----------------------------------------------------
--      tabulous: Fabulous tabs for awesome       --
--                                                --
-- © 2008 Julien Danjou <julien@danjou.info>      --
-- © 2008 Lucas de Vries <lucasdevries@gmail.com> --
----------------------------------------------------

require('awful')

--------------------
-- Module loading --
--------------------
local P = {}
if _REQUIREDNAME == nil then
    tabulous = P
else
    _G[_REQUIREDNAME] = P
end

-- Grab environment we need
local client = client
local table = table
local pairs = pairs
local awful = awful

-- Reset env
setfenv(1, P)

tabbed = {}

-- Hook creation
awful.hooks.userhook_create('tabbed')
awful.hooks.userhook_create('untabbed')
awful.hooks.userhook_create('tabdisplay')
awful.hooks.userhook_create('tabhide')

---------------
-- Functions --
---------------

--- Find a key in a table.
-- @param table The table to look into
-- @param value The value to find.
-- @return The key or nil if not found.
function P.findkey(table, value)
    for k, v in pairs(table) do
        if v == value then
            return k
        end
    end
end

--- Swap and select which client in tab is displayed.
-- @param tabindex The tab index.
-- @param cl The client to show.
function P.display(tabindex, cl)
    local p = tabbed[tabindex][1]
    
    if cl and p ~= cl then
        cl:hide(false)
        cl:swap(p)
        p:hide(true)
        cl:focus_set()

        tabbed[tabindex][1] = cl

        awful.hooks.userhook_call('tabhide', {p})
        awful.hooks.userhook_call('tabdisplay', {cl})
    end
end

--- Check if the client is in the given tabindex.
-- @param tabindex The tab index.
-- @param cl The client
-- @return The key.
function P.tabindex_check(tabindex, cl)
    local c = cl or client.focus_get()
    return P.findkey(tabbed[tabindex], c)
end

--- Find the tab index or return nil if not tabbed.
-- @param cl The client to search.
-- @return The tab index.
function P.tabindex_get(cl)
    local c = cl or client.focus_get()

    for tabindex, tabdisplay in pairs(tabbed) do
        -- Loop through all tab displays
        local me = P.tabindex_check(tabindex, c)

        if me ~= nil then
            return tabindex 
        end
    end

    return nil
end

--- Get all clients on a tabbed display.
-- @param tabindex The tab index.
-- @return All tabbed clients.
function P.clients_get(tabindex)
    if tabbed[tabindex] == nil then return nil end
    return tabbed[tabindex][2]
end

--- Get the displayed client on a tabbed display.
-- @param tabindex The tab index.
-- @return The displayed client.
function P.displayed_get(tabindex)
    if tabbed[tabindex] == nil then return nil end
    return tabbed[tabindex][1]
end

--- Get a client by tab number.
-- @param tabindex The tab index.
-- @param pos The position in the tab.
-- @return The client at the given position.
function P.position_get(tabindex, pos)
    if tabbed[tabindex] == nil then return nil end
    return tabbed[tabindex][2][pos]
end

--- Get the next client in a tab display.
-- @param tabindex The tab index.
-- @param cl The current client.
-- @return The next client.
function P.next(tabindex, cl)
    local c = cl or tabbed[tabindex][1]

    local i = P.findkey(tabbed[tabindex][2], c)

    if i == nil then
        return nil
    end

    if tabbed[tabindex][2][i+1] == nil then
        return tabbed[tabindex][2][1]
    end

    return tabbed[tabindex][2][i + 1]
end

--- Get the previous client in a tabdisplay
-- @param tabindex The tab index.
-- @param cl The current client.
-- @return The previous client.
function P.prev(tabindex, cl)
    local c = cl or tabbed[tabindex][1]

    local i = P.findkey(tabbed[tabindex][2], c)

    if i == nil then
        return nil
    end

    if tabbed[tabindex][2][i-1] == nil then
        return tabbed[tabindex][2][table.maxn(tabbed[tabindex][2])]
    end

    return tabbed[tabindex][2][i - 1]
end

--- Remove a client from a tabbed display.
-- @param cl The client to remove.
-- @return True if the client has been untabbed.
function P.untab(cl)
    local c = cl or client.focus_get()
    local tabindex = P.tabindex_get(c)

    if tabindex == nil then return false end

    local cindex = P.findkey(tabbed[tabindex][2], c)

    if tabbed[tabindex][1] == c then
        P.display(tabindex, P.next(tabindex, c))
    end

    table.remove(tabbed[tabindex][2], cindex)

    if table.maxn(tabbed[tabindex][2]) == 0 then
        -- Table is empty now, remove the tabbed display
        table.remove(tabbed, tabindex)
    end

    c:hide(false)
    awful.hooks.userhook_call('untabbed', {c})
end

--- Untab all clients in a tabbed display.
-- @param tabindex The tab index.
function P.untab_all(tabindex)
    for i,c in pairs(tabbed[tabindex][2]) do
        c:hide(false)
        awful.hooks.userhook_call('untabbed', {c})
    end

    if tabbed[tabindex] ~= nil then
        table.remove(tabbed, tabindex)
    end
end

--- Create a new tabbed display with client as the master.
-- @param cl The client to set into the tab, focused one otherwise.
-- @return The created tab index.
function P.tab_create(cl)
    local c = cl or client.focus_get()

    if not c then return end

    table.insert(tabbed, {
        c,    -- Window currently being displayed
        { c } -- List of windows in tabbed display
    })

    awful.hooks.userhook_call('tabbed', {c})
    return P.tabindex_get(c)
end

--- Add a client to a tabbed display.
-- @param tabindex The tab index.
-- @param cl The client to add, or the focused one otherwise.
function P.tab(tabindex, cl)
    local c = cl or client.focus_get()

    if tabbed[tabindex] ~= nil then
        local x = P.tabindex_get(c)

        if x == nil then
            -- Add untabbed client to tabindex
            table.insert(tabbed[tabindex][2], c)
            P.display(tabindex, c)

            awful.hooks.userhook_call('tabbed', {c})
        elseif x ~= tabindex then
            -- Merge two tabbed views
            local cc = tabbed[tabindex][1]
            local clients = P.clients_get(x)
            P.untab_all(x)

            tabindex = P.tabindex_get(cc)

            for i,b in pairs(clients) do
                P.tab(tabindex, b)
            end
        end
    end
end

--- Start autotabbing, this automatically tabs new clients when the current
-- client is tabbed.
function P.autotab_start()
    awful.hooks.manage(function (c)
        local sel = client.focus_get()
        local index = P.tabindex_get(sel)

        if index ~= nil then
            -- Currently focussed client is tabbed, 
            -- add the new window to the tabbed display
            P.tab(index, c)
        end
    end)
end

-- Set up hook so we don't leave lost hidden clients
awful.hooks.unmanage(function (c) P.untab(c) end)

return P