local TEXTURE = 'Interface\\AddOns\\tCastBars\\Texture'
local FONT = 'Interface\\AddOns\\tCastBars\\Font.ttf'
local BACKDROP = {
    bgFile = TEXTURE,
    insets = {top = -0.8, bottom = -0.8, left = -0.8, right = -0.8}
}

local castbars = {
    player = true,
    target = true,
    focus = true,
    pet = true,
}

local CastingBarFinishSpell = function(self) --this is called at the end of casts or channels
    self.barTexture:SetColorTexture(0.1, 0.9, 0.1) --set it green to show completion (to be honest you don't see this color change)
    self.fadeOut = 1 --we want to fade the frame out now
    self.casting = nil --we're no longer casting
    self.channeling = nil --we're no longer channeling
end

local function unitSpellcastStart(frame, event, unit) --this function gets called whenever a UNIT_SPELLCAST_START event fires for player, focus, pet, or target
    local name, text, texture, startTime, endTime, _, _, notInterruptible, spellID = UnitCastingInfo(unit)
    if not name then
        frame:Hide()
        return
    end

    if frame.lag then
        frame.lag:Show()
    end

    frame.value = GetTime() - (startTime / 1000)
    frame.maxValue = (endTime - startTime) / 1000
    frame.bar:SetMinMaxValues(0, frame.maxValue)
    frame.bar:SetValue(frame.value)
    frame.bar.text:SetText(text)
    frame.icon:SetTexture(texture)
    frame:SetAlpha(1)
    frame.holdTime = 0 --this is like a time to fade after a cast finishes that is checked in our OnUpdate
    frame.casting = 1
    frame.spellID = spellID
    frame.channeling = nil --we're not channeling, we're casting
    frame.fadeOut = nil
    if notInterruptible then --red if protected, green if interruptible
        frame.barTexture:SetColorTexture(0.7, 0.1, 0.1)
    else
        frame.barTexture:SetColorTexture(0.1, 0.9, 0.1)
    end

    if frame.showCastbar then
        frame:Show()
    end
end

local function unitSpellcastStop(frame, event, unit, ...) --this function gets called whenever a UNIT_SPELLCAST_STOP or UNIT_SPELLCAST_CHANNELING_STOP fires for player, focus, pet, or target
    local _, _, spellID = ...
    if ((frame.casting and event == 'UNIT_SPELLCAST_STOP' and spellID == frame.spellID) or (frame.channeling and event == 'UNIT_SPELLCAST_CHANNEL_STOP')) then
        frame.bar:SetValue(frame.maxValue)
        if event == 'UNIT_SPELLCAST_STOP' then
            frame.casting = nil
            frame.barTexture:SetColorTexture(0.8, 0.8, 0) --yellow for a cast that was stopped by movement or escaping (NOT INTERRUPTED)
        else
            frame.channeling = nil
        end

        frame.fadeOut = 1
        frame.holdTime = 0
    end
end

local function unitSpellcastFailedInterrupted(frame, event, unit, ...) --this function gets called whenever a UNIT_SPELLCAST_FAILED or UNIT_SPELLCAST_INTERRUPTED fires for player, focus, pet or target
    local _, _, spellID = ...
    if (frame:IsShown() and frame.casting and spellID == frame.spellID and not frame.fadeOut) then
        frame.bar:SetValue(frame.maxValue)
        frame.barTexture:SetColorTexture(1, 0.4, 0) --orange for interrupted or failed
        if event == 'UNIT_SPELLCAST_FAILED' then
            frame.bar.text:SetText('FAILED')
        else
            frame.bar.text:SetText('INTERRUPTED')
        end

        if frame.lag then
            frame.lag:Hide()
        end

        frame.casting = nil
        frame.channeling = nil
        frame.fadeOut = 1
        frame.holdTime = GetTime()
    end
end

local function unitSpellcastDelayed(frame, event, unit) --this function gets called whenever a UNIT_SPELLCAST_DELAYED occurs for player, pet, target, or focus
    if frame:IsShown() then
        local name, _, _, startTime, endTime = UnitCastingInfo(unit)
        if not name then
            frame:Hide()
            return
        end

        frame.value = GetTime() - (startTime / 1000)
        frame.maxValue = (endTime - startTime) / 1000
        frame.bar:SetMinMaxValues(0, frame.maxValue)
        if not frame.casting then
            frame.casting = 1
            frame.channeling = nil
            frame.fadeOut = 0
        end
    end
end

local function unitSpellcastChannelStart(frame, event, unit) --this function gets called whenever a UNIT_SPELLCAST_CHANNEL_START fires for player, target, focus, or pet
    local name, text, texture, startTime, endTime, _, notInterruptible = UnitChannelInfo(unit)
    if not name then
        frame:Hide()
        return
    end

    if frame.lag then
        frame.lag:Hide()
    end

    frame.value = (endTime / 1000) - GetTime()
    frame.maxValue = (endTime - startTime) / 1000
    frame.bar:SetMinMaxValues(0, frame.maxValue)
    if notInterruptible then --red  if protected, green for interruptible
        frame.barTexture:SetColorTexture(0.7, 0.1, 0.1)
    else
        frame.barTexture:SetColorTexture(0.1, 0.9, 0.1)
    end

    frame.bar:SetValue(frame.value)
    frame.bar.text:SetText(text)
    frame.icon:SetTexture(texture)
    frame:SetAlpha(1)
    frame.holdTime = 0
    frame.casting = nil
    frame.channeling = 1
    frame.fadeOut = nil
    if frame.showCastbar then
        frame:Show()
    end
end

local function unitSpellcastChannelUpdate(frame, event, unit) --this function gets called whenever a UNIT_SPELLCAST_CHANNEL_UPDATE fires for player, target, focus, or pet
    if frame:IsShown() then
        local name, text, texture, startTime, endTime, _, notInterruptible = UnitChannelInfo(unit)
        if not name then
            frame:Hide()
            return
        end

        frame.value = (endTime / 1000) - GetTime()
        frame.maxValue = (endTime - startTime) / 1000
        frame.bar:SetMinMaxValues(0, frame.maxValue)
        frame.bar:SetValue(frame.value)
    end
end

local MakeCastBarFunctions = function(frame, event) --this function gets called during our MakeCastBars function, during which, it will create functions for the individual units (player, target, focus, pet)
    function frame:UNIT_SPELLCAST_START(event, unit)
        unitSpellcastStart(frame, event, unit)
    end

    function frame:UNIT_SPELLCAST_STOP(event, unit)
        unitSpellcastStop(frame, event, unit)
    end

    function frame:UNIT_SPELLCAST_CHANNEL_STOP(event, unit, ...)
        unitSpellcastStop(frame, event, unit, ...)
    end

    function frame:UNIT_SPELLCAST_FAILED(event, unit, ...)
        unitSpellcastFailedInterrupted(frame, event, unit, ...)
    end

    function frame:UNIT_SPELLCAST_INTERRUPTED(event, unit, ...)
        unitSpellcastFailedInterrupted(frame, event, unit, ...)
    end

    function frame:UNIT_SPELLCAST_DELAYED(event, unit)
        unitSpellcastDelayed(frame, event, unit)
    end

    function frame:UNIT_SPELLCAST_CHANNEL_START(event, unit)
        unitSpellcastChannelStart(frame, event, unit)
    end

    function frame:UNIT_SPELLCAST_CHANNEL_UPDATE(event, unit)
        unitSpellcastChannelUpdate(frame, event, unit)
    end

    function frame:UNIT_SPELLCAST_INTERRUPTIBLE()
        frame.barTexture:SetColorTexture(0.1, 0.9, 0.1)
    end

    function frame:UNIT_SPELLCAST_NOT_INTERRUPTIBLE()
        frame.barTexture:SetColorTexture(0.7, 0.1, 0.1)
    end
end

local MakeCastBar = function(unit, enable) --this function will make castbars, place them, register their events, and make their functions for player, target, focus, and pet units
    local frame = _G[unit..'tCastBar'] or CreateFrame('frame', unit..'tCastBar', UIParent)
    frame:SetSize(228, 22)
    frame:SetBackdrop(BACKDROP)
    frame:SetBackdropColor(0, 0, 0)
    frame:SetPoint('CENTER', UIParent, 'CENTER')

    if not frame.bar then
        frame.bar = CreateFrame('StatusBar', nil, frame)
        frame.bar:SetAllPoints()
        frame.bar:SetMinMaxValues(0, 1)
        frame.bar:SetValue(0)

        frame.barTexture = frame:CreateTexture(nil, 'BORDER')
        frame.barTexture:SetTexture(TEXTURE)

        frame.bar:SetStatusBarTexture(frame.barTexture)

        frame.bar.bg = frame.bar:CreateTexture(nil, 'BACKGROUND')
        frame.bar.bg:SetTexture(TEXTURE)
        frame.bar.bg:SetColorTexture(0.2, 0.2, 0.2)
        frame.bar.bg:SetAllPoints()

        frame.bar.text = frame.bar:CreateFontString(nil, 'OVERLAY')
        frame.bar.text:SetFont(FONT, 12, 'OUTLINE')
        frame.bar.text:SetJustifyH('CENTER')
        frame.bar.text:SetJustifyV('MIDDLE')
        frame.bar.text:SetPoint('CENTER')

        frame.bar.timer = frame.bar:CreateFontString(nil, 'OVERLAY')
        frame.bar.timer:SetFont(FONT, 12, 'OUTLINE')
        frame.bar.timer:SetJustifyH('RIGHT')
        frame.bar.timer:SetJustifyV('MIDDLE')
        frame.bar.timer:SetPoint('RIGHT', frame, 'RIGHT', -3, 0)

        frame.icon = frame:CreateTexture(nil, 'ARTWORK')
        frame.icon:SetSize(22, 22)
        frame.icon:SetPoint('TOPRIGHT', frame, 'TOPLEFT', -1, 1)
        frame.icon:SetPoint('BOTTOMRIGHT', frame, 'BOTTOMLEFT', -1, -1)
        frame.icon:SetTexCoord(.06, .94, .06, .94)
    end

    if unit == 'player' then
        frame.lag = _G[frame:GetName()..'Lag'] or frame.bar:CreateTexture(frame:GetName()..'Lag', 'BORDER')
        frame.lag:SetPoint('TOPRIGHT') --this anchors the lag frame to the right of the cast bar (since we cast from left to right)
        frame.lag:SetPoint('BOTTOMRIGHT')
        frame.lag:SetTexture(TEXTURE)
        frame.lag:SetColorTexture(1, 0.4, 0)
        frame:SetPoint('CENTER', UIParent, 'CENTER', 11, -238)
    elseif unit == 'pet' then
        frame:SetPoint('CENTER', UIParent, 'CENTER', 11, -375)
    elseif unit == 'target' then
        frame:SetPoint('CENTER', UIParent, 'CENTER', 11, 100)
    elseif unit == 'focus' then
        frame:SetPoint('CENTER', UIParent, 'CENTER', 11, -150)
    end

    frame.timerUpdate = 0.1 --this controls how many times per second our OnUpdate fires (1/frame.timerUpdate) = # of times updated in a second, lower = more = smoother appearance = more CPU usage

    frame:RegisterEvent('PLAYER_TARGET_CHANGED')
    frame:RegisterEvent('PLAYER_FOCUS_CHANGED')
    frame:RegisterUnitEvent('UNIT_SPELLCAST_START', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_STOP', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_FAILED', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_INTERRUPTED', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_DELAYED', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_CHANNEL_START', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_CHANNEL_UPDATE', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_CHANNEL_STOP', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_INTERRUPTIBLE', unit)
    frame:RegisterUnitEvent('UNIT_SPELLCAST_NOT_INTERRUPTIBLE', unit)
    frame:RegisterEvent('PLAYER_ENTERING_WORLD')

    frame.unit = unit
    frame.casting = nil
    frame.channeling = nil
    frame.holdTime = 0
    frame.showCastbar = castbars[unit]
    frame.locked = true
    frame:Hide()

    frame:SetScript('OnShow', function(self)
        if not self.locked then return end

        if self.casting then
            local _, _, _, startTime = UnitCastingInfo(self.unit)
            if startTime then
                self.value = GetTime() - (startTime / 1000)
            end
        else
            local _, _, _, _, endTime = UnitChannelInfo(self.unit)
            if endTime then
                self.value = (endTime / 1000) - GetTime()
            end
        end
    end)

    MakeCastBarFunctions(frame, event) --make our functions for the frame

    frame:SetScript('OnEvent', function(self, event, ...)
        if not self.locked then return end

        local arg1 = ...
        local unit = self.unit
        if (event == 'PLAYER_ENTERING_WORLD' or event == 'PLAYER_TARGET_CHANGED' or event == 'PLAYER_FOCUS_CHANGED') then
            local spellChannel = UnitChannelInfo(unit)
            local spellName = UnitCastingInfo(unit)
            if spellChannel then
                event = 'UNIT_SPELLCAST_CHANNEL_START'
                arg1 = unit
            elseif spellName then
                event = 'UNIT_SPELLCAST_START'
                arg1 = unit
            else
                CastingBarFinishSpell(self)
            end
        end

        if arg1 ~= unit then return end
        if self[event] then --handle the event for our frame
            self[event](frame, event, unit, ...)
        end
    end)

    frame:SetScript('OnUpdate', function(self, elapsed)
        if not self.bar.timer then return end

        if (self.timerUpdate and self.timerUpdate < elapsed) then
            if self.casting then
                self.bar.timer:SetText(format('%.1f', max(self.maxValue - self.value, 0)))
            elseif self.channeling then
                self.bar.timer:SetText(format('%.1f', max(self.value, 0)))
            else
                self.bar.timer:SetText('')
            end

            self.timerUpdate = 0.1
        else
            self.timerUpdate = self.timerUpdate - elapsed
        end

        if self.casting then
            self.value = self.value + elapsed
            if self.value >= self.maxValue then
                self.bar:SetValue(self.maxValue)
                CastingBarFinishSpell(self)
                return
            end

            self.bar:SetValue(self.value)
            if self.unit == 'player' then
                local down, up, lag = GetNetStats()
                local castingmin, castingmax = self.bar:GetMinMaxValues()
                local lagvalue = (lag / 1000) / (castingmax - castingmin)
                if lagvalue < 0 then
                    lagvalue = 0
                elseif lagvalue > 1 then
                    lagvalue = 1
                end

                self.lag:ClearAllPoints()
                self.lag:SetPoint('RIGHT')
                self.lag:SetHeight(self.bar:GetHeight())
                self.lag:SetWidth(self.bar:GetWidth() * lagvalue)
            end
        elseif self.channeling then
            self.value = self.value - elapsed
            if self.value <= 0 then
                CastingBarFinishSpell(self)
                return
            end

            self.bar:SetValue(self.value)
        elseif GetTime() < self.holdTime then
            return
        elseif self.fadeOut then
            self.fadeOut = nil
            self:Hide()
        end
    end)
end

local tCastBars = _G['tCastBars'] or CreateFrame('frame', 'tCastBars', UIParent)
tCastBars:RegisterEvent('PLAYER_TALENT_UPDATE')
tCastBars:RegisterEvent('PLAYER_ENTERING_WORLD')
tCastBars:RegisterEvent('ADDON_LOADED')
tCastBars:SetScript('OnEvent', function(self, event, arg1, ...)
    if (event == 'PLAYER_ENTERING_WORLD' or event == 'PLAYER_TALENT_UPDATE') then
        CastingBarFrame.showCastbar = false
        CastingBarFrame:UnregisterAllEvents()
        CastingBarFrame:SetScript('OnUpdate', function() end)

        TargetFrameSpellBar.showCastbar = false
        TargetFrameSpellBar:UnregisterAllEvents()
        TargetFrameSpellBar:SetScript('OnUpdate', function() end)

        FocusFrameSpellBar.showCastbar = false
        FocusFrameSpellBar:UnregisterAllEvents()
        FocusFrameSpellBar:SetScript('OnUpdate', function() end)

        PetCastingBarFrame.showCastbar = false
        PetCastingBarFrame:UnregisterAllEvents()
        PetCastingBarFrame:SetScript('OnUpdate', function() end)

        for unit, enable in pairs(castbars) do
            if enable then
                MakeCastBar(unit, enable)
            end
        end
    end
end)