---------------------------------------------------------
-- general setup
---------------------------------------------------------

-- set true to enable debug logging
local DEBUG = false

-- Location connection directional options
local BIDIRECTIONAL = 0
local ONE_WAY = 1

-- Connector draw parameters
local CONNECTION_THICKNESS = 0.015
local CONNECTION_COLOR = { 0.4, 0.4, 0.4, 1 }
local DIRECTIONAL_ARROW_DISTANCE = 3.5
local ARROW_ARM_LENGTH = 0.9
local ARROW_ANGLE = 25

-- Height to draw the connector lines, places them just above the table and always below cards
local CONNECTION_LINE_Y = 1.529

-- we use this to turn off collision handling until onLoad() is complete
local collisionEnabled = false

local INVESTIGATOR_COUNTER_GUID = "f182ee"
local clueData = {}
local spawnedLocationGUIDs = {}

local locations = { }
local locationConnections = { }
local draggingGuids = { }

local locationData

---------------------------------------------------------
-- general code
---------------------------------------------------------

function onSave()
  return JSON.encode({
    spawnedLocations = spawnedLocationGUIDs,
    trackedLocations = locations
  })
end

function onLoad(saveState)
  -- records locations we have spawned clues for
  local save = JSON.decode(saveState) or { }
  spawnedLocationGUIDs = save.spawnedLocations or { }
  locations = save.trackedLocations or { }

  local TOKEN_DATA = Global.getTable('TOKEN_DATA')
  clueData = {
    thickness    = 0.1,
    stackable    = true,
    type         = 2,
    image        = TOKEN_DATA.clue.image,
    image_bottom = TOKEN_DATA.doom.image
  }

  local dataHelper = getObjectFromGUID('708279')
  locationData = dataHelper.getTable('LOCATIONS_DATA')

  self.interactable = DEBUG
  Wait.time(function() collisionEnabled = true end, 1)
end

function log(message)
  if DEBUG then print(message) end
end

---------------------------------------------------------
-- clue spawning
---------------------------------------------------------

-- try the compound key then the name alone as default
function getLocation(object)
  return locationData[object.getName() .. '_' .. object.getGUID()] or locationData[object.getName()]
end

-- Return the number of clues to spawn on this location
function getClueCount(object, isFaceDown, playerCount)
  local details = getLocation(object)
  if details == nil then
    error('attempted to get clue for unexpected object: ' .. object.getName())
  end

  log(object.getName() .. ' : ' .. details['type'] .. ' : ' .. details['value'] .. ' : ' .. details['clueSide'])
  if ((isFaceDown and details['clueSide'] == 'back') or (not isFaceDown and details['clueSide'] == 'front')) then
    if details['type'] == 'fixed' then
      return details['value']
    elseif details['type'] == 'perPlayer' then
      return details['value'] * playerCount
    end
    error('unexpected location type: ' .. details['type'])
  end
  return 0
end

function spawnCluesAtLocation(clueCount, object)
  if spawnedLocationGUIDs[object.getGUID()] ~= nil then
    error('tried to spawn clue for already spawned location:' .. object.getName())
  end

  log('spawning clues for ' .. object.getName() .. '_' .. object.getGUID())
  log('player count is ' .. getInvestigatorCount() .. ', clue count is ' .. clueCount)

  -- mark this location as spawned, can't happen again
  spawnedLocationGUIDs[object.getGUID()] = true

  -- spawn clues (starting top right, moving to the next row after 4 clues)
  local pos = object.getPosition()
  for i = 1, clueCount do
    local row = math.floor(1 + (i - 1) / 4)
    local column = (i - 1) % 4
    spawnClue({ pos.x + 1.5 - 0.55 * row, pos.y, pos.z - 0.825 + 0.55 * column })
  end
end

function spawnClue(position)
  local token = spawnObject({
    position = position,
    rotation = { 3.88, -90, 0.24 },
    type     = 'Custom_Tile'
  })

  token.setCustomObject(clueData)
  token.scale { 0.25, 1, 0.25 }
  token.use_snap_points = false
end

function updateLocations(args)
  custom_data_helper_guid = args[1]
  local custom_data_helper = getObjectFromGUID(args[1])

  for k, v in pairs(custom_data_helper.getTable("LOCATIONS_DATA")) do
    locationData[k] = v
  end
end

function onCollisionEnter(collisionInfo)
  if not collisionEnabled then return end

  -- check if we should spawn clues here and do so according to playercount
  local object = collisionInfo.collision_object
  if getLocation(object) ~= nil and spawnedLocationGUIDs[object.getGUID()] == nil then
    local clueCount = getClueCount(object, object.is_face_down, getInvestigatorCount())
    if clueCount > 0 then spawnCluesAtLocation(clueCount, object) end
  end
  draggingGuids[object.getGUID()] = nil
  maybeTrackLocation(collisionInfo.collision_object)
end

function onCollisionExit(collisionInfo)
  maybeUntrackLocation(collisionInfo.collision_object)
end

-- Destroyed objects don't trigger onCollisionExit(), so check on destruction to untrack as well
function onObjectDestroy(object)
  maybeUntrackLocation(object)
end

function onObjectPickUp(player, object)
  -- onCollisionExit fires first, so we have to check the card to see if it's a location we should
  -- be tracking
  if isInPlayArea(object) and object.getGMNotes() ~= nil and object.getGMNotes() ~= "" then
    local pickedUpGuid = object.getGUID()
    local metadata = JSON.decode(object.getGMNotes())
    if (metadata.type == "Location") then
      draggingGuids[pickedUpGuid] = metadata
      rebuildConnectionList()
    end
  end
end

function onUpdate()
  -- Due to the frequence of onUpdate calls, ensure that we only process any changes to the
  -- connection list once, and only redraw once
  local needsConnectionRebuild = false
  local needsConnectionDraw = false
  for guid, _ in pairs(draggingGuids) do
    local obj = getObjectFromGUID(guid)
    if obj == nil or not isInPlayArea(obj) then
      draggingGuids[guid] = nil
      needsConnectionRebuild = true
    end
    -- Even if the last location left the play area, need one last draw to clear the lines
    needsConnectionDraw = true
  end
  if (needsConnectionRebuild) then
    rebuildConnectionList()
  end
  if needsConnectionDraw then
    drawConnections()
  end
end

-- Checks the given card and adds it to the list of locations tracked for connection purposes.
-- A card will be added to the tracking if it is a location in the play area (based on centerpoint).
-- @param A card object, possibly a location.
function maybeTrackLocation(card)
  -- Collision checks for any part of the card overlap, but our other tracking is centerpoint
  -- Ignore any collision where the centerpoint isn't in the area
  if isInPlayArea(card) then
    local metadata = JSON.decode(card.getGMNotes()) or { }
    if metadata.type == "Location" then
      locations[card.getGUID()] = metadata
      rebuildConnectionList()
      drawConnections()
    end
  end
end

-- Stop tracking a location for connection drawing.  This should be called for both collision exit
-- and destruction, as a destroyed object does not trigger collision exit.  An object can also be
-- deleted mid-drag, but the ordering for drag events means we can't clear those here and those will
-- be cleared in the next onUpdate() cycle.
-- @param card Card to (maybe) stop tracking
function maybeUntrackLocation(card)
  -- Locked objects no longer collide (hence triggering an exit event) but are still in the play
  -- area.  If the object is now locked, don't remove it.
  if locations[card.getGUID()] ~= nil and not card.locked then
    locations[card.getGUID()] = nil
    rebuildConnectionList()
    drawConnections()
  end
end

-- Builds a list of GUID to GUID connection information based on the currently tracked locations.
-- This will update the connection information and store it in the locationConnections data member,
-- but does not draw those connections.  This should often be followed by a call to
-- drawConnections()
function rebuildConnectionList()
  local iconCardList = { }

  -- Build a list of cards with each icon as their location ID
  for cardId, metadata in pairs(draggingGuids) do
    buildLocListByIcon(cardId, iconCardList)
  end
  for cardId, metadata in pairs(locations) do
    buildLocListByIcon(cardId, iconCardList)
  end

  -- Pair up all the icons
  locationConnections = { }
  for cardId, metadata in pairs(draggingGuids) do
    buildConnection(cardId, iconCardList)
  end
  for cardId, metadata in pairs(locations) do
    if draggingGuids[cardId] == nil then
      buildConnection(cardId, iconCardList)
    end
  end
end

-- Extracts the card's icon string into a list of individual location icons
-- @param cardID GUID of the card to pull the icon data from
-- @param iconCardList A table of icon->GUID list.  Mutable, will be updated by this method
function buildLocListByIcon(cardId, iconCardList)
  local card = getObjectFromGUID(cardId)
  local locData = getLocationData(card)
  if locData ~= nil and locData.icons ~= nil then
    for icon in string.gmatch(locData.icons, "%a+") do
      if iconCardList[icon] == nil then
        iconCardList[icon] = { }
      end
      table.insert(iconCardList[icon], card.getGUID())
    end
  end
end

-- Builds the connections for the given cardID by finding matching icons and adding them to the
-- Playarea's locationConnections table.
-- @param cardId GUID of the card to build the connections for
-- @param iconCardList A table of icon->GUID List.  Used to find matching icons for connections.
function buildConnection(cardId, iconCardList)
  local card = getObjectFromGUID(cardId)
  local locData = getLocationData(card)
  if locData ~= nil and locData.connections ~= nil then
    locationConnections[card.getGUID()] = { }
    for icon in string.gmatch(locData.connections, "%a+") do
      if iconCardList[icon] ~= nil then
        for _, connectedGuid in ipairs(iconCardList[icon]) do
          -- If the reciprocal exists, convert it to BiDi, otherwise add as a one-way
          if locationConnections[connectedGuid] ~= nil
              and locationConnections[connectedGuid][card.getGUID()] ~= nil then
            locationConnections[connectedGuid][card.getGUID()] = BIDIRECTIONAL
          else
            locationConnections[card.getGUID()][connectedGuid] = ONE_WAY
          end
        end
      end
    end
  end
end

-- Helper method to extract the location metadata from a card based on whether it's front or back
-- is showing.
-- @param card Card object to extract data from
-- @return Table with either the locationFront or locationBack metadata structure, or nil if the
--     metadata doesn't exist
function getLocationData(card)
  if card == nil then
    return nil
  end
  if card.is_face_down then
    return JSON.decode(card.getGMNotes()).locationBack
  else
    return JSON.decode(card.getGMNotes()).locationFront
  end
end

-- Draws the lines for connections currently in locationConnections.
function drawConnections()
  local cardConnectionLines = { }

  for originGuid, targetGuids in pairs(locationConnections) do
    -- Objects should reliably exist at this point, but since this can be called during onUpdate the
    -- object checks are conservative just to make sure.
    local origin = getObjectFromGUID(originGuid)
    if origin != nil then
      for targetGuid, direction in pairs(targetGuids) do
        local target = getObjectFromGUID(targetGuid)
        if target != nil then
          if direction == BIDIRECTIONAL then
            addBidirectionalVector(origin, target, cardConnectionLines)
          elseif direction == ONE_WAY then
            addOneWayVector(origin, target, cardConnectionLines)
          end
        end
      end
    end
  end
  self.setVectorLines(cardConnectionLines)
end

-- Draws a bidirectional location connection between the two cards, adding the lines to do so to the
-- given lines list.
-- @param card1 One of the card objects to connect
-- @param card2 The other card object to connect
-- @param lines List of vector line elements.  Mutable, will be updated to add this connector
function addBidirectionalVector(card1, card2, lines)
  local cardPos1 = card1.getPosition()
  local cardPos2 = card2.getPosition()
  cardPos1.y = CONNECTION_LINE_Y
  cardPos2.y = CONNECTION_LINE_Y
  local pos1 = self.positionToLocal(cardPos1)
  local pos2 = self.positionToLocal(cardPos2)
  table.insert(lines, {
      points = { pos1, pos2 },
      color = CONNECTION_COLOR,
      thickness = CONNECTION_THICKNESS,
  });
end

-- Draws a one-way location connection between the two cards, adding the lines to do so to the
-- given lines list.  Arrows will point towards the target card.
-- @param origin Origin card in the connection
-- @param target Target card object to connect
-- @param lines List of vector line elements.  Mutable, will be updated to add this connector
function addOneWayVector(origin, target, lines)
  -- Start with the BiDi then add the arrow lines to it
  addBidirectionalVector(origin, target, lines)
  local originPos = origin.getPosition()
  local targetPos = target.getPosition()
  originPos.y = CONNECTION_LINE_Y
  targetPos.y = CONNECTION_LINE_Y

  -- Calculate card distance to be closer for horizontal positions than vertical, since cards are
  -- taller than they are wide
  local heading = Vector(originPos):sub(targetPos):heading("y")
  local distanceFromCard = DIRECTIONAL_ARROW_DISTANCE * 0.7 + DIRECTIONAL_ARROW_DISTANCE * 0.3 * math.abs(math.sin(math.rad(heading)))

  -- Calculate the three possible arrow positions.  These are offset by half the arrow length to
  -- make them visually balanced by keeping the arrows centered, not tracking the point
  local midpoint = Vector(originPos):add(targetPos):scale(Vector(0.5, 0.5, 0.5)):moveTowards(targetPos, ARROW_ARM_LENGTH / 2)
  local closeToOrigin = Vector(originPos):moveTowards(targetPos, distanceFromCard + ARROW_ARM_LENGTH / 2)
  local closeToTarget = Vector(targetPos):moveTowards(originPos, distanceFromCard - ARROW_ARM_LENGTH / 2)

  if (originPos:distance(closeToOrigin) > originPos:distance(closeToTarget)) then
    addArrowLines(midpoint, originPos, lines)
  else
    addArrowLines(closeToOrigin, originPos, lines)
    addArrowLines(closeToTarget, originPos, lines)
  end
end

-- Draws an arrowhead at the given position.
-- @param arrowheadPosition Centerpoint of the arrowhead to draw (NOT the tip of the arrow)
-- @param originPos Origin point of the connection, used to position the arrow arms
-- @param lines List of vector line elements.  Mutable, will be updated to add this arrow
function addArrowLines(arrowheadPos, originPos, lines)
  local arrowArm1 = Vector(arrowheadPos):moveTowards(originPos, ARROW_ARM_LENGTH):sub(arrowheadPos):rotateOver("y", -1 * ARROW_ANGLE):add(arrowheadPos)
  local arrowArm2 = Vector(arrowheadPos):moveTowards(originPos, ARROW_ARM_LENGTH):sub(arrowheadPos):rotateOver("y", ARROW_ANGLE):add(arrowheadPos)

  local head = self.positionToLocal(arrowheadPos)
  local arm1 = self.positionToLocal(arrowArm1)
  local arm2 = self.positionToLocal(arrowArm2)
  table.insert(lines, {
    points = { arm1, head, arm2},
    color = CONNECTION_COLOR,
    thickness = CONNECTION_THICKNESS
  })
end

function getInvestigatorCount()
  local investigatorCounter = getObjectFromGUID('f182ee')
  return investigatorCounter.getVar("val")
end

-- Check to see if the given object is within the bounds of the play area, based solely on the X and
-- Z coordinates, ignoring height
-- @param object Object to check
-- @return True if the object is inside the play area
function isInPlayArea(object)
  local bounds = self.getBounds()
  local position = object.getPosition()
  -- Corners are arbitrary since it's all global - c1 goes down both axes, c2 goes up
  local c1 = { x = bounds.center.x - bounds.size.x / 2, z = bounds.center.z - bounds.size.z / 2}
  local c2 = { x = bounds.center.x + bounds.size.x / 2, z = bounds.center.z + bounds.size.z / 2}

  return position.x > c1.x and position.x < c2.x and position.z > c1.z and position.z < c2.z
end