local Tinkr, Bastion = ...

local ObjectManager = Tinkr.Util.ObjectManager

local Unit = Bastion.Unit

local prefixes = {
    '^player',
    '^pet',
    '^vehicle',
    '^target',
    '^focus',
    '^mouseover',
    '^none',
    '^npc',
    '^party[1-4]',
    '^raid[1-4]?[0-9]',
    '^boss[1-5]',
    '^arena[1-5]'
}

-- Validate a unit is a valid token
local function Validate(token)
    local start, index
    local length, offset = string.len(token), 0
    for i = 1, #prefixes do
        start, index = string.find(token, prefixes[i])
        if start then
            offset = index + 1
            if offset > length then
                return true
            else
                while true do
                    start, index = string.find(token, 'target', offset, true)
                    if start then
                        offset = index + 1
                        if offset > length then
                            return true
                        end
                    else
                        return false
                    end
                end
            end
        end
    end
    return false
end

-- Create a new UnitManager class
local UnitManager = {
    units = {},
    customUnits = {},
    objects = {},
    cache = {}
}

function UnitManager:__index(k)
    if UnitManager[k] then
        return UnitManager[k]
    end

    local k = k or 'none'

    -- if custom unit exists, return it it's cache expired return a new one
    if self.customUnits[k] then
        if not self.cache:IsCached(k) then
            self.customUnits[k].unit:Update()
            self.cache:Set(k, self.customUnits[k].unit, 0.5)
        end

        return self.customUnits[k].unit
    end

    local kguid = ObjectGUID(k)

    if kguid and self.objects[kguid] then
        return self.objects[kguid]
    end

    -- if not Validate(k) then
    --     error("UnitManager:Get - Invalid token: " .. k)
    -- end

    if self.objects[kguid] == nil then
        local unit = Unit:New(Object(k))
        self:SetObject(unit)
    end

    return self.objects[kguid]
end

-- Constructor
function UnitManager:New()
    local self = setmetatable({}, UnitManager)
    self.units = {}
    self.customUnits = {}
    self.cache = Bastion.Cache:New()
    return self
end

function UnitManager:Validate(token)
    return Validate(token)
end

-- Get or create a unit
function UnitManager:Get(token)
    -- if not Validate(token) then
    --     error("UnitManager:Get - Invalid token: " .. token)
    -- end

    local tguid = ObjectGUID(token)

    if self.objects[tguid] == nil then
        self.objects[tguid] = Unit:New(Object(tguid))
    end

    return self.objects[tguid]
end

function UnitManager:GetObject(guid)
    return self.objects[guid]
end

function UnitManager:SetObject(unit)
    self.objects[unit:GetGUID()] = unit
end

-- Create a custom unit and cache it for .5 seconds
function UnitManager:CreateCustomUnit(token, cb)
    local unit = cb()
    local cachedUnit = Bastion.Cacheable:New(unit, cb)

    if unit == nil then
        error("UnitManager:CreateCustomUnit - Invalid unit: " .. token)
    end

    if self.customUnits[token] == nil then
        self.customUnits[token] = {
            unit = cachedUnit,
            cb = cb
        }
    end

    self.cache:Set(token, cachedUnit, 0.5)

    return cachedUnit
end

-- Enum Friends (party/raid members)
function UnitManager:EnumFriends(cb)
    local isRaid = IsInRaid()
    local n = GetNumGroupMembers()

    if cb(self:Get('player')) then
        return
    end

    if isRaid then
        for i = 1, n do
            local unit = self:Get('raid' .. i)
            if unit:IsValid() then
                if cb(unit) then
                    break
                end
            end
        end
    else
        for i = 1, n do
            local unit = self:Get('party' .. i)
            if unit:IsValid() then
                if cb(unit) then
                    break
                end
            end
        end
    end
end

-- Enum Enemies (object manager)
function UnitManager:EnumEnemies(cb)
    for obj in ObjectManager:Objects() do
        if ObjectType(obj) == 5 or ObjectType(obj) == 6 then
            local unit = UnitManager:GetObject(ObjectGUID(obj))
            if not unit then
                unit = Unit:New(obj)
                UnitManager:SetObject(unit)
            end
            if unit:IsHostile() and unit:IsAffectingCombat() and unit:IsAlive()
            then
                if cb(unit) then
                    break
                end
            end
        end
    end
end

-- Enum Units (object manager)
function UnitManager:EnumUnits(cb)
    local objs = Objects()
    for i = 1, #objs do
        local obj = objs[i]
        if ObjectType(obj) == 5 or ObjectType(obj) == 6 then
            local unit = UnitManager:GetObject(ObjectGUID(obj))
            if not unit then
                unit = Unit:New(obj)
                UnitManager:SetObject(unit)
            end
            if cb(unit) then
                break
            end
        end
    end
end

-- Enum enemies (nameplates)
function UnitManager:EnumNameplates(cb)
    local n = GetNumNameplates()
    for i = 1, n do
        local unit = self:Get('nameplate' .. i)
        if unit:IsValid() then
            if cb(unit) then
                break
            end
        end
    end
end

-- Get the number of friends with a buff (party/raid members)
function UnitManager:GetNumFriendsWithBuff(spell)
    local count = 0
    self:EnumFriends(function(unit)
        if unit:GetAuras():FindMy(spell):IsUp() then
            count = count + 1
        end
    end)
    return count
end

-- Get the number of friends alive (party/raid members)
function UnitManager:GetNumFriendsAlive()
    local count = 0
    self:EnumFriends(function(unit)
        if unit:IsAlive() then
            count = count + 1
        end
    end)
    return count
end

-- Get the friend with the most friends within a given radius (party/raid members)
-- Return unit, friends
function UnitManager:GetFriendWithMostFriends(radius)
    local unit = nil
    local count = 0
    local friends = {}
    self:EnumFriends(function(u)
        if u:IsAlive() then
            local c = 0
            self:EnumFriends(function(other)
                if other:IsAlive() and u:GetDistance(other) <= radius then
                    c = c + 1
                end
            end)
            if c > count then
                unit = u
                count = c
                friends = {}
                self:EnumFriends(function(other)
                    if other:IsAlive() and u:GetDistance(other) <= radius then
                        table.insert(friends, other)
                    end
                end)
            end
        end
    end)
    return unit, friends
end

-- Find the centroid of the most dense area of friends (party/raid members) of a given radius within a given range
function UnitManager:FindFriendsCentroid(radius, range)
    local unit, friends = self:GetFriendWithMostFriends(radius)
    if unit == nil then
        return nil
    end

    local centroid = Bastion.Vector3:New(0, 0, 0)
    local zstart = -math.huge
    for i = 1, #friends do
        local p = friends[i]:GetPosition()
        centroid = centroid + p
        zstart = p.z > zstart and p.z or zstart
    end

    centroid = centroid / #friends

    if unit:GetPosition():Distance(centroid) > range then
        return unit:GetPosition()
    end

    local _, _, z = TraceLine(
        centroid.x,
        centroid.y,
        centroid.z + 5,
        centroid.x,
        centroid.y,
        centroid.z - 5,
        0x100151
    )

    centroid.z = z + 0.01

    return centroid
end

return UnitManager