local mod_name = minetest.get_current_modname()

local mod_version = "2.15"

local function log(level, message)
    minetest.log(level, ('[%s] %s'):format(mod_name, message))
end

log('action', 'CSM cs_waypoints '..mod_version..' loading...')

minetest.display_chat_message("CSM cs_waypoints "..mod_version.." loading...")

local mod_storage = minetest.get_mod_storage()


local search_delta_default = 10

local daydelay_default = 5
local bouncedelay_default = 10

--
--
-- local functions
--
--

local function load_waypoints()
    if string.find(mod_storage:get_string('waypoints'), 'return') then
        return minetest.deserialize(mod_storage:get_string('waypoints'))
    else
        return {}
    end
end

local function load_waypoints_stack()
    if string.find(mod_storage:get_string('waypoints_stack'), 'return nil') then
       return {}
    end
    if string.find(mod_storage:get_string('waypoints_stack'), 'return') then
        return minetest.deserialize(mod_storage:get_string('waypoints_stack'))
    else
        return {}
    end
end

local waypoints = load_waypoints()


local function safe(func)
    -- wrap a function w/ logic to avoid crashing the game
    local f = function(...)
        local status, out = pcall(func, ...)
        if status then
            return out
        else
            log('warning', 'Error (func):  ' .. out)
            return nil
        end
    end
    return f
end


local function round(x)
   return math.floor(x+0.5)
end


local function pairsByKeys(t, f)
    local a = {}
    for n in pairs(t) do
        table.insert(a, n)
    end
    table.sort(a, f)
    local i = 0
    return function()
        i = i + 1
        if a[i] == nil then
            return nil
        else
            return a[i], t[a[i]]
        end
    end
end


local function lc_cmp(a, b)
    return a:lower() < b:lower()
end


local function tostring_point(point)
   if not point then 
      return " - - - "
   end 
   return ('%i %i %i'):format(round(point.x), round(point.y), round(point.z))
end




local function teleport_to(position_name)
   local wpname = position_name
   local waypoint = waypoints[wpname]
   if waypoint ~= nil then
      minetest.run_server_chatcommand('teleport', tostring_point(waypoint))
   else
      minetest.display_chat_message(('waypoint "%s" not found.'):format(wpname))
   end
   return true
end

local function show_pos(position_name)
   local wpname = position_name
   local waypoint = waypoints[wpname]
   local rg = ""
   if waypoint ~= nil then
      rg = wpname .. ": " .. tostring_point(waypoint)
   else
      rg = ('waypoint "%s" not found.'):format(wpname)
   end
   return true,rg
end



local function stack_push()
   local point = minetest.localplayer:get_pos()
   local wp_stack = load_waypoints_stack()
   local count = #wp_stack +1
   wp_stack[count] = point
   mod_storage:set_string('waypoints_stack', minetest.serialize(wp_stack))
end

local function stack_pop()
   local wp_stack = load_waypoints_stack()
   local count = 0
   if nil ~= wp_stack then count = #wp_stack end
   if count<1 then
      minetest.display_chat_message('stack empty - no teleporting')
      return
   end
   minetest.run_server_chatcommand('teleport', tostring_point(wp_stack[count]))
   wp_stack[count] = nil
   mod_storage:set_string('waypoints_stack', minetest.serialize(wp_stack))
   return true   
end

local function stack_use()
   local wp_stack = load_waypoints_stack()
   count = 0
   if nil ~= wp_stack then count = #wp_stack end
   if count<1 then
      minetest.display_chat_message('stack empty - no teleporting')
      return
   end
   minetest.run_server_chatcommand('teleport', tostring_point(wp_stack[count]))
   return true   
end

local function stack_exch()
   local wp_stack = load_waypoints_stack()
   count = 0
   if nil ~= wp_stack then count = #wp_stack end
   if count<2 then
      minetest.display_chat_message('less than 2 entries - no change')
      return
   end
   local exch        = wp_stack[count]
   wp_stack[count]   = wp_stack[count-1]
   wp_stack[count-1] = exch
   mod_storage:set_string('waypoints_stack', minetest.serialize(wp_stack))
   return true   
end


local function stack_show()
   local wp_stack = load_waypoints_stack()
   count = 0
   if nil ~= wp_stack then count = #wp_stack end
   if count<1 then
      minetest.display_chat_message('stack empty')
      return true
   end
   output = ""
   for i = count,1,-1 do
      output = output .. tostring(i) .. "  " ..  tostring_point(wp_stack[i]).."\n"
   end
   return true ,output
end

local function stack_clear()
   mod_storage:set_string('waypoints_stack', minetest.serialize(nil))
end

local function  stack_search(d)   
   local delta = d
   if delta then       delta = tonumber(delta) end
   if nil == delta then delta = search_delta_default  end 
   if delta < 0 then delta = 0 end
   
   here = minetest.localplayer:get_pos()
   minetest.display_chat_message(
                ('%s : %s'):format("current position", tostring_point(here))
            )
   for name,pos in pairsByKeys(waypoints, lc_cmp) do
      if math.abs(here.y-pos.y) <= delta then
	 if math.abs(here.x-pos.x) <= delta then
	    if math.abs(here.z-pos.z) <= delta then
	       minetest.display_chat_message(
		     ('%s -> %s'):format(name, tostring_point(pos)))
	    end
	 end
      end
   end
   return true
end

local function position_shift(p)   
   local param = p
   if not p then return end
   while p:sub(1,1) == " " and p:len()> 3 do
      p = p:sub(2,99)
   end
   if p:len()<3 then return end
   direction = p:sub(1,1)
   d = ""
   if direction == "x" or direction == "X" then d = "x" end 
   if direction == "y" or direction == "Y" then d = "y" end 
   if direction == "z" or direction == "Z" then d = "z" end 
   if d == "" then return end

   here = minetest.localplayer:get_pos()

   distance = tonumber(p:sub(2,8))
   if not distance then return end
   if distance == 0 then return end
   
   here[d] = here[d] + distance 
   -- here.y  = here.y  - 1        -- correction

   minetest.run_server_chatcommand('teleport', tostring_point(here))

end

-- new shift with more than one possible shift coordinate
-- only the last value for one coordinate is used
-- viewing direction (?) added by Maverick2797 on 2021-09-23
local function position_shift2(p)
   if not p then return end
   local player = minetest.localplayer
   local param = p:split(" ")
   
   local shift = {}
   shift.x = 0
   shift.y = 0
   shift.z = 0
   
   local vp = 1
   while (vp+1 <= #param ) do
      local direction = param[vp]
      
      local distance = tonumber(param[vp+1])
      if not distance then 
	 distance = 0
      end
      
      local d = ""
      if direction == "x" or direction == "X" then d = "x" end
      if direction == "y" or direction == "Y" then d = "y" end
      if direction == "z" or direction == "Z" then d = "z" end
      if direction == "?" then
	 --tp according to facing angle
	 local yaw = player:get_last_look_horizontal()
	 local pitch = player:get_last_look_vertical()
	 shift.x = distance*math.cos(yaw)*math.cos(pitch)
	 shift.z = distance*math.sin(yaw)*math.cos(pitch)
	 shift.y = distance*math.sin(pitch)
      elseif d ~= "" then 
	 shift[direction] = distance
      end
      vp = vp+2
   end
   
   if shift.x == 0 and shift.y == 0 and shift.z == 0 then
      return
   end
   
   local here = player:get_pos()
   here.x = here.x+shift.x
   here.y = here.y+shift.y
   here.z = here.z+shift.z
   
   -- here.y  = here.y  - 1        -- correction
   
   minetest.run_server_chatcommand('teleport', tostring_point(here))
   
end


local function calc_distance(wp)
   local wpname = wp
   local waypoint = waypoints[wpname]
   local rg = ""
   if waypoint == nil then
      rg = ('waypoint "%s" not found.'):format(wp)
   else
      here = minetest.localplayer:get_pos()
      dx = math.abs(here.x-waypoint.x)
      dy = math.abs(here.y-waypoint.y)
      dz = math.abs(here.z-waypoint.z)
      l1 = "x: " .. tostring(round(100*dx)/100) .. "   y: " 
	 .. tostring(round(100*dy)/100) .. "   z: " 
	 .. tostring(round(100*dz)/100)
      delta_hor = math.floor(math.sqrt(dx*dx+dz*dz)*100)/100
      delta_3d =  math.floor(math.sqrt(dx*dx+dy*dy+dz*dz)*100)/100
      l2 = "distance: " .. tostring(delta_3d) 
	 .. "    horizontal distance: " .. tostring(delta_hor) 
      rg = l1 .. "\n" .. l2
   end

   return true,rg
end


local function teleport_day_back(x,y,z)
   minetest.run_server_chatcommand('teleport', 
				   string.format("%f %f %f",x,y+1,z)
				)
   return
end


local function teleport_day(params)
   local daypos = mod_storage:get_string('daypos')
   local daydelay = mod_storage:get_string('daydelay')
   daypos = minetest.deserialize(daypos) 
   daydelay = (daydelay and tonumber(minetest.deserialize(daydelay))) or 
               daydelay_default

   if not params or
      params == "" 
   
   then
      -- no parameter - execute the function
      if not daypos  then
	 minetest.display_chat_message("no saved position")	 
	 return
      end
      local pstr = tostring_point(daypos)
      minetest.display_chat_message("position "..pstr)
      minetest.run_server_chatcommand('teleport', pstr)
      local point = minetest.localplayer:get_pos()
      minetest.after(daydelay,teleport_day_back,point.x,point.y,point.z)
      return
   end

   if params == "show" then
      minetest.display_chat_message("position: "..tostring_point(daypos)..
				    "   delay:"..daydelay)
      return
   end
   if params == "setpos" then
      local point = minetest.localplayer:get_pos()
      local pstr = tostring_point(point)
      minetest.display_chat_message("position "..pstr)
      mod_storage:set_string('daypos', minetest.serialize(point))
      minetest.display_chat_message("position saved")
      return
   end
   local sdp = string.find(params,"setdelay ",1,false)
   if sdp and sdp == 1 then
      local newtime = tonumber(params:sub(10,16))
      if newtime and newtime>0 then
	 mod_storage:set_string('daydelay', minetest.serialize(newtime))
	 minetest.display_chat_message("delay saved")	 
      end
      return
   end
   -- wrong parameters - what now?
   return
end





local function teleport_bounce(params)

   if not params or
      params == "" 
   
   then
      -- no parameter - return
      minetest.display_chat_message("no waypoint given")	 
      return
   end

   local bouncedelay = mod_storage:get_string('bouncedelay')
   bouncedelay = (bouncedelay and tonumber(minetest.deserialize(bouncedelay))) or 
                bouncedelay_default
   
   local sdp = string.find(params,"setdelay",1,false)
   if sdp and sdp == 1 then
      local newtime = tonumber(params:sub(10,16))

      if newtime and newtime>0 then
	 mod_storage:set_string('bouncedelay', minetest.serialize(newtime))
	 minetest.display_chat_message("delay saved")	 
      else
	 minetest.display_chat_message("delay: "..bouncedelay)	 	 
      end
      return
   end
      
   local bouncepos = params
   local bouncetarget = waypoints[bouncepos]
   if not bouncetarget then
      minetest.display_chat_message("unknown waypoint")	 
      return
   end
   
   local pstr = tostring_point(bouncetarget)
   local point = minetest.localplayer:get_pos()

--  from Maverick2897 with some small changes
   local player = minetest.localplayer
   local hud_id = player:hud_add({
				    hud_elem_type = "text",
				    position = {x=0.0,y=0.8},
				    size = {x=-20,y=-20},
				    alignment = {x=1,y=0},
				    offset = {x=8,y=0},
				    number = 0xffffff,
				 })
   for i=bouncedelay,1,-1 do
      minetest.after(bouncedelay-i,
		     function()
			local text = ""
			if i == 1 then
			   text = "Returning Now"
			else
			   text = "Returning in "..i.."s\nTarget Pos: "..bouncepos.." ("..pstr..")\nReturn Pos: "..tostring_point(point)
			end
			player:hud_change(hud_id,"text",text)
		     end)
   end
   minetest.after(bouncedelay,function()player:hud_remove(hud_id)end)
--

   minetest.after(bouncedelay,teleport_day_back,point.x,point.y,point.z)
   minetest.display_chat_message("position "..pstr)
   minetest.run_server_chatcommand('teleport', pstr)
   return
end


local function wp_export(param)
   local wpl = load_waypoints()
   if not wpl then return end
   local list = ""
   for k,p in pairsByKeys(wpl,lc_cmp) do
      if param == "" or string.find(k,param,1,true) then
	 local line = "("..p.x..","..p.y..","..p.y..")  name = "..k.."\n"
	 list = list .. line
      end
   end
   minetest.display_chat_message(list)
         minetest.show_formspec("cs_waypoints:export",
        "size[15,12]" ..
        "label[3.5,0;Waypoint List]"..
        "textarea[0.3,1;15,11;note;;".. list .."]"..
        "button_exit[4.5,11.2;1.4,1;e;Close]")

   return
end


--
--
-- chat commands
--
--


minetest.register_chatcommand('wp_set', {
    params = '<name>',
    description = 'set a waypoint',
    func = safe(function(param)
        waypoints = load_waypoints()
        local point = minetest.localplayer:get_pos()
        if waypoints[param] then
	   minetest.display_chat_message(
		 ('waypoint "%s" not saved: already set'):format(param)
				      )
	   return
	end
	   
        waypoints[param] = point
        mod_storage:set_string('waypoints', minetest.serialize(waypoints))

        minetest.display_chat_message(
            ('set waypoint "%s" to "%s"'):format(param, tostring_point(point))
        )
    end),
})


minetest.register_chatcommand('wp_unset', {
    params = '<name>',
    description = 'remove a waypoint',
    func = safe(function(param)
        waypoints = load_waypoints()
        waypoints[param] = nil
        mod_storage:set_string('waypoints', minetest.serialize(waypoints))

        minetest.display_chat_message(
            ('removed waypoint "%s"'):format(param)
        )
    end),
})


minetest.register_chatcommand('wp_list', {
    params = '',
    description = 'lists waypoints',
    func = safe(function(_)
        for name, point in pairsByKeys(waypoints, lc_cmp) do
            minetest.display_chat_message(
                ('%s -> %s'):format(name, tostring_point(point))
            )
        end
    end),
})


minetest.register_chatcommand('tw', {
	params = '<waypoint>',
	description = 'teleport to a waypoint',
	func = safe(function(param)
		       safe(teleport_to(param))
		    end),
     }
  )


minetest.register_chatcommand('tw_push', {
	params = '<waypoint>',
	description = 'teleport to a waypoint and save old position',
	func = safe(function(param)
		       stack_push()
		       safe(teleport_to(param))
		    end),
     }
  )

minetest.register_chatcommand('wp_push', {
	params = '<position/player>',
	description = 'teleport to a position/player and save old position',
	func = safe(function(param)
		       stack_push()
		       minetest.run_server_chatcommand('teleport', param)
		    end),
      }
   )

minetest.register_chatcommand('tw_pop', {
	params = '',
	description = 'return to the last saved position',
	func = stack_pop,
     }
  )

minetest.register_chatcommand('wp_pop', {
	params = '',
	description = 'return to the last saved position',
	func = stack_pop,
     }
  )

minetest.register_chatcommand('tw_use', {
	params = '',
	description = "use the last saved position but don't remove it",
	func = stack_use,
     }
  )

minetest.register_chatcommand('wp_use', {
	params = '',
	description = "use the last saved position but don't remove it",
	func = stack_use,
     }
  )

minetest.register_chatcommand('tw_exch', {
	params = '',
	description = 'exchange the top two stack entried',
	func = stack_exch,
     }
  )

minetest.register_chatcommand('wp_exch', {
	params = '',
	description = 'exchange the top two stack entried',
	func = stack_exch,
     }
  )
minetest.register_chatcommand('wp_stack', {
	params = '',
	description = 'shows the stack content',
	func = stack_show,
     }
  )

minetest.register_chatcommand('wp_stack_clear', {
	params = '',
	description = 'clears the position stack',
	func = stack_clear,
     }
  )


minetest.register_chatcommand('wp_search', {
	params = '(<delta>)',
	description = 'search a waypoint near the current position',
	func = stack_search,
     }
  )


minetest.register_chatcommand('wp_shift', {
	params = '<axis> <distance>',
	description = '"shift" the player along the given axis and add the given number',
	func = position_shift2,
     }
  )


minetest.register_chatcommand('wp_dist', {
	params = '<waypoint>',
	description = 'calculate the distance to a given waypoint',
	func = calc_distance,
     }
  )
        

minetest.register_chatcommand('wp_show', {
	params = '<waypoint>',
	description = 'show the coordinates of a given waypoint',
	func = show_pos,
     }
  )


minetest.register_chatcommand('tp', {
	params = '<position/player>',
	description = 'shortcut for /teleport',
	func = safe(function(param)
		       safe(minetest.run_server_chatcommand('teleport',param ))
		    end),
     }
  )
        

--  wp_grep    written by erstazi (player at Linux-Forks.de )
minetest.register_chatcommand('wp_grep', {
    params = '<name>',
    description = 'lists matching waypoints',
    func = safe(function(param)
        local wpname = param
        local count = 0
        for name, point in pairsByKeys(waypoints, lc_cmp) do
            if string.find(name, wpname) then
                count = count + 1
                minetest.display_chat_message(
                    ('%s -> %s'):format(name, tostring_point(point))
                )
            end
        end

        if count == 0 then
            minetest.display_chat_message(('waypoint "%s" not found.'):format(wpname))
        end
    end),
})

--  wp_fgrep   derived from wp_grep by erstazi
minetest.register_chatcommand('wp_fgrep', {
    params = '<name>',
    description = 'lists matching waypoints',
    func = safe(function(param)
        local wpname = param
        local count = 0
        for name, point in pairsByKeys(waypoints, lc_cmp) do
            if string.find(name, wpname,1,true) then
                count = count + 1
                minetest.display_chat_message(
                    ('%s -> %s'):format(name, tostring_point(point))
                )
            end
        end

        if count == 0 then
            minetest.display_chat_message(('waypoint "%s" not found.'):format(wpname))
        end
    end),
})


minetest.register_chatcommand('day', {
	params = '[show|setpos|setdelay <number>]',
	description = 'teleports to the day button and return after a few seconds ',
	func = teleport_day,
     }
  )


-- bounce  name idea by Maverick2797 on 2021-05-20
-- jump to a waypoint and 'bounce' back to the start point after a delay
minetest.register_chatcommand('bounce', {
	params = '[<waypoint>|setdelay [<number>]]',
	description = 'teleports to the given waypoint and returns after a few seconds ',
	func = teleport_bounce,
     }
  )

minetest.register_chatcommand('wp_export', {
	params = '[<name part>]',
	description = 'Export all waypoints as list',
	func = wp_export,
     }
  )



log('action', 'CSM cs_waypoints '..mod_version..' loaded')
minetest.display_chat_message("CSM cs_waypoints "..mod_version.." loaded")