinkSegment),
	}
}

func (s *Simulation) getAId() string {
	id := strconv.Itoa(s.idGenerator)
	s.idGenerator++
	return id
}

func buildLinks(sim *Simulation) error {
	visitedTurnoutPortMap := make(map[string]bool)
	allTurnouts := sim.repository.TurnoutList()
	for {
		//找一个未遍历过的道岔端口
		startTp := getATurnoutPort(allTurnouts, visitedTurnoutPortMap)
		if startTp == nil {
			break
		}
		//以始端道岔的公里标作为公里标换算的基准
		baseKm := startTp.turnout.km
		//创建基础Link
		link := &Link{Identity: identity{sim.getAId(), proto.DeviceType_DeviceType_Link}}
		//以此道岔端口作为Link的A端节点
		err := buildAndRelateLinkNode(sim, startTp, link, proto.Port_A)
		if err != nil {
			return err
		}
		//沿着道岔端口方向，一直寻找到轨道尽头或者下一个道岔端口。构建并关联中间的设备在link上的位置
		endTp, endKm, err := findEndTurnoutPortOrEndKm(sim, link, startTp, baseKm)
		if err != nil {
			return err
		}
		//以下一个道岔端口作为Link的B端节点
		if endTp != nil {
			visitedTurnoutPortMap[buildTurnoutPortKey(endTp)] = true
			endKm = endTp.turnout.km
			err = buildAndRelateLinkNode(sim, endTp, link, proto.Port_B)
			if err != nil {
				return err
			}
		}
		//计算Link长度
		convertedKm, err := convertKilometer(sim.repository, endKm, baseKm.CoordinateSystem, baseKm.Direction)
		if err != nil {
			return err
		}
		link.length = int64(math.Abs(float64(convertedKm.Value - baseKm.Value)))

		sim.linkMap[link.Id()] = link
	}
	return nil
}

func findEndTurnoutPortOrEndKm(sim *Simulation, link *Link, startTp *TurnoutPort,
	baseKm *proto.Kilometer) (*TurnoutPort, *proto.Kilometer, error) {

	var endTp *TurnoutPort
	var endKm *proto.Kilometer
	var err error

	visitedModelMap := make(map[string]bool)
	var currentDp DevicePort = startTp
	devices := startTp.turnout.getDevicesByPort(startTp.port)
	for {
		//遍历设备并构建、关联其在Link上的位置
		err = buildAndRelateDeviceLinkPositions(sim, link, baseKm, visitedModelMap, devices...)
		if err != nil {
			return nil, nil, err
		}
		//顺着端口寻找下一个设备端口
		var nextDp DevicePort
		switch currentDp.Device().Type() {
		case proto.DeviceType_DeviceType_PhysicalSection:
			section := currentDp.Device().(*PhysicalSection)
			nextDp = section.findOtherDevicePort(currentDp.Port())
			if nextDp == nil {
				endKm = section.findOtherBoundaryKmByPort(currentDp.Port())
			}
		case proto.DeviceType_DeviceType_Turnout:
			turnout := currentDp.Device().(*Turnout)
			nextDp = turnout.getDevicePortByPort(currentDp.Port())
			if nextDp == nil {
				endKm = turnout.findBoundaryKmByPort(currentDp.Port())
			}
		}
		//根据下一个端口设备的信息决定是否结束循环
		if nextDp == nil {
			break
		}
		currentDp = nextDp
		var nextIsTp bool
		switch nextDp.Device().Type() {
		case proto.DeviceType_DeviceType_PhysicalSection:
			devices = nextDp.Device().(*PhysicalSection).devices
		case proto.DeviceType_DeviceType_Turnout:
			nextIsTp = true
			endTp = nextDp.(*TurnoutPort)
			devices = nextDp.Device().(*Turnout).getDevicesByPort(nextDp.Port())
			err = buildAndRelateDeviceLinkPositions(sim, link, baseKm, visitedModelMap, devices...)
			if err != nil {
				return nil, nil, err
			}
		}
		if nextIsTp {
			break
		}
	}

	return endTp, endKm, err
}

func getATurnoutPort(turnouts []*Turnout, visitedTurnoutMap map[string]bool) *TurnoutPort {
	portSlice := []proto.Port{proto.Port_A, proto.Port_B, proto.Port_C}
	for _, turnout := range turnouts {
		for _, port := range portSlice {
			tp := &TurnoutPort{
				turnout: turnout,
				port:    port,
			}
			key := buildTurnoutPortKey(tp)
			if !visitedTurnoutMap[key] {
				visitedTurnoutMap[key] = true
				return tp
			}
		}
	}
	return nil
}

func buildTurnoutPortKey(tp *TurnoutPort) string {
	return fmt.Sprintf("%v-%s", tp.turnout, tp.port)
}

func buildAndRelateDeviceLinkPositions(sim *Simulation, link *Link, startKm *proto.Kilometer, visitedModelMap map[string]bool, devices ...Identity) error {

	for _, device := range devices {
		if visitedModelMap[device.Id()] {
			continue
		}
		km := findModelKm(device)
		if km == nil {
			continue
		}
		convertedKm, err := convertKilometer(sim.repository, km, startKm.CoordinateSystem, startKm.Direction)
		if err != nil {
			return err
		}
		offset := int64(math.Abs(float64(convertedKm.Value - startKm.Value)))
		dlps := &DeviceLinkPosition{
			device: device,
			position: LinkPosition{
				link:   link,
				offset: offset,
			},
		}
		sim.devicePositionMap[dlps.device.Id()] = dlps
		link.bindDevicesLinkPositions(dlps)
	}
	return nil
}

func buildAndRelateLinkNode(sim *Simulation, tp *TurnoutPort, link *Link, port proto.Port) error {
	ln := sim.linkNodeMap[tp.turnout.Id()]
	if ln == nil {
		ln = &LinkNode{
			Identity: identity{sim.getAId(), proto.DeviceType_DeviceType_LinkNode},
			turnout:  tp.turnout,
		}
	}
	//LinkNode关联Link
	err := ln.bindDevicePort(port, &LinkPort{
		link: link,
		port: port,
	})
	if err != nil {
		return err
	}
	//Link关联LinkNode
	err = link.bindDevicePort(port, &LinkNodePort{
		node: ln,
		port: tp.port,
	})
	return err
}

func findModelKm(model Identity) *proto.Kilometer {
	signal, ok := model.(*Signal)
	if ok {
		return signal.km
	}
	responder, ok := model.(*Responder)
	if ok {
		return responder.km
	}
	cp, ok := model.(*CheckPoint)
	if ok {
		return cp.km
	}
	turnout, ok := model.(*Turnout)
	if ok {
		return turnout.km
	}
	return nil
}

func buildSlopeLinkSegments(simulation *Simulation) error {
	repo := simulation.repository
	slopeMap := repo.slopeMap
	for _, slope := range slopeMap {
		start, end, err := calculateLinkSegment(simulation, slope.kms[0], slope.kms[1])
		if err != nil {
			return err
		}
		simulation.slopeLinkSegmentMap[slope.Id()] = SlopeLinkSegment{
			slope: slope,
			start: start,
			end:   end,
		}
	}
	return nil
}

func calculateLinkSegment(simulation *Simulation, startKm *proto.Kilometer,
	endKm *proto.Kilometer) (*LinkPosition, *LinkPosition, error) {

	repo := simulation.repository
	endKm, err := convertKilometer(repo, endKm, startKm.CoordinateSystem, startKm.Direction)
	if err != nil {
		return nil, nil, err
	}
	var start *LinkPosition
	var end *LinkPosition
	var minKmValue float64
	var minKmLink *Link
	var maxKmValue float64
	var maxKmLink *Link
	for _, link := range simulation.linkMap {
		//将link两端的公里标转为aKm同坐标系的公里标
		linkAKm, err := convertKilometer(repo, link.aKm, startKm.CoordinateSystem, startKm.Direction)
		if err != nil || linkAKm.Direction != startKm.Direction {
			continue
		}
		linkBKm, err := convertKilometer(repo, link.bKm, startKm.CoordinateSystem, startKm.Direction)
		if err != nil || linkBKm.Direction != startKm.Direction {
			continue
		}
		//记录公里标最小/最大的Link
		newMinKmValue := math.Min(float64(linkAKm.Value), float64(linkBKm.Value))
		newMaxKmValue := math.Max(float64(linkAKm.Value), float64(linkBKm.Value))
		if minKmLink == nil || newMinKmValue < minKmValue {
			minKmValue = newMinKmValue
			minKmLink = link
		}
		if maxKmLink == nil || newMaxKmValue > maxKmValue {
			maxKmValue = newMaxKmValue
			maxKmLink = link
		}
		//若start/end公里标落在link上，构建LinkPosition
		if util.IsBetween(startKm.Value, linkAKm.Value, linkBKm.Value) {
			start = &LinkPosition{
				link:   link,
				offset: int64(math.Abs(float64(startKm.Value - linkAKm.Value))),
			}
		}
		if util.IsBetween(endKm.Value, linkAKm.Value, linkBKm.Value) {
			end = &LinkPosition{
				link:   link,
				offset: int64(math.Abs(float64(endKm.Value - linkAKm.Value))),
			}
		}
		if start != nil && end != nil {
			break
		}
	}
	//处理start/end公里标没落在Link上的情况
	if start == nil {
		if startKm.Value < endKm.Value {
			offset, _ := minKmLink.findEndOffset()
			start = &LinkPosition{
				link:   minKmLink,
				offset: offset,
			}
		} else {
			offset, _ := maxKmLink.findEndOffset()
			start = &LinkPosition{
				link:   maxKmLink,
				offset: offset,
			}
		}
	}
	if end == nil {
		if endKm.Value < startKm.Value {
			offset, _ := minKmLink.findEndOffset()
			end = &LinkPosition{
				link:   minKmLink,
				offset: offset,
			}
		} else {
			offset, _ := maxKmLink.findEndOffset()
			end = &LinkPosition{
				link:   maxKmLink,
				offset: offset,
			}
		}
	}

	return start, end, nil
}

func buildSectionalCurvatureLinkSegments(sim *Simulation) error {
	repo := sim.repository
	for _, curvature := range repo.sectionalCurvatureMap {
		start, end, err := calculateLinkSegment(sim, curvature.kms[0], curvature.kms[1])
		if err != nil {
			return err
		}
		sim.sectionalCurvatureLinkSegmentMap[curvature.Id()] = SectionalCurvatureLinkSegment{
			sectionalCurvature: curvature,
			start:              start,
			end:                end,
		}
	}
	return nil
}