Add support for class mounts and flight form

When an equally capable item mount is found in the bags they take
priority over the class mounts and flight form.

src/main.lua

@@ -17,6 +17,23 @@ local NONFLYABLE_ZONES = {
 
 local RIDING_SKILLS = { [75] = false, [150] = false, [225] = true, [300] = true }
 
+local MOUNT_SPELLS = {
+    DRUID = {
+        [40120] = 3, -- swift flight form
+        [33943] = 2, -- flight form
+    },
+    PALADIN = {
+        [34767] = 1, -- Summon Charger (horde)
+        [34769] = 0, -- Summon Warhorse (horde)
+        [13819] = 0, -- Summon Warhorse (alliance)
+        [23214] = 1, -- Summon Charger (alliance)
+    },
+    WARLOCK = {
+        [5784] = 0, -- Summon Felsteed
+        [23161] = 1, -- Summon Dreadsteed
+    },
+}
+
 local function IsFlyable()
     local mapId = select(8, GetInstanceInfo())
     if not FLYABLE_MAPS[mapId] then
@@ -80,6 +97,16 @@ local function FindBestMount(flyable)
             end
         end
     end
+
+    local mount_spells = MOUNT_SPELLS[(select(2, UnitClass("player")))]
+    if mount_spells then
+        for spellId, priority in pairs(mount_spells) do
+            if priority > bestPriority and priority <= maxPriority and C_SpellBook.IsSpellKnown(spellId) then
+                best = spellId
+                bestPriority = priority
+            end
+        end
+    end
     return best
 end
 
@@ -93,13 +120,19 @@ local function MakeMountButton(name, forceGround)
         end
         local flyable = not forceGround and IsFlyable()
         local mount = FindBestMount(flyable)
-        if mount then
+        if mount and type(mount) == "table" then
+            self:SetAttribute("spell1", nil)
+            self:SetAttribute("type1", "item")
             self:SetAttribute("item1", mount.bag .. " " .. mount.slot)
+        elseif mount and type(mount) == "number" then
+            self:SetAttribute("type1", "spell")
+            self:SetAttribute("item1", nil)
+            self:SetAttribute("spell1", mount)
         else
             self:SetAttribute("item1", nil)
+            self:SetAttribute("spell1", nil)
         end
     end)
-    button:SetAttribute("type1", "item")
     return button
 end