local _;
local format = string.format;
local stancebar = CreateFrame("Frame", "OmaStanceBar", UIParent);

function create(slot, bar, prev)
    local frame = CreateFrame("CheckButton", "OmaBTStance"..slot, bar, "StanceButtonTemplate");
    bar[slot] = frame;
    frame:SetID(slot);
    frame:SetWidth(32);
    frame:SetHeight(32);
    frame:GetNormalTexture():SetTexture("");
    frame.cooldown = { SetSwipeColor = function() end, };
    frame.base = frame:CreateTexture(nil, "BACKGROUND");
    frame.base:SetAllPoints();
    frame.base:SetColorTexture(0, 0, 0, 0.5);
    frame.icon = frame:CreateTexture(nil, "ARTWORK");
    frame.icon:SetPoint("TOPLEFT", frame.base, "TOPLEFT", 1, -1);
    frame.icon:SetPoint("BOTTOMRIGHT", frame.base, "BOTTOMRIGHT", -1, 1);
    frame.icon:SetTexCoord(0.07, 0.93, 0.07, 0.93);

    if slot == 1 then
        frame:SetPoint("TOPLEFT");
    else
        frame:SetPoint("TOPLEFT", prev, "TOPRIGHT");
    end
    frame:RegisterForClicks("AnyUp");
end

-- FIXME if more stances necessary use NUM_STANCE_SLOTS for the max, paladins have 3
function update(bar)
    local n = GetNumShapeshiftForms();
    --for i=1,NUM_STANCE_SLOTS do
    for i=1,4 do
        local button = bar[i];
        if i <= n then
            local tex, active, castable = GetShapeshiftFormInfo(i);
            local icon = button.icon;
            icon:SetTexture(tex);
            if active then
                button:SetChecked(true);
            else
                button:SetChecked(false);
            end
            if castable then
                icon:SetVertexColor(1, 1, 1);
            else
                icon:SetVertexColor(0.4, 0.4, 0.4);
            end
            --button:Show();
        else
            --button:Hide();
        end
    end
end

stancebar:SetScript("OnEvent", function(self, event)
    if event == "UPDATE_SHAPESHIFT_COOLDOWN" then
        update(self);
    elseif event == "PLAYER_LOGIN" then
        -- TODO do class detection and only create necessary buttons
        stancebar:UnregisterAllEvents();
        local _, class = UnitClass("player");
        if class ~= "PALADIN" and class ~= "DRUID" then
            return
        end
        for i=1,4 do
            create(i, self, self[i-1]);
        end
        update(self);
        _G["BINDING_HEADER_OMAABSTANCE"] = "Stance Bar";
        for i = 1,4 do
            _G[format("BINDING_NAME_CLICK OmaBTStance%d:LeftButton", i)] = format("Stance Bar Button %d", i);
        end
        stancebar:RegisterEvent("UPDATE_SHAPESHIFT_COOLDOWN");
    end
end);
stancebar:SetPoint("BOTTOMLEFT", UIParent, "BOTTOMLEFT", 580, 40);
stancebar:SetFrameStrata("LOW");
stancebar:SetWidth(1);
stancebar:SetHeight(1);
stancebar:RegisterEvent("PLAYER_LOGIN");
stancebar:Show();