---------------------------------------------------------------------------
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2009 Julien Danjou
-- @release @AWESOME_VERSION@
---------------------------------------------------------------------------

-- Grab environment we need
local capi =
{
    awesome = awesome,
    screen = screen,
    wibox = wibox
}
local setmetatable = setmetatable
local ipairs = ipairs
local table = table
local type = type
local hooks = require("awful.hooks")

--- Wibox module for awful.
module("awful.wibox")

-- Array of table with wiboxes inside.
-- It's an array so it is ordered.
local wiboxes = {}

hooks.user.create("wibox_position")

--- Get the workarea space without wiboxes geometry.
-- @param s The screen number.
-- @return The screen workarea.
function get_workarea(s)
    local area = capi.screen[s].workarea
    for _, wprop in ipairs(wiboxes) do
        if wprop.wibox.visible and wprop.wibox.screen == s then
            if wprop.position == "top" then
                area.y = area.y + wprop.wibox:geometry().height
                area.height = area.height - wprop.wibox:geometry().height
            elseif wprop.position == "bottom" then
                area.height = area.height - wprop.wibox:geometry().height
            elseif wprop.position == "left" then
                area.x = area.x + wprop.wibox:geometry().width
                area.width = area.width - wprop.wibox:geometry().width
            elseif wprop.position == "right" then
                area.width = area.width - wprop.wibox:geometry().width
            end
        end
    end
    return area
end

local function compute_area(wibox, position, s)
    local s = wibox.screen or s or 1
    local area = capi.screen[s].workarea
    local ignore = false
    for _, wprop in ipairs(wiboxes) do
        if wprop.wibox == wibox then
            ignore = true
        elseif wprop.wibox.visible and wprop.wibox.screen == s
           and not (ignore and wprop.position == position) then
            if (wprop.position == "right" or wprop.position == "left")
                and wprop.position == position then
                area.x = area.x + wibox:geometry().width
            elseif wprop.position == "top" then
                if position == "top" then
                    area.y = area.y + wprop.wibox:geometry().height
                elseif position == "left" or position == "right" then
                    area.height = area.height - wprop.wibox:geometry().height
                    area.y = area.y + wprop.wibox:geometry().height
                end
            elseif wprop.position == "bottom" then
                if position == "bottom" then
                    area.y = area.y - wprop.wibox:geometry().height
                elseif position == "left" or position == "right" then
                    area.height = area.height - wprop.wibox:geometry().height
                end
            end
        end
    end
    return area
end

--- Get a wibox position if it has been set, or return top.
-- @param wibox The wibox
-- @return The wibox position.
function get_position(wibox)
    for _, wprop in ipairs(wiboxes) do
        if wprop.wibox == wibox then
            return wprop.position
        end
    end
    return "top"
end

--- Attach a wibox to a screen at the position.
-- @param wibox The wibox to attach.
-- @param position The position: top, bottom left or right.
-- @param screen If the wibox it not attached to a screen, specified on which
-- screen the position should be set.
function set_position(wibox, position, screen)
    local area = compute_area(wibox, position, screen)

    local wingeom = wibox:geometry()

    -- The "length" of a wibox is always chosen to be the optimal size
    -- (non-floating).
    -- The "width" of a wibox is kept if it exists.
    if position == "right" then
        wingeom.x = area.x + area.width - wingeom.width
    elseif position == "left" then
        wingeom.x = area.x
    elseif position == "bottom" then
        wingeom.y = (area.y + area.height) - wingeom.height
    elseif position == "top" then
        wingeom.y = area.y
    end

    wibox:geometry(wingeom)
end

-- Reset all wiboxes positions.
local function update_all_wiboxes_position()
    for _, wprop in ipairs(wiboxes) do
        set_position(wprop.wibox, wprop.position)
        hooks.user.call("wibox_position", wprop.wibox)
    end
end

--- Attach a wibox to a screen.
-- If a wibox is attached, it will be automatically be moved when other wiboxes
-- will be attached.
-- @param wibox The wibox to attach.
-- @param position The position of the wibox: top, bottom, left or right.
function attach(wibox, position)
    -- Store wibox as attached in a weak-valued table
    local wibox_prop_table
    -- Start from end since we sometimes remove items
    for i = #wiboxes, 1, -1 do
        -- Since wiboxes are stored as weak value, they can disappear.
        -- If they did, remove their entries
        if wiboxes[i].wibox == nil then
            table.remove(wiboxes, i)
        elseif wiboxes[i].wibox == wibox then
            wibox_prop_table = wiboxes[i]
            -- We could break here, but well, let's check if there is no other
            -- table with their wiboxes been garbage collected.
        end
    end

    if not wibox_prop_table then
        table.insert(wiboxes,
        setmetatable({ wibox = wibox, position = position }, { __mode = 'v' }))
    else
        wibox_prop_table.position = position
    end

    if wibox.screen and wibox.visible then
        update_all_wiboxes_position()
    end
end

--- Align a wibox.
-- @param wibox The wibox.
-- @param align The alignment: left, right or center.
-- @param screen If the wibox is not attached to any screen, you can specify the
-- screen where to align. Otherwise 1 is assumed.
function align(wibox, align, screen)
    local position = get_position(wibox)
    local area = compute_area(wibox, position, screen)
    local wingeom = wibox:geometry()

    if position == "right" then
        if align == "right" then
            wingeom.y = area.y
        elseif align == "left" then
            wingeom.y = area.y + area.height - wingeom.height
        elseif align == "center" then
            wingeom.y = area.y + (area.height - wingeom.height) / 2
        end
    elseif position == "left" then
        if align == "right" then
            wingeom.y = (area.y + area.height) - wingeom.height
        elseif align == "left" then
            wingeom.y = area.y
        elseif align == "center" then
            wingeom.y = area.y + (area.height - wingeom.height) / 2
        end
    elseif position == "bottom" then
        if align == "right" then
            wingeom.x = area.x + area.width - wingeom.width
        elseif align == "left" then
            wingeom.x = area.x
        elseif align == "center" then
            wingeom.x = area.x + (area.width - wingeom.width) / 2
        end
    elseif position == "top" then
        if align == "right" then
            wingeom.x = area.x + area.width - wingeom.width
        elseif align == "left" then
            wingeom.x = area.x
        elseif align == "center" then
            wingeom.x = area.x + (area.width - wingeom.width) / 2
        end
    end

    wibox:geometry(wingeom)
end

--- Stretch a wibox so it takes all screen width or height.
-- @param wibox The wibox.
function stretch(wibox)
    local position = get_position(wibox)
    local area = compute_area(wibox, position)
    local wingeom = {}
    if position == "right" or position == "left" then
        wingeom.height = area.height
        wibox:geometry(wingeom)
        align(wibox, "center")
    else
        wingeom.width = area.width
        wibox:geometry(wingeom)
        align(wibox, "left")
    end
end

--- Create a new wibox and attach it to a screen edge.
-- @see capi.wibox
-- @param args A table with standard arguments to wibox() creator.
-- You can add also position key with value top, bottom, left or right.
-- You can also set the screen key with a screen number to attach the wibox.
-- If not specified, 1 is assumed.
-- @return The wibox created.
function new(arg)
    local screen = screen or 1
    local arg = arg or {}
    local position = arg.position or "top"
    -- Empty position and align in arg so we are passing deprecation warning
    arg.position = nil

    local w = capi.wibox(arg)

    if position == "left" then
        w.orientation = "north"
        w:geometry({ width = capi.awesome.font_height * 1.5 })
    elseif position == "right" then
        w.orientation = "south"
        w:geometry({ width = capi.awesome.font_height * 1.5 })
    end

    w.screen = arg.screen or 1

    attach(w, position)
    stretch(w)

    return w
end

local function update_wiboxes_position(obj, prop)
    if (type(obj) == "wibox"
        and (prop == nil
             or prop == "visible"
             or prop == "screen"))
        or (type(obj) == "client"
            and prop == "struts") then
            update_all_wiboxes_position()
    end
end

local function update_wiboxes_on_struts(c)
    local struts = c:struts()
    if struts.left ~= 0 or struts.right ~= 0
       or struts.top ~= 0 or struts.bottom ~= 0 then
        update_all_wiboxes_position()
    end
end

-- Hook registered to reset all wiboxes position.
hooks.property.register(update_wiboxes_position)
hooks.manage.register(update_wiboxes_on_struts)
hooks.unmanage.register(update_wiboxes_on_struts)

setmetatable(_M, { __call = function(_, ...) return new(...) end })

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