-- DIY Combat Engine version 2.2

local g_skill  = {}
local g_lastaction = ""
-- Holds the created timers
local DIYCE_Timers = {}

function Msg(outstr,a1,a2,a3)
    DEFAULT_CHAT_FRAME:AddMessage(tostring(outstr),a1,a2,a3)
end

function ReadSkills()
    g_skill = {}
    local skillname,slot

    for page = 1,4 do
        slot = 1
        skillname = GetSkillDetail(page,slot)
        repeat
            local a1,a2,a3,a4,a5,a6,a7,a8,skillusable = GetSkillDetail(page,slot)
            if skillusable then
                g_skill[skillname] = { ["page"] = page, ["slot"] = slot }
            end
            slot = slot + 1
            skillname = GetSkillDetail(page,slot)
        until skillname == nil
    end
end

-- Read Skills on Log-In/Class Change/Level-Up
        local DIYCE_EventFrame = CreateUIComponent("Frame","DIYCE_EventFrame","UIParent")
        DIYCE_EventFrame:SetScripts("OnUpdate", [=[ DIYCE_TimerUpdate(elapsedTime) ]=] )
            DIYCE_EventFrame:SetScripts("OnEvent", [=[ 
                    if event == "PLAYER_SKILLED_CHANGED" then
                        ReadSkills()
                        end
                    ]=] )
            DIYCE_EventFrame:RegisterEvent("PLAYER_SKILLED_CHANGED")

function PctH(tgt)
    return (UnitHealth(tgt)/UnitMaxHealth(tgt))
end

function PctM(tgt)
    return (UnitMana(tgt)/UnitMaxMana(tgt))
end

function PctS(tgt)
    return (UnitSkill(tgt)/UnitMaxSkill(tgt))
end

function CancelBuff(buffname)
    local i = 1
    local buff = UnitBuff("player",i)

    while buff ~= nil do
        if buff == buffname then
            CancelPlayerBuff(i)
            return true
        end

        i = i + 1
        buff = UnitBuff("player",i)
    end
    return false
end

function BuffList(tgt)
    local list = {}
    local buffcmd = UnitBuff
    local infocmd = UnitBuffLeftTime

    if UnitCanAttack("player",tgt) then
        buffcmd = UnitDebuff
        infocmd = UnitDebuffLeftTime
    end

    -- There is a max of 100 buffs/debuffs per unit apparently
    for i = 1,100 do
        local buff, _, stackSize, ID = buffcmd(tgt, i)
        local timeRemaining = infocmd(tgt,i)
        if buff then
            -- Ad to list by name
            list[buff:gsub("(%()(.)(%))", "%2")] = { stack = stackSize, time = timeRemaining or 0, id = ID }
            -- We also list by ID in case two different buffs/debuffs have the same name.
            list[ID] = {stack = stackSize, time = timeRemaining or 0, name = buff:gsub("(%()(.)(%))", "%2") }
        else
            break
        end
    end

    return list
end

function CD(skillname)
    local firstskill = GetSkillDetail(2,1)
    if (g_skill[firstskill] == nil) or (g_skill[firstskill].page ~= 2) then
        ReadSkills()
    end

    if g_skill[skillname] ~= nil then
        local tt,cd = GetSkillCooldown(g_skill[skillname].page,g_skill[skillname].slot)
        return cd <= 0.4
    elseif skillname == nil then
        return false
    else
        Msg("Skill not available: "..skillname)        --Comment this line out if you do not wish to recieve this error message.
        return
    end
end

function MyCombat(Skill, arg1)
    local spell_name = UnitCastingTime("player")
    local talktome = ((arg1 == "v1") or (arg1 == "v2"))
    local action,actioncd,actiondef,actioncnt
    
    if spell_name ~= nil then
        if (arg1 == "v2") then Msg("- ["..spell_name.."]", 0, 1, 1) end
        return true
    end

    for x,tbl in ipairs(Skill) do
        
    local useit = type(Skill[x].use) ~= "function" and Skill[x].use or (type(Skill[x].use) == "function" and Skill[x].use() or false)
        if useit then
            if string.find(Skill[x].name, "Action:") then
                action = tonumber((string.gsub(Skill[x].name, "(Action:)( *)(%d+)(.*)", "%3")))
                _1,actioncd = GetActionCooldown(action)
                actiondef,_1,actioncnt = GetActionInfo(action)
                if GetActionUsable(action) and (actioncd == 0) and (actiondef ~= nil) and (actioncnt > 0) then
                    if talktome then Msg("- "..Skill[x].name) end
                    UseAction(action)
                    return true
                end
            elseif string.find(Skill[x].name, "Custom:") then
                action = string.gsub(Skill[x].name, "(Custom:)( *)(.*)", "%3")
                if CustomAction(action) then
                    return true
                end
            elseif string.find(Skill[x].name, "Item:") then
                action = string.gsub(Skill[x].name, "(Item:)( *)(.*)", "%3")
                if talktome then Msg("- "..Skill[x].name) end
                UseItemByName(action)
                return true
            elseif (Skill[x].ignoretimer or GetDIYCETimerValue(Skill[x].timer) == 0) and CD(Skill[x].name) then
                if talktome then Msg("- "..Skill[x].name) end
                CastSpellByName(Skill[x].name)
                StartDIYCETimer(Skill[x].timer)
                return true
            elseif string.find(Skill[x].name, "Pet Skill:") then
                action = string.gsub(Skill[x].name, "(Pet Skill:)( *)(%d+)(.*)", "%3")
                    UsePetAction(action)
                if (arg1 == "v2") then Msg(Skill[x].name.." has been fully processed") end
                return true
            end
        end
    end
    if (arg1 == "v2") then Msg("- [IDLE]", 0, 1, 1) end
    
    return false
end

--[[ Timer Update function ]]--
-- Tick down any active timers
function DIYCE_TimerUpdate(elapsed)
    for k,v in pairs(DIYCE_Timers) do
        v.timeLeft = v.timeLeft - elapsed
        if v.timeLeft < 0 then
            v.timeLeft = 0
        end
    end
end

--[[ Create a named timer ]]--
-- if the named timer already exists, this does nothing.
function CreateDIYCETimer(timerName, waitTime)
    if not DIYCE_Timers[timerName] then
        DIYCE_Timers[timerName] = { timeLeft = 0, waitTime = waitTime }
    end
end

--[[ Set/reset waitTimer of an existing timer ]]--
-- if the timer doesn't exist, this does nothing
function SetDIYCETimerDelay(timerName, waitTime)
    if DIYCE_Timers[timerName] then
        DIYCE_Timers[timerName].waitTime = waitTime
    end
end

--[[ Delete named timer ]]--
-- if the timer doesn't exist, this does nothing
-- Not really needed, but added for completeness
function DeleteDIYCETimer(timerName)
    if DIYCE_Timers[timerName] then
        DIYCE_Timers[timerName] = nil
    end
end

--[[ Get a timer's current time ]]--
-- if the timer doesn't exist, this returns 0
function GetDIYCETimerValue(timerName)
    if timerName then
        return DIYCE_Timers[timerName] and DIYCE_Timers[timerName].timeLeft or 0
    end
    return 0
end

--[[ Starts a timer ticking down ]]--
-- if timer doesn't exist, this does nothing
function StartDIYCETimer(timerName)
    if timerName and DIYCE_Timers[timerName] then
        DIYCE_Timers[timerName].timeLeft = DIYCE_Timers[timerName].waitTime
    end
end

function CustomAction(action)
    if CD(action) then
        if IsShiftKeyDown() then Msg("- "..action) end
        g_lastaction = action
        CastSpellByName(action)
        return true
    else
        return false
    end
end

function BuffTimeLeft(tgt, buffname)
    local cnt = 1
    local buff = UnitBuff(tgt,cnt)

    while buff ~= nil do
        if string.find(buff,buffname) then
            return UnitBuffLeftTime(tgt,cnt)
        end
        cnt = cnt + 1
        buff = UnitBuff(tgt,cnt)
    end

    return 0
end

function BuffParty(arg1,arg2)
--    arg1 = Quickbar slot # for targetable, instant-cast buff without a cooldown (eg. Amp Attack) for range checking.
--    arg2 = buff expiration time cutoff (in seconds) for refreshing buffs, default is 45 seconds.

    local selfbuffs = { "Soul Bond", "Enhanced Armor", "Holy Seal" }
    local groupbuffs = { "Grace of Life", "Amplified Attack", "Angel's Blessing", "Essence of Magic", "Magic Barrier", "Blessed Spring Water", "Fire Ward", "Savage Blessing", "Concentration Prayer", "Shadow Fury"  }

    local buffrefresh = arg2 or 45           -- Refresh buff time (seconds)
    local spell = UnitCastingTime("player")  -- Spell being cast?
    local vocal = IsShiftKeyDown()           -- Generate feedback if Shift key held

    if (spell ~= nil) then
        return
    end

    if vocal then Msg("- Checking self buffs on "..UnitName("player")) end
    for i,buff in ipairs(selfbuffs) do
        if (g_skill[buff] ~= nil) and CD(buff) and (BuffTimeLeft("player",buff) <= buffrefresh) then
            if vocal then Msg("- Casting "..buff.." on "..UnitName("player")) end
            TargetUnit("player")
            CastSpellByName(buff)
            return
        end
    end

    if vocal then Msg("- Checking group buffs on "..UnitName("player")) end
    for i,buff in ipairs(groupbuffs) do
        if (g_skill[buff] ~= nil) and CD(buff) and (BuffTimeLeft("player",buff) <= buffrefresh) then
            if vocal then Msg("- Casting "..buff.." on "..UnitName("player")) end
            TargetUnit("player")
            CastSpellByName(buff)
            return
        end
    end

    for num=1,GetNumPartyMembers()-1 do
        TargetUnit("party"..num)
        if GetActionUsable(arg1) and (UnitHealth("party"..num) > 0) then
            if vocal then Msg("- Checking group buffs on "..UnitName("party"..num)) end
            for i,buff in ipairs(groupbuffs) do
                if (g_skill[buff] ~= nil) and CD(buff) and (BuffTimeLeft("target",buff) <= buffrefresh) then
                    if UnitIsUnit("target","party"..num) then
                        if vocal then Msg("- Casting "..buff.." on "..UnitName("target")) end
                        CastSpellByName(buff)
                        return
                    else
                        if vocal then Msg("- Error: "..UnitName("target").." != "..UnitName("party"..num)) end
                    end
                end
            end
        else
            if vocal then Msg("- Player "..UnitName("party"..num).." out of range or dead.") end
        end
    end

    if vocal then Msg("- Nothing to do.") end
end