local onlyBossAlert = true;
local deadGUIDs, pulledGUIDs, petOwners = {}, {}, {};
local msgColor, npcColor = "FF6600", "B30000";
local classColors = {
    ["DEATHKNIGHT"] = "C41F3B",
    ["DEMONHUNTER"] = "A330C9",
    ["DRUID"] = "FF7D0A",
    ["HUNTER"] = "ABD473",
    ["MAGE"] = "69CCF0",
    ["MONK"] = "00FF96",
    ["PALADIN"] = "F58CBA",
    ["PRIEST"] = "FFFFFF",
    ["ROGUE"] = "FFF569",
    ["SHAMAN"] = "0070DE",
    ["WARLOCK"] = "9482C9",
    ["WARRIOR"] = "C79C6E"
};
local ignoredSpells = {
    "Death Grip",
    "Imprison",
    "Hunter's Mark",
    "Beast Lore",
    "Flare",
    "Soothe",
    "Marked for Death",
    "Shadowstep",
    "Blind",
    "Sap",
    "Hex"
};

local function isIgnoredSpell(spellName)
    for _, ignoredSpellName in pairs(ignoredSpells) do
        if ignoredSpellName == spellName then
            return true;
        end
    end
    return false;
end

local function getClassColor(guid)
    local _, engClass = GetPlayerInfoByGUID(guid);
    if engClass then
        return classColors[engClass];
    end
    return nil;
end

local function isDead(guid)
    if deadGUIDs[guid] then
        return true;
    end
    return false;
end

local function isAlreadyPulled(guid)
    if pulledGUIDs[guid] then
        return true;
    end
    return false;
end

local function isBoss(guid)
    local _, _, _, _, _, mobID = strsplit("-", guid)
    if LibStub("LibBossIDs-1.0").BossIDs[tonumber(mobID)] then
        return true;
    end
    return false;
end

local function isInPVEInstance()
    local inInstance, instanceType = IsInInstance();
    if inInstance and (instanceType == "party" or instanceType == "raid") then
        return true;
    end
    return false;
end

local function isInPartyOrRaid()
    if GetNumGroupMembers(LE_PARTY_CATEGORY_HOME) > 0 or GetNumGroupMembers(LE_PARTY_CATEGORY_INSTANCE) > 0 then
        return true;
    end
    return false;
end

local function getPetOwner(petGUID)
    if petGUID then
        if petOwners[petGUID] then
            return petOwners[petGUID][1], petOwners[petGUID][2];
        end
        if UnitInRaid("player") then
            for i = 1, 40 do
                if UnitGUID("raidpet" .. i) == petGUID then
                    return UnitGUID("raid" .. i), UnitName("raid" .. i);
                end
            end
        else  -- player is alone or in party.
            if UnitGUID("pet") == petGUID then  -- access to player's pet if alone or in a party the same way.
                return UnitGUID("player"), UnitName("player");
            end
            for i = 1, 4 do  -- 4 members of the group.
                if UnitGUID("partypet" .. i) == petGUID then
                    return UnitGUID("party" .. i), UnitName("party" .. i);
                end
            end
        end
    end
    return nil;
end

local function setColor(msg, color)
    return string.format("|cFF" .. color .. "%s|r", msg);
end

local function buildPullAlertMessage(event, isBodyPull, isPet, unitGUID, unitName, npcGUID, npcName, spellID, spellName)
    if (onlyBossAlert and not isBoss(npcGUID)) or isDead(npcGUID) then
        return nil;
    end
    local msg, classColor;
    npcName = setColor(npcName, npcColor);
    if string.find(event, "SWING") then
        spellLink = GetSpellLink("Auto Attack");
    else
        spellLink = GetSpellLink(spellID) or spellName;
    end
    if isPet then  -- unitName == petName
        local petOwnerGUID, petOwnerName = getPetOwner(unitGUID);
        if petOwnerName then
            classColor = getClassColor(petOwnerGUID);
            petOwnerName = setColor(petOwnerName, classColor);
            if isBodyPull then
                msg = string.format("%s's %s body pulled %s.", petOwnerName, unitName, npcName);
            else
                msg = string.format("%s's %s pulled %s with " .. spellLink .. ".", petOwnerName, unitName, npcName);
            end
        else
            if isBodyPull then
                msg = string.format("%s (pet) body pulled %s.", unitName, npcName);
            else
                msg = string.format("%s (pet) pulled %s with " .. spellLink .. ".", unitName, npcName);
            end
        end
    else  -- unitName == playerName
        classColor = getClassColor(unitGUID);
        unitName = setColor(unitName, classColor);
        if isBodyPull then
            msg = string.format("%s body pulled %s.", unitName, npcName);
        else
            msg = string.format("%s pulled %s with " .. spellLink .. ".", unitName, npcName);
        end
    end
    return msg;
end

function convertHexToRgb(hex)
    local hex = hex:gsub("#", "");
    if hex:len() == 3 then
        return (tonumber("0x" .. hex:sub(1, 1)) * 17) / 255, (tonumber("0x" .. hex:sub(2, 2)) * 17) / 255, (tonumber("0x" .. hex:sub(3, 3)) * 17) / 255;
    else
        return tonumber("0x" .. hex:sub(1, 2)) / 255, tonumber("0x" .. hex:sub(3, 4)) / 255, tonumber("0x" .. hex:sub(5, 6)) / 255;
    end
end

local function printAllChatFrames(msg, color)
    if msg then
        local r, g, b = convertHexToRgb(color);
        for i = 1, 20 do
            _G["ChatFrame" .. i]:AddMessage(msg, r, g, b);
        end
    end
end

local function whoTFPulled(...)
    local _, event, _, srcGUID, srcName, srcFlags, _, destGUID, destName, destFlags, _, spellID, spellName = select(1, ...);
    if event == "UNIT_DIED" then
        deadGUIDs[destGUID] = true;
        return;
    end
    if destName and srcName and destName ~= srcName and not string.find(event, "_RESURRECT") and not string.find(event, "_CREATE") and (string.find(event, "SWING") or string.find(event, "RANGE") or string.find(event, "SPELL")) then
        -- Register owners of special pets like Army of the Dead or Totems.
        if string.find(event, "_SUMMON") then
            petOwners[destGUID] = {srcGUID, srcName};
            return;
        end
        local isBodyPull, isPet;
        -- A player is attacking a mob.
        if bit.band(srcFlags, COMBATLOG_OBJECT_TYPE_PLAYER) ~= 0 and bit.band(destFlags, COMBATLOG_OBJECT_TYPE_NPC) ~= 0 then
            if not isAlreadyPulled(destGUID) and not isIgnoredSpell(spellName) then
                pulledGUIDs[destGUID] = true;
                isBodyPull = false;
                isPet = false;
                printAllChatFrames(buildPullAlertMessage(event, isBodyPull, isPet, srcGUID, srcName, destGUID, destName, spellID, spellName), msgColor);
            end
        -- A mob is attacking a player.
        elseif bit.band(destFlags, COMBATLOG_OBJECT_TYPE_PLAYER) ~= 0 and bit.band(srcFlags, COMBATLOG_OBJECT_TYPE_NPC) ~= 0 then
            if not isAlreadyPulled(srcGUID) then
                pulledGUIDs[srcGUID] = true;
                isBodyPull = true;
                isPet = false;
                printAllChatFrames(buildPullAlertMessage(event, isBodyPull, isPet, destGUID, destName, srcGUID, srcName, spellID, spellName), msgColor);
            end
        -- A player's pet attacks a mob.
        elseif bit.band(srcFlags, COMBATLOG_OBJECT_CONTROL_PLAYER) ~= 0 and bit.band(destFlags, COMBATLOG_OBJECT_TYPE_NPC) ~= 0 then
            if not isAlreadyPulled(destGUID) then
                pulledGUIDs[destGUID] = true;
                isBodyPull = false;
                isPet = true;
                printAllChatFrames(buildPullAlertMessage(event, isBodyPull, isPet, srcGUID, srcName, destGUID, destName, spellID, spellName), msgColor);
            end
        -- A mob attacks a player's pet.
        elseif bit.band(destFlags, COMBATLOG_OBJECT_CONTROL_PLAYER) ~= 0 and bit.band(srcFlags, COMBATLOG_OBJECT_TYPE_NPC) ~= 0 then
            if not isAlreadyPulled(srcGUID) then
                pulledGUIDs[srcGUID] = true;
                isBodyPull = true;
                isPet = true;
                printAllChatFrames(buildPullAlertMessage(event, isBodyPull, isPet, destGUID, destName, srcGUID, srcName, spellID, spellName), msgColor);
            end
        end
    end
end

local function eventHandler(self, event, ...)
    if event == "COMBAT_LOG_EVENT_UNFILTERED" then
        if isInPVEInstance() and isInPartyOrRaid() then
            whoTFPulled(...);
        else
            wipe(deadGUIDs);
        end
    elseif event == "PLAYER_REGEN_ENABLED" then
        -- print("PLAYER_REGEN_ENABLED");
        if not UnitIsDeadOrGhost("player") and not UnitIsFeignDeath("player") and not UnitAffectingCombat("pet") then
            -- print("PLAYER_REGEN_ENABLED: wipe pulledGUIDs");
            wipe(pulledGUIDs);
            wipe(petOwners);
        end
    elseif event == "PLAYER_ALIVE" then
        -- print("PLAYER_ALIVE");
        if not IsEncounterInProgress() and not UnitAffectingCombat("player") then
            -- print("PLAYER_ALIVE: wipe pulledGUIDs");
            wipe(pulledGUIDs);
            wipe(petOwners);
        end
    end
end

local frame = CreateFrame("Frame");
frame:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED");
frame:RegisterEvent("PLAYER_REGEN_ENABLED");
frame:RegisterEvent("PLAYER_ALIVE");
frame:SetScript("OnEvent", eventHandler);