local ReplicatedStorage = game:GetService("ReplicatedStorage")

local clock =           require(ReplicatedStorage.TimeSyncManager)
local NG =              require(script.NameGenerator)
local DecisionTree =    require(script.NPCDecisionTree)

local sin = math.sin

local NPC_IdCount = 1
local NPC_Count = 0

local events = {}
local folder = Instance.new("Folder")
    folder.Name = "NPC_Events"
    folder.Parent = ReplicatedStorage

local function registerEvent(name)
    local NewNpcEvent = Instance.new("RemoteEvent")
    NewNpcEvent.Name = name
    NewNpcEvent.Parent = folder
    events[name] = NewNpcEvent
    return NewNpcEvent
end
registerEvent("NewNpc")
registerEvent("WatchNpc")

local npcFolder = Instance.new("Folder")
    npcFolder.Name = "NPCs"
    npcFolder.Parent = workspace

local boidTemp = Instance.new("Part")
    boidTemp.Anchored = true
    boidTemp.CanCollide = false
    boidTemp.Size = Vector3.new(1,2,1)
    boidTemp.CFrame = CFrame.new(0,5,0)
    boidTemp.TopSurface = "Smooth"
    boidTemp.BottomSurface = "Smooth"
    boidTemp.Material = "SmoothPlastic"
local boidProperties = Instance.new("Folder")
    boidProperties.Name = "Properties"
    boidProperties.Parent = boidTemp


---------------------------------------------------------------------------------------------------------------------------------
                        -- / Private Methods /--
---------------------------------------------------------------------------------------------------------------------------------


local function RunStatChanges(self)
    --print("A second has passed, updating for NPC_"..self.id)
    local s = self.stats
    s.stamina = s.stamina - .1
    s.thirst = s.thirst < 100 and s.thirst + .25 or 100
    s.hunger = s.hunger < 100 and s.hunger + .1 or 100
    local t, h = s.thirst, s.hunger

    if t > 85 or h > 85 then
        s.health = s.health - 1
        --s.walkSpeed = 12 -- slowdown when starving
    elseif h < 30 then
        s.health = s.health < 100 and s.health + .5 or 100
    end

    if s.health <= 0 then
        -- kill npc
    end

    if s.stamina <= 0 then
        s.stamina = 0
        --s.walkSpeed = 16
    else
        -- reset walkspeed?
    end
    --[[
    for stat, val in pairs(self.stats) do
        print(stat..": "..val)
    end]]
end


local function BeginUpdateCycle(self)
    local HB
    local t = 0 -- time passed tracker
    local logic = DecisionTree()
    logic:setObject(self)
    HB = game:GetService("RunService").Heartbeat:Connect(function(timePassed)
        logic:run()

        t = t + timePassed
        if t >= 1 then
            t = t - 1
            RunStatChanges(self)
        end
    end)
    return HB
end


local function newBoid(id)
    local b = boidTemp:Clone()
    b.Name = id
    b.Parent = npcFolder
    return b
end

local function initStats(stats)
    local function newItem(Type,Value)
        local obj = Instance.new(Type)
        obj.Value = Value
        obj.Parent = stats[2]
    end
    for stat, value in pairs(stats[1]) do
        local t = typeof(value)
        if t == "number" then
            newItem("NumberValue",value)
        elseif t == "boolean" then
            newItem("BoolValue",value)
        elseif t == "string" then
            newItem("StringValue",value)
        elseif t == "Instance" then
            newItem("ObjectValue",value)
        else
            warn("Illegal Type:",t,"for property:",stat)
        end
    end
end

---------------------------------------------------------------------------------------------------------------------------------
                        -- / Metatable Handling / --
---------------------------------------------------------------------------------------------------------------------------------
local NPC = {npcs = {}}
NPC.__index = NPC
NPC.__tostring = function(t)
    return "NPC_"..t.id..":\t"..t.firstName.." "..t.lastName.."\n\tAge: "..t.age.."\n\tSex: "..(t.sex == 1 and "Male" or "Female")
end

function NPC:Init()
    print("Initialized Server Side")
end

local StatManager = {}
StatManager.__index = function(t,k)
    return t[1][k:lower()]
end
StatManager.__newindex = function(t,k,v)
    k = k:lower()
    t[1][k] = v
    local prop = t[2]:FindFirstChild(k)
    if prop then
        prop.Value = v
    end
end


---------------------------------------------------------------------------------------------------------------------------------
                        -- / Constructors / --
---------------------------------------------------------------------------------------------------------------------------------

function NPC.new()
    -- Prebuild setup for multi use data
    local s = math.random(1,2) -- sex: 1 is male, 2 is female

    -- put custom data here (you can erase anything in this table)
    local container = setmetatable({
            mom = nil,
            dad = nil,
            children = {},

            sex = s,
            firstName = NG.NewFirstName(s),
            lastName = NG.LastNames[math.random(#NG.LastNames)],
            age = math.random(18,64),

            home = nil,
            job = nil,
    }, NPC)

    container.__index = container
    container.__newindex = function(t,k,v)
        t:Set(k,v)
    end

    local b = newBoid(NPC_IdCount)
    local self = setmetatable({
        -- Core Data (Immutable)
        id = NPC_IdCount,
        boid = b,
        event = registerEvent("UpdateRegisterNPC_"..NPC_Count),

        -- Stat Data (represented as object values) (change however you like)
        stats = setmetatable({{
            health = 100,
            hunger = 0,
            thirst = 0,
            stamina = 100,
            walkspeed = 10
        },b.Properties},StatManager),

        -- properties to update to client
        watchList = {},
    }, container)

    -- Finalizations
    NPC_IdCount = NPC_IdCount + 1
    NPC_Count = NPC_Count + 1
    initStats(self.stats)
    NPC.npcs[self.boid] = self
    events.NewNpc:FireAllClients(self.event,self.boid)
    self.updateCycle = BeginUpdateCycle(self)

    return self
end

--[[
function NPC.birth(mom,dad)
    local self = NPC.new()
    self.mom = mom
    self.dad = dad
    self.age = 0
    return self
end]]

function NPC:CreateOnClient(plr)
    events.NewNpc:FireClient(plr,self.event,self.boid)
end


---------------------------------------------------------------------------------------------------------------------------------
                        -- / Public Methods / -- (Dont mess with these)
---------------------------------------------------------------------------------------------------------------------------------

function NPC:Destroy()
    NPC.npcs[self.boid] = nil
    -- tell clients to destroy their copy

    self.updateCycle:Disconnect()
    self.boid:Destroy()
    NPC_Count = NPC_Count - 1
end

-- Client manager for custom data
function NPC:Set(property, newVal)

end

function NPC:Watch(plr,...)
    local props = type(...) == "table" and ... or {...}

end

function NPC:StopWatching(property)

end


function NPC:GetWalkSpeed()
    return self.stats.walkSpeed - self.age/40
end


function NPC:GoTo(pos)
    return self:MoveTo(pos)
end


function NPC:MoveTo(pos)
    local dist = (self.boid.Position - pos).magnitude
    local t = dist/self:GetWalkSpeed()
    local startTime = clock:GetTime()
    self.boid.CFrame = CFrame.new(pos)
    self.event:FireAllClients("MoveTo", pos, startTime, startTime+t)
    --print("time to complete:",t)
    wait(t-.05)
    return true
end

---------------------------------------------------------------------------------------------------------------------------------
                        -- / Custom Public Methods / -- (Put your custom methods here)
---------------------------------------------------------------------------------------------------------------------------------

-- Optional
-- Takes a string and sets the npcs name
function NPC:SetName(newName)
    self.firstName = newName
end

-- Optional
-- Ages the npc by one year
function NPC:Age()
    self.age = self.age + 1
    return self.age
end




-- Module Close --
return NPC