-- updater.lua
-- 2019 Aleksi Blinnikka
--
-- Main update function for all frames. Gets around issues with events.
local _, addon = ...;
local unpack = unpack;
local min = math.min;
local UnitDebuff, UnitIsCharmed = UnitDebuff, UnitIsCharmed;
local UnitHealth, UnitHealthMax = UnitHealth, UnitHealthMax;
local UnitIsAFK, UnitIsDND = UnitIsAFK, UnitIsDND;
local UnitGetIncomingHeals, UnitGetTotalAbsorbs = UnitGetIncomingHeals, UnitGetTotalAbsorbs;
local UnitIsDeadOrGhost, UnitIsConnected = UnitIsDeadOrGhost, UnitIsConnected;
local UnitGetTotalHealAbsorbs = UnitGetTotalHealAbsorbs;

local dispelcolor = addon.Colors.OverlayColorDispel;
local charmcolor = addon.Colors.OverlayColorCharm;
local majorcolor = addon.Colors.OverlayColorAlert;
local healcolor = addon.Colors.OverlayColorHeal;

local function updateAuras()
    -- TODO
    return false;
end

function addon.FrameUpdate(frame)
    assert(type(frame) == "table", "FrameUpdate received invalid frame parameter!");

    local unit = frame.displayed;
    local width = frame.barwidth;
    -- range check (doesn't have an event)
    local inrange, checked = UnitInRange(unit);
    if checked and not inrange then
        frame:SetAlpha(0.55);
    else
        frame:SetAlpha(1);
    end
    -- states
    if UnitIsDeadOrGhost(unit) then
        frame.text:SetText("Dead");
        if not frame.text:IsShown() then frame.text:Show() end
        if frame.health:IsShown() then frame.health:Hide() end
        if frame.shield:IsShown() then frame.shield:Hide() end
        if frame.shieldhl:IsShown() then frame.shieldhl:Hide() end
        if frame.healpred:IsShown() then frame.healpred:Hide() end
        if frame.healabsorb:IsShown() then frame.healabsorb:Hide() end
        --if frame.auras:IsShown() then frame.auras:Hide() end
        frame.prev.health = nil;
        frame.prev.hmax = nil;
    elseif not UnitIsConnected(unit) then
        frame.text:SetText("DC");
        if not frame.text:IsShown() then frame.text:Show() end
        if frame.health:IsShown() then frame.health:Hide() end
        if frame.shield:IsShown() then frame.shield:Hide() end
        if frame.shieldhl:IsShown() then frame.shieldhl:Hide() end
        if frame.healpred:IsShown() then frame.healpred:Hide() end
        if frame.healabsorb:IsShown() then frame.healabsorb:Hide() end
        --if frame.auras:IsShown() then frame.auras:Hide() end
        frame.prev.health = nil;
        frame.prev.hmax = nil;
    else
        if UnitIsAFK(unit) then
            frame.text:SetText("afk");
            if not frame.text:IsShown() then frame.text:Show() end
        elseif UnitIsDND(unit) then
            frame.text:SetText("dnd");
            if not frame.text:IsShown() then frame.text:Show() end
        else
            if frame.text:IsShown() then frame.text:Hide() end
        end
        -- health
        local current, hmax = UnitHealth(unit), UnitHealthMax(unit);
        if frame.prev.health ~= current or frame.prev.hmax ~= hmax then
            frame.prev.health = current;
            frame.prev.hmax = hmax;
            if hmax < current or hmax <= 1 then
                frame.health:SetWidth(width);
                frame.health.width = width;
                if not frame.health:IsShown() then frame.health:Show() end
            elseif current <= 0 then
                if frame.health:IsShown() then frame.health:Hide() end
            else
                local w = current/hmax*width;
                frame.health:SetWidth(w);
                frame.health.width = w;
                if not frame.health:IsShown() then frame.health:Show() end
            end
        end
        -- shield
        local hwidth = frame.health.width;
        current = UnitGetTotalAbsorbs(unit) or 0;
        if current > 0 then
            local space = width - hwidth;
            current = (current / hmax) * width;
            if space == 0 then
                if frame.shield:IsShown() then frame.shield:Hide() end
                if not frame.shieldhl:IsShown() then frame.shieldhl:Show() end
            elseif space < current then
                frame.shield:SetWidth(space);
                if not frame.shield:IsShown() then frame.shield:Show() end
                if not frame.shieldhl:IsShown() then frame.shieldhl:Show() end
            else
                frame.shield:SetWidth(current);
                if not frame.shield:IsShown() then frame.shield:Show() end
                if frame.shieldhl:IsShown() then frame.shieldhl:Hide() end
            end
        else
            if frame.shield:IsShown() then frame.shield:Hide() end
            if frame.shieldhl:IsShown() then frame.shieldhl:Hide() end
        end
        -- heal absorb
        current = UnitGetTotalHealAbsorbs(unit) or 0;
        if current > 0 then
            current = (current / hmax) * width;
            frame.healabsorb:SetWidth(min(hwidth, current));
            if not frame.healabsorb:IsShown() then frame.healabsorb:Show() end
        elseif frame.healabsorb:IsShown() then
            frame.healabsorb:Hide();
        end
        -- heal prediction
        current = UnitGetIncomingHeals(unit) or 0;
        if current > 0 then
            current = (current / hmax) * width;
            -- at least 1 pixel prediction shown
            frame.healpred:SetWidth(min(width - hwidth + 1, current));
            if not frame.healpred:IsShown() then frame.healpred:Show() end
        elseif frame.healpred:IsShown() then
            frame.healpred:Hide();
        end
        -- auras
        if next(frame.alert) then
            -- major
            if frame.overlay.color ~= majorcolor then
                frame.overlay:SetVertexColor(unpack(majorcolor));
                frame.overlay.color = majorcolor;
                if not frame.overlay:IsShown() then frame.overlay:Show() end
            end
        elseif next(frame.heal) then
            -- major heals needed
            if frame.overlay.color ~= healcolor then
                frame.overlay:SetVertexColor(unpack(healcolor));
                frame.overlay.color = healcolor;
                if not frame.overlay:IsShown() then frame.overlay:Show() end
            end
        elseif UnitIsCharmed(unit) and frame.unit == frame.displayed then
            -- charmed
            if frame.overlay.color ~= charmcolor then
                frame.overlay:SetVertexColor(unpack(charmcolor));
                frame.overlay.color = charmcolor;
                if not frame.overlay:IsShown() then frame.overlay:Show() end
            end
        elseif UnitDebuff(unit, 1, "RAID") ~= nil then
            -- dispellable
            if frame.overlay.color ~= dispelcolor then
                frame.overlay:SetVertexColor(unpack(dispelcolor));
                frame.overlay.color = dispelcolor;
                if not frame.overlay:IsShown() then frame.overlay:Show() end
            end
        else
            if frame.overlay.color ~= nil then
                frame.overlay.color = nil;
                if frame.overlay:IsShown() then frame.overlay:Hide() end
            end
        end
    end
end