local n = nrequire("sv_npcsystem.lua")
local ncom = nrequire("sv_common.lua")
local NPC = {}
NPC.Name 			= "Zombie"
NPC.Desc 			= "The living dead, argh!"
NPC.Class 			= "Ambient" --Ambient, Agressive, Boss
NPC.Model			= "models/Zombie/Classic.mdl"
--[[
models/Zombie/Fast.mdl
models/Zombie/Poison.mdl
models/Humans/corpse1.mdl
models/Humans/Charple01.mdl
models/fallout/tunneler.mdl
models/fallout/streettrog.mdl
models/fallout/deathclaw.mdl
models/fallout/deathclaw_alphamale.mdl
models/fallout/deathclaw_baby.mdl
models/fallout/deathclaw_mother.mdl
models/fallout/gecko.mdl
models/fallout/giantrat.mdl
models/fallout/sporecarrier.mdl
]]

NPC.Stats = {
    ["Vitality"]    = 400,
    ["Speed"]       = 40,
    ["AwareDist"]   = 1000,
    ["Accel"]       = 25,
    ["Decel"]       = 40,
    ["Step"]        = 20, --Step height
    ["Hull"]        = HULL_HUMAN
}

--Some npc's like birds have diffent names for their idle sequences
NPC.IdleSequences = {
    [0] = "idle",
}

--Drops should be formated as [index]={["item name"], percent_drop} where percent_drop is a number from 0 to 100

NPC.Drops           = {
    [0] = {"Rat Meat",100},--Rats will drop at least 1 meat, and have a 50% chance of dropping 2
    [1] = {"Rat Meat",50},
}

local checkattack = function(self,ply)
    print("Checking attack")
    if not ply or not self then return -1 end
    local pp,sp = ply:GetPos(),self:GetPos()
    local isnear = (pp:Distance(sp) < 100) and (math.abs(pp.z - sp.z) < 20)
    local canattack = CurTime() - self.lastattack > 2
    if isnear and canattack then
        local tr = util.TraceLine({
            start = self:GetPos() + Vector(0,0,50),
            endpos = ply:GetPos() + Vector(0,0,50),
            filter = self,
        })
        if tr.Hit and tr.Entity == ply then
            return 2
        else
            return 0
        end
    else
        return 0
    end
end

local doattack = function(self,ply)
    print("Doing attack")
    self.lastattack = CurTime()
    self:StartActivity(ACT_MELEE_ATTACK1)
    timer.Simple(1,function() --It looks like you're hit about 1/2s after animation start
        if (not IsValid(self)) or( not IsValid(ply)) then return end --Make sure we're both still alive!
        local sp,pp = self:GetPos(),ply:GetPos()
        local cross = sp:Cross(pp)
        local fppj = cross:GetNormalized():Dot(self:GetForward())
        if math.abs(fppj) < 0.1 and sp:Distance(pp) < 75 then --If the player is still in front of us, do a trace
            local tr = util.TraceLine({
                start = sp + Vector(0,0,50),
                endpos = pp + Vector(0,0,50),
                filter = self,
            })
            if tr.Hit and tr.Entity == ply then
                ply:TakeDamage(20,self,self)
            else
                print("tr.hit was",tr.Hit,"entity was",tr.Entity)
            end
        else
            print('Player was not in front, or distance too great')
            print(fppj)
            print(sp:Distance(pp))
        end
    end)
end

--At least 1 check function must return greater than -1
local checkrun = function(self,ply)
    local isnearby = (1000 - ply:GetPos():Distance(self:GetPos()))/1000 --Zombies work on smell or something, idk, line of sight is hard to do cheaply
    --But we want attack priority to override this, so only return a max of 1
    return isnearby
end

local dorun = function(self,ply)
    if CurTime() - self.lastwalk > 3 then
        self:StartActivity(  ACT_WALK   )
        self.lastwalk = CurTime()
    end
    if not ply or not ply:IsValid() then return end
    local ppos = ply:GetPos()
    self.TargetPos = ppos
    if self.TargetPos ~= nil then
        self.loco:Approach(self.TargetPos,1)
    end
end

NPC.Attacks         = {
    [1] =   {--attack the player if they're in front of us
        [checkattack] = doattack
    },
    [2] =   {--Run at the player
        [checkrun] = dorun
    }
}

--A function that takes a position and returns true if this is an acceptable place to spawn
function NPC:SpawnLocations(pos)
    return true
end

--The entity that is this npc's current target, if it has one. Nil otherwise
NPC.Target          = nil

--All enemies that this NPC is aware of
NPC.AwareEnemies    = {}
--Attack priority is a fucntion that takes a player, and returns an int describing it's prority to attack (higher = more important) NPC will always attack the player with the highest priority
function NPC:AttackPriority(ply)
    if not ply then return 0 end
    local plypos = ply:GetPos()
    local mypos = self:GetPos()
    if not plypos then return 0 end
    local dist = plypos:Distance(mypos)
    return self.Stats["AwareDist"] - dist
end

--What to replace the ENT:RunBehaviour with
function NPC:Act(deltat)
end

--What to replace ENT:OnStuck with
function NPC:Stuck()
    --Find out what we're stuck on
    local tr = util.TraceLine({
        start = self:GetPos() + Vector(0,0,50), --Start at about waist height
        endpos =( self:GetForward()*50) + self:GetPos() + Vector(0,0,50),
        filter = self
    })
    
end

--These are just here to tell the editors/develoeprs what functions are available.. dont un-comment them out, as this could affect all the items.

function NPC:OnSpawn()
    self.lastattack = CurTime()
    self.lastwalk = CurTime()
end
/*
--If we need to do more than just reduce health on dammage
function NPC:OnDammage(ammount)
end

--If we need to do more than just drop items on death
function NPC:OnDeath()
end

--A particular spell was cast on this npc by player
function NPC:OnSpell(spell, player)
end

function NPC:OnFindEnemy(enemy)
end

--Called when the npc is attacking anything with any attack
function NPC:OnAttack(target)
end
*/

n.RegisterNPC(NPC)