-- Ability to read what card is there
local getopt = require('getopt')
local cmds = require('commands')
local taglib = require('taglib')

local desc =
[[This script will automatically recognize and dump full content of a NFC NDEF Initialized tag; non-initialized tags will be ignored.

It also write the dump to an eml-file <uid>.eml.

(The difference between an .eml-file and a .bin-file is that the eml file contains
ASCII representation of the hex-data, with linebreaks between 'rows'. A .bin-file contains the
raw data, but when saving into that for, we lose the infromation about how the memory is structured.
For example: 24 bytes could be 6 blocks of 4 bytes, or vice versa.
Therefore, the .eml is better to use file when saving dumps.)

Arguments:
    -h              this help
    -d              debug logging on

]]
local example = "script run xxx"
local author = "Martin Holst Swende & Asper"
---
-- PrintAndLog
local function prlog(...)
    -- TODO; replace this with a call to the proper PrintAndLog
    print(...)
end
---
-- This is only meant to be used when errors occur
local function oops(err)
    prlog("ERROR: ",err)
    return nil,err
end


-- Perhaps this will be moved to a separate library at one point
local utils = {
    --- Writes an eml-file.
    -- @param uid - the uid of the tag. Used in filename
    -- @param blockData. Assumed to be on the format {'\0\1\2\3,'\b\e\e\f' ...,
    -- that is, blockData[row] contains a string with the actual data, not ascii hex representation
    -- return filename if all went well,
    -- @reurn nil, error message if unsuccessfull
    writeDumpFile = function(uid, blockData)
        local destination = string.format("%s.eml", uid)
        local file = io.open(destination, "w")
        if file == nil then
            return nil, string.format("Could not write to file %s", destination)
        end
        local rowlen = string.len(blockData[1])

        for i,block in ipairs(blockData) do
            if rowlen ~= string.len(block) then
                prlog(string.format("WARNING: Dumpdata seems corrupted, line %d was not the same length as line 1",i))
            end

            local formatString = string.format("H%d", string.len(block))
            local _,hex = bin.unpack(formatString,block)
            file:write(hex.."\n")
        end
        file:close()
        return destination
    end,
}

---
-- Usage help
local function help()
    prlog(desc)
    prlog("Example usage")
    prlog(example)
end

local function debug(...)
    if DEBUG then
        prlog("debug:", ...)
    end
end


--- This function is a lua-implementation of
-- cmdhf14a.c:waitCmd(uint8_t iSelect)
local function waitCmd(iSelect)
    local response = core.WaitForResponseTimeout(cmds.CMD_ACK,1000)
    if response then
        local count,cmd,arg0,arg1,arg2 = bin.unpack('LLLL',response)

        local iLen = arg0
        if iSelect then iLen = arg1 end
        debug(("Received %i octets (arg0:%d, arg1:%d)"):format(iLen, arg0, arg1))
        if iLen == 0 then return nil, "No response from tag" end
        local recv = string.sub(response,count, iLen+count-1)
        return recv
    end
    return nil, "No response from device"
end


local function show(data)
    if DEBUG then
        local formatString = ("H%d"):format(string.len(data))
        local _,hexdata = bin.unpack(formatString, data)
        debug("Hexdata" , hexdata)
    end
end
--- Fire up a connection with a tag, return uid
-- @return UID if successfull
-- @return nil, errormessage if unsuccessfull

local function open()
    debug("Opening connection")
    core.clearCommandBuffer()
    local x = string.format("hf 14a raw -r -p -s")
    debug(x)
    core.console(x)
    debug("done")
    data, err = waitCmd(true)
    if err then return oops(err) end
    show(data)
    local formatString = ("H%d"):format(string.len(data))
    local _,uid = bin.unpack(formatString, data)
    return uid
end
--- Shut down tag communication
-- return no return values
local function close()
    debug("Closing connection")
    core.clearCommandBuffer()
    local x = string.format("hf 14a raw -r")
    debug(x)
    core.console(x)
    debug("done")
    --data, err = waitCmd(true)
    --data, err = waitCmd(false)

end


---_ Gets data from a block
-- @return {block, block+1, block+2, block+3} if successfull
-- @return nil, errormessage if unsuccessfull
local function getBlock(block)
    local data, err

    core.clearCommandBuffer()

    local x = string.format("hf 14a raw -r -c -p 30 %02x", block)
    debug(x)
    core.console(x)
    debug("done")
    -- By now, there should be an ACK waiting from the device, since
    -- we used the -r flag (don't read response).

    data, err = waitCmd(false)
    if err then return oops(err) end
    show(data)

    if string.len(data) < 18 then
        return nil, ("Expected at least 18 bytes, got %d - this tag is not NDEF-compliant"):format(string.len(data))
    end
    -- Now, parse out the block data
    -- 0534 00B9 049C AD7F 4A00 0000 E110 1000 2155
    -- b0b0 b0b0 b1b1 b1b1 b2b2 b2b2 b3b3 b3b3 CRCC
    b0 = string.sub(data,1,4)
    b1 = string.sub(data,5,8)
    b2 = string.sub(data,9,12)
    b3 = string.sub(data,13,16)
    return {b0,b1,b2,b3}
end




local function main( args)
    debug("script started")
    local err, data, data2,k,v,i
    -- Read the parameters
    for o, a in getopt.getopt(args, 'hd') do
        if o == "h" then help() return end
        if o == "d" then DEBUG = true end
    end

    -- Info contained within the tag (block 0 example)
    -- 0534 00B9 049C AD7F 4A00 0000 E110 1000 2155
    -- b0b0 b0b0 b1b1 b1b1 b2b2 b2b2 b3b3 b3b3 CRCC
    -- MM?? ???? ???? ???? ???? ???? NNVV SS?? ----
    -- M = Manufacturer info
    -- N = NDEF-Structure-Compliant (if value is E1)
    -- V = NFC Forum Specification version (if 10 = v1.0)

    -- First, 'connect' (fire up the field) and get the uid
    local uidHexstr = open()

    -- First, get blockt 3 byte 2
    local blocks, err = getBlock(0)
    if err then return oops(err) end
    -- Block 3 contains number of blocks
    local b3chars = {string.byte(blocks[4], 1,4)}
    local numBlocks = b3chars[3] * 2 + 6
    prlog("Number of blocks:", numBlocks)

    -- NDEF compliant?
    if b3chars[1] ~= 0xE1 then
        return oops("This tag is not NDEF-Compliant")
    end

    local ndefVersion = b3chars[2]

    -- Block 1, byte 1 contains manufacturer info
    local bl1_b1 = string.byte(blocks[1], 1)
    local manufacturer = taglib.lookupManufacturer(bl1_b1)

    -- Reuse existing info
    local blockData = {blocks[1],blocks[2],blocks[3],blocks[4]}


    --[[ Due to the infineon my-d move bug
    (if I send 30 0F i receive block0f+block00+block01+block02 insted of block0f+block10+block11+block12)
    the only way to avoid this is to send the read command as many times as block numbers
    removing bytes from 5 to 18 from each answer.
    --]]
    prlog("Dumping data...please wait")
    for i=4,numBlocks-1,1 do
        blocks, err = getBlock(i)
        if err then return oops(err) end
        table.insert(blockData,blocks[1])
    end
    -- Deactivate field
    close()
    -- Print results
    prlog(string.format("Tag manufacturer: %s", manufacturer))
    prlog(string.format("Tag UID: %s", uidHexstr))
    prlog(string.format("Tag NDEF version: 0x%02x", ndefVersion))

    for k,v in ipairs(blockData) do
        prlog(string.format("Block %02x: %02x %02x %02x %02x",k-1, string.byte(v, 1,4)))
    end
    local filename, err = utils.writeDumpFile(uidHexstr, blockData)
    if err then return oops(err) end

    prlog(string.format("Dumped data into %s", filename))

end
main(args)