--[[
# Element: Auras

Handles creation of [aura containers](https://warcraft.wiki.gg/wiki/INTRINSIC_AuraContainer), groups,
slots, and [buttons](https://warcraft.wiki.gg/wiki/INTRINSIC_AuraButton).

## Notes

This is not a traditional element; similar to Tags it only exposes meta functions.

The options detailed below are attributes on the element returned from the meta function, see each
method documented further down for additional options. These options are shared across all buttons,
groups and slots for each element.

## Options (for buttons)

> Note: these options can be set on either the element or within the options table for groups and slots

.size                   - Aura button size. Defaults to 16 (number?)
.width                  - Aura button width. Takes priority over `size` (number?)
.height                 - Aura button height. Takes priority over `size` (number?)
.showBuffBorder         - Show dispel border texture when it's a buff (boolean?)
.showDebuffBorder       - Show dispel border texture when it's a debuff (boolean?)
.dispelBorderStyle      - Which style to use for the dispel border ([Enum.CustomAuraButtonDispelTypeTextureStyle](https://warcraft.wiki.gg/wiki/Enum.CustomAuraButtonDispelTypeTextureStyle)?)
.showBuffIndicator      - Show dispel indicator texture when it's a buff (boolean?)
.showDebuffIndicator    - Show dispel indicator texture when it's a debuff (boolean?)
.showStealableBorder    - Show a border texture when it's a stealable buff (boolean?)
.stealableBorderFilter  - Filter to use for the stealable border. Defaults to `Enum.CustomAuraButtonDispelTypeStealableFilter.Stealable` ([Enum.CustomAuraButtonDispelTypeTextureStyle](https://warcraft.wiki.gg/wiki/Enum.CustomAuraButtonDispelTypeStealableFilter)?)
.showCount              - Show Count fontstring representing aura applications (boolean?)
.countFormatter         - Formatter used to adjust the text displayed on the Count fontstring ([NumericFormatter](https://warcraft.wiki.gg/wiki/ScriptObject_NumericFormatter)?)
.showDuration           - Show Duration fontstring representing time remaining of the aura (boolean?)
.durationBinding        - Duration binding base object ([DurationTextBinding](https://warcraft.wiki.gg/wiki/ScriptObject_DurationTextBinding)?)
.durationFormat         - Text format for the text displayed on the Duration fontstring. `durationFormat` takes presedence (string?)
.durationFormatter      - Formatter used to adjust the text displayed on the Duration fontstring ([NumericFormatter](https://warcraft.wiki.gg/wiki/ScriptObject_NumericFormatter)?)
.durationColors         - Curve used to color the text displayed on the Duration fontstring ([ColorCurve](https://warcraft.wiki.gg/wiki/ScriptObject_ColorCurveObject)?)
.disableMouse           - Disables mouse events (boolean?)
.disableCooldown        - Disables the provided cooldown spiral frame (boolean?)
.cancelButton           - A list of mouse buttons and actions used to cancel the aura, if possible ([string](https://warcraft.wiki.gg/wiki/API_Button_RegisterForClicks)?)
.tooltipAnchor          - Anchor point for the tooltip. Defaults to 'ANCHOR_BOTTOMLEFT' (string?)
.tooltipOffsetX         - Horizontal anchor offset for the tooltip (number?)
.tooltipOffsetY         - Vertical anchor offset for the tooltip (number?)
.tooltipHideInCombat    - Whether to hide the tooltip during combat (boolean?)

## Options (for groups)

> Note: these are shared attributes for all groups of an element, and can be set within group options as well

.maxFrameCount    - Number of buttons to display. Defaults to an infinite number (number)
.elementSpacing   - Spacing between each button (number)
.lineSpacing      - Spacing between each button row or column (number)
.groupSpacing     - Spacing between each group (number)
.groupLineSpacing - Spacing between each group row or column
.forceNewLine     - Whether to force a new row or column between each group (boolean)

## Examples

  -- Initialize
  local Auras = self:CreateAuras()
  Auras.num = 10 -- per-group option

  -- Position and size
  Auras:SetPoint('TOP', self, 'BOTTOM')

  -- Enable some sub-widgets
  Auras.showCount = true
  Auras.showBuffBorder = true

  -- Register a group using a filter and some options
  Auras:AddGroup('HELPFUL', {
    maxFrameCount = 20, -- overrides Auras.num
    initializeFrame = PostCreateAuraButton, -- overrides CreateButton override
    showDebuffBorder = true, -- group-specific option for its buttons
  })

  -- Register another group using a different filter and no options
  Auras:AddGroup('HARMFUL')

  -- Register a slot with a filter to only include Mark of the Wild
  Auras:AddSlot('HELPFUL', {
    candidateFilters = {
      includeSpellIDs = {
        [1126] = true,
      }
    }
  })

--]]
local _, ns = ...
local oUF = ns.oUF

local Private = oUF.Private
local argcheck = Private.argcheck

local STATE = {}

local function CreateButton(element, options, button)
	local size = options.size or element.size or 16
	local width = options.width or element.width or size
	local height = options.height or element.height or size
	button:SetSize(width, height)
	button:EnableMouse(not (options.disableMouse or element.disableMouse))

	local tooltipAnchor = options.tooltipAnchor or element.tooltipAnchor or 'ANCHOR_BOTTOMLEFT'
	local tooltipOffsetX = options.tooltipOffsetX or element.tooltipOffsetX or 0
	local tooltipOffsetY = options.tooltipOffsetY or element.tooltipOffsetY or 0
	button:SetTooltipAnchorPoint(tooltipAnchor, tooltipOffsetX, tooltipOffsetY)
	button:SetHideTooltipInCombat(options.tooltipHideInCombat or element.tooltipHideInCombat)

	if(not (options.disableCooldown or element.disableCooldown)) then
		local cooldown = CreateFrame('Cooldown', '$parentCooldown', button, 'CooldownFrameTemplate')
		cooldown:SetAllPoints()
		button.Cooldown = cooldown
		button:SetDurationCooldown(cooldown)
	end

	local icon = button:CreateTexture(nil, 'BORDER')
	icon:SetAllPoints()
	button.Icon = icon
	button:SetIcon(icon)

	local textParent
	if((options.showCount or element.showCount) or (options.showDuration or element.showDuration)) then
		if(options.disableCooldown or element.disableCooldown) then
			textParent = button
		else
			-- raise frame level to render text above cooldown
			textParent = CreateFrame('Frame', nil, button)
			textParent:SetAllPoints()
			textParent:SetFrameLevel(button.Cooldown:GetFrameLevel() + 1)
		end
	end

	if(options.showCount or element.showCount) then
		local count = textParent:CreateFontString(nil, 'OVERLAY', 'NumberFontNormal')
		count:SetPoint('BOTTOMRIGHT', -1, 0)
		button.Count = count
		button:SetApplicationCount(count, {
			formatter = options.countFormatter or element.countFormatter,
		})
	end

	if((options.showBuffBorder or element.showBuffBorder) or (options.showDebuffBorder or element.showDebuffBorder)) then
		local border = button:CreateTexture(nil, 'OVERLAY')
		border:SetAllPoints()
		button.Border = border
		button:AddDispelTypeTexture(border, {
			style = options.dispelBorderStyle or element.dispelBorderStyle or Enum.CustomAuraButtonDispelTypeTextureStyle.Border,
			showWhenHarmful = options.showDebuffBorder or element.showDebuffBorder,
			showWhenHelpful = options.showBuffBorder or element.showBuffBorder,
			customDispelColorMap = element.__owner.colors.dispel,
		})
	end

	if((options.showDebuffIndicator or element.showDebuffIndicator) or (options.showBuffIndicator or element.showBuffIndicator)) then
		local dispelIndicator = button:CreateTexture(nil, 'OVERLAY', nil, 1) -- above other overlay widgets
		dispelIndicator:SetPoint('CENTER', button, 'TOPRIGHT')
		dispelIndicator:SetSize(18, 18)
		button.DispelIndicator = dispelIndicator
		button:AddDispelTypeTexture(dispelIndicator, {
			style = Enum.CustomAuraButtonDispelTypeTextureStyle.Icon,
			showWhenHarmful = options.showDebuffIndicator or element.showDebuffIndicator,
			showWhenHelpful = options.showBuffIndicator or element.showBuffIndicator,
		})
	end

	if(options.showStealableBorder or element.showStealableBorder) then
		local stealable = button:CreateTexture(nil, 'OVERLAY')
		stealable:SetPoint('TOPLEFT', -3, 3)
		stealable:SetPoint('BOTTOMRIGHT', 3, -3)
		stealable:SetTexture([[Interface\TargetingFrame\UI-TargetingFrame-Stealable]])
		stealable:SetBlendMode('ADD')
		button.Stealable = stealable
		button:AddDispelTypeTexture(stealable, {
			style = Enum.CustomAuraButtonDispelTypeTextureStyle.PreserveAsset, -- since we use a texture
			showWhenHelpful = true, -- this is required for stealableFilter option
			showWithoutDispelType = true, -- this is _probably_ required for stealableFilter option
			stealableFilter = options.stealableBorderFilter or element.stealableBorderFilter or Enum.CustomAuraButtonDispelTypeStealableFilter.Stealable
		})
	end

	if(options.showDuration or element.showDuration) then
		local time = textParent:CreateFontString(nil, 'OVERLAY', 'NumberFontNormal')
		time:SetPoint('TOPLEFT', 1, 0) -- TBD
		button.Time = time
		button:SetDurationText(time, {
			binding = options.durationBinding or element.durationBinding,
			textFormatter = options.durationFormatter or element.durationFormatter,
			textFormat = options.durationFormat or element.durationFormat,
			textColor = options.durationColors or element.durationColors,
		})
	end

	if(options.cancelButton or element.cancelButton) then
		button:SetCancelAuraButtons(options.cancelButton or element.cancelButton)
	end

	--[[ Callback: Auras:PostCreateButton(button)
	Called after a new aura button has been created.

	* self    - the element used to represent the aura buttons
	* button  - the aura button (AuraButton)
	* options - the aura group/slot options passed through to CreateButton (table)
	--]]
	if(element.PostCreateButton) then element:PostCreateButton(button, options) end
end

local elementMixin = {}
--[[ Auras: auras:AddGroup(filter[, options])
Defines a group of auras to display on the element.  
This can be defined multiple times.

* filter  - aura filter for this group ([AuraFilter](https://warcraft.wiki.gg/wiki/API_types/AuraFilters))
* options - options for this group ([CustomAuraContainerGroupDefaultOptions](https://warcraft.wiki.gg/wiki/FrameXML_types/CustomAuraContainerGroupDefaultOptions))

## Notes

* Many of the options will fall back to element-wide options unless specified.
* All of the button-specific options can be set in the group options to override the
element-provided values
* The groupKey is an arbitrary string used to identify the aura group after creation, and is derived
from the element's inherited name, suffixed by a growing integer.

## Returns

* groupKey - unique identifier for this specific aura group (string)
--]]
function elementMixin:AddGroup(filter, options)
	argcheck(filter, 2, 'string')
	argcheck(options, 3, 'table', 'nil')

	-- we use this to pad the options provided (if any) with familiar defaults from
	-- element attributes like we've been doing for years.
	if(not options) then
		options = {}
	end

	-- attributes inherited from the element
	options.maxFrameCount = options.maxFrameCount or self.maxFrameCount

	-- layout attributes inherited from the element
	local layout = options.layout or {}
	layout.elementSpacing = layout.elementSpacing or self.elementSpacing
	layout.lineSpacing = layout.lineSpacing or self.lineSpacing
	layout.groupSpacing = layout.groupSpacing or self.groupSpacing
	layout.groupLineSpacing = layout.groupLineSpacing or self.groupLineSpacing
	layout.forceNewLine = layout.forceNewLine or self.forceNewLine
	options.layout = layout

	-- some nice shorthands for stuff that might be shared across groups, with more familiar defaults
	options.sortMethod = options.sortMethod or self.sortMethod or AuraContainerSortMethod.ExpirationOnly
	options.sortDirection = options.sortDirection or self.sortDirection or AuraContainerSortDirection.Normal

	if(not options.initializeFrame) then
		-- we want to provide a default set of widgets for buttons, and we load it late so we can
		-- pass group-specific options to it

		--[[ Override: Auras:CreateButton(options, button)
		Used to initialize an aura button.

		* self    - the element used to represent the aura buttons
		* options - options passed through from auras:AddGroup and auras:AddSlot
		* button  - the aura button (AuraButton)
		--]]
		options.initializeFrame = GenerateClosure(options.CreateButton or self.CreateButton or CreateButton, self, options)
	end

	-- keep track of how many groups we've created, for key generation purposes
	local frame = self.__owner
	STATE[frame].groupIndex = STATE[frame].groupIndex + 1

	local key = 'Group' .. STATE[frame].groupIndex
	self:AddAuraGroup(key, filter, options)

	return key
end

--[[ Auras: auras:AddSlot(filter[, options])
Defines a slot for a single buff or debuff to create from the element.  
The slot can be manually positioned if necessary.  
This can be defined multiple times.

* filter  - aura filter for this group ([AuraFilter](https://warcraft.wiki.gg/wiki/API_types/AuraFilters))
* options - options for this group ([CustomAuraContainerSlotDefaultOptions](https://warcraft.wiki.gg/wiki/FrameXML_types/CustomAuraContainerSlotDefaultOptions))

## Notes

* Many of the options will fall back to element-wide options unless specified.
* All of the button-specific options can be set in the group options to override the
element-provided values
* Slots will be automatically positioned with each other, this can be overridden with ClearAllPoints
and SetPoint.
* The slotKey is an arbitrary string used to identify the aura slot after creation, and is derived
from the element's inherited name, suffixed by a growing integer.

## Returns

* slotKey - unique identifier for this specific aura slot (string)
--]]
function elementMixin:AddSlot(filter, options)
	argcheck(filter, 2, 'string')
	argcheck(options, 3, 'table', 'nil')

	-- we use this to pad the options provided (if any) with familiar defaults from
	-- element attributes like we've been doing for years.
	if(not options) then
		options = {}
	end

	if(not options.initializeFrame) then
		-- we want to provide a default set of widgets for buttons
		options.initializeFrame = GenerateClosure(options.CreateButton or self.CreateButton or CreateButton, self, options)
	end

	-- keep track of how many groups we've created, for key generation purposes
	local frame = self.__owner
	STATE[frame].slotIndex = STATE[frame].slotIndex + 1

	local key = 'Slot' .. STATE[frame].slotIndex
	self:AddAuraSlot(key, filter, options)

	return key
end

--[[ Auras: auras:ForceUpdate()
Forcefully update all auras within groups and slots on the element.
--]]
function elementMixin:ForceUpdate()
	self:UpdateAllAuras()
end

--[[ Auras: frame:CreateAuras([options])
Create and return a aura element.

* self     - the unit frame on which to create the element
* options  - extra options to provide to the element

## Options

All of these options are provided as a convenience, and can be applied after creation through
methods on the element.

.layout        - Which way to layout groups. Defaults to AnchorUtil.FlowLayoutAxis.Horizontal (number?)
.layoutLimit   - Max width or height of the element, depending on the layout. Defaults to the parent width or height (number?)
.initialAnchor - Anchor point for the element. Defaults to 'TOPLEFT' (string?)
.growthX       - Horizontal growth direction. Defaults to 'RIGHT' (string?)
.growthY       - Vertical growth direction. Defaults to 'UP' (string?)
.padding       - Padding around the element. Defaults to 0 (number?)
.paddingLeft   - Padding on the left side of the element. Takes priority over `padding` (number?)
.paddingRight  - Padding on the right side of the element. Takes priority over `padding` (number?)
.paddingTop    - Padding on the top side of the element. Takes priority over `padding` (number?)
.paddingBottom - Padding on the bottom side of the element. Takes priority over `padding` (number?)
.policy        - Policy for how auras should be processed. See [CustomAuraContainerProcessAuraPolicyDefaultOptions](https://warcraft.wiki.gg/wiki/FrameXML_types/CustomAuraContainerProcessAuraPolicyDefaultOptions) (table?)
.templates     - Extra templates to use for the aura element (string?)

## Returns

* auras - the element used to represent the aura buttons
--]]
local function Create(self, options)
	-- keep a local state of elements created for each frame
	if(not STATE[self]) then
		STATE[self] = {
			index = 0,
			elements = {},
			groupIndex = 0,
			slotIndex = 0,
		}
	end

	local templates = 'CustomAuraContainerTemplate'
	if(options and options.templates) then
		templates = templates .. ',' .. options.templates
	end

	STATE[self].index = STATE[self].index + 1
	local element = CreateFrame('AuraContainer', '$parentAuras' .. STATE[self].index, self, templates)
	STATE[self].elements[STATE[self].index] = element

	element.__owner = self

	if(options) then
		-- element-wide options we'll just set directly from options
		element:SetFlowLayoutAnchorPoint(options.initialAnchor or 'TOPLEFT')

		if(options.layout) then
			element:SetFlowLayoutAxis(options.layout)
		end

		if(options.layout == AnchorUtil.FlowLayoutAxis.Vertical) then
			element:SetFlowLayoutMaximumLineSize(options.layoutLimit or self:GetHeight())
		else
			element:SetFlowLayoutMaximumLineSize(options.layoutLimit or self:GetWidth())
		end

		local growthX = (options.growthX == 'LEFT' and -1) or 1
		local growthY = (options.growthY == 'DOWN' and -1) or 1
		element:SetFlowLayoutGrowthDirection(growthX, growthY)

		local paddingLeft = options.paddingLeft or options.padding or 0
		local paddingRight = options.paddingRight or options.padding or 0
		local paddingTop = options.paddingTop or options.padding or 0
		local paddingBottom = options.paddingBottom or options.padding or 0
		element:SetFlowLayoutPadding(paddingLeft, paddingRight, paddingTop, paddingBottom)

		if(options.policy) then
			-- just expose it easily for layouts in case they want to use it
			element:SetAuraProcessingPolicy(CustomAuraContainerAuraProcessingPolicy.ProcessAura, options.policy)
		end
	end

	return Mixin(element, elementMixin)
end

local function Update(self)
	if(STATE[self] and STATE[self].elements) then
		for _, element in next, STATE[self].elements do
			if element:GetUnit() ~= self.__unit then
				element:SetUnit(self.__unit) -- triggers a full update
			else
				element:ForceUpdate()
			end
		end
	end
end

local function Enable(self)
	if(STATE[self] and STATE[self].elements) then
		for _, element in next, STATE[self].elements do
			element:SetEnabled(true) -- triggers a full update
		end

		return true
	end
end

local function Disable(self)
	if(STATE[self] and STATE[self].elements) then
		for _, element in next, STATE[self].elements do
			element:SetEnabled(false)
		end
	end
end

oUF:AddMetaElement('Auras', Create, Update, Enable, Disable)