---------------------------------------------------------------------------
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2008 Julien Danjou
-- @release @AWESOME_VERSION@
---------------------------------------------------------------------------

-- Grab environment we need
local hooks = require("awful.hooks")
local util = require("awful.util")
local pairs = pairs
local ipairs = ipairs
local table = table
local math = math
local otable = otable
local capi =
{
    client = client,
    mouse = mouse,
    screen = screen,
}

--- Client module for awful
module("awful.client")

-- Private data
local data = {}
data.maximize = otable()
data.focus = {}
data.urgent = {}
data.marked = {}

-- Urgent functions
urgent = {}
focus = {}
focus.history = {}

-- User hooks
hooks.user.create('marked')
hooks.user.create('unmarked')

--- Get the first client that got the urgent hint.
-- @return The first urgent client.
function urgent.get()
    if #data.urgent > 0 then
        return #data.urgent[1]
    else
        -- fallback behaviour: iterate through clients and get the first urgent
        local clients = capi.client.get()
        for k, cl in pairs(clients) do
            if cl.urgent then
                return cl
            end
        end
    end
end

--- Jump to the client that received the urgent hint first.
function urgent.jumpto()
    local c = urgent.get()
    if c then
        local s = capi.client.focus and capi.client.focus.screen or capi.mouse.screen
        -- focus the screen
        if s ~= c.screen then
            capi.mouse.screen = c.screen
        end
        -- focus the tag
        tag.viewonly(c:tags()[1])
        -- focus the client
        capi.client.focus = c
        c:raise()
    end
end

--- Adds client to urgent stack.
-- @param c The client object.
-- @param prop The property which is updated.
function urgent.add(c, prop)
    if prop == "urgent" and c.urgent then
        table.insert(data.urgent, c)
    end
end

--- Remove client from urgent stack.
-- @param c The client object.
function urgent.delete(c)
    for k, cl in ipairs(data.urgent) do
        if c == cl then
            table.remove(data.urgent, k)
            break
        end
    end
end

--- Remove a client from the focus history
-- @param c The client that must be removed.
function focus.history.delete(c)
    for k, v in ipairs(data.focus) do
        if v == c then
            table.remove(data.focus, k)
            break
        end
    end
end

--- Filter out window that we do not want handled by focus.
-- This usually means that desktop, dock and splash windows are
-- not registered and cannot get focus.
-- @param c A client.
-- @return The same client if it's ok, nil otherwise.
function focus.filter(c)
    if c.type == "desktop"
        or c.type == "dock"
        or c.type == "splash" then
        return nil
    end
    return c
end

--- Update client focus history.
-- @param c The client that has been focused.
function focus.history.add(c)
    if focus.filter(c) then
        -- Remove the client if its in stack
        focus.history.delete(c)
        -- Record the client has latest focused
        table.insert(data.focus, 1, c)
    end
end

--- Get the latest focused client for a screen in history.
-- @param screen The screen number to look for.
-- @param idx The index: 0 will return first candidate,
-- 1 will return second, etc.
-- @return A client.
function focus.history.get(screen, idx)
    -- When this counter is equal to idx, we return the client
    local counter = 0
    local vc = visible(screen)
    for k, c in ipairs(data.focus) do
        if c.screen == screen then
            for j, vcc in ipairs(vc) do
                if vcc == c then
                    if counter == idx then
                        return c
                    end
                    -- We found one, increment the counter only.
                    counter = counter + 1
                    break
                end
            end
        end
    end
    -- Argh nobody found in history, give the first one visible if there is one
    if counter == 0 then
        return vc[1]
    end
end

--- Focus the previous client in history.
function focus.history.previous()
    local sel = capi.client.focus
    local s
    if sel then
        s = sel.screen
    else
        s = capi.mouse.screen
    end
    local c = focus.history.get(s, 1)
    if c then capi.client.focus = c end
end

--- Get visible clients from a screen.
-- @param The screen number, or nil for all screen.
-- @return A table with all visible clients.
function visible(screen)
    local cls = capi.client.get(screen)
    local vcls = {}
    for k, c in pairs(cls) do
        if c:isvisible() then
            table.insert(vcls, c)
        end
    end
    return vcls
end

--- Get a client by its relative index to the focused window.
-- @usage Set i to 1 to get next, -1 to get previous.
-- @param i The index.
-- @param c Optional client.
-- @return A client, or nil if no client is available.
function next(i, c)
    -- Get currently focused client
    local sel = c or capi.client.focus
    if sel then
        -- Get all visible clients
        local cls = visible(sel.screen)
        -- Remove all no-normal clients
        for idx, c in ipairs(cls) do
            if not focus.filter(c) then
                table.remove(cls, idx)
            end
        end
        -- Loop upon each client
        for idx, c in ipairs(cls) do
            if c == sel then
                -- Cycle
                return cls[util.cycle(#cls, idx + i)]
            end
        end
    end
end

--- Return true whether client B is in the right direction
-- compared to client A.
-- @param dir The direction.
-- @param cA The first client.
-- @param cB The second client.
-- @return True if B is in the direction of A.
local function is_in_direction(dir, cA, cB)
    if dir == "up" then
        return cA['y'] > cB['y']
    elseif dir == "down" then
        return cA['y'] < cB['y']
    elseif dir == "left" then
        return cA['x'] > cB['x']
    elseif dir == "right" then
        return cA['x'] < cB['x']
    end
    return false
end

--- Calculate distance between two points.
-- i.e: if we want to move to the right, we will take the right border
-- of the currently focused client and the left side of the checked client.
-- This avoid the focus of an upper client when you move to the right in a
-- tilebottom layout with nmaster=2 and 5 clients open, for instance.
-- @param dir The direction.
-- @param cA The first client.
-- @param cB The second client.
-- @return The distance between the clients.
local function calculate_distance(dir, cA, cB)
    local xA = cA['x']
    local xB = cB['x']
    local yA = cA['y']
    local yB = cB['y']

    if dir == "up" then
        yB = yB + cB['height']
    elseif dir == "down" then
        yA = yA + cA['height']
    elseif dir == "left" then
        xB = xB + cB['width']
    elseif dir == "right" then
        xA = xA + cA['width']
    end

    return math.sqrt(math.pow(xB - xA, 2) + math.pow(yB - yA, 2))
end

--- Focus a client by the given direction.
-- @param dir The direction, can be either "up", "down", "left" or "right".
-- @param c Optional client.
function focus.bydirection(dir, c)
    local sel = c or capi.client.focus
    if sel then
        local coords = sel:coords()
        local dist, dist_min
        local target = nil
        local cls = visible(sel.screen)

        -- We check each client.
        for i, c in ipairs(cls) do
            -- Check coords to see if client is located in the right direction.
            if is_in_direction(dir, coords, c:coords()) then

                -- Calculate distance between focused client and checked client.
                dist = calculate_distance(dir, coords, c:coords())

                -- If distance is shorter then keep the client.
                if not target or dist < dist_min then
                    target = c
                    dist_min = dist
                end
            end
        end

        -- If we found a client to focus, then do it.
        if target then
            capi.client.focus = target
        end
    end
end

function focusbyidx(i, c)
    util.deprecate()
    return focus.byidx(i, c)
end

--- Focus a client by its relative index.
-- @param i The index.
-- @param c Optional client.
function focus.byidx(i, c)
    local target = next(i, c)
    if target then
        capi.client.focus = target
    end
end

--- Swap a client by its relative index.
-- @param i The index.
-- @param c Optional client, otherwise focused one is used.
function swap(i, c)
    local sel = c or capi.client.focus
    local target = next(i, sel)
    if target then
        target:swap(sel)
    end
end

--- Get the master window.
-- @param screen Optional screen number, otherwise screen mouse is used.
-- @return The master window.
function master(screen)
    local s = screen or capi.mouse.screen
    return visible(s)[1]
end

-- Set the client as slave: put it at the end of other windows.
-- @param c The window to set as slave.
-- @return 
function setslave(c)
    local cls = visible(c.screen)
    for k, v in pairs(cls) do
        c:swap(v)
    end
end

--- Move/resize a client relative to current coordinates.
-- @param x The relative x coordinate.
-- @param y The relative y coordinate.
-- @param w The relative width.
-- @param h The relative height.
-- @param c The optional client, otherwise focused one is used.
function moveresize(x, y, w, h, c)
    local sel = c or capi.client.focus
    local coords = sel:coords()
    coords['x'] = coords['x'] + x
    coords['y'] = coords['y'] + y
    coords['width'] = coords['width'] + w
    coords['height'] = coords['height'] + h
    sel:coords(coords)
end

--- Maximize a client to use the full workarea.
-- @param c A client, or the focused one if nil.
function maximize(c)
    local sel = c or capi.client.focus
    if sel then
        local ws = capi.screen[sel.screen].workarea
        ws.width = ws.width - 2 * sel.border_width
        ws.height = ws.height - 2 * sel.border_width
        if sel.floating and client.data.maximize[sel] then
            sel.floating = client.data.maximize[sel].floating
            if sel.floating then
                sel:coords(client.data.maximize[sel].coords)
            end
            data.maximize[sel] = nil
        else
            data.maximize[sel] = { coords = sel:coords(), floating = sel.floating }
            sel.floating = true
            sel:coords(ws)
        end
    end
end


--- Erase eventual client data in maximize.
-- @param c The client.
local function maximize_clean(c)
    data.maximize[c] = nil
end

--- Move a client to a tag.
-- @param target The tag to move the client to.
-- @param c Optional client to move, otherwise the focused one is used.
function movetotag(target, c)
    local sel = c or capi.client.focus
    if sel then
        -- Check that tag and client screen are identical
        if sel.screen ~= target.screen then return end
        sel:tags({ target })
    end
end

--- Toggle a tag on a client.
-- @param target The tag to toggle.
-- @param c Optional client to toggle, otherwise the focused one is used.
function toggletag(target, c)
    local sel = c or capi.client.focus
    -- Check that tag and client screen are identical
    if sel and sel.screen == target.screen then
        local tags = sel:tags()
        if tags[target] then
            -- If it's the only tag for the window, stop.
            if #tags == 1 then return end
            tags[tags[target]] = nil
        else
            tags[target] = target
        end
        sel:tags(tags)
    end
end

--- Toggle the floating status of a client.
-- @param c Optional client, the focused on if not set.
function togglefloating(c)
    local sel = c or capi.client.focus
    if sel then
        sel.floating = not sel.floating
    end
end

--- Move a client to a screen. Default is next screen, cycling.
-- @param c The client to move.
-- @param s The screen number, default to current + 1.
function movetoscreen(c, s)
    local sel = c or capi.client.focus
    if sel then
        local sc = capi.screen.count()
        if not s then
            s = sel.screen + 1
        end
        if s > sc then s = 1 elseif s < 1 then s = sc end
        sel.screen = s
        capi.mouse.coords(capi.screen[s].coords)
        capi.client.focus = sel
    end
end

--- Mark a client, and then call 'marked' hook.
-- @param c The client to mark, the focused one if not specified.
-- @return True if the client has been marked. False if the client was already marked.
function mark(c)
    local cl = c or capi.client.focus
    if cl then
        for k, v in pairs(data.marked) do
            if cl == v then
                return false
            end
        end

        table.insert(data.marked, cl)

        -- Call callback
        hooks.user.call('marked', cl)
        return true
    end
end

--- Unmark a client and then call 'unmarked' hook.
-- @param c The client to unmark, or the focused one if not specified.
-- @return True if the client has been unmarked. False if the client was not marked.
function unmark(c)
    local cl = c or capi.client.focus

    for k, v in pairs(data.marked) do
        if cl == v then
            table.remove(data.marked, k)
            hooks.user.call('unmarked', cl)
            return true
        end
    end

    return false
end

--- Check if a client is marked.
-- @param c The client to check, or the focused one otherwise.
function ismarked(c)
    local cl = c or capi.client.focus
    if cl then
        for k, v in pairs(data.marked) do
            if cl == v then
                return true
            end
        end
    end
    return false
end

--- Toggle a client as marked.
-- @param c The client to toggle mark.
function togglemarked(c)
    local cl = c or capi.client.focus

    if not client.mark(c) then
        client.unmark(c)
    end
end

--- Return the marked clients and empty the marked table.
-- @return A table with all marked clients.
function getmarked()
    for k, v in pairs(data.marked) do
        hooks.user.call('unmarked', v)
    end

    t = data.marked
    data.marked = {}
    return t
end

-- Register standards hooks
hooks.focus.register(focus.history.add)
hooks.unmanage.register(focus.history.delete)
hooks.unmanage.register(maximize_clean)

hooks.property.register(urgent.add)
hooks.focus.register(urgent.delete)
hooks.unmanage.register(urgent.delete)

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