-- Events.lua
local _;
local unpack = unpack;
local ssub = string.sub;
local min = math.min;
local ceil = math.ceil;
local UnitName, UnitClass, UnitExists = UnitName, UnitClass, UnitExists;
local UnitPower, UnitPowerMax, UnitPowerType = UnitPower, UnitPowerMax, UnitPowerType;
local UnitHealth, UnitHealthMax = UnitHealth, UnitHealthMax;
local UnitGetIncomingHeals, UnitGetTotalAbsorbs = UnitGetIncomingHeals, UnitGetTotalAbsorbs;
local UnitThreatSituation, GetThreatStatusColor = UnitThreatSituation, GetThreatStatusColor;
local UnitIsDeadOrGhost, UnitIsConnected = UnitIsDeadOrGhost, UnitIsConnected;
local UnitGetTotalHealAbsorbs = UnitGetTotalHealAbsorbs;
local UnitHasVehicleUI, UnitTargetsVehicleInRaidUI = UnitHasVehicleUI, UnitTargetsVehicleInRaidUI;
local UnitLevel, UnitClassification = UnitLevel, UnitClassification;
local UnitAffectingCombat, IsResting = UnitAffectingCombat, IsResting;
local UnitIsPVPFreeForAll, UnitIsPVP = UnitIsPVPFreeForAll, UnitIsPVP;
local UnitFactionGroup, UnitIsMercenary = UnitFactionGroup, UnitIsMercenary;
local UnitIsGroupLeader, UnitIsGroupAssistant = UnitIsGroupLeader, UnitIsGroupAssistant;
local HasLFGRestrictions = HasLFGRestrictions;
local UnitPlayerControlled, UnitIsPlayer = UnitPlayerControlled, UnitIsPlayer;
local UnitIsTapDenied, UnitSelectionColor = UnitIsTapDenied, UnitSelectionColor;
local GetRaidTargetIndex, SetRaidTargetIconTexture = GetRaidTargetIndex, SetRaidTargetIconTexture;
local RAID_CLASS_COLORS = RAID_CLASS_COLORS;

local updateAuraFrames = OmaUFAuras.UpdateAuras;

local Settings = OmaUFSettings;
local baseColor = Settings.BaseColor;
local healthColor = Settings.HealthColor;
local powerColors = Settings.PowerColors;

local M = {};
OmaUFEvents = M;
function M.RegisterUnitEvents(frame)
    -- events are taken from FrameXML/CompactUnitFrame.lua and FrameXML/TargetFrame.lua
    -- TODO player flags support (/afk, /dnd)
    frame:RegisterEvent("RAID_TARGET_UPDATE"); -- have to register all and just check
    local displayed = frame.unit ~= frame.displayed and frame.displayed or nil;
    frame:RegisterUnitEvent("UNIT_HEALTH", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_HEALTH_FREQUENT", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_MAXHEALTH", frame.unit, displayed);
    if frame.mana then
        frame:RegisterUnitEvent("UNIT_POWER", frame.unit, displayed);
        frame:RegisterUnitEvent("UNIT_MAXPOWER", frame.unit, displayed);
        frame:RegisterUnitEvent("UNIT_DISPLAYPOWER", frame.unit, displayed);
        frame:RegisterUnitEvent("UNIT_POWER_BAR_SHOW", frame.unit, displayed);
        frame:RegisterUnitEvent("UNIT_POWER_BAR_HIDE", frame.unit, displayed);
    end
    if frame.shield then
        frame:RegisterUnitEvent("UNIT_ABSORB_AMOUNT_CHANGED", frame.unit, displayed);
    end
    if frame.healabsorb then
        frame:RegisterUnitEvent("UNIT_HEAL_ABSORB_AMOUNT_CHANGED", frame.unit, displayed);
    end
    if frame.auras then
        frame:RegisterUnitEvent("UNIT_AURA", frame.unit, displayed);
    end
    frame:RegisterUnitEvent("UNIT_NAME_UPDATE", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_THREAT_SITUATION_UPDATE", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_CONNECTION", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_FACTION", frame.unit, displayed);
end
local registerUnitEvents = M.RegisterUnitEvents;

local function updateMaxHealth(frame, unit)
    frame.health.max = UnitHealthMax(unit);
end

local function updateHealth(frame, unit)
    local current, max = UnitHealth(unit), frame.health.max;
    if current > max or max <= 0 then
        -- somehow current health has gone over the maximum (missed maxhealth event)
        frame.health:SetWidth(frame.width);
        updateMaxHealth(frame, unit);
        frame.health:Show();
    elseif current <= 0 or UnitIsDeadOrGhost(unit) then
        frame.health:Hide();
    else
        frame.health:SetWidth(current/max*frame.width);
        frame.health:Show();
    end
end

local function updateHealthText(frame, unit)
    if UnitIsDeadOrGhost(unit) then
        frame.healthText:SetText("Dead");
    elseif not UnitIsConnected(unit) then
        frame.healthText:SetText("DC");
    elseif frame.healthText.percent then
        frame.healthText:SetFormattedText("%.1f", UnitHealth(unit)/frame.health.max*100);
    else
        local current = UnitHealth(unit);
        if current > 1000000000 then -- 1.0B
            frame.healthText:SetFormattedText("%.2fB", current / 1000000000);
        elseif current > 1000000 then -- 1.0M
            frame.healthText:SetFormattedText("%.2fM", current / 1000000);
        elseif current > 1000 then -- 1K
            frame.healthText:SetFormattedText("%.1fK", current / 1000);
        else
            frame.healthText:SetFormattedText("%d", current)
        end
    end
end

local function updateMaxPower(frame, unit)
    frame.mana.max = UnitPowerMax(unit);
end

local function updatePower(frame, unit)
    local current, max = UnitPower(unit), frame.mana.max;
    if current <= 0 then
        frame.mana:Hide();
    elseif current > max or max <= 0 then
        frame.mana:SetWidth(frame.width);
        updateMaxPower(frame, unit);
        frame.mana:Show();
    else
        frame.mana:SetWidth(current/max*frame.width);
        frame.mana:Show();
    end
end

local function updatePowerText(frame, unit)
    local current, max = UnitPower(unit), frame.mana.max;
    if UnitIsDeadOrGhost(unit) or not UnitIsConnected(unit) then
        frame.manaText:Hide();
    elseif max > 0 and current > 0 and current < max then
        frame.manaText:SetText(ceil(current/max*100));
        frame.manaText:Show();
    else
        frame.manaText:Hide();
    end
end

local function updatePowerColor(frame, unit)
    frame.mana:SetVertexColor(unpack(powerColors[UnitPowerType(unit)]));
end

local function updateName(frame, unit)
    local name = UnitName(unit);
    if not name then return end
    frame.name:SetText(ssub(name, 1, frame.name.count));
end

local function updateShield(frame, unit)
    local shield = UnitGetTotalAbsorbs(unit) or 0;
    if shield > 0 then
        local space = frame.width - frame.health:GetWidth();
        shield = (shield / frame.health.max) * frame.width;
        if space == 0 then
            frame.shield:Hide();
            frame.shieldhl:Show();
        elseif space < shield then
            frame.shield:SetWidth(space);
            frame.shield:Show();
            frame.shieldhl:Show();
        else
            frame.shield:SetWidth(shield);
            frame.shield:Show();
            frame.shieldhl:Hide();
        end
    else
        frame.shield:Hide();
        frame.shieldhl:Hide();
    end
end

local function updateHealAbsorb(frame, unit)
    local absorb = UnitGetTotalHealAbsorbs(unit) or 0;
    if absorb > 0 then
        local space = frame.health:GetWidth();
        absorb = (absorb / frame.health.max) * frame.width;
        frame.healabsorb:SetWidth(min(space, absorb));
        frame.healabsorb:Show();
    else
        frame.healabsorb:Hide();
    end
end

local function updateAuras(frame, unit)
    if frame.auras then updateAuraFrames(frame, unit) end
end

local function updateAggro(frame, unit)
    local status = UnitThreatSituation(unit);
    if status and status > 0 then
        frame.base:SetVertexColor(GetThreatStatusColor(status));
    else
        frame.base:SetVertexColor(unpack(baseColor));
    end
end

-- only works for player frame
local function updateVehicle(frame)
    local shouldTargetVehicle = UnitHasVehicleUI("player") and
        UnitTargetsVehicleInRaidUI("player") and UnitExists("vehicle");
    if shouldTargetVehicle then
        if not frame.inVehicle then
            frame.inVehicle = true;
            frame.displayed = frame.vehicle;
            registerUnitEvents(frame);
        end
    elseif frame.inVehicle then
        frame.inVehicle = false;
        frame.displayed = frame.unit;
        registerUnitEvents(frame);
    end
end

local function updateLevelText(frame, unit, levelup)
    if levelup then
        -- PLAYER_LEVEL_UP
        frame.level:SetText(levelup);
    else
        local level = UnitLevel(unit);
        local class = UnitClassification(unit);
        local leveltext, classtext;
        if level < 0 then
            if class == "worldboss" then
                leveltext = "Boss";
            else
                leveltext = "??";
            end
        else
            leveltext = level;
        end
        if class == "rareelite" then
            classtext = " Rare Elite";
        elseif class == "elite" then
            classtext = " Elite";
        elseif class == "rare" then
            classtext = " Rare";
        else
            classtext = "";
        end
        frame.level:SetFormattedText("%s%s", leveltext, classtext);
    end
end

local function updateStatus(frame, unit)
    -- coords from FrameXML/PlayerFrame.lua
    if frame.inCombat or UnitAffectingCombat(unit) then
        frame.status:SetTexCoord(0.5, 1, 0, 0.484375);
        frame.status:Show();
    elseif unit == "player" and IsResting() then
        frame.status:SetTexCoord(0, 0.5, 0, 0.421875);
        frame.status:Show();
    else
        frame.status:Hide();
    end
end

local pvpIcons = {
    Alliance = "Interface\\TARGETINGFRAME\\UI-PVP-Alliance",
    Horde = "Interface\\TARGETINGFRAME\\UI-PVP-Horde"
};
local function updatePVP(frame, unit)
    if UnitIsPVPFreeForAll(unit) then
        frame.pvp:SetTexture("Interface\\TARGETINGFRAME\\UI-PVP-FFA");
        frame.pvp:Show();
    elseif UnitIsPVP(unit) then
        local faction = UnitFactionGroup(unit);
        if faction and faction ~= "Neutral" then
            -- from FrameXML/PlayerFrame.lua, mercenary checks
            if UnitIsMercenary(unit) then
                if faction == "Horde" then
                    faction = "Alliance";
                elseif faction == "Alliance" then
                    faction = "Horde";
                end
            end
            frame.pvp:SetTexture(pvpIcons[faction]);
            frame.pvp:Show();
        else
            frame.pvp:Hide();
        end
    else
        frame.pvp:Hide();
    end
end

local function updateLeaderIcon(frame, unit)
    if UnitIsGroupLeader(frame.unit) then
        if HasLFGRestrictions() then
            frame.leader:SetTexture("Interface\\LFGFrame\\UI-LFG-ICON-PORTRAITROLES");
            frame.leader:SetTexCoord(0, 0.296875, 0.015625, 0.3125);
        else
            frame.leader:SetTexture("Interface\\GROUPFRAME\\UI-Group-LeaderIcon");
            frame.leader:SetTexCoord(0, 1, 0, 1);
        end
        frame.leader:Show();
    elseif UnitIsGroupAssistant(frame.unit) then
        frame.leader:SetTexture("Interface\\GROUPFRAME\\UI-Group-AssistantIcon");
        frame.leader:SetTexCoord(0, 1, 0, 1);
        frame.leader:Show();
    else
        frame.leader:Hide();
    end
end

local function updateHealthColor(frame, unit)
    if not UnitPlayerControlled(unit) and UnitIsTapDenied(unit) then
        frame.health:SetVertexColor(0.5, 0.5, 0.5);
    elseif UnitIsPlayer(unit) then
        local _, class = UnitClass(unit);
        local color = RAID_CLASS_COLORS[class];
        if color then
            frame.health:SetVertexColor(color.r, color.g, color.b)
        else
            frame.health:SetVertexColor(unpack(healthColor))
        end
    elseif UnitPlayerControlled(unit) then
        frame.health:SetVertexColor(0, 1, 0);
    else
        frame.health:SetVertexColor(UnitSelectionColor(unit));
    end
end

local function updateRaidMarker(frame, unit)
    local index = GetRaidTargetIndex(unit);
    if index then
        SetRaidTargetIconTexture(frame.targeticon, index);
        frame.targeticon:Show();
    else
        frame.targeticon:Hide();
    end
end

local eventFuncs = {
    ["UNIT_HEALTH"] = function(frame)
        updateHealth(frame, frame.displayed);
        updateHealthText(frame, frame.displayed);
        if frame.shield then updateShield(frame, frame.displayed) end
        if frame.healabsorb then updateHealAbsorb(frame, frame.displayed) end
    end,
    ["UNIT_POWER"] = function(frame)
        updatePower(frame, frame.displayed);
        updatePowerText(frame, frame.displayed);
    end,
    ["UNIT_AURA"] = function(frame)
        updateAuras(frame, frame.displayed);
    end,
    ["UNIT_ABSORB_AMOUNT_CHANGED"] = function(frame)
        updateShield(frame, frame.displayed);
    end,
    ["UNIT_HEAL_ABSORB_AMOUNT_CHANGED"] = function(frame)
        updateHealAbsorb(frame, frame.displayed);
    end,
    ["UNIT_THREAT_SITUATION_UPDATE"] = function(frame)
        updateAggro(frame, frame.displayed);
    end,
    ["UNIT_MAXHEALTH"] = function(frame)
        updateMaxHealth(frame, frame.displayed);
        updateHealth(frame, frame.displayed);
        updateHealthText(frame, frame.displayed);
        if frame.shield then updateShield(frame, frame.displayed) end
        if frame.healabsorb then updateHealAbsorb(frame, frame.displayed) end
    end,
    ["UNIT_MAXPOWER"] = function(frame)
        updateMaxPower(frame, frame.displayed);
        updatePower(frame, frame.displayed);
        updatePowerText(frame, frame.displayed);
    end,
    ["UNIT_DISPLAYPOWER"] = function(frame)
        updatePowerColor(frame, frame.displayed);
        updateMaxPower(frame, frame.displayed);
        updatePower(frame, frame.displayed);
        updatePowerText(frame, frame.displayed);
    end,
    ["UNIT_NAME_UPDATE"] = function(frame)
        if frame.name then updateName(frame, frame.displayed) end
        updateHealthColor(frame, frame.displayed);
    end,
    ["UNIT_CONNECTION"] = function(frame)
        updateHealthText(frame, frame.displayed);
        updatePowerText(frame, frame.displayed);
    end,
    ["UNIT_LEVEL"] = function(frame)
        -- if this is registered, frame has frame.level
        updateLevelText(frame, frame.unit);
    end,
    ["PLAYER_LEVEL_UP"] = function(frame, arg1)
        updateLevelText(frame, frame.unit, arg1);
    end,
    ["PLAYER_UPDATE_RESTING"] = function(frame)
        -- player frame has frame.status
        updateStatus(frame, frame.unit);
    end,
    ["PLAYER_REGEN_DISABLED"] = function(frame)
        frame.inCombat = true;
        if frame.status then updateStatus(frame, frame.unit) end
    end,
    ["PLAYER_REGEN_ENABLED"] = function(frame)
        frame.inCombat = false;
        if frame.status then updateStatus(frame, frame.unit) end
    end,
    ["UNIT_FACTION"] = function(frame)
        if frame.pvp then updatePVP(frame, frame.unit) end
        updateHealthColor(frame, frame.displayed);
    end,
    ["PARTY_LEADER_CHANGED"] = function(frame)
        updateLeaderIcon(frame, frame.unit);
    end,
    ["RAID_TARGET_UPDATE"] = function(frame)
        updateRaidMarker(frame, frame.displayed);
    end,
    ["UPDATE_ALL_BARS"] = function(frame)
        if frame.vehicle then updateVehicle(frame) end
        updateMaxHealth(frame, frame.displayed);
        updateHealth(frame, frame.displayed);
        updateHealthText(frame, frame.displayed);
        updateHealthColor(frame, frame.displayed);
        updateAggro(frame, frame.displayed);
        updateRaidMarker(frame, frame.displayed);
        if frame.mana then
            updateMaxPower(frame, frame.displayed);
            updatePower(frame, frame.displayed);
            updatePowerText(frame, frame.displayed);
            updatePowerColor(frame, frame.displayed);
        end
        if frame.auras then updateAuras(frame, frame.displayed) end
        if frame.shield then updateShield(frame, frame.displayed) end
        if frame.healabsorb then updateHealAbsorb(frame, frame.displayed) end
        if frame.name then updateName(frame, frame.displayed) end
        if frame.level then updateLevelText(frame, frame.unit) end
        if frame.status then updateStatus(frame, frame.unit) end
        if frame.pvp then updatePVP(frame, frame.unit) end
        if frame.leader then updateLeaderIcon(frame, frame.unit) end
    end,
};
eventFuncs["UNIT_HEALTH_FREQUENT"] = eventFuncs["UNIT_HEALTH"];
eventFuncs["UNIT_POWER_BAR_SHOW"] = eventFuncs["UNIT_DISPLAYPOWER"];
eventFuncs["UNIT_POWER_BAR_HIDE"] = eventFuncs["UNIT_DISPLAYPOWER"];
eventFuncs["UNIT_ENTERED_VEHICLE"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["UNIT_EXITED_VEHICLE"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["UNIT_PET"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["GROUP_ROSTER_UPDATE"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["PLAYER_ENTERING_WORLD"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["PLAYER_TARGET_CHANGED"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["INSTANCE_ENCOUNTER_ENGAGE_UNIT"] = eventFuncs["UPDATE_ALL_BARS"];
eventFuncs["UNIT_TARGETABLE_CHANGED"] = eventFuncs["UPDATE_ALL_BARS"];

function M.UnitEvent(self, event, arg1)
    eventFuncs[event](self, arg1);
end