---------------------------------------------------------------------------
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2008 Julien Danjou
-- @release @AWESOME_VERSION@
---------------------------------------------------------------------------

-- Grab environment we need
local assert = assert
local io = io
local table = table
local math = math
local capi =
{
    keygrabber = keygrabber
}
local util = require("awful.util")
local beautiful = require("awful.beautiful")

--- Prompt module for awful
module("awful.prompt")

--- Private data
local data = {}
data.history = {}

--- Load history file in history table
-- @param id The data.history identifier which is the path to the filename
-- @param max Optional parameter, the maximum number of entries in file
local function history_check_load(id, max)
    if id and id ~= ""
        and not data.history[id] then
	data.history[id] = { max = 50, table = {} }

	if max then
            data.history[id].max = max
	end

	local f = io.open(id, "r")

	-- Read history file
	if f then
            for line in f:lines() do
                table.insert(data.history[id].table, line)
                if #data.history[id].table >= data.history[id].max then
                   break
		end
            end
	end
    end
end

--- Save history table in history file
-- @param id The data.history identifier
local function history_save(id)
    if data.history[id] then
        local f = io.open(id, "w")
        if not f then
            local i = 0
            for d in id:gmatch(".-/") do
                i = i + #d
            end
            util.mkdir(id:sub(1, i - 1))
            f = assert(io.open(id, "w"))
        end
	for i = 1, math.min(#data.history[id].table, data.history[id].max) do
            f:write(data.history[id].table[i] .. "\n")
        end
       f:close()
    end
end

--- Return the number of items in history table regarding the id
-- @param id The data.history identifier
-- @return the number of items in history table, -1 if history is disabled
local function history_items(id)
    if data.history[id] then
        return #data.history[id].table
    else
        return -1
    end
end

--- Add an entry to the history file
-- @param id The data.history identifier
-- @param command The command to add
local function history_add(id, command)
    if data.history[id] then
        if command ~= ""
            and command ~= data.history[id].table[#data.history[id].table] then
            table.insert(data.history[id].table, command)

            -- Do not exceed our max_cmd
            if #data.history[id].table > data.history[id].max then
                table.remove(data.history[id].table, 1)
            end

            history_save(id)
        end
    end
end


--- Draw the prompt text with a cursor.
-- @param text The text.
-- @param text_color The text color.
-- @param cursor_color The cursor color.
-- @param cursor_pos The cursor position.
-- @param cursor_pos The cursor underline style.
local function prompt_text_with_cursor(text, text_color, cursor_color, cursor_pos, cursor_ul)
    local char
    if not text then text = "" end
    if #text < cursor_pos then
        char = " "
    else
        char = util.escape(text:sub(cursor_pos, cursor_pos))
    end
    local underline = cursor_ul or "none"
    local text_start = util.escape(text:sub(1, cursor_pos - 1))
    local text_end = util.escape(text:sub(cursor_pos + 1))
    return text_start .. "<span background=\"" .. util.color_strip_alpha(cursor_color) .. "\" foreground=\"" .. util.color_strip_alpha(text_color) .. "\" underline=\"" .. underline .. "\">" .. char .. "</span>" .. text_end
end

--- Run a prompt in a box.
-- @param args A table with optional arguments: fg_cursor, bg_cursor, ul_cursor, prompt.
-- @param textbox The textbox to use for the prompt.
-- @param exe_callback The callback function to call with command as argument when finished.
-- @param completion_callback The callback function to call to get completion.
-- @param history_path Optional parameter: file path where the history should be saved, set nil to disable history
-- @param history_max Optional parameter: set the maximum entries in history file, 50 by default
-- @param done_callback Optional parameter: the callback function to always call without arguments, regardless of whether the prompt was cancelled.
function run(args, textbox, exe_callback, completion_callback, history_path, history_max, done_callback)
    local theme = beautiful.get()
    if not args then args = {} end
    local command = ""
    local command_before_comp
    local cur_pos_before_comp
    local prettyprompt = args.prompt or ""
    local inv_col = args.fg_cursor or theme.fg_focus or "black"
    local cur_col = args.bg_cursor or theme.bg_focus or "white"
    local cur_ul = args.ul_cursor

    history_check_load(history_path, history_max)
    local history_index = history_items(history_path) + 1
    -- The cursor position
    local cur_pos = 1
    -- The completion element to use on completion request.
    local ncomp = 1
    if not textbox or not exe_callback then
        return
    end
    textbox.text = prettyprompt .. prompt_text_with_cursor(text, inv_col, cur_col, cur_pos, cur_ul)
    capi.keygrabber.run(
    function (mod, key)
        -- Get out cases
        if mod.Control then
            if key == "c" or key == "g" then
                textbox.text = ""
                if done_callback then done_callback() end
                return false
            elseif key == "j" or key == "m" then
                textbox.text = ""
                exec_callback(command)
                if done_callback then done_callback() end
                return false
            end
        else
            if key == "Return" then
                textbox.text = ""
                history_add(history_path, command)
                exe_callback(command)
                if done_callback then done_callback() end
                return false
            elseif key == "Escape" then
                textbox.text = ""
                if done_callback then done_callback() end
                return false
            end
        end

        -- Control cases
        if mod.Control then
            if key == "a" then
                cur_pos = 1
            elseif key == "b" then
                if cur_pos > 1 then
                    cur_pos = cur_pos - 1
                end
            elseif key == "d" then
                if cur_pos <= #command then
                    command = command:sub(1, cur_pos - 1) .. command:sub(cur_pos + 1)
                end
            elseif key == "e" then
                cur_pos = #command + 1
            elseif key == "f" then
                if cur_pos <= #command then
                    cur_pos = cur_pos + 1
                end
            elseif key == "h" then
                if cur_pos > 1 then
                    command = command:sub(1, cur_pos - 2) .. command:sub(cur_pos)
                    cur_pos = cur_pos - 1
                end
            elseif key == "k" then
                command = command:sub(1, cur_pos - 1)
            elseif key == "u" then
                command = command:sub(cur_pos, #command)
                cur_pos = 1
            elseif key == "w" then
                local wstart = 1
                local wend = 1
                local cword_start = 1
                local cword_end = 1
                while wend < cur_pos do
                    wend = command:find(" ", wstart)
                    if not wend then wend = #command + 1 end
                    if cur_pos >= wstart and cur_pos <= wend + 1 then
                        cword_start = wstart
                        cword_end = cur_pos - 1
                        break
                    end
                    wstart = wend + 1
                end
                command = command:sub(1, cword_start - 1) .. command:sub(cword_end + 1)
                cur_pos = cword_start
            end
        else
            if completion_callback then
                -- That's tab
                if key:byte() == 9 or key == "ISO_Left_Tab" then
                    if key == "ISO_Left_Tab" then
                        if ncomp == 1 then return true end
                        if ncomp == 2 then
                            command = command_before_comp
                            textbox.text = prettyprompt .. prompt_text_with_cursor(command_before_comp, inv_col, cur_col, cur_pos)
                            return true
                        end

                        ncomp = ncomp - 2
                    elseif ncomp == 1 then
                        command_before_comp = command
                        cur_pos_before_comp = cur_pos
                    end
                    command, cur_pos = completion_callback(command_before_comp, cur_pos_before_comp, ncomp)
                    ncomp = ncomp + 1
                    key = ""
                else
                    ncomp = 1
                end
            end

            -- Typin cases
            if key == "Home" then
                cur_pos = 1
            elseif key == "End" then
                cur_pos = #command + 1
            elseif key == "BackSpace" then
                if cur_pos > 1 then
                    command = command:sub(1, cur_pos - 2) .. command:sub(cur_pos)
                    cur_pos = cur_pos - 1
                end
            -- That's DEL
            elseif key:byte() == 127 then
                command = command:sub(1, cur_pos - 1) .. command:sub(cur_pos + 1)
            elseif key == "Left" then
                cur_pos = cur_pos - 1
            elseif key == "Right" then
                cur_pos = cur_pos + 1
            elseif key == "Up" then
                if history_index > 1 then
                    history_index = history_index - 1

                    command = data.history[history_path].table[history_index]
                    cur_pos = #command + 2
                end
            elseif key == "Down" then
               if history_index < history_items(history_path) then
                    history_index = history_index + 1

                    command = data.history[history_path].table[history_index]
                    cur_pos = #command + 2
                elseif history_index == history_items(history_path) then
                    history_index = history_index + 1

                    command = ""
                    cur_pos = 1
                end
            else
                -- len() is UTF-8 aware but #key is not,
                -- so check that we have one UTF-8 char but advance the cursor of # position
                if key:len() == 1 then
                    command = command:sub(1, cur_pos - 1) .. key .. command:sub(cur_pos)
                    cur_pos = cur_pos + #key
                end
            end
            if cur_pos < 1 then
                cur_pos = 1
            elseif cur_pos > #command + 1 then
                cur_pos = #command + 1
            end
        end

        -- Update textbox
        textbox.text = prettyprompt .. prompt_text_with_cursor(command, inv_col, cur_col, cur_pos, cur_ul)

        return true
    end)
end

-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80