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 (self, ...)
    return my_prompt.new(...)
end

return setmetatable(my_prompt, my_prompt.mt)