--[[
--** --------------------------------------------------------------------------
--** /etc/telegram-cli/tg-cmd-exec.sh - exec script
--**
--** Copyright (c) 2015       Lukas Rose 2015
--** Copyright (c) 2018-2018  The Eisfair Team, team(at)eisfair(dot)org
--**
--** Creation:     2018-03-23  jed
--** Last Update:  $Id$
--**
--** Usage:        tg-cmd-exec.sh cmd message-text
--**
--** Changes:
--**
--** 23.03.2018/JED
--**      - added new function 'trim(s)'.
--**      - made sure that the default separator ' ' (space) is
--**        used in function 'split(str, pat)' if not defined.
--**      - improved function 'check(file, string, separator)'
--**        by adding additional checks and skipping comments.
--**
--** Source: https://github.com/LukeLR/scripts/blob/master/
--**         check-string-in-file/check-string-in-file_tg-example.lua
--**
--** This file is part of LukeLR/scripts.
--**
--** LukeLR/scripts is free software: you can redistribute it and/or
--** modify it under the terms of the cc-by-nc-sa (Creative Commons
--** Attribution-NonCommercial-ShareAlike) as released by the
--** Creative Commons organisation, version 3.0.
--**
--** LukeLR/scripts is distributed in the hope that it will be useful,
--** but without any warranty.
--**
--** You should have received a copy of the cc-by-nc-sa-license along
--** with this copy of LukeLR/scripts. If not, see
--** <https://creativecommons.org/licenses/by-nc-sa/3.0/legalcode>.
--** --------------------------------------------------------------------------
--]]

-- checks if file contains string. only first argument in each line
-- is checked, separated by the given separator, e.g. ' ' (space).

-- checks if file exists. Returns boolean true or false.
function file_exists(file)
    local f = io.open(file, "rb")
    if f then f:close() end
    return f ~= nil
end

-- reads all lines from a file given by path. Result is returned as a table.
function lines_from(file)
    if not file_exists(file) then return {} end
    lines = {}
    local pos = 1
    for line in io.lines(file) do
        lines[pos] = line
        pos = pos+1
    end
    return lines
end

-- trim - trim spaces
function trim(s)
    return s:match'^%s*(.*%S)%s*$' or ''
end

-- print all line numbers and their contents (debug purposes)
function printtable(lines)
    for k,v in pairs(lines) do
        print('line[' .. k .. ']', v)
    end
end

--[[
--** This function splits a given string, which is passed as
--** str into substrings. The separating character is given
--** as pat. The substrings are returned as a table.
--]]
function split(str, pat)
    local t = {}  -- NOTE: use {n = 0} in Lua-5.0
    if (pat == nil) then
        pat = ' '
    end
    local fpat = "(.-)" .. pat
    local last_end = 1
    local s, e, cap = str:find(fpat, 1)
    while s do
        if s ~= 1 or cap ~= "" then
            table.insert(t,cap)
        end
        last_end = e+1
        s, e, cap = str:find(fpat, last_end)
    end
    if last_end <= #str then
        cap = str:sub(last_end)
        table.insert(t, cap)
    end
    return t
end

--[[
--** this function reads a table of string lines (read from
--** the text file in this case), and cuts out the comments
--** which may be included in the line after a seperator Char.
--** The seperator char that splits the lines in arguments and
--** comments is passed as 'separator'. It returns a table of
--** all the arguments that were included in the lines (any text
--** in each line until an instance of 'separator' occurs).
--]]
function extract(lines, separator)
    local result = {}
    for k,v in pairs(lines) do
        local splitted = split(v, separator)
        result[k] = splitted[1]
    end
    while (not lines[count] == nil) do
        local splitted = Split(lines[count], separator)
        result[pos] = splitted[1]
        pos = pos + 1
        count = count + 1
    end
    return result
end

--[[
--** This is the actual main function. It will check if a given
--** string is included in a file specified by file path. Only
--** the first argument in each line of the text file will be
--** read, anything else that follows in that line is treated
--** as a comment and will be ignored. The char passed as
--** 'separator' defines where the argument ends and the comment
--** starts. It will return a Boolean true or false whether the
--** string was included in the file or not.
--]]
function check(file, string, separator)
    if file_exists(file) then
        string    = trim(tostring(string))
        separator = tostring(separator)

        for num, value1, value2 in pairs(extract(lines_from(file), separator)) do
            if (string.match(value1, "^ *%-%-") == nil) then
                -- no comment, compare values ...
                if(trim(tostring(value1)) == string) then
                    print("INFO: file '" .. file .."' contains '" .. string .. "'!")
                    return true
                end
            end
        end
        print("ERROR: file '" .. file .. "' does not contain '" .. string .. "'!")
    else
        print("ERROR: file '" .. file .. "' does not exist!")
    end
    return false
end