local awibar = require 'awful.wibar'
local awful = require 'awful'
local battery_widget = require 'battery-widget'
local beautiful = require 'beautiful'

local container_background = require 'wibox.container.background'
local container_margin = require 'wibox.container.margin'
local container_place = require 'wibox.container.place'

local gshape = require 'gears.shape'

local layout_align = require 'wibox.layout.align'
local layout_fixed = require 'wibox.layout.fixed'

local systray = require 'wibox.widget.systray'
local textclock = require 'wibox.widget.textclock'
local widget = require 'wibox.widget'

local mycommands = require 'rc.configuration.prompt_commands'
local mymainmenu = require 'rc.ui.menu.mymainmenu'
local mytaglist = require 'MyTagListWidget'

local bar_widgets = require 'rc.ui.desktop_decoration.bar.widgets'
local mybattery = bar_widgets.battery
local myprompt = bar_widgets.prompt

local capi = {
    screen = _G.screen
}

local abs = math.abs
local dpi = beautiful.xresources.apply_dpi

local function get_screen_id (screen)
    local s = capi.screen[screen or 1]

    return s.index
end

--- Build a widget box in the bar.
-- A widget box is a combinaision of "shaped" `wibox.container/background` and
-- `wibox.container.margin` to create this nice round-colored-buttons I like.
-- @tparam args table
-- @tparam args.screen The screen where the widget will be drawn.
-- @tparam args.widget The widget to draw.
-- @tparam[opt] args.bg The box's background.
-- @tpram[opt] args.fg The box's foreground (used mainly for textbox text color).
-- @treturn wibox.container.background The builded widget.
local function build_widget (args)
    local screen_id = get_screen_id(args.screen)

    -- Callback for the shape function.
    -- If the widget is almost a square: draw a circle. Otherwise, draw a
    -- rounded_bar.
    local shape_callback = function (cr, width, height)
        local shape = gshape.circle

        -- 10 is an arbitrary value I found after some tests :shrug:
        if abs(width - height) > 10 then
            shape = gshape.rounded_bar
        end

        return shape(cr, width, height)
    end

    local box_widget = widget {
        widget = container_background,
        shape = shape_callback,
        bg = args.bg,
        fg = args.fg,
        {
            widget = container_margin,
            draw_empty = false,
            top = dpi(beautiful.bar_box_padding_y, screen_id),
            bottom = dpi(beautiful.bar_box_padding_y, screen_id),
            right = dpi(beautiful.bar_box_padding_x, screen_id),
            left = dpi(beautiful.bar_box_padding_x, screen_id),
            args.widget
        }
    }

    return box_widget
end

local bar = { _private = { instances = {} }, mt = {} }

bar.widgets = bar_widgets

--- Get the bar instance for a given screen.
-- If no instance was found, we build a new one.
-- @tparam screen screen|integer The bar's screen.
-- @treturn wibox.wibar
function bar:instance (screen)
    local screen_id = get_screen_id(screen)
    local instance = self._private.instances[screen_id]

    if not instance then
        instance = bar.new(screen)
        self._private.instances[screen_id] = instance
    end

    return instance
end

function bar.new (screen)
    local my_bar = {}

    my_bar.launcher = build_widget {
        screen = screen,
        bg = '#2196F3',
        widget = awful.widget.launcher {
            image = beautiful.icon_apps,
            menu = mymainmenu()
        }
    }

    my_bar.textclock = build_widget {
        bg = '#FF5722',
        fg = '#ECEFF1',
        widget = textclock('%l:%M %p')
    }

    my_bar.promptbox = myprompt {
        commands = mycommands
    }

    -- This widget needs to be reworded and integrated inside the project.
    my_bar.taglist = mytaglist.new {
        screen = screen
    }

    my_bar.battery = build_widget {
        screen = screen,
        bg = '#673AB7',
        widget = mybattery {
            screen = screen,
            device_path = battery_widget.get_BAT0_device_path(),
            color = '#ECEFF1'
        }
    }

    my_bar.systray = build_widget {
        screen = screen,
        bg = '#455A64',
        widget = systray()
    }

    my_bar.wibar = awibar {
        screen = screen,
        position = 'bottom',
        height = dpi(beautiful.bar_height, screen),
        width = beautiful.bar_width -- Width is a percentage of the screen size
    }

    my_bar.wibar:setup {
        -- Bar margins
        widget = container_margin,
        top = dpi(beautiful.bar_margin_y, screen),
        bottom = dpi(beautiful.bar_margin_y, screen),
        right = dpi(beautiful.bar_margin_x, screen),
        left = dpi(beautiful.bar_margin_x, screen),
        {
            -- Physical bar
            widget = container_background,
            bg = '#263238D9',
            shape = function (cr, width, height)
                gshape.rounded_rect(cr, width, height, 10)
            end,
            {
                -- Bar paddings
                widget = container_margin,
                top = dpi(beautiful.bar_padding_y, screen),
                bottom = dpi(beautiful.bar_padding_y, screen),
                right = dpi(beautiful.bar_padding_x, screen),
                left = dpi(beautiful.bar_padding_x, screen),
                {
                    -- Bar content
                    layout = layout_align.horizontal,
                    {
                        -- Left side of the bar, box margins
                        widget = container_margin,
                        top = dpi(beautiful.bar_box_margin_y, screen),
                        bottom = dpi(beautiful.bar_box_margin_y, screen),
                        right = dpi(beautiful.bar_box_margin_x, screen),
                        left = dpi(beautiful.bar_box_margin_x, screen),
                        {
                            -- Left widget boxes
                            layout = layout_fixed.horizontal,
                            spacing = dpi(beautiful.bar_box_spacing, screen),
                            my_bar.launcher,
                            my_bar.promptbox
                        }
                    },

                    -- Middle widget is the custom taglist
                    -- it doesn't need box/margins/...
                    {
                        widget = container_place,
                        my_bar.taglist
                    },
                    {
                        -- Right side of the bar, box margins
                        widget = container_margin,
                        top = dpi(beautiful.bar_box_margin_y, screen),
                        bottom = dpi(beautiful.bar_box_margin_y, screen),
                        right = dpi(beautiful.bar_box_margin_x, screen),
                        left = dpi(beautiful.bar_box_margin_x, screen),
                        {
                            -- Right widget boxes
                            layout = layout_fixed.horizontal,
                            spacing = dpi(beautiful.bar_box_spacing, screen),
                            my_bar.systray,
                            my_bar.battery,
                            my_bar.textclock
                        }
                    }
                }
            }
        }
    }

    return my_bar
end

function bar.mt:__call (...)
    return self:instance(...)
end

return setmetatable(bar, bar.mt)