local M = {}

local awful     = require("awful")
local beautiful = require("beautiful")
local wibox     = require("wibox")

local Page = {}

function Page:set_active(active)
    local border_color = nil
    if active then
        border_color = beautiful.border_focus or '#ffffff'
    else
        border_color = beautiful.border_normal or '#000000'
    end
    self.border:set_color(border_color)
end

function Page:update()
    local font = beautiful.small_text_font or "sans 7"

    self.client_container:reset()
    for i, client in pairs(self.tag:clients()) do
        local text     = client.name

        local bg_normal = beautiful.bg_normal or "#000000"
        local fg_normal = beautiful.fg_normal or "#ffffff"
        local bg_focus  = beautiful.bg_focus  or "#ffffff"
        local fg_focus  = beautiful.fg_focus  or "#000000"

        local tb       = wibox.widget.textbox(text, true)
        local bg       = wibox.container.background(tb, bg)

        tb:set_font(font)

        client:connect_signal("property::name", function() tb:set_text(client.name or "") end)
        client:connect_signal("focus",
            function(c)
                if c.screen == self.pager.init_data.screen then
                    bg:set_bg(bg_focus)
                    bg:set_fg(fg_focus)
                end
            end)
        client:connect_signal("unfocus",
            function(c)
                if c.screen == self.pager.init_data.screen then
                    bg:set_bg(bg_normal)
                    bg:set_fg(fg_normal)
                end
            end)

        self.client_container:add(bg)
    end
end

function Page:new(tag, index, width, height, pager)
    local ret = setmetatable({}, self)
    self.__index = self

    local client_container = wibox.layout.flex.vertical()

    local border_width = beautiful.border_width or 1
    local margin       = wibox.container.margin(client_container)
    margin:set_top(border_width)
    margin:set_bottom(border_width)

    ret.widget = wibox.container.constraint(margin, 'exact', width, height)

    ret.client_container = client_container
    ret.border           = margin
    ret.tag              = tag
    ret.pager            = pager

    tag:connect_signal('tagged',   function (c) ret:update() end)
    tag:connect_signal('untagged', function (c) ret:update() end)

    ret:set_active(false)
    ret:update()

    return ret
end

local function pager_set_active(self, screen, page_idx)
    if self.init_data.screen == screen then
        if self.active_page then
            self.active_page:set_active(false)
        end
        self.pages[page_idx]:set_active(true)
        self.active_page = self.pages[page_idx]
    end
end

local function pager_set_desktop(self, desktop)
    if self._desktop == desktop then
        print('same desktop')
        return
    end

    local init_data = self.init_data

    print("pager " .. init_data.screen.index .. " set desktop")

    self.widget:reset()

    self.active_page = nil
    self.pages       = {}

    local nb_pages = #desktop.pages
    local page_height = self.init_data.height / nb_pages

    local title = wibox.widget.textbox(desktop.name, false)
    title:set_align("center")
    local title_bg = beautiful.bg_focus or "#ffffff"
    local title_fg = beautiful.fg_focus or "#000000"
    local title_container = wibox.container.background(title, title_bg)
    title_container:set_fg(title_fg)

    desktop:connect_signal("desktop:name",
        function(desktop, name)
            title:set_text(name)
        end)

    self.widget:add(title_container)

    for i = 1, nb_pages do
        local page = desktop.pages[i]
        self.pages[i] = Page:new(page, i, self.init_data.width, page_height, self)
        self.widget:add(self.pages[i].widget)
    end

    desktop:connect_signal("page:view",
        function(desktop, s, page_idx)
            pager_set_active(self, s, page_idx) end)

    self._desktop = desktop
end

local Pager = {}

function Pager:new(screen, width, height)
    local ret = setmetatable({}, self)
    self.__index = self

    ret.widget = wibox.layout.fixed.vertical()

    ret.init_data = { screen = screen, width = width, height = height }
    ret.set_desktop = pager_set_desktop

    return ret
end

M.Pager = Pager

return M