---@type Tinkr
local Tinkr,
---@class Bastion
Bastion = ...

-- Create a new Unit class
---@class Bastion.Unit
---@field id boolean | number
---@field ttd_ticker false | cbObject
---@field unit? TinkrObjectReference
---@field aura_table Bastion.AuraTable | nil
local Unit = {
    ---@type Bastion.Cache
    cache = nil,
    aura_table = nil,
    ---@type UnitId | WowGameObject
    unit = nil,
    ttd_ticker = false,
    ttd = 0,
    id = false, --[[ @asnumber ]]
    watching_for_swings = false,
    health = {}
}

function Unit:UpdateHealth()
    if #self.health > 60 then
        table.remove(self.health, 1)
    end
    table.insert(self.health, {
        time = GetTime(),
        percent = self:GetHP(),
        health = self:GetHealth(),
        maxHealth =
            self:GetMaxHealth()
    })
end

function Unit:__index(k)
    local response = Bastion.ClassMagic:Resolve(Unit, k)

    if k == "unit" then
        return rawget(self, k)
    end

    if response == nil then
        response = rawget(self, k)
    end

    if response == nil then
        error("Unit:__index: " .. k .. " does not exist")
    end

    return response
end

-- Equals
---@param other Bastion.Unit
---@return boolean
function Unit:__eq(other)
    return UnitIsUnit(self:GetOMToken(), other:GetOMToken())
end

-- tostring
---ToString
---
---```lua
---print(Unit:New('player'))
---```
---@return string
function Unit:__tostring()
    return "Bastion.__Unit(" .. tostring(self:GetOMToken()) .. ")" .. " - " .. (self:GetName() or "")
end

-- Constructor
---@param unit? TinkrObjectReference
---@return Bastion.Unit
function Unit:New(unit)
    ---@class Bastion.Unit
    local self = setmetatable({}, Unit)
    self.unit = unit
    self.last_shadow_techniques = 0
    self.swings_since_sht = 0
    self.last_off_attack = 0
    self.last_main_attack = 0
    self.last_combat_time = 0
    self.cache = Bastion.Cache:New()
    self.aura_table = Bastion.AuraTable:New(self)
    self.regression_history = {}
    self.health = {}
    return self
end

-- Check if the unit is valid
---@return boolean
function Unit:IsValid()
    return self:GetOMToken() ~= nil and self:Exists()
end

-- Check if the unit exists
---@return boolean
function Unit:Exists()
    return Object(self:GetOMToken()) ~= false
end

-- Get the units token
function Unit:Token()
    return self:GetOMToken()
end

-- Get the units name
function Unit:GetName()
    local unitName, realm = UnitName(self:GetOMToken())
    return unitName
end

-- Get the units GUID
function Unit:GetGUID()
    return ObjectGUID(self:GetOMToken())
end

-- Get the units health
---@return number
function Unit:GetHealth()
    return UnitHealth(self:GetOMToken())
end

-- Get the units max health
---@return number
function Unit:GetMaxHealth()
    return UnitHealthMax(self:GetOMToken())
end

-- Return Health Percent as an integer (0-100)
---@return number
function Unit:GetHP()
    return self:GetHealth() / self:GetMaxHealth() * 100
end

-- Get realized health
---@return number
function Unit:GetRealizedHealth()
    return self:GetHealth() - self:GetHealAbsorbedHealth()
end

-- get realized health percentage
---@return number
function Unit:GetRealizedHP()
    return self:GetRealizedHealth() / self:GetMaxHealth() * 100
end

-- Get the abosorbed unit health
---@return number
function Unit:GetHealAbsorbedHealth()
    return UnitGetTotalHealAbsorbs(self:GetOMToken())
end

-- Return Health Percent as an integer (0-100)
---@return number
function Unit:GetHealthPercent()
    return self:GetHP()
end

-- Get the units power type
---@return Enum.PowerType
function Unit:GetPowerType()
    return select(1, UnitPowerType(self:GetOMToken()))
end

-- Get the units power
---@param powerType? number
---@return number
function Unit:GetPower(powerType)
    local powerType = powerType or self:GetPowerType()
    return UnitPower(self:GetOMToken(), powerType)
end

-- Get the units max power
---@param powerType? number
---@return number
function Unit:GetMaxPower(powerType)
    local powerType = powerType or self:GetPowerType()
    return UnitPowerMax(self:GetOMToken(), powerType)
end

-- Get the units power percentage
---@param powerType number | nil
---@return number
function Unit:GetPP(powerType)
    local powerType = powerType or self:GetPowerType()
    return self:GetPower(powerType) / self:GetMaxPower(powerType) * 100
end

-- Get the units power deficit
---@param powerType number | nil
---@return number
function Unit:GetPowerDeficit(powerType)
    local powerType = powerType or self:GetPowerType()
    return self:GetMaxPower(powerType) - self:GetPower(powerType)
end

-- Get the units position
function Unit:GetPosition()
    local x, y, z = ObjectPosition(self:GetOMToken())
    return Bastion.Vector3:New(x, y, z)
end

-- Get the units distance from another unit
---@param unit Bastion.Unit
---@return number
function Unit:GetDistance(unit)
    local pself = self:GetPosition()
    local punit = unit:GetPosition()

    return pself:Distance(punit)
end

-- Is the unit dead
---@return boolean
function Unit:IsDead()
    return UnitIsDeadOrGhost(self:GetOMToken())
end

-- Is the unit alive
---@return boolean
function Unit:IsAlive()
    return not UnitIsDeadOrGhost(self:GetOMToken())
end

-- Is the unit a pet
---@return boolean
function Unit:IsPet()
    return UnitIsUnit(self:GetOMToken(), "pet")
end

function Unit:IsOtherPet()
    local petName = self:GetName()
    local ownerName = ""
    ownerName = (
        string.match(petName, string.gsub(UNITNAME_TITLE_PET, "%%s", "(%.*)"))
        or string.match(petName, string.gsub(UNITNAME_TITLE_MINION, "%%s", "(%.*)"))
        or string.match(petName, string.gsub(UNITNAME_TITLE_GUARDIAN, "%%s", "(%.*)"))
    )
    return ownerName ~= nil
end

-- Is the unit a friendly unit
---@return boolean
function Unit:IsFriendly()
    return UnitIsFriend("player", self:GetOMToken())
end

-- IsEnemy
---@return boolean
function Unit:IsEnemy()
    return UnitCanAttack("player", self:GetOMToken())
end

-- Is the unit a hostile unit
---@return boolean
function Unit:IsHostile()
    return UnitCanAttack(self:GetOMToken(), "player")
end

---@param unit Bastion.Unit
function Unit:GetReaction(unit)
    return UnitReaction(unit:GetOMToken(), self:GetOMToken())
end

-- Is the unit a boss
---@return boolean
function Unit:IsBoss()
    if UnitClassification(self:GetOMToken()) == "worldboss" then
        return true
    end

    for i = 1, 5 do
        local bossGUID = UnitGUID("boss" .. i)

        if self:GetGUID() == bossGUID then
            return true
        end
    end

    return false
end

---@return UnitIds
function Unit:GetOMToken()
    if not self.unit then
        return "none"
    end
    return self.unit:unit()
end

-- Is the unit a target
---@return boolean
function Unit:IsTarget()
    return UnitIsUnit(self:GetOMToken(), "target")
end

-- Is the unit a focus
---@return boolean
function Unit:IsFocus()
    return UnitIsUnit(self:GetOMToken(), "focus")
end

-- Is the unit a mouseover
---@return boolean
function Unit:IsMouseover()
    return UnitIsUnit(self:GetOMToken(), "mouseover")
end

-- Is the unit a tank
---@return boolean
function Unit:IsTank()
    return UnitGroupRolesAssigned(self:GetOMToken()) == "TANK"
end

-- Is the unit a healer
---@return boolean
function Unit:IsHealer()
    return UnitGroupRolesAssigned(self:GetOMToken()) == "HEALER"
end

-- Is the unit a damage dealer
---@return boolean
function Unit:IsDamage()
    return UnitGroupRolesAssigned(self:GetOMToken()) == "DAMAGER"
end

-- Get the units role
---@return "TANK" | "HEALER" | "DAMAGER" | "NONE"
function Unit:GetRole()
    return UnitGroupRolesAssigned(self:GetOMToken())
end

---@return number | boolean
function Unit:GetSpecializationID()
    if CanInspect(self:GetOMToken(), false) then
        return ObjectSpecializationID(self:GetOMToken())
    end
    return false
end

---@param fallback? boolean
---@return "TANK" | "HEALER" | "DAMAGER" | "NONE" | false
function Unit:GetSpecializationRole(fallback)
    local specID = self:GetSpecializationID()
    if type(specID) == "number" then
        return GetSpecializationRoleByID(specID)
    end
    return fallback and self:GetRole() or false
end

-- Is the unit a player
---@return boolean
function Unit:IsPlayer()
    return UnitIsPlayer(self:GetOMToken())
end

-- Is the unit a player controlled unit
---@return boolean
function Unit:IsPCU()
    return UnitPlayerControlled(self:GetOMToken())
end

-- Get if the unit is affecting combat
---@return boolean
function Unit:IsAffectingCombat()
    return UnitAffectingCombat(self:GetOMToken())
end

-- Get the units class id
---@return Bastion.Class
function Unit:GetClass()
    local locale, class, classID = UnitClass(self:GetOMToken())
    return Bastion.Class:New(locale, class, classID)
end

-- Get the units auras
---@return Bastion.AuraTable
function Unit:GetAuras()
    return self.aura_table
end

-- Get the raw unit
---@return string
function Unit:GetRawUnit()
    return self:GetOMToken()
end

local isClassicWow = select(4, GetBuildInfo()) < 40000

-- Check if two units are in melee
-- function Unit:InMelee(unit)
--     return UnitInMelee(self:GetOMToken(), unit:GetOMToken())
-- end

local losFlag = bit.bor(0x1, 0x10)

-- Check if the unit can see another unit
---@param unit Bastion.Unit
---@return boolean
function Unit:CanSee(unit)
    -- mechagon smoke cloud
    -- local mechagonID = 2097
    -- local smokecloud = 298602

    -- local name, instanceType, difficultyID, difficultyName, maxPlayers, dynamicDifficulty, isDynamic, instanceID, instanceGroupSize, LfgDungeonID =
    -- GetInstanceInfo()

    -- otherUnit = otherUnit and otherUnit or "player"
    -- if instanceID == 2097 then
    --     if (self:debuff(smokecloud, unit) and not self:debuff(smokecloud, otherUnit))
    --         or (self:debuff(smokecloud, otherUnit) and not self:debuff(smokecloud, unit))
    --     then
    --         return false
    --     end
    -- end
    local ignoreLoS = {
        [98696] = true -- Illysanna Ravencrest (BRH)
    }
    if not unit:IsPlayer() then
        local id = unit:GetID()
        if id and ignoreLoS[id] then
            return true
        end
    end
    local ax, ay, az = ObjectPosition(self:GetOMToken())
    local ah = ObjectHeight(self:GetOMToken())
    local attx, atty, attz = GetUnitAttachmentPosition(unit:GetOMToken(), 34)

    if not attx or not ax then
        return false
    end

    if not ah then
        return false
    end

    if (ax == 0 and ay == 0 and az == 0) or (attx == 0 and atty == 0 and attz == 0) then
        return true
    end

    if not attx or not ax then
        return false
    end

    local x, y, z = TraceLine(ax, ay, az + ah, attx, atty, attz, losFlag)
    if x ~= 0 or y ~= 0 or z ~= 0 then
        return false
    else
        return true
    end
end

-- Check if the unit is casting a spell
---@return boolean
function Unit:IsCasting()
    return UnitCastingInfo(self:GetOMToken()) ~= nil
end

---@param percent number
---@return number
function Unit:GetTimeCastIsAt(percent)
    local name, text, texture, startTimeMS, endTimeMS, isTradeSkill, castID, notInterruptible, spellId = UnitCastingInfo(
        self:GetOMToken())

    if not name then
        name, text, texture, startTimeMS, endTimeMS, isTradeSkill, notInterruptible, spellId = UnitChannelInfo(self
            :GetOMToken())
    end

    if name and startTimeMS and endTimeMS then
        local castLength = endTimeMS - startTimeMS
        local startTime = startTimeMS / 1000
        local timeUntil = (castLength / 1000) * (percent / 100)

        return startTime + timeUntil
    end

    return 0
end

-- Get Casting or channeling spell
---@return Bastion.Spell | boolean
function Unit:GetCastingOrChannelingSpell()
    local name, text, texture, startTimeMS, endTimeMS, isTradeSkill, castID, notInterruptible, spellId = UnitCastingInfo(
        self:GetOMToken())

    if not name then
        name, text, texture, startTimeMS, endTimeMS, isTradeSkill, notInterruptible, spellId = UnitChannelInfo(self
            :GetOMToken())
    end

    if name then
        return Bastion.Globals.SpellBook:GetSpell(spellId)
    end
    return false
end

-- Get the end time of the cast or channel
---@return number
function Unit:GetCastingOrChannelingEndTime()
    local name, text, texture, startTimeMS, endTimeMS, isTradeSkill, castID, notInterruptible, spellId = UnitCastingInfo(
        self:GetOMToken())

    if not name then
        name, text, texture, startTimeMS, endTimeMS, isTradeSkill, notInterruptible, spellId = UnitChannelInfo(self
            :GetOMToken())
    end

    if name then
        return endTimeMS / 1000
    end

    return 0
end

-- Check if the unit is channeling a spell
---@return boolean
function Unit:IsChanneling()
    return UnitChannelInfo(self:GetOMToken()) ~= nil
end

-- Check if the unit is casting or channeling a spell
---@return boolean
function Unit:IsCastingOrChanneling()
    return self:IsCasting() or self:IsChanneling()
end

---@return Bastion.Unit
function Unit:CastTarget()
    ---@diagnostic disable-next-line: param-type-mismatch
    return self:IsCastingOrChanneling() and Bastion.UnitManager:Get(ObjectCastingTarget(self:GetOMToken())) or
        Bastion.UnitManager:Get("none")
end

---@param unit Bastion.Unit
---@return boolean
function Unit:CastTargetIsUnit(unit)
    return self:IsCastingOrChanneling() and self:CastTarget():IsUnit(unit)
end

---@return boolean
function Unit:IsImmobilized()
    return bit.band(self:GetMovementFlag(), 0x400) > 0
end

-- Check if the unit can attack the target
---@param unit Bastion.Unit
---@return boolean
function Unit:CanAttack(unit)
    return UnitCanAttack(self:GetOMToken(), unit:GetOMToken())
end

---@return number
function Unit:GetChannelOrCastPercentComplete()
    local name, text, texture, startTimeMS, endTimeMS, isTradeSkill, castID, notInterruptible, spellId = UnitCastingInfo(
        self:GetOMToken())

    if not name then
        name, text, texture, startTimeMS, endTimeMS, isTradeSkill, notInterruptible, spellId = UnitChannelInfo(self
            :GetOMToken())
    end

    if name and startTimeMS and endTimeMS then
        local start = startTimeMS / 1000
        local finish = endTimeMS / 1000
        local current = GetTime()

        return ((current - start) / (finish - start)) * 100
    end
    return 0
end

-- Check if unit is interruptible
---@return boolean
function Unit:IsInterruptible()
    local name, text, texture, startTimeMS, endTimeMS, isTradeSkill, castID, notInterruptible, spellId = UnitCastingInfo(
        self:GetOMToken())

    if not name then
        name, text, texture, startTimeMS, endTimeMS, isTradeSkill, notInterruptible, spellId = UnitChannelInfo(self
            :GetOMToken())
    end

    if name then
        return not notInterruptible
    end

    return false
end

-- Check if unit is interruptible
---@param percent? number
---@param ignoreInterruptible? boolean
---@return boolean
function Unit:IsInterruptibleAt(percent, ignoreInterruptible)
    if not ignoreInterruptible and not self:IsInterruptible() then
        return false
    end

    local percent = percent or math.random(2, 20)

    local castPercent = self:GetChannelOrCastPercentComplete()
    if castPercent >= percent then
        return true
    end

    return false
end

-- Get the number of enemies in a given range of the unit and cache the result for .5 seconds
---@param range number
---@return number
function Unit:GetEnemies(range)
    local enemies = self.cache:Get("enemies_" .. range)
    if enemies then
        return enemies
    end

    local count = 0

    Bastion.UnitManager:EnumEnemies(function(unit)
        if not self:IsUnit(unit) and self:IsWithinCombatDistance(unit, range) and unit:IsAlive() and self:CanSee(unit) and unit:IsEnemy() then
            count = count + 1
        end
        return false
    end)

    self.cache:Set("enemies_" .. range, count, 0.5)
    return count
end

-- Get the number of melee attackers
---@param facing? boolean
---@return number
function Unit:GetMeleeAttackers(facing)
    local enemies = self.cache:Get("melee_attackers")
    if enemies then
        return enemies
    end

    local count = 0

    Bastion.UnitManager:EnumEnemies(function(unit)
        if not self:IsUnit(unit) and unit:IsAlive() and self:CanSee(unit) and self:InMelee(unit) and unit:IsEnemy() and (not facing or self:IsFacing(unit)) then
            count = count + 1
        end
        return false
    end)

    self.cache:Set("melee_attackers", count, 0.5)
    return count
end

---@param distance number
---@param percent number
---@return number
function Unit:GetPartyHPAround(distance, percent)
    local count = 0

    Bastion.UnitManager:EnumFriends(function(unit)
        if not self:IsUnit(unit) and unit:GetDistance(self) <= distance and unit:IsAlive() and self:CanSee(unit) and unit:GetHP() <= percent then
            count = count + 1
        end
        return false
    end)

    return count
end

-- Is moving
---@return boolean
function Unit:IsMoving()
    return GetUnitSpeed(self:GetOMToken()) > 0
end

---@return TinkrMovementFlags
function Unit:GetMovementFlag()
    return ObjectMovementFlag(self:GetOMToken())
end

-- Is moving at all
---@return boolean
function Unit:IsMovingAtAll()
    return ObjectMovementFlag(self:GetOMToken()) ~= 0
end

---@param unit? Bastion.Unit
---@return number
function Unit:GetComboPoints(unit)
    if Tinkr.classic or Tinkr.era then
        if not unit then
            return 0
        end
        return GetComboPoints(self:GetOMToken(), unit:GetOMToken())
    end
    return UnitPower(self:GetOMToken(), Enum.PowerType.ComboPoints)
end

---@return number
function Unit:GetComboPointsMax()
    if Tinkr.classic or Tinkr.era then
        return 5
    end
    return UnitPowerMax(self:GetOMToken(), 4)
end

-- Get combopoints deficit
---@param unit Bastion.Unit | nil
---@return number
function Unit:GetComboPointsDeficit(unit)
    if Tinkr.classic or Tinkr.era then
        return self:GetComboPointsMax() - self:GetComboPoints(unit)
    end
    return self:GetComboPointsMax() - self:GetComboPoints()
end

-- IsUnit
---@param unit Bastion.Unit
---@return boolean
function Unit:IsUnit(unit)
    return UnitIsUnit(self:GetOMToken(), unit and unit:GetOMToken() or "none")
end

-- IsTanking
---@param unit Bastion.Unit
---@return boolean
function Unit:IsTanking(unit)
    local isTanking, status, threatpct, rawthreatpct, threatvalue = UnitDetailedThreatSituation(self:GetOMToken(),
        unit:GetOMToken())
    return isTanking
end

-- IsFacing
---@param unit Bastion.Unit
---@return boolean
function Unit:IsFacing(unit)
    local rot = ObjectRotation(self:GetOMToken())
    local x, y, z = ObjectPosition(self:GetOMToken())
    local x2, y2, z2 = ObjectPosition(unit:GetOMToken())

    if not x or not x2 or not rot then
        return false
    end

    ---@diagnostic disable-next-line: deprecated
    local angle = math.atan2(y2 - y, x2 - x) - rot
    angle = math.deg(angle)
    angle = angle % 360
    if angle > 180 then
        angle = angle - 360
    end

    return math.abs(angle) < 90
end

-- IsBehind
---@param unit Bastion.Unit
---@return boolean
function Unit:IsBehind(unit)
    local rot = ObjectRotation(unit:GetOMToken())
    local x, y, z = ObjectPosition(unit:GetOMToken())
    local x2, y2, z2 = ObjectPosition(self:GetOMToken())

    if not x or not x2 then
        return false
    end
    ---@diagnostic disable-next-line: deprecated
    local angle = math.atan2(y2 - y, x2 - x) - rot
    angle = math.deg(angle)
    angle = angle % 360
    if angle > 180 then
        angle = angle - 360
    end

    return math.abs(angle) > 90
end

-- IsInfront
---@param unit Bastion.Unit
---@return boolean
function Unit:IsInfront(unit)
    return not self:IsBehind(unit)
end

---@return number
function Unit:GetMeleeBoost()
    local meleeBoost = 0
    if IsPlayerSpell(197524) then
        local astralInfluenceNode = C_Traits.GetNodeInfo(C_ClassTalents.GetActiveConfigID() or 0, 82210)
        local currentSpec = select(1, GetSpecializationInfo(GetSpecialization()))
        if astralInfluenceNode then
            local currentRank = astralInfluenceNode.activeRank
            if currentRank > 0 then
                meleeBoost = ((currentSpec == 103 or currentSpec == 104) and 1 or 3) + (currentRank == 2 and 2 or 0)
            end
        end
    elseif IsPlayerSpell(196924) then
        meleeBoost = 3
    end
    return meleeBoost
end

function Unit:GetModelId()
    return ObjectModelId(self:GetOMToken())
end

-- Melee calculation
-- float fMaxDist = fmaxf((float)(*(float*)((uintptr_t)this + 0x1BF8) + 1.3333) + *(float*)((uintptr_t)target + 0x1BF8), 5.0);
-- fMaxDist = fMaxDist + 1.0;
-- Vector3 myPos = ((WoWGameObject*)this)->GetPosition();
-- Vector3 targetPos = ((WoWGameObject*)target)->GetPosition();
-- return ((myPos.x - targetPos.x) * (myPos.x - targetPos.x)) + ((myPos.y - targetPos.y) * (myPos.y - targetPos.y)) + ((myPos.z - targetPos.z) * (myPos.z - targetPos.z)) <= (float)(fMaxDist * fMaxDist);

-- InMelee
---@param unit Bastion.Unit
---@return boolean
function Unit:InMelee(unit)
    local x, y, z = ObjectPosition(self:GetOMToken())
    local x2, y2, z2 = ObjectPosition(unit:GetOMToken())

    if not x or not x2 then
        return false
    end

    local scr = ObjectCombatReach(self:GetOMToken())
    local ucr = ObjectCombatReach(unit:GetOMToken())

    if not scr or not ucr then
        return false
    end

    local dist = math.sqrt((x - x2) ^ 2 + (y - y2) ^ 2 + (z - z2) ^ 2)
    local maxDist = math.max((scr + 1.3333) + ucr, 5.0)
    maxDist = maxDist + 1.0 + self:GetMeleeBoost()

    return dist <= maxDist
end

-- Get object id
---@return number
function Unit:GetID()
    if self.id ~= false then
        ---@type number
        return self.id
    end
    self.id = ObjectID(self:GetOMToken())
    ---@type number
    return self.id or 0
end

-- In party
---@return boolean
function Unit:IsInParty()
    return UnitInParty(self:GetOMToken())
end

-- In party
---@return boolean
function Unit:IsInRaid()
    return UnitInRaid(self:GetOMToken()) ~= nil
end

---@return boolean
function Unit:IsInPartyOrRaid()
    return self:IsInParty() or self:IsInRaid()
end

-- Linear regression between time and percent to something
---@param time table
---@param percent table
---@return number, number
function Unit:LinearRegression(time, percent)
    local x = time
    local y = percent

    local n = #x
    local sum_x = 0
    local sum_y = 0
    local sum_xy = 0
    local sum_xx = 0
    local sum_yy = 0

    for i = 1, n do
        sum_x = sum_x + x[i]
        sum_y = sum_y + y[i]
        sum_xy = sum_xy + x[i] * y[i]
        sum_xx = sum_xx + x[i] * x[i]
        sum_yy = sum_yy + y[i] * y[i]
    end

    local slope = (n * sum_xy - sum_x * sum_y) / (n * sum_xx - sum_x * sum_x)
    local intercept = (sum_y - slope * sum_x) / n

    return slope, intercept
end

-- Use linear regression to get the health percent at a given time in the future
---@param time number
---@return number
function Unit:PredictHealth(time)
    local x = {}
    local y = {}

    if #self.regression_history > 60 then
        table.remove(self.regression_history, 1)
    end

    table.insert(self.regression_history, { time = GetTime(), percent = self:GetHP() })

    for i = 1, #self.regression_history do
        local entry = self.regression_history[i]
        table.insert(x, entry.time)
        table.insert(y, entry.percent)
    end

    local slope, intercept = self:LinearRegression(x, y)
    return slope * (GetTime() + time) + intercept
end

-- Use linear regression to guess the time until a given health percent
---@param percent number
---@return number
function Unit:PredictTime(percent)
    local x = {}
    local y = {}

    if #self.regression_history > 60 then
        table.remove(self.regression_history, 1)
    end

    table.insert(self.regression_history, { time = GetTime(), percent = self:GetHP() })

    for i = 1, #self.regression_history do
        local entry = self.regression_history[i]
        table.insert(x, entry.time)
        table.insert(y, entry.percent)
    end

    local slope, intercept = self:LinearRegression(x, y)
    return (percent - intercept) / slope
end

-- Start time to die ticker
function Unit:StartTTDTicker()
    if self.ttd_ticker then
        return
    end

    self.ttd_ticker = C_Timer.NewTicker(0.5, function()
        local timeto = self:PredictTime(0) - GetTime()
        self.ttd = timeto
    end)
end

-- Time until death
---@return number
function Unit:TimeToDie()
    if self:IsDead() then
        self.regression_history = {}
        if self.ttd_ticker then
            self.ttd_ticker:Cancel()
            self.ttd_ticker = false
        end
        return 0
    end

    if not self.ttd_ticker then
        self:StartTTDTicker()
    end

    -- If there's not enough data to make a prediction return 0 unless the unit has more than 5 million health
    if #self.regression_history < 5 and self:GetMaxHealth() < 5000000 then
        return 0
    end

    -- if the unit has more than 5 million health but there's not enough data to make a prediction we can assume there's roughly 250000 damage per second and estimate the time to die
    if #self.regression_history < 5 and self:GetMaxHealth() > 5000000 then
        return self:GetMaxHealth() /
            250000 -- 250000 is an estimate of the average damage per second a well geared group will average
    end

    if self.ttd ~= self.ttd or self.ttd < 0 or self.ttd == math.huge then
        return 0
    end

    return self.ttd
end

---@param lower number
---@param upper? number
---@return boolean
function Unit:TTD(lower, upper)
    upper = type(upper) == "nil" and lower or upper
    local ttd = self:TimeToDie()
    return ttd >= lower and ttd <= upper
end

-- Set combat time if affecting combat and return the difference between now and the last time
---@return number
function Unit:GetCombatTime()
    return GetTime() - self.last_combat_time
end

-- Set last combat time
---@param time number
function Unit:SetLastCombatTime(time)
    self.last_combat_time = time
end

-- Get combat odds (if the last combat time is less than 1 minute ago return 1 / time, else return 0)
-- the closer to 0 the more likely the unit is to be in combat (0 = 100%) 60 = 0%
---@return number
function Unit:InCombatOdds()
    local time = self:GetCombatTime()

    local percent = 1 - (time / 60)

    return percent * 100
end

-- Get units gcd time
---@return number
function Unit:GetGCD()
    local start, duration = GetSpellCooldown(61304)

    return start == 0 and 0 or duration - (GetTime() - start)
end

-- Get units max gcd time
--[[
    The GCD without Haste is 1.5 seconds
With 50% Haste the GCD is 1 second
With 100% Haste the GCD is 0.5 seconds
The GCD won't drop below 1 second
More than 50% Haste will drop a spell below 1 second

]]
---@return number
function Unit:GetMaxGCD()
    local haste = UnitSpellHaste(self:GetOMToken())
    if haste > 50 then
        haste = 50
    end

    -- if the unit uses focus their gcd is 1.0 seconds not 1.5
    local base = 1.5
    if self:GetPowerType() == 3 then
        base = 1.0
    end
    return base / (1 + haste / 100)
end

-- IsStealthed
---@return boolean
function Unit:IsStealthed()
    local Stealth = Bastion.Globals.SpellBook:GetSpell(1784)
    local Vanish = Bastion.Globals.SpellBook:GetSpell(1856)
    local ShadowDance = Bastion.Globals.SpellBook:GetSpell(185422)
    local Subterfuge = Bastion.Globals.SpellBook:GetSpell(115192)
    local Shadowmeld = Bastion.Globals.SpellBook:GetSpell(58984)
    local Sepsis = Bastion.Globals.SpellBook:GetSpell(328305)

    local stealthList = Bastion.List:New({
        Stealth,
        Vanish,
        ShadowDance,
        Subterfuge,
        Shadowmeld,
        Sepsis,
    })

    return self:GetAuras():FindAnyOf(stealthList):IsUp()
end

-- Get unit swing timers
---@return number, number
function Unit:GetSwingTimers()
    local main_speed, off_speed = UnitAttackSpeed(self:GetOMToken())
    local main_speed = main_speed or 2
    local off_speed = off_speed or 2

    local main_speed_remains = main_speed - (GetTime() - self.last_main_attack)
    local off_speed_remains = off_speed - (GetTime() - self.last_off_attack)

    if main_speed_remains < 0 then
        main_speed_remains = 0
    end

    if off_speed_remains < 0 then
        off_speed_remains = 0
    end

    return main_speed_remains, off_speed_remains
end

function Unit:WatchForSwings()
    if not self.watching_for_swings then
        Bastion.Globals.EventManager:RegisterWoWEvent("COMBAT_LOG_EVENT_UNFILTERED", function()
            local _, subtype, _, sourceGUID, sourceName, _, _, destGUID, destName, destFlags, _, spellID, spellName, _, amount, interrupt, a, b, c, d, offhand, multistrike =
                CombatLogGetCurrentEventInfo()

            if sourceGUID == self:GetGUID() and subtype then
                if subtype == "SPELL_ENERGIZE" and spellID == 196911 then
                    self.last_shadow_techniques = GetTime()
                    self.swings_since_sht = 0
                end

                if subtype:sub(1, 5) == "SWING" and not multistrike then
                    if subtype == "SWING_MISSED" then
                        offhand = spellName
                    end

                    local now = GetTime()

                    if now > self.last_shadow_techniques + 3 then
                        self.swings_since_sht = self.swings_since_sht + 1
                    end

                    if offhand then
                        self.last_off_attack = GetTime()
                    else
                        self.last_main_attack = GetTime()
                    end
                end
            end
        end)
        self.watching_for_swings = true
    end
end

-- ismounted
---@return boolean
function Unit:IsMounted()
    local mountedFormId = {
        [3] = true,  -- Mount / Travel Form
        [27] = true, -- Swift Flight Form
        [29] = true, -- Flight Form
    }
    return UnitIsMounted(self.unit) or (GetShapeshiftFormID() and mountedFormId[GetShapeshiftFormID()])
end

-- isindoors
---@return boolean
function Unit:IsOutdoors()
    return ObjectIsOutdoors(self.unit)
end

-- IsIndoors
---@return boolean
function Unit:IsIndoors()
    return not ObjectIsOutdoors(self.unit)
end

-- IsSubmerged
---@return boolean
function Unit:IsSubmerged()
    return ObjectIsSubmerged(self.unit)
end

-- IsDry
---@return boolean
function Unit:IsDry()
    return not ObjectIsSubmerged(self.unit)
end

-- The unit stagger amount
---@return number
function Unit:GetStagger()
    return UnitStagger(self:GetOMToken())
end

-- The percent of health the unit is currently staggering
---@return number
function Unit:GetStaggerPercent()
    local stagger = self:GetStagger()
    local max_health = self:GetMaxHealth()

    return (stagger / max_health) * 100
end

-- Get the units power regen rate
---@return number, number
function Unit:GetPowerRegen()
    ---@diagnostic disable-next-line: redundant-parameter
    return GetPowerRegen(self:GetOMToken())
end

-- Get the units staggered health relation
---@return number
function Unit:GetStaggeredHealth()
    local stagger = self:GetStagger()
    local max_health = self:GetMaxHealth()

    return (stagger / max_health) * 100
end

-- get the units combat reach
---@return number
function Unit:GetCombatReach()
    return ObjectCombatReach(self:GetOMToken()) or 0
end

-- Get the units combat distance (distance - combat reach (realized distance))
---@return number
function Unit:GetCombatDistance(Target)
    return self:GetDistance(Target) - Target:GetCombatReach()
end

-- Is the unit within distance of the target (combat reach + distance)
--- If the target is within 8 combat yards (8 + combat reach) of the unit
---@param Target Bastion.Unit
---@param Distance number
---@return boolean
function Unit:IsWithinCombatDistance(Target, Distance)
    if not Target:Exists() then
        return false
    end
    return self:GetDistance(Target) <= Distance + Target:GetCombatReach()
end

-- Check if the unit is within X yards (consider combat reach)
---@param Target Bastion.Unit
---@param Distance number
---@return boolean
function Unit:IsWithinDistance(Target, Distance)
    return self:GetDistance(Target) <= Distance
end

-- Get the angle between the unit and the target in raidans
---@param Target Bastion.Unit
---@return number
function Unit:GetAngle(Target)
    if not Target:Exists() then
        return 0
    end

    local sp = self:GetPosition()
    local tp = Target:GetPosition()

    local an = Tinkr.Common.GetAnglesBetweenPositions(sp.x, sp.y, sp.z, tp.x, tp.y, tp.z)

    return an
end

function Unit:GetFacing()
    return ObjectRotation(self:GetOMToken()) or 0
end

-- Check if target is within a arc around the unit (angle, distance) accounting for a rotation of self
---@param Target Bastion.Unit
---@param Angle number
---@param Distance number
---@param rotation? number
---@return boolean
function Unit:IsWithinCone(Target, Angle, Distance, rotation)
    if not Target:Exists() then
        return false
    end

    local angle = self:GetAngle(Target)
    rotation = rotation or self:GetFacing()

    local diff = math.abs(angle - rotation)

    if diff > math.pi then
        diff = math.abs(diff - math.pi * 2)
    end

    return diff <= Angle and self:GetDistance(Target) <= Distance
end

---@return number
function Unit:GetEmpoweredStage()
    local stage = 0
    local _, _, _, startTime, _, _, _, spellID, _, numStages = UnitChannelInfo(self:GetOMToken())

    if numStages and numStages > 0 then
        startTime = startTime / 1000
        local currentTime = GetTime()
        local stageDuration = 0
        for i = 1, numStages do
            stageDuration = stageDuration + GetUnitEmpowerStageDuration((self:GetOMToken()), i - 1) / 1000
            if startTime + stageDuration > currentTime then
                break
            end
            stage = i
        end
    end
    return stage
end

---@return boolean
function Unit:IsConnected()
    return UnitIsConnected(self:GetOMToken())
end

---@return boolean
function Unit:HasIncomingRessurection()
    ---@diagnostic disable-next-line: return-type-mismatch
    return self:IsDead() and UnitHasIncomingResurrection(self:GetOMToken())
end

---@return WowGameObject | false
function Unit:LootTarget()
    return ObjectLootTarget(self:GetOMToken())
end

---@return boolean
function Unit:CanLoot()
    return ObjectLootable(self:GetOMToken())
end

---@return boolean
function Unit:HasTarget()
    return ObjectTarget(self:GetOMToken()) ~= false
end

---@return Bastion.Unit
function Unit:Target()
    return self:HasTarget() and Bastion.UnitManager:Get(ObjectTarget(self:GetOMToken()):unit()) or
        Bastion.UnitManager:Get("none")
end

local dummyUnits = {
    -- City (SW, Orgri, ...)
    [31146] = true,   -- Raider's Training Dummy
    [31144] = true,   -- Training Dummy
    [32666] = true,   -- Training Dummy
    [32667] = true,   -- Training Dummy
    [46647] = true,   -- Training Dummy
    [114832] = true,  -- PvP Training Dummy
    [153285] = true,  -- Training Dummy
    [153292] = true,  -- Training Dummy
    -- MoP Shrine of Two Moons
    [67127] = true,   -- Training Dummy
    -- WoD Alliance Garrison
    [87317] = true,   -- Mage Tower Damage Training Dummy
    [87318] = true,   -- Mage Tower Damage Dungeoneer's Training Dummy (& Garrison)
    [87320] = true,   -- Mage Tower Damage Raider's Training Dummy
    [88314] = true,   -- Tanking Dungeoneer's Training Dummy
    [88316] = true,   -- Healing Training Dummy ----> FRIENDLY
    -- WoD Horde Garrison
    [87760] = true,   -- Mage Tower Damage Training Dummy
    [87761] = true,   -- Mage Tower Damage Dungeoneer's Training Dummy (& Garrison)
    [87762] = true,   -- Mage Tower Damage Raider's Training Dummy
    [88288] = true,   -- Tanking Dungeoneer's Training Dummy
    [88289] = true,   -- Healing Training Dummy ----> FRIENDLY
    -- Legion Druid Class Order Hall
    [113964] = true,  -- Raider's Training Dummy
    [113966] = true,  -- Dungeoneer's Training Dummy
    -- Legion Mage Class Order Hall
    [103397] = true,  -- Greater Bullwark Construct
    [103404] = true,  -- Bullwark Construct
    [103402] = true,  -- Lesser Bullwark Construct
    -- Legion Priest Class Order Hall
    [107555] = true,  -- Bound void Wraith
    [107556] = true,  -- Bound void Walker
    -- Legion Rogue Class Order Hall
    [92164] = true,   -- Training Dummy
    [92165] = true,   -- Dungeoneer's Training Dummy
    [92166] = true,   -- Raider's Training Dummy
    -- Legion Warlock Class Order Hall
    [101956] = true,  -- Rebellious Fel Lord
    [102045] = true,  -- Rebellious WrathGuard
    [102048] = true,  -- Rebellious Felguard
    [102052] = true,  -- Rebellious imp
    -- BfA Dazar'Alor
    [144081] = true,  -- Training Dummy
    [144082] = true,  -- Training Dummy
    [144085] = true,  -- Training Dummy
    [144086] = true,  -- Raider's Training Dummy
    -- BfA Boralus
    [126781] = true,  -- Training Dummy
    [131983] = true,  -- Raider's Training Dummy
    [131989] = true,  -- Training Dummy
    [131992] = true,  -- Dungeoneer's Training Dummy
    -- Shadowlands Kyrian
    [154564] = true,  -- Valiant's Humility
    [154567] = true,  -- Purity's Cleaning
    [154580] = true,  -- Reinforced Guardian
    [154583] = true,  -- Starlwart Guardian
    [154585] = true,  -- Valiant's Resolve
    [154586] = true,  -- Stalwart Phalanx
    [160325] = true,  -- Humility's Obedience
    -- Shadowlands Venthyr
    [173942] = true,  -- Training Dummy
    [175449] = true,  -- Raider's Training Dummy
    [175450] = true,  -- Dungeoneer's Training Dummy
    [175451] = true,  -- Dungeoneer's Tanking Dummy
    [175452] = true,  -- Raider's Tanking Dummy
    [175455] = true,  -- Cleave Training Dummy
    [175456] = true,  -- Swarm Training Dummy
    [175462] = true,  -- Sinfall Fiend
    -- Shadowlands Night Fae
    [174565] = true,  -- Dungeoneer's Tanking Dummy
    [174566] = true,  -- Raider's Tanking Dummy
    [174567] = true,  -- Raider's Training Dummy
    [174568] = true,  -- Dungeoneer's Training Dummy
    [174569] = true,  -- Training Dummy
    [174570] = true,  -- Swarm Training Dummy
    [174571] = true,  -- Cleave Training Dummy
    -- Shadowlands Necrolord
    [174484] = true,  -- Dungeoneer's Training Dummy
    [174487] = true,  -- Training Dummy
    [174488] = true,  -- Raider's Training Dummy
    [174491] = true,  -- Tanking Dummy
    -- DargonFlight Valdrakken
    [198594] = true,  -- Cleave Training Dummy
    [194648] = false, -- Training Dummy
    [189632] = true,  -- Animated Duelist
    [194643] = true,  -- Dungeoneer's Training Dummy
    [194644] = true,  -- Dungeoneer's Training Dummy
    [197833] = true,  -- PvP Training Dummy
    [189617] = true,  -- Boulderfist
    [194649] = true,  -- Normal Tank Dummy
    -- DargonFlight Iskaara
    [193563] = true,  -- Training Dummy
    -- Other
    [65310] = true,   -- Turnip Punching Bag (toy)
    [66374] = true,   -- Anatomical Dummy (toy)
    [196394] = true,  -- Tuskarr Training Dummy (toy)
    [196406] = true,  -- Rubbery Fish Head (toy)
    [199057] = true,  -- Black Dragon's Challenge Dummy (toy)
}

---@return boolean
function Unit:IsDummy()
    local npcId = self:GetID()
    return npcId and npcId >= 0 and dummyUnits[npcId] == true or false
end

---@param npcId? number
---@return boolean
function Unit:IsInBossList(npcId)
    npcId = npcId or self:GetID()
    for i = 1, 4 do
        local thisUnit = Bastion.UnitManager:Get(string.format("boss%d", i))
        if thisUnit:Exists() and thisUnit:GetID() == npcId then
            return true
        end
    end
    return false
end

---@param npcId number
---@return number
function Unit:SpecialTTDPercentage(npcId)
    local specialTTDPercentage = Bastion.TimeToDie.specialTTDPercentageData[npcId]
    if not specialTTDPercentage then return 0 end

    if type(specialTTDPercentage) == "number" then
        return specialTTDPercentage
    end

    return specialTTDPercentage(self)
end

---@param npcId? number
---@param hp? number
---@return boolean
function Unit:CheckHPFromBossList(npcId, hp)
    npcId = npcId or self:GetID()
    local thisHP = hp or 100
    for i = 1, 4 do
        local thisUnit = Bastion.UnitManager:Get(string.format("boss%d", i))
        if thisUnit:Exists() and thisUnit:GetID() == npcId and thisUnit:GetHealthPercent() <= thisHP then
            return true
        end
    end

    return false
end

---@param percentage number
---@param minSamples? number
---@return Bastion.TimeToDie.Enums | integer
function Unit:TimeToX(percentage, minSamples)
    --if self:IsDummy() then return 6666 end
    if self:IsPlayer() and Bastion.UnitManager:Get("player"):CanAttack(self) then return Bastion.TimeToDie.Enums.PLAYER end
    local seconds = 0
    local unitGuid = self:GetGUID()
    if not unitGuid then
        return Bastion.TimeToDie.Enums.NO_GUID
    end
    local unitTable = Bastion.TimeToDie.Units[unitGuid]
    -- Simple linear regression
    -- ( E(x^2)  E(x) )  ( a )  ( E(xy) )
    -- ( E(x)     n  )  ( b ) = ( E(y)  )
    -- Format of the above: ( 2x2 Matrix ) * ( 2x1 Vector ) = ( 2x1 Vector )
    -- Solve to find a and b, satisfying y = a + bx
    -- Matrix arithmetic has been expanded and solved to make the following operation as fast as possible
    if unitTable then
        minSamples = minSamples or 3
        local history = unitTable.history
        local n = #history
        if n > minSamples then
            local a, b = 0, 0
            local ex2, ex, exy, ey = 0, 0, 0, 0

            for i = 1, n do
                local value = history[i]
                local x, y = value.time, value.percentage

                ex2 = ex2 + x * x
                ex = ex + x
                exy = exy + x * y
                ey = ey + y
            end
            -- Invariant to find matrix inverse
            local invariant = 1 / (ex2 * n - ex * ex)
            -- Solve for a and b
            a = (-ex * exy * invariant) + (ex2 * ey * invariant)
            b = (n * exy * invariant) - (ex * ey * invariant)
            if b ~= 0 then
                -- Use best fit line to calculate estimated time to reach target health
                seconds = (percentage - a) / b
                -- Subtract current time to obtain "time remaining"
                seconds = seconds - (GetTime() - unitTable.time)
                if seconds < 0 then seconds = Bastion.TimeToDie.Enums.NEGATIVE_TTD end
            end
        end
    end
    return seconds
end

---@param minSamples? number
---@return Bastion.TimeToDie.Enums | integer
function Unit:TimeToDie2(minSamples)
    if not self:Exists() then
        return Bastion.TimeToDie.Enums.DOES_NOT_EXIST
    end
    local unitGuid = self:GetGUID()
    if not unitGuid then
        return Bastion.TimeToDie.Enums.NO_GUID
    end

    minSamples = minSamples or 3
    ---@type {TTD: {[number]: number}}
    local unitInfo = Bastion.Globals.UnitInfo:IsCached(unitGuid) and
        Bastion.Globals.UnitInfo:Get(unitGuid) or {}

    local ttd = unitInfo.TTD
    if not ttd then
        ttd = {}
        unitInfo.TTD = ttd
    end
    local v
    if not ttd[minSamples] then
        v = self:TimeToX(self:SpecialTTDPercentage(self:GetID()), minSamples)
        if v >= 0 then
            ttd[minSamples] = v
            Bastion.Globals.UnitInfo:Set(unitGuid, unitInfo, .5)
        end
    end


    return ttd[minSamples] or v
end

-- Get the boss unit TimeToDie
---@param minSamples? number
---@return Bastion.TimeToDie.Enums | integer
function Unit:BossTimeToDie(minSamples)
    if self:IsInBossList() or self:IsDummy() then
        return self:TimeToDie2(minSamples)
    end

    return Bastion.TimeToDie.Enums.DOES_NOT_EXIST
end

-- Get if the unit meets the TimeToDie requirements.
---@param operator CompareThisTable
---@param value number
---@param offset number
---@param valueThreshold number
---@param minSamples? number
---@return boolean
function Unit:FilteredTimeToDie(operator, value, offset, valueThreshold, minSamples)
    local TTD = self:TimeToDie2(minSamples)

    return TTD > -1 and TTD < valueThreshold and Bastion.Util:CompareThis(operator, TTD + (offset or 0), value) or false
end

-- Get if the boss unit meets the TimeToDie requirements.
---@param operator CompareThisTable
---@param value number
---@param offset number
---@param valueThreshold number
---@param minSamples? number
---@return boolean
function Unit:BossFilteredTimeToDie(operator, value, offset, valueThreshold, minSamples)
    if self:IsInBossList() or self:IsDummy() then
        return self:FilteredTimeToDie(operator, value, offset, valueThreshold, minSamples)
    end

    return false
end

-- Get if the Time To Die is Valid for an Unit (i.e. not returning a warning code).
---@param minSamples? number
---@return boolean
function Unit:TimeToDieIsNotValid(minSamples)
    return self:TimeToDie2(minSamples) > -1
end

-- Get if the Time To Die is Valid for a boss Unit (i.e. not returning a warning code or not being a boss).
---@param minSamples? number
---@return boolean
function Unit:BossTimeToDieIsNotValid(minSamples)
    if self:IsInBossList() then
        return self:TimeToDieIsNotValid(minSamples)
    end

    return true
end

Bastion.Unit = Unit