#!/usr/bin/env lua5.3

-- needs xsel, clipnotify
-- needs luaposix, luarocks-5.3 install --local luaposix
-- cat .clip_history | dmenu -l 10 | xsel -ib
local function default_luarocks_modules()
    local luarocks_handle = io.popen("luarocks-5.3 path --bin")
    local path_b = false
    local cpath_b = false
    for line in luarocks_handle:lines() do
        local path = string.match(line, "LUA_PATH%s*=%s*('.+')")
        local cpath = string.match(line, "LUA_CPATH%s*=%s*('.+')")
        if path ~= nil then
            package.path = package.path .. ";" .. string.sub(path, 2, -2)
        end
        if cpath ~= nil then
            package.cpath = package.cpath .. ";" .. string.sub(cpath, 2, -2)
        end
    end

    if path_b then os.exit(1) end
    if cpath_b then os.exit(1) end
end
default_luarocks_modules()

local string = require("string")
local signal = require("posix.signal")

signal.signal(signal.SIGINT, function(signum) os.exit(128 + signum) end)

local function sleep(n) os.execute("sleep " .. tonumber(n)) end

local function loop()
    local clip_hist_size = 100
    local clip_hist = "/home/devi/.clip_history"

    local matched = false
    while true do
        local wait_for_event = io.popen("clipnotify")

        local handle = io.popen("xsel -ob")
        local last_clip_entry = handle:read("*a")
        local hist_file = io.open(clip_hist, "r")
        local hist_current_count = 0
        local clips_table = {}

        for line in hist_file:lines() do
            hist_current_count = hist_current_count + 1
            if (string.sub(line, 0, string.len(line)) == last_clip_entry) then
                matched = true
            end
            if line ~= "\n" and line ~= "" and line ~= "\r\n" and line ~= " " then
                table.insert(clips_table, line)
            end
        end
        hist_file:close()
        hist_file = io.open(clip_hist, "w")
        if matched ~= true then
            if last_clip_entry[-1] == "\n" then
                table.insert(clips_table, string.sub(last_clip_entry, 0,
                                                     string.len(last_clip_entry)))
            else
                table.insert(clips_table, last_clip_entry)
            end
        end
        if hist_current_count >= clip_hist_size then
            table.remove(clips_table, 1)
        end
        for _, v in ipairs(clips_table) do hist_file:write(v .. "\n") end
        matched = false
        hist_file:close()
        wait_for_event:close()
        handle:close()
        sleep(.2)
    end
end

loop()