-- The getopt-functionality is loaded from pm3/getopt.lua
-- Have a look there for further details
getopt = require('getopt')
bin = require('bin')

copyright = ''
version = ''
example = "script run dumptoemul-mfu -i dumpdata-foobar.bin"
author = "Martin Holst Swende \n @Marshmellow \n @iceman"
usage = "script run dumptoemul-mfu [-i <file>] [-o <file>]"
desc =[[
This script takes a dumpfile from 'hf mfu dump' and converts it to a format that can be used
by the emulator

Arguments:
    -h              This help
    -i <file>       Specifies the dump-file (input). If omitted, 'dumpdata.bin' is used
    -o <filename>   Specifies the output file. If omitted, <uid>.eml is used.

]]
local DEBUG = false

---
-- A debug printout-function
local function dbg(args)
    if not DEBUG then return end

    if type(args) == 'table' then
        local i = 1
        while result[i] do
            dbg(result[i])
            i = i+1
        end
    else
        print('###', args)
    end
end
---
-- This is only meant to be used when errors occur
local function oops(err)
    print('ERROR: ',err)
    return nil,err
end
---
-- Usage help
function help()
    print(desc)
    print(author)
    print("Example usage")
    print(example)
end

local function convert_to_ascii(hexdata)
    if string.len(hexdata) % 8 ~= 0 then
        return oops(("Bad data, length should be a multiple of 8 (was %d)"):format(string.len(hexdata)))
    end

    local js,i = "[";
    for i = 1, string.len(hexdata),8 do
        js = js .."'" ..string.sub(hexdata,i,i+7).."',\n"
    end
    js = js .. "]"
    return js
end

local function readdump(infile)
     t = infile:read("*all")
     len = string.len(t)
     local len,hex = bin.unpack(("H%d"):format(len),t)
     return hex
end

local function convert_to_emulform(hexdata)
    if string.len(hexdata) % 8 ~= 0 then
        return oops(("Bad data, length should be a multiple of 8 (was %d)"):format(string.len(hexdata)))
    end
    local ascii,i = "";
    for i = 1, string.len(hexdata), 8 do
        ascii = ascii..string.sub(hexdata, i, i+7).."\n"
    end
    return string.sub(ascii, 1, -2)
end

local function main(args)

    local input = "dumpdata.bin"
    local output

    for o, a in getopt.getopt(args, 'i:o:h') do
        if o == "h" then return help() end
        if o == "i" then input = a end
        if o == "o" then output = a end
    end
    -- Validate the parameters

    local infile = io.open(input, "rb")
    if infile == nil then
        return oops("Could not read file ", input)
    end
    local dumpdata = readdump(infile)
    -- The hex-data is now in ascii-format,

    -- But first, check the uid
    -- lua uses start index and endindex,  not count.
    -- UID is  3three skip bcc0 then 4bytes.
    -- 1 lua is one-index.
    -- 1 + 112 (56*2)  new dump format has version/signature/counter data here
    -- 113,114,115,116,117,118   UID first three bytes
    -- 119,120 bcc0
    -- 121---  UID last four bytes
    local uid = string.sub(dumpdata, 113, 113+5)..string.sub(dumpdata, 113+8, 113+8+7)
    output = output or (uid .. ".eml")

    -- Format some linebreaks
    dumpdata = convert_to_emulform(dumpdata)

    local outfile = io.open(output, "w")
    if outfile == nil then
        return oops("Could not write to file ", output)
    end

    outfile:write(dumpdata:lower())
    io.close(outfile)
    print(("Wrote an emulator-dump to the file %s"):format(output))
end

--[[
In the future, we may implement so that scripts are invoked directly
into a 'main' function, instead of being executed blindly. For future
compatibility, I have done so, but I invoke my main from here.
--]]
main(args)