-- Imported and modified API functions from Mobs_Redo
-- WIP; pathfinding is not functional

-- Localize math functions
local pi = math.pi
local square = math.sqrt
local sin = math.sin
local cos = math.cos
local abs = math.abs
local min = math.min
local max = math.max
local atann = math.atan
local random = math.random
local floor = math.floor
local atan = function(x)
	if not x or x ~= x then
		--error("atan bassed NaN")
		return 0
	else
		return atann(x)
	end
end

local helper = adaptive_ai.helper
local set_yaw = helper.mobs.set_yaw
local do_jump = helper.mobs.do_jump
local set_velocity = helper.mobs.set_velocity
local is_at_cliff = helper.mobs.is_at_cliff
local flight_check = helper.mobs.flight_check
local get_distance = helper.mobs.get_distance
local mob_sound = helper.mobs.mob_sound
local do_env_damage = helper.mobs.do_env_damage
local replace = helper.mobs.replace
local flop = helper.mobs.flop
local runaway_from = helper.mobs.runaway_from
local set_animation = helper.mobs.set_animation

local mobs_griefing = helper.mobs.mobs_griefing
local los_switcher = false
local height_switcher = false

local chat_log = adaptive_ai.chat_log

-- Edited from mob_redo's smart_mobs pathfinding function
-- path finding and smart mob routine by rnd, line_of_sight and other edits by Elkien3
local ai_pathfinding = function(self, s, p, dist, dtime)
	chat_log("pathfinding tete")
	local s1 = self.path.lastpos
	local target_pos = self.target.pos

	-- is it becoming stuck?
	if abs(s1.x - s.x) + abs(s1.z - s.z) < .5 then
		self.path.stuck_timer = self.path.stuck_timer + dtime
	else
		self.path.stuck_timer = 0
	end

	self.path.lastpos = {x = s.x, y = s.y, z = s.z}

	local use_pathfind = false
	local has_lineofsight = minetest.line_of_sight(
		{x = s.x, y = (s.y) + .5, z = s.z},
		{x = target_pos.x, y = (target_pos.y) + 1.5, z = target_pos.z},
        .2)

	-- im stuck, search for path
	if not has_lineofsight then
		if los_switcher == true then
			use_pathfind = true
			los_switcher = false
		end -- cannot see target!
	else
		if los_switcher == false then
			los_switcher = true
			use_pathfind = false

			minetest.after(1, function(self)
				if has_lineofsight then self.path.following = false end
			end, self)
		end -- can see target!
	end

	if (self.path.stuck_timer > stuck_timeout and not self.path.following) then
		use_pathfind = true
		self.path.stuck_timer = 0

		minetest.after(1, function(self)
			if has_lineofsight then self.path.following = false end
		end, self)
	end

	if (self.path.stuck_timer > stuck_path_timeout and self.path.following) then
		use_pathfind = true
		self.path.stuck_timer = 0

		minetest.after(1, function(self)
			if has_lineofsight then self.path.following = false end
		end, self)
	end

	if abs(vector.subtract(s,target_pos).y) > self.stepheight then
		if height_switcher then
			use_pathfind = true
			height_switcher = false
		end
	else
		if not height_switcher then
			use_pathfind = false
			height_switcher = true
		end
	end

	if use_pathfind then
		-- lets try find a path, first take care of positions
		-- since pathfinder is very sensitive
		local sheight = self.collisionbox[5] - self.collisionbox[2]

		-- round position to center of node to avoid stuck in walls
		-- also adjust height for player models!
		s.x = floor(s.x + 0.5)
        -- s.y = floor(s.y + 0.5) - sheight
		s.z = floor(s.z + 0.5)

		local ssight, sground = minetest.line_of_sight(s, {x = s.x, y = s.y - 4, z = s.z}, 1)

		-- determine node above ground
		if not ssight then
			s.y = sground.y + 1
		end

		local p1 = self.target.pos
		p1.x, p1.y, p1.z = floor(p1.x + 0.5), floor(p1.y + 0.5), floor(p1.z + 0.5)

		local dropheight = 6
		if self.fear_height ~= 0 then dropheight = self.fear_height end

		self.path.way = minetest.find_path(s, p1, self.view_range, self.stepheight, dropheight, "A*")
		self.state = "move"
        self.target.dir = "towards"

		-- no path found, try something else
		if not self.path.way then
			self.path.following = false

			 -- lets make way by digging/building if not accessible
			if self.pathfinding == 2 and mobs_griefing then

				-- is player higher than mob?
				if s.y < p1.y then

					-- build upwards
					if not minetest.is_protected(s, "") then
						local ndef1 = minetest.registered_nodes[self.standing_in]

						if ndef1 and (ndef1.buildable_to or ndef1.groups.liquid) then
							minetest.set_node(s, {name = mobs.fallback_node})
						end
					end

					local sheight = math.ceil(self.collisionbox[5]) + 1

					-- assume mob is 2 blocks high so it digs above its head
					s.y = s.y + sheight

					-- remove one block above to make room to jump
					if not minetest.is_protected(s, "") then
						local node1 = node_ok(s, "air").name
						local ndef1 = minetest.registered_nodes[node1]

						if node1 ~= "air"
						and node1 ~= "ignore"
						and ndef1
						and not ndef1.groups.level
						and not ndef1.groups.unbreakable
						and not ndef1.groups.liquid then

							minetest.set_node(s, {name = "air"})
							minetest.add_item(s, ItemStack(node1))
						end
					end

					s.y = s.y - sheight
					self.object:setpos({x = s.x, y = s.y + 2, z = s.z})

				else -- dig 2 blocks to make door toward player direction
					local yaw1 = self.object:get_yaw() + pi / 2
					local p1 = {x = s.x + cos(yaw1), y = s.y, z = s.z + sin(yaw1)}

					if not minetest.is_protected(p1, "") then
						local node1 = node_ok(p1, "air").name
						local ndef1 = minetest.registered_nodes[node1]

						if node1 ~= "air"
							and node1 ~= "ignore"
							and ndef1
							and not ndef1.groups.level
							and not ndef1.groups.unbreakable
							and not ndef1.groups.liquid then

							minetest.add_item(p1, ItemStack(node1))
							minetest.set_node(p1, {name = "air"})
						end

						p1.y = p1.y + 1
						node1 = node_ok(p1, "air").name
						ndef1 = minetest.registered_nodes[node1]

						if node1 ~= "air"
						and node1 ~= "ignore"
						and ndef1
						and not ndef1.groups.level
						and not ndef1.groups.unbreakable
						and not ndef1.groups.liquid then

							minetest.add_item(p1, ItemStack(node1))
							minetest.set_node(p1, {name = "air"})
						end
					end
				end
			end

			-- will try again in 2 second
			self.path.stuck_timer = stuck_timeout - 2

			-- frustration! cant find the damn path :(
			mob_sound(self, self.sounds.random)
		else
			-- yay I found path
			mob_sound(self, self.sounds.war_cry)
			set_velocity(self, self.walk_velocity)

			-- follow path now that I have it
			self.path.following = true
		end
	end
end

-- Pieced together from mob_redo's state management functions
-- self.target.pos
-- self.target.dir = "towards" or "away"
local ai_manager = function(self, dtime)
	if self.action_managers then
		-- there's a manager function per action
		if self.action then
			--chat_log("action managers in action")
			self.action_managers[self.action](self, dtime)
		end
	end

	--chat_log(self.state == "manager on")
    if self.target and self.target.obj then
		self.target.pos = self.target.obj:get_pos()
	end
    local yaw = self.object:get_yaw() or 0
    local s = self.object:get_pos()
    local lp = nil

    if self.state == "stand" then
		--chat_log("I am idle standing")
		if random(1, 4) == 1 then
			local objs = minetest.get_objects_inside_radius(s, 3)
			for n = 1, #objs do
				if objs[n]:is_player() then
					lp = objs[n]:get_pos()
					break
				end
			end

			-- look at any players nearby, otherwise turn randomly
			if lp then
				local vec = {x = lp.x - s.x, z = lp.z - s.z}
				yaw = (atan(vec.z / vec.x) + pi / 2) - self.rotate
				if lp.x > s.x then yaw = yaw + pi end
			else
				yaw = yaw + random(-0.5, 0.5)
			end

			yaw = set_yaw(self, yaw, 8)
		end

        if self.walk_chance ~= 0
		and self.facing_fence ~= true
		and random(1, 100) <= self.walk_chance
		and is_at_cliff(self) == false then

			set_velocity(self, self.walk_velocity)
			self.state = "wander"
			set_animation(self, "walk")
        else
            set_velocity(self, 0)
    		set_animation(self, "stand")
        end
    elseif self.state == "wander" then
		--chat_log("I am idle wandering")
        -- is there something I need to avoid?
        local avoid = {}
		if self.water_damage > 0 then table.insert(avoid, "group:water") end
        if self.lava_damage > 0 then table.insert(avoid, "group:lava") end

        if #avoid > 0 then lp = minetest.find_node_near(s, 1, avoid) end

		if lp then
			-- if mob in water or lava then look for land
			if (self.lava_damage and minetest.registered_nodes[self.standing_in].groups.lava)
			or (self.water_damage and minetest.registered_nodes[self.standing_in].groups.water) then
				lp = minetest.find_node_near(s, 5, {"group:soil", "group:stone", "group:sand", node_ice, node_snowblock})

				-- did we find land?
				if lp then
					local vec = {x = lp.x - s.x, z = lp.z - s.z}
					yaw = (atan(vec.z / vec.x) + pi / 2) - self.rotate

					if lp.x > s.x then yaw = yaw + pi end

					-- look towards land and jump/move in that direction
					yaw = set_yaw(self, yaw, 6)
					do_jump(self)
					set_velocity(self, self.walk_velocity)
				else
					yaw = yaw + random(-0.5, 0.5)
				end

			else
				local vec = {x = lp.x - s.x, z = lp.z - s.z}
				yaw = (atan(vec.z / vec.x) + pi / 2) - self.rotate
				if lp.x > s.x then yaw = yaw + pi end
			end

			yaw = set_yaw(self, yaw, 8)

		-- otherwise randomly turn
		elseif random(1, 100) <= 30 then
			yaw = yaw + random(-0.5, 0.5)
			yaw = set_yaw(self, yaw, 8)
		end

        -- stand for great fall in front
		local temp_is_cliff = is_at_cliff(self)

		if self.facing_fence == true or temp_is_cliff or random(1, 100) <= 30 then
			set_velocity(self, 0)
			self.state = "stand"
			set_animation(self, "stand")
		else
			set_velocity(self, self.walk_velocity)

			if flight_check(self)
			and self.animation
			and self.animation.fly_start and self.animation.fly_end then
				set_animation(self, "fly")
			else
				set_animation(self, "walk")
			end
		end
    elseif self.state == "runaway" then
		--chat_log("I am moving away")
        self.runaway_timer = self.runaway_timer + 1

		-- stop after 5 seconds or when at cliff
		if self.runaway_timer > 5
		or is_at_cliff(self) then
			self.runaway_timer = 0
			set_velocity(self, 0)
			self.state = "stand"
			set_animation(self, "stand")
			self.runaway_timer = 0
		else
			set_velocity(self, self.run_velocity)
			set_animation(self, "walk")
		end
	elseif self.state == "move" then
	    -- is there something I need to avoid?
	    if self.water_damage > 0
	    and self.lava_damage > 0 then
	        lp = minetest.find_node_near(s, 1, {"group:water", "group:lava"})
	    elseif self.water_damage > 0 then
	        lp = minetest.find_node_near(s, 1, {"group:water"})
	    elseif self.lava_damage > 0 then
	        lp = minetest.find_node_near(s, 1, {"group:lava"})
	    end

	    if lp then
	        -- if mob in water or lava then look for land
	        if (self.lava_damage
	            and minetest.registered_nodes[self.standing_in].groups.lava)
	        or (self.water_damage
	            and minetest.registered_nodes[self.standing_in].groups.water) then

	            lp = minetest.find_node_near(s, 5, {"group:soil", "group:stone",
	                "group:sand", node_ice, node_snowblock})

	            -- did we find land?
	            if lp then
	                local vec = {
	                    x = lp.x - s.x,
	                    z = lp.z - s.z
	                }
	                yaw = (atan(vec.z / vec.x) + pi / 2) - self.rotate

	                if lp.x > s.x then yaw = yaw + pi end

	                -- look towards land and jump/move in that direction
	                yaw = set_yaw(self, yaw, 6)
	                local jumped = do_jump(self)
	                if jumped then chat_log("Jumping while moving") end
	                set_velocity(self, self.walk_velocity)
	            else
	                yaw = yaw + random(-0.5, 0.5)
	            end
	        else
	            local vec = {
	                x = lp.x - s.x,
	                z = lp.z - s.z
	            }

	            yaw = (atan(vec.z / vec.x) + pi / 2) - self.rotate

	            if lp.x > s.x then yaw = yaw + pi end
	        end

	        yaw = set_yaw(self, yaw, 8)
	    end

	    -- stand for great fall in front
	    local temp_is_cliff = is_at_cliff(self)

	    if self.facing_fence == true
	    or temp_is_cliff then
	        set_velocity(self, 0)
	        self.state = "stand"
	        set_animation(self, "stand")
	    else
	        set_velocity(self, self.walk_velocity)

	        if flight_check(self)
	        and self.animation
	        and self.animation.fly_start
	        and self.animation.fly_end then
	            set_animation(self, "fly")
	        else
	            set_animation(self, "walk")
	        end
	    end
	end
-- end ai_manager
end

local ai_on_step = function(self, dtime)
    -- To do: add rest of mob_redo functionality, like:
    -- Attacking
    -- Follow
    -- Etc
    -- mob plays random sound at times
	if random(1, 100) == 1 then
		mob_sound(self, self.sounds.random)
	end

	-- environmental damage timer (every 1 second)
	self.env_damage_timer = self.env_damage_timer + dtime

	if (self.env_damage_timer > 1) then
		self.env_damage_timer = 0
		-- check for environmental damage (water, fire, lava etc.)
		do_env_damage(self)
		-- node replace check (cow eats grass etc.)
		replace(self, pos)
	end
	--flop(self)
	do_jump(self)
	runaway_from(self)
end

adaptive_ai.ai_pathfinding = ai_pathfinding
adaptive_ai.ai_manager = ai_manager
adaptive_ai.ai_on_step = ai_on_step