local awful = require "awful"
local gtable = require "gears.table"
local gdebug = require "gears.debug"
local gfs = require "gears.filesystem"
local h = require "misc.helpers"
local cfg = require "misc.cfg"
local vars = require "misc.vars"
local wibox = require "wibox"
local beautiful = require "beautiful"
local rubato = require "lib.rubato"
local al_prompt = require "lib.bling.widget.app_launcher.prompt"
local btn = awful.button.names

package.cpath = package.cpath .. ";" .. gfs.get_configuration_dir() .. "ui/fresnel/lenses/target/debug/lib?.so"

local lenses = require "lenses"
local max_entries = 10

local fresnel = {}

fresnel._toggled = false
fresnel._entries_exec = {}
fresnel._entries_offset = 0
fresnel._entries_count = 0
fresnel._visible_entries = 0
fresnel._selected_index = 1

function fresnel:_exec_entry(entry_index)
    local exec = self._entries_exec[entry_index]
    if type(exec) ~= "userdata" then
        awful.spawn((exec[2] and cfg.terminal .. " -e " or "") .. exec[1])
    end
end

function fresnel:_update(query, scrolled)
    query = query or ""
    scrolled = scrolled or false

    if not scrolled then
        self._selected_index = 1
        self._entries_offset = 0
    end

    local layout = self._widget.widget:get_children_by_id("entry_layout")[1]
    local status = self._widget.widget:get_children_by_id("status")[1]
    local all_providers = {}
    local entries_count = 0

    self._entries_exec = {}
    layout:reset()
    
    for _, provider in h.opairs(lenses) do
        local entries = provider(query)
        
        table.sort(entries, function(a, b)
            return a.message < b.message
        end)

        all_providers = gtable.join(all_providers, entries)
    end

    self._entries_count = #all_providers

    for i, entry in ipairs(all_providers) do
        if i <= self._entries_offset then
            goto continue
        end
        if entries_count == max_entries then break end
        table.insert(self._entries_exec, entry.exec)

        local entry_widget = wibox.widget {
            widget = wibox.container.background,
            shape = vars.shape,
            {
                widget = wibox.container.margin,
                margins = vars.padding,
                {
                    widget = wibox.container.constraint,
                    strategy = "max",
                    height = vars.char_height,
                    {
                        {
                            widget = wibox.container.background,
                            fg = vars.colors.dim.fg,
                            {
                                widget = wibox.widget.textbox,
                                text = entry.provider .. " | "
                            }
                        },
                        {
                            widget = wibox.widget.textbox,
                            text = entry.message
                        },
                        spacing = vars.padding,
                        layout = wibox.layout.fixed.horizontal
                    }
                }
            },
            buttons = {
                awful.button {
                    modifiers = {},
                    button = btn.LEFT,
                    on_press = function()
                        self:_exec_entry(i)
                    end
                }
            },
            _selected = false
        }

        if self._selected_index + self._entries_offset == i then
            entry_widget._selected = true
            entry_widget.bg = vars.colors.black
        end

        entry_widget:connect_signal("mouse::enter", function()
            if entry_widget._selected == true then return end
            entry_widget.bg = vars.colors.black
        end)

        entry_widget:connect_signal("mouse::leave", function()
            if entry_widget._selected == true then return end
            entry_widget.bg = vars.colors.bg
        end)

        layout:add(entry_widget)

        entries_count = entries_count + 1
        self._visible_entries = entries_count
        ::continue::
    end

    status.text = self._entries_offset + self._selected_index .. "/" .. self._entries_count
end

fresnel._text = ""
fresnel._prompt = al_prompt {
    prompt = "",
    reset_on_stop = true,
    ul_cursor = "low",
    bg_cursor = vars.colors.black,
    changed_callback = function(text)
        if fresnel._text == text then return end
        if fresnel._toggled == false then return end
        fresnel:_update(text)
        fresnel._text = text
    end,
    keypressed_callback = function(mod, key)
        if key == "Escape" or key == " " and mod.Mod4 then
            fresnel:hide()
        elseif key == "Return" then
            fresnel:_exec_entry(fresnel._selected_index)
            fresnel:hide()
        elseif key == "Up" then
            local next_index = fresnel._selected_index - 1
            if next_index < 1 and fresnel._entries_offset == 0 then 
                return
            elseif next_index < 1 and fresnel._entries_offset > 0 then
                fresnel._entries_offset = fresnel._entries_offset - 1
            else
                fresnel._selected_index = next_index
            end

            fresnel:_update(fresnel._text, true)
        elseif key == "Down" then
            local next_index = fresnel._selected_index + 1
            if next_index > fresnel._visible_entries and fresnel._entries_offset + fresnel._visible_entries == fresnel._entries_count then 
                return
            elseif next_index > fresnel._visible_entries and fresnel._entries_offset + fresnel._visible_entries < fresnel._entries_count then
                fresnel._entries_offset = fresnel._entries_offset + 1
            else
                fresnel._selected_index = next_index
            end

            fresnel:_update(fresnel._text, true)
        end
    end
}

fresnel._widget = h.popup {
    visible = false,
    ontop = true,
    placement = function(d)
        awful.placement.top(d, {
            margins = {
                top = beautiful.useless_gap * 2
            }
        })
    end,
    minimum_width = screen[1].geometry.width / 2,
    maximum_width = screen[1].geometry.width / 2,
    widget = {
        {
            widget = wibox.container.background,
            bg = vars.colors.black,
            fg = vars.colors.dim.fg,
            shape = vars.shape,
            {
                widget = wibox.container.margin,
                margins = vars.padding,
                {
                    {
                        widget = wibox.widget.textbox,
                        text = ">"
                    },
                    {
                        widget = wibox.container.margin,
                        margins = {
                            left = vars.padding,
                            right = vars.padding
                        },
                        {
                            widget = wibox.container.constraint,
                            strategy = "max",
                            height = vars.char_height,
                            {
                                widget = wibox.container.background,
                                fg = vars.colors.fg,
                                fresnel._prompt.textbox
                            }
                        }
                    },
                    {
                        widget = wibox.widget.textbox,
                        text = "0/0",
                        id = "status"
                    },
                    layout = wibox.layout.align.horizontal
                }
            }
        },
        {
            widget = wibox.container.margin,
            margins = {
                top = vars.padding
            },
            {
                spacing = vars.padding,
                layout = wibox.layout.fixed.vertical,
                id = "entry_layout"
            }
        },
        layout = wibox.layout.align.vertical
    }
}
fresnel._widget.maximum_height = vars.big_padding * 2 + (vars.padding * 2 + vars.char_height) * (1 + 10) + vars.padding + vars.padding * 9

function fresnel:show()
    self._toggled = true
    self._timed.target = 1
    self:_update()
    self._prompt:start()
end

function fresnel:hide()
    self._toggled = false
    self._timed.target = 0
    self._prompt:stop()
end

fresnel._timed = rubato.timed {
    duration = vars.anim_duration,
    intro = vars.anim_intro,
    pos = 0,
    subscribed = function(pos)
        fresnel._widget.opacity = pos

        if pos == 0 then
            fresnel._widget.visible = false
        else
            fresnel._widget.visible = true
        end
    end
}

return fresnel