--[[
Copyright (c) 2015-2020, Hendrik "nevcairiel" Leppkes <h.leppkes@gmail.com>

All rights reserved.

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, 
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, 
      this list of conditions and the following disclaimer in the documentation 
      and/or other materials provided with the distribution.
    * Neither the name of the developer nor the names of its contributors 
      may be used to endorse or promote products derived from this software without 
      specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
]]
local MAJOR_VERSION = "LibButtonGlow-1.0"
local MINOR_VERSION = 8

if not LibStub then error(MAJOR_VERSION .. " requires LibStub.") end
local lib, oldversion = LibStub:NewLibrary(MAJOR_VERSION, MINOR_VERSION)
if not lib then return end

local Masque = LibStub("Masque", true)

lib.unusedOverlays = lib.unusedOverlays or {}
lib.numOverlays = lib.numOverlays or 0

local tinsert, tremove, tostring = table.insert, table.remove, tostring

local function OverlayGlowAnimOutFinished(animGroup)
    local overlay = animGroup:GetParent()
    local frame = overlay:GetParent()
    overlay:Hide()
    tinsert(lib.unusedOverlays, overlay)
    frame.__LBGoverlay = nil
end

local function OverlayGlow_OnHide(self)
    if self.animOut:IsPlaying() then
        self.animOut:Stop()
        OverlayGlowAnimOutFinished(self.animOut)
    end
end

local function OverlayGlow_OnUpdate(self, elapsed)
    AnimateTexCoords(self.ants, 256, 256, 48, 48, 22, elapsed, 0.01)
    local cooldown = self:GetParent().cooldown
    -- we need some threshold to avoid dimming the glow during the gdc
    -- (using 1500 exactly seems risky, what if casting speed is slowed or something?)
    if cooldown and cooldown:IsShown() and cooldown:GetCooldownDuration() > 3000 then
        self:SetAlpha(0.5)
    else
        self:SetAlpha(1.0)
    end
end

local function CreateScaleAnim(group, target, order, duration, x, y, delay)
    local scale = group:CreateAnimation("Scale")
    scale:SetTarget(target)
    scale:SetOrder(order)
    scale:SetDuration(duration)
    scale:SetScale(x, y)

    if delay then
        scale:SetStartDelay(delay)
    end
end

local function CreateAlphaAnim(group, target, order, duration, fromAlpha, toAlpha, delay)
    local alpha = group:CreateAnimation("Alpha")
    alpha:SetTarget(target)
    alpha:SetOrder(order)
    alpha:SetDuration(duration)
    alpha:SetFromAlpha(fromAlpha)
    alpha:SetToAlpha(toAlpha)

    if delay then
        alpha:SetStartDelay(delay)
    end
end

local function AnimIn_OnPlay(group)
    local frame = group:GetParent()
    local frameWidth, frameHeight = frame:GetSize()
    frame.spark:SetSize(frameWidth, frameHeight)
    frame.spark:SetAlpha(0.3)
    frame.innerGlow:SetSize(frameWidth / 2, frameHeight / 2)
    frame.innerGlow:SetAlpha(1.0)
    frame.innerGlowOver:SetAlpha(1.0)
    frame.outerGlow:SetSize(frameWidth * 2, frameHeight * 2)
    frame.outerGlow:SetAlpha(1.0)
    frame.outerGlowOver:SetAlpha(1.0)
    frame.ants:SetSize(frameWidth * 0.85, frameHeight * 0.85)
    frame.ants:SetAlpha(0)
    frame:Show()
end

local function AnimIn_OnFinished(group)
    local frame = group:GetParent()
    local frameWidth, frameHeight = frame:GetSize()
    frame.spark:SetAlpha(0)
    frame.innerGlow:SetAlpha(0)
    frame.innerGlow:SetSize(frameWidth, frameHeight)
    frame.innerGlowOver:SetAlpha(0.0)
    frame.outerGlow:SetSize(frameWidth, frameHeight)
    frame.outerGlowOver:SetAlpha(0.0)
    frame.outerGlowOver:SetSize(frameWidth, frameHeight)
    frame.ants:SetAlpha(1.0)
end

local function CreateOverlayGlow()
    lib.numOverlays = lib.numOverlays + 1

    -- create frame and textures
    local name = "ButtonGlowOverlay" .. tostring(lib.numOverlays)
    local overlay = CreateFrame("Frame", name, UIParent)

    -- spark
    overlay.spark = overlay:CreateTexture(name .. "Spark", "BACKGROUND")
    overlay.spark:SetPoint("CENTER")
    overlay.spark:SetAlpha(0)
    overlay.spark:SetTexture([[Interface\SpellActivationOverlay\IconAlert]])
    overlay.spark:SetTexCoord(0.00781250, 0.61718750, 0.00390625, 0.26953125)

    -- inner glow
    overlay.innerGlow = overlay:CreateTexture(name .. "InnerGlow", "ARTWORK")
    overlay.innerGlow:SetPoint("CENTER")
    overlay.innerGlow:SetAlpha(0)
    overlay.innerGlow:SetTexture([[Interface\SpellActivationOverlay\IconAlert]])
    overlay.innerGlow:SetTexCoord(0.00781250, 0.50781250, 0.27734375, 0.52734375)

    -- inner glow over
    overlay.innerGlowOver = overlay:CreateTexture(name .. "InnerGlowOver", "ARTWORK")
    overlay.innerGlowOver:SetPoint("TOPLEFT", overlay.innerGlow, "TOPLEFT")
    overlay.innerGlowOver:SetPoint("BOTTOMRIGHT", overlay.innerGlow, "BOTTOMRIGHT")
    overlay.innerGlowOver:SetAlpha(0)
    overlay.innerGlowOver:SetTexture([[Interface\SpellActivationOverlay\IconAlert]])
    overlay.innerGlowOver:SetTexCoord(0.00781250, 0.50781250, 0.53515625, 0.78515625)

    -- outer glow
    overlay.outerGlow = overlay:CreateTexture(name .. "OuterGlow", "ARTWORK")
    overlay.outerGlow:SetPoint("CENTER")
    overlay.outerGlow:SetAlpha(0)
    overlay.outerGlow:SetTexture([[Interface\SpellActivationOverlay\IconAlert]])
    overlay.outerGlow:SetTexCoord(0.00781250, 0.50781250, 0.27734375, 0.52734375)

    -- outer glow over
    overlay.outerGlowOver = overlay:CreateTexture(name .. "OuterGlowOver", "ARTWORK")
    overlay.outerGlowOver:SetPoint("TOPLEFT", overlay.outerGlow, "TOPLEFT")
    overlay.outerGlowOver:SetPoint("BOTTOMRIGHT", overlay.outerGlow, "BOTTOMRIGHT")
    overlay.outerGlowOver:SetAlpha(0)
    overlay.outerGlowOver:SetTexture([[Interface\SpellActivationOverlay\IconAlert]])
    overlay.outerGlowOver:SetTexCoord(0.00781250, 0.50781250, 0.53515625, 0.78515625)

    -- ants
    overlay.ants = overlay:CreateTexture(name .. "Ants", "OVERLAY")
    overlay.ants:SetPoint("CENTER")
    overlay.ants:SetAlpha(0)
    overlay.ants:SetTexture([[Interface\SpellActivationOverlay\IconAlertAnts]])

    -- setup antimations
    overlay.animIn = overlay:CreateAnimationGroup()
    CreateScaleAnim(overlay.animIn, overlay.spark,          1, 0.2, 1.5, 1.5)
    CreateAlphaAnim(overlay.animIn, overlay.spark,          1, 0.2, 0, 1)
    CreateScaleAnim(overlay.animIn, overlay.innerGlow,      1, 0.3, 2, 2)
    CreateScaleAnim(overlay.animIn, overlay.innerGlowOver,  1, 0.3, 2, 2)
    CreateAlphaAnim(overlay.animIn, overlay.innerGlowOver,  1, 0.3, 1, 0)
    CreateScaleAnim(overlay.animIn, overlay.outerGlow,      1, 0.3, 0.5, 0.5)
    CreateScaleAnim(overlay.animIn, overlay.outerGlowOver,  1, 0.3, 0.5, 0.5)
    CreateAlphaAnim(overlay.animIn, overlay.outerGlowOver,  1, 0.3, 1, 0)
    CreateScaleAnim(overlay.animIn, overlay.spark,          1, 0.2, 2/3, 2/3, 0.2)
    CreateAlphaAnim(overlay.animIn, overlay.spark,          1, 0.2, 1, 0, 0.2)
    CreateAlphaAnim(overlay.animIn, overlay.innerGlow,      1, 0.2, 1, 0, 0.3)
    CreateAlphaAnim(overlay.animIn, overlay.ants,           1, 0.2, 0, 1, 0.3)
    overlay.animIn:SetScript("OnPlay", AnimIn_OnPlay)
    overlay.animIn:SetScript("OnFinished", AnimIn_OnFinished)

    overlay.animOut = overlay:CreateAnimationGroup()
    CreateAlphaAnim(overlay.animOut, overlay.outerGlowOver, 1, 0.2, 0, 1)
    CreateAlphaAnim(overlay.animOut, overlay.ants,          1, 0.2, 1, 0)
    CreateAlphaAnim(overlay.animOut, overlay.outerGlowOver, 2, 0.2, 1, 0)
    CreateAlphaAnim(overlay.animOut, overlay.outerGlow,     2, 0.2, 1, 0)
    overlay.animOut:SetScript("OnFinished", OverlayGlowAnimOutFinished)

    -- scripts
    overlay:SetScript("OnUpdate", OverlayGlow_OnUpdate)
    overlay:SetScript("OnHide", OverlayGlow_OnHide)

    overlay.__LBGVersion = MINOR_VERSION

    return overlay
end

local function GetOverlayGlow()
    local overlay = tremove(lib.unusedOverlays)
    if not overlay then
        overlay = CreateOverlayGlow()
    end
    return overlay
end

function lib.ShowOverlayGlow(frame)
    if frame.__LBGoverlay then
        if frame.__LBGoverlay.animOut:IsPlaying() then
            frame.__LBGoverlay.animOut:Stop()
            frame.__LBGoverlay.animIn:Play()
        end
    else
        local overlay = GetOverlayGlow()
        local frameWidth, frameHeight = frame:GetSize()
        overlay:SetParent(frame)
        overlay:SetFrameLevel(frame:GetFrameLevel() + 5)
        overlay:ClearAllPoints()
        --Make the height/width available before the next frame:
        overlay:SetSize(frameWidth * 1.2, frameHeight * 1.2)
        overlay:SetPoint("TOPLEFT", frame, "TOPLEFT", -frameWidth * 0.2, frameHeight * 0.2)
        overlay:SetPoint("BOTTOMRIGHT", frame, "BOTTOMRIGHT", frameWidth * 0.2, -frameHeight * 0.2)
        overlay.animIn:Play()
        frame.__LBGoverlay = overlay

        if Masque and Masque.UpdateSpellAlert and (not frame.overlay or not issecurevariable(frame, "overlay")) then
            local old_overlay = frame.overlay
            frame.overlay = overlay
            Masque:UpdateSpellAlert(frame)

            frame.overlay = old_overlay
        end
    end
end

function lib.HideOverlayGlow(frame)
    if frame.__LBGoverlay then
        if frame.__LBGoverlay.animIn:IsPlaying() then
            frame.__LBGoverlay.animIn:Stop()
        end
        if frame:IsVisible() then
            frame.__LBGoverlay.animOut:Play()
        else
            OverlayGlowAnimOutFinished(frame.__LBGoverlay.animOut)
        end
    end
end
