-- Events.lua
local _;
local unpack = unpack;
local ssub = string.sub;
local min = math.min;
local UnitName, UnitClass, UnitExists = UnitName, UnitClass, UnitExists;
local UnitDebuff, UnitIsCharmed = UnitDebuff, UnitIsCharmed;
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 UnitHasIncomingResurrection = UnitHasIncomingResurrection;
local UnitGetTotalHealAbsorbs = UnitGetTotalHealAbsorbs;
local UnitHasVehicleUI, UnitTargetsVehicleInRaidUI = UnitHasVehicleUI, UnitTargetsVehicleInRaidUI;
local UnitGroupRolesAssigned = UnitGroupRolesAssigned;
local RAID_CLASS_COLORS = RAID_CLASS_COLORS;

local checkIndicators = OmaRFIndicators.CheckIndicators;

local Settings = OmaRFSettings;
local baseColor = Settings.BaseColor;
local overlayColorDispel = Settings.OverlayColorDispel;
local overlayColorCharm = Settings.OverlayColorCharm;
local overlayColorAlert = Settings.OverlayColorAlert;
local powerColors = Settings.PowerColors;
local width = 10;

local M = {};
OmaRFEvents = M;
function M.RegisterEvents(frame)
    -- events are taken from FrameXML/CompactUnitFrame.lua
    -- TODO ready check support, raid marker support,
    -- player flags support (/afk, /dnd)
    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);
    frame:RegisterUnitEvent("UNIT_POWER", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_MAXPOWER", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_DISPLAYPOWER", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_NAME_UPDATE", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_AURA", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_HEAL_PREDICTION", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_ABSORB_AMOUNT_CHANGED", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_HEAL_ABSORB_AMOUNT_CHANGED", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_THREAT_SITUATION_UPDATE", frame.unit, displayed);
    frame:RegisterUnitEvent("UNIT_CONNECTION", frame.unit, displayed);
    frame:RegisterUnitEvent("INCOMING_RESURRECT_CHANGED", frame.unit, displayed);
end
local registerEvents = M.RegisterEvents;

local function updateHealth(frame, unit)
    local current, max = UnitHealth(unit), frame.health.max;
    frame.health:Show();
    -- sanity check, occasionally UnitHealthMax gives zero
    if current > max then
        -- somehow current health has gone over the maximum (missed maxhealth event)
        frame.health.max = UnitHealthMax(unit);
        max = frame.health.max;
        if current > max then
            -- error state, still over maximum
            frame.health:SetWidth(width);
            return;
        end
    elseif max > 0 then
        frame.health:SetWidth(current/frame.health.max*width);
    else
        frame.health:SetWidth(width);
        return;
    end

    if UnitIsDeadOrGhost(unit) then
        frame.health:Hide();
    end
end

local function updateText(frame, unit)
    local current, max = UnitHealth(unit), frame.health.max;
    local healthLost = max - current;
    if UnitIsDeadOrGhost(unit) then
        frame.text:SetText("Dead");
        frame.text:Show();
    elseif not UnitIsConnected(unit) then
        frame.text:SetText("DC");
        frame.text:Show();
    elseif healthLost > 0 then
        if healthLost > 1200000000 then -- 1.2B
            frame.text:SetFormattedText("-%.1fB", healthLost / 1000000000);
        elseif healthLost > 1200000 then -- 1.2M
            frame.text:SetFormattedText("-%.1fM", healthLost / 1000000);
        elseif healthLost > 1000 then -- 1K
            frame.text:SetFormattedText("-%dK", healthLost / 1000);
        else
            frame.text:SetFormattedText("-%d", healthLost)
        end
        frame.text:Show();
    else
        frame.text:Hide();
    end
end

local function updateIncomingRes(frame, unit)
    if UnitHasIncomingResurrection(unit) then
        frame.rez:Show();
    else
        frame.rez:Hide();
    end
end

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

local function updatePower(frame, unit)
    local current, max = UnitPower(unit), frame.mana.max;
    -- sanity check, occasionally UnitPowerMax gives zero
    if current > max then
        frame.mana.max = UnitPowerMax(unit);
        max = frame.mana.max;
        if current > max then
            -- error
            frame.mana:SetWidth(width);
            return;
        end
    elseif max > 0 then
        frame.mana:SetWidth(UnitPower(unit)/max*width);
    else
        frame.mana:SetWidth(width);
    end
end

local function updateMaxPower(frame, unit)
    frame.mana.max = UnitPowerMax(unit);
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, 6));

    local _, class = UnitClass(unit);
    local color = RAID_CLASS_COLORS[class];
    if color then frame.name:SetVertexColor(color.r, color.g, color.b) end
end

local function updateHealPred(frame, unit)
    local incoming = UnitGetIncomingHeals(unit) or 0;
    if incoming > 0 then
        local max = frame.health.max;
        local space = width - frame.health:GetWidth() + 1;
        local pred = (incoming / max) * width;
        frame.healpred:SetWidth(min(space, pred));
        frame.healpred:Show();
    else
        frame.healpred:Hide();
    end
end

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

local function updateAuras(frame, unit)
    checkIndicators(frame, unit);
    if UnitDebuff(unit, 1, "RAID") ~= nil then
        -- something dispellable
        if frame.overlay.color ~= overlayColorDispel then
            frame.overlay:SetVertexColor(unpack(overlayColorDispel));
            frame.overlay:Show();
            frame.overlay.color = overlayColorDispel;
        end
    -- don't overlay charmed when in vehicle
    elseif UnitIsCharmed(unit) and unit == frame.unit then
        if frame.overlay.color ~= overlayColorCharm then
            frame.overlay:SetVertexColor(unpack(overlayColorCharm));
            frame.overlay:Show();
            frame.overlay.color = overlayColorCharm;
        end
    else
        if frame.overlay.color ~= nil then
            frame.overlay:Hide();
            frame.overlay.color = nil;
        end
    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

local function updateVehicle(frame)
    local shouldTargetVehicle = UnitHasVehicleUI(frame.unit) and UnitTargetsVehicleInRaidUI(frame.unit) and UnitExists(frame.vehicle);
    if shouldTargetVehicle then
        if not frame.inVehicle then
            frame.inVehicle = true;
            frame.displayed = frame.vehicle;
            registerEvents(frame);
        end
    elseif frame.inVehicle then
        frame.inVehicle = false;
        frame.displayed = frame.unit;
        registerEvents(frame);
    end
end

local function updateRole(frame, unit)
    local role = UnitGroupRolesAssigned(unit);
    if role == "HEALER" then
        frame.role:SetTexCoord(0.75, 1, 0, 1);
        frame.role:Show();
    elseif role == "TANK" then
        frame.role:SetTexCoord(0.5, 0.75, 0, 1);
        frame.role:Show();
    else
        frame.role:Hide();
    end
end

local eventFuncs = {
    ["UNIT_HEALTH"] = function(frame)
        updateHealth(frame, frame.displayed);
        updateText(frame, frame.displayed);
        updateShield(frame, frame.displayed);
        updateHealAbsorb(frame, frame.displayed);
        -- no heal prediction update, that doesn't overflow too much
    end,
    ["UNIT_POWER"] = function(frame)
        updatePower(frame, frame.displayed);
    end,
    ["UNIT_AURA"] = function(frame)
        updateAuras(frame, frame.displayed);
    end,
    ["UNIT_HEAL_PREDICTION"] = function(frame)
        updateHealPred(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);
        updateText(frame, frame.displayed);
        updateShield(frame, frame.displayed);
        updateHealAbsorb(frame, frame.displayed);
    end,
    ["UNIT_MAXPOWER"] = function(frame)
        updateMaxPower(frame, frame.displayed);
        updatePower(frame, frame.displayed);
    end,
    ["UNIT_DISPLAYPOWER"] = function(frame)
        updatePowerColor(frame, frame.displayed);
    end,
    ["UNIT_NAME_UPDATE"] = function(frame)
        updateName(frame, frame.displayed);
    end,
    ["UNIT_CONNECTION"] = function(frame)
        updateText(frame, frame.displayed);
    end,
    ["INCOMING_RESURRECT_CHANGED"] = function(frame)
        updateIncomingRes(frame, frame.unit);
    end,
    ["PARTY_MEMBER_ENABLE"] = function(frame)
        -- new power info possibly (FrameXML/CompactUnitFrame.lua)
        updateMaxPower(frame, frame.displayed);
        updatePowerColor(frame, frame.displayed);
    end,
    ["PLAYER_ROLES_ASSIGNED"] = function(frame)
        updateRole(frame, frame.unit);
    end,
    ["UPDATE_ALL_BARS"] = function(frame)
        updateVehicle(frame);
        updateMaxHealth(frame, frame.displayed);
        updateMaxPower(frame, frame.displayed);
        updateHealth(frame, frame.displayed);
        updateText(frame, frame.displayed);
        updatePower(frame, frame.displayed);
        updateAuras(frame, frame.displayed);
        updateShield(frame, frame.displayed);
        updateHealPred(frame, frame.displayed);
        updateHealAbsorb(frame, frame.displayed);
        updatePowerColor(frame, frame.displayed);
        updateIncomingRes(frame, frame.unit);
        updateAggro(frame, frame.displayed);
        updateName(frame, frame.displayed);
        updateRole(frame, frame.unit);
    end,
};
eventFuncs["UNIT_HEALTH_FREQUENT"] = eventFuncs["UNIT_HEALTH"];
eventFuncs["PARTY_MEMBER_DISABLE"] = eventFuncs["PARTY_MEMBER_ENABLE"];
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"];
function M.UnitEvent(self, event)
    eventFuncs[event](self);
end

function M.LoadChar()
    width = Settings.Character.Width;
end