-- A cooldown text display
local _, Addon = ...

-- the expected size of an icon
local ICON_SIZE = 36
local DEFAULT_STATE = 'seconds'

function Round(value)
	if value < 0 then
		return ceil(value - .5);
	end
	return floor(value + .5);
end

---@type { [Region]: OmniCCDisplay }
local displays = {}

---@class OmniCCDisplay
local Display = Addon:CreateHiddenFrame('Frame')

Display.__index = Display

---@param owner Frame
---@return OmniCCDisplay
function Display:Get(owner)
    return displays[owner]
end

---@param owner Frame?
---@return OmniCCDisplay?
function Display:GetOrCreate(owner)
    if not owner then
        return
    end

    return displays[owner] or self:Create(owner)
end

function Display:Create(owner)
    local display = setmetatable(Addon:CreateHiddenFrame('Frame', nil, owner), Display)

    display.text = display:CreateFontString(nil, 'OVERLAY')
    display.cooldowns = {}

    display.updateSize = function()
        local oldSize = display.sizeRatio
        local newSize = display:CalculateSizeRatio()

        local oldScale = display.scaleRatio
        local newScale = display:CalculateScaleRatio()

        if not (oldSize == newSize and oldScale == newScale) then
            display:UpdateCooldownTextPositionSizeAndColor()
        end

        display.updatingSize = nil
    end

    display:UpdateSize()
    display:SetScript('OnSizeChanged', self.UpdateSize)

    displays[owner] = display
    return display
end

-- defer updating size until the next frame
-- this is to work around SUF scaling auras after setting timers
function Display:UpdateSize()
    if self.updatingSize then
        return
    end

    self.updatingSize = true
    Addon.Updater:RunNextFrame(self.updateSize)
end

---@param timer OmniCCTimer
---@param text string
function Display:OnTimerTextUpdated(timer, text)
    if timer ~= self.timer then
        return
    end

    self.text:SetText(text or '')
end

---@param timer OmniCCTimer
---@param state OmniCCTimerState?
function Display:OnTimerStateUpdated(timer, state)
    if timer ~= self.timer then
        return
    end

    state = state or DEFAULT_STATE

    if (self.state ~= state) then
        self.state = state
        -- when the period style changes, recompute font size (scaling via font)
        self:UpdateCooldownTextFont()
        self:UpdateCooldownTextPositionSizeAndColor()
    end
end

---@param timer OmniCCTimer
function Display:OnTimerDestroyed(timer)
    if self.timer == timer then
        if timer.finished and self.activeCooldown then
            Addon.Cooldown.TryShowFinishEffect(self.activeCooldown)
        end

        self:RemoveCooldown(self.activeCooldown)
    end
end

function Display:CalculateSizeRatio()
    local sizeRatio
    local sets = self:GetSettings()

    if sets and sets.scaleText then
        sizeRatio = Round(min(self:GetSize())) / ICON_SIZE
    else
        sizeRatio = 1
    end

    self.sizeRatio = sizeRatio

    return sizeRatio
end

function Display:CalculateScaleRatio()
    local scaleRatio = self:GetEffectiveScale() / UIParent:GetEffectiveScale()

    self.scaleRatio = scaleRatio

    return scaleRatio
end

function Display:AddCooldown(cooldown)
    self.cooldowns[cooldown] = true
    self:UpdateActiveCooldown()
end

function Display:RemoveCooldown(cooldown)
    local cooldowns = self.cooldowns

    if cooldowns[cooldown] then
        cooldowns[cooldown] = nil
        self:UpdateActiveCooldown()
    end
end

function Display:UpdateActiveCooldown()
    local cooldown = self:GetCooldownWithHighestPriority()

    if self.activeCooldown ~= cooldown then
        self.activeCooldown = cooldown

        -- reposition the display to be above the cooldown
        if cooldown then
            -- anchor at CENTER and mirror size instead of SetAllPoints (3.3.5a-safe)
            self:ClearAllPoints()
            self:SetPoint('CENTER', cooldown)
            self:SetFrameLevel(cooldown:GetFrameLevel() + 5)
            self:SetSize(cooldown:GetSize())

            -- hook to keep size in sync when the cooldown resizes
            if not self._occ_hookedSize then
                cooldown:HookScript('OnSizeChanged', function(cd, w, h)
                    if self and self.SetSize then
                        self:SetSize(w, h)
                        if self.UpdateSize then
                            self:UpdateSize()
                        end
                    end
                end)
                self._occ_hookedSize = true
            end

            self:UpdateCooldownTextFont()
            self:UpdateCooldownTextPositionSizeAndColor()
        end
    end

    -- always try to update the timer here
    -- as the active cooldown's duration may have changed
    self:UpdateTimer()
end

function Display:UpdateTimer()
    local oldTimer = self.timer and self.timer
    local oldTimerKey = oldTimer and oldTimer.key

    ---@type OmniCCTimer?
    local newTimer = self.activeCooldown and Addon.Timer:GetOrCreate(self.activeCooldown)
    local newTimerKey = newTimer and newTimer.key

    -- update subscription if we're watching a different timer
    if oldTimer ~= newTimer then
        self.timer = newTimer

        if oldTimer then
            oldTimer:Unsubscribe(self)
        end
    end

    -- only show display if we have a timer to watch
    if newTimer then
        newTimer:Subscribe(self)

        -- only update text if the timer we're watching has changed
        if newTimerKey ~= oldTimerKey then
            self:OnTimerTextUpdated(newTimer, newTimer.text)
            self:OnTimerStateUpdated(newTimer, newTimer.state)
            self:Show()
        end

        self:UpdateSize()
    else
        self:Hide()
    end
end

do
    -- given two cooldown cooldowns, returns the more important one
    ---@param lhs OmniCCCooldown
    ---@param rhs OmniCCCooldown?
    ---@return OmniCCCooldown?
    local function cooldown_Compare(lhs, rhs)
        if lhs == rhs then
            return lhs
        end

        -- prefer the one that isn't nil
        if rhs == nil then
            return lhs
        end

        if lhs == nil then
            return rhs
        end

        -- prefer cooldownProxies ending first
        local lEnd = lhs._occ_start + lhs._occ_duration
        local rEnd = rhs._occ_start + rhs._occ_duration

        if lEnd < rEnd then
            return lhs
        end

        if lEnd > rEnd then
            return rhs
        end

        -- then check priority
        if lhs._occ_priority < rhs._occ_priority then
            return lhs
        end

        return rhs
    end

    function Display:GetCooldownWithHighestPriority()
        local result

        for cooldown in pairs(self.cooldowns) do
            result = cooldown_Compare(cooldown, result)
        end

        return result
    end
end

function Display:UpdateCooldownText()
    self:UpdateCooldownTextFont()
    self:UpdateCooldownTextPositionSizeAndColor()
end

function Display:UpdateCooldownTextFont()
    local sets = self:GetSettings()
    local text = self.text

    if not sets then
        text:SetFont(STANDARD_TEXT_FONT, 8, 'OUTLINE')
        self._occ_effFontSize = 8
        return
    end

    local sizeRatio = self.sizeRatio or self:CalculateSizeRatio()
    local style = sets.textStyles[self.state or DEFAULT_STATE]
    local periodScale = (style and style.scale) or 1

    local effSize = Round((sets.fontSize or 12) * sizeRatio * periodScale)
    if effSize < 1 then effSize = 1 end

    if not text:SetFont(sets.fontFace, effSize, sets.fontOutline) then
        text:SetFont(STANDARD_TEXT_FONT, effSize, sets.fontOutline)
    end

    local shadow = sets.fontShadow
    text:SetShadowColor(shadow.r, shadow.g, shadow.b, shadow.a)
    text:SetShadowOffset(shadow.x, shadow.y)

    self._occ_effFontSize = effSize
end

-- props:{size, scale, state, anchor, xOff, yOff}
function Display:UpdateCooldownTextPositionSizeAndColor()
    local sets = self:GetSettings()
    if not sets then
        return
    end

    local text = self.text
    local sizeRatio = self.sizeRatio or self:CalculateSizeRatio()
    local scaleRatio = self.scaleRatio or self:CalculateScaleRatio()

    local style = sets.textStyles[self.state or DEFAULT_STATE]
    local styleRatio = style and style.scale or 1

    local effFont = self._occ_effFontSize or Round((sets.fontSize or 12) * sizeRatio * styleRatio)
    local effPixels = scaleRatio * effFont
    local minPixels = sets.minSize or 0

    -- hide text if the scale ratio is zero or below
    if effPixels <= minPixels or styleRatio <= 0 then
        text:Hide()
        return
    end

    text:Show()

    text:SetTextColor(style.r, style.g, style.b, style.a)

    text:ClearAllPoints()
    local textScale = sizeRatio * styleRatio
    text:SetPoint(sets.anchor, sets.xOff / textScale, sets.yOff / textScale)
end

function Display:GetSettings()
    return self.activeCooldown and self.activeCooldown._occ_settings
end

---@param method string
function Display:ForAll(method, ...)
    for _, display in pairs(displays) do
        local func = display[method]
        if type(func) == 'function' then
            func(display, ...)
        end
    end
end

---@param method string
function Display:ForActive(method, ...)
    for _, display in pairs(displays) do
        if display.timer ~= nil then
            local func = display[method]
            if type(func) == 'function' then
                func(display, ...)
            end
        end
    end
end

-- exports
Addon.Display = Display