local acompletion = require "awful.completion"
local aspawn = require "awful.spawn"
local gstring = require "gears.string"
local gtable = require "gears.table"
local prompt = require "awful.widget.prompt"

local string = string

local function completion_cb(
    self,
    command_before_comp,
    cur_pos_before_comp,
    ncomp
)
    return acompletion.generic(
        command_before_comp,
        cur_pos_before_comp,
        ncomp,
        self.completion_keywords
    )
end

local function exe_cb(self, input)
    -- Exit if the input is empty
    if not input or #input == 0 then
        return
    end

    -- Trim
    input = string.gsub(input, "^%s*(.-)%s*$", "%1")

    -- If the input is not a VI command, spawn it
    if input:sub(1, 1) ~= ":" then
        aspawn(input)
        return
    end

    -- Parse the custom command
    local command, parameters = input:gmatch ":([%w-]+)%s*(.*)"()
    command = command:sub(1, 1)
    parameters = gstring.split(parameters, "%s")

    -- Quit if the command doesn't exist
    if not self.commands[command] then
        print('":' .. command .. '" not reconized as a command')
        return
    end

    self.commands[command].callback(parameters)
end

local my_prompt = { mt = {} }

function my_prompt.new(args)
    local prompt_widget = nil
    prompt_widget = prompt {
        prompt = "<b></b>   ", -- needs the 3 spaces
        completion_callback = function(...)
            return completion_cb(prompt_widget, ...)
        end,
        exe_callback = function(...)
            return exe_cb(prompt_widget, ...)
        end,
    }

    prompt_widget.commands = args.commands
    prompt_widget.completion_keywords = gtable.join(
        -- TODO: find applications list
        gtable.find_keys(args.commands, function()
            return true
        end, false),
        args.completion_keywords or {}
    )

    return prompt_widget
end

function my_prompt.mt:__call(...)
    return my_prompt.new(...)
end

return setmetatable(my_prompt, my_prompt.mt)