--------------------------------------------------------------------
-- Author - jareckib - 25.01.2025
-- Based on Equipter's tutorial - Downgrade Paxton to EM410x
---------------------------------------------------------------------
local getopt = require('getopt')
local utils = require('utils')
local ac = require('ansicolors')
local os = require('os')
local dash = string.rep('--', 32)

local function read_log_file(logfile)
    local file = io.open(logfile, "r")
    if not file then
        error("Could not open the file")
    end
    local content = file:read("*all")
    file:close()
    return content
end

local function parse_blocks(result)
    local blocks = {}
    for line in result:gmatch("[^\r\n]+") do
        local block_num, block_data = line:match("%[%=%]%s+%d/0x0([4-7])%s+%|%s+([0-9A-F ]+)")
        if block_num and block_data then
            block_num = tonumber(block_num)
            block_data = block_data:gsub("%s+", "")
            blocks[block_num] = block_data
        end
    end
    return blocks
end

local function hex_to_bin(hex_string)
    local bin_string = ""
    local hex_to_bin_map = {
        ['0'] = "0000", ['1'] = "0001", ['2'] = "0010", ['3'] = "0011",
        ['4'] = "0100", ['5'] = "0101", ['6'] = "0110", ['7'] = "0111",
        ['8'] = "1000", ['9'] = "1001", ['A'] = "1010", ['B'] = "1011",
        ['C'] = "1100", ['D'] = "1101", ['E'] = "1110", ['F'] = "1111"
    }
    for i = 1, #hex_string do
        bin_string = bin_string .. hex_to_bin_map[hex_string:sub(i, i)]
    end
    return bin_string
end

local function remove_last_two_bits(binary_str)
    return binary_str:sub(1, #binary_str - 2)
end

local function split_into_5bit_chunks(binary_str)
    local chunks = {}
    for i = 1, #binary_str, 5 do
        table.insert(chunks, binary_str:sub(i, i + 4))
    end
    return chunks
end

local function remove_parity_bit(chunks)
    local no_parity_chunks = {}
    for _, chunk in ipairs(chunks) do
        if #chunk == 5 then
            table.insert(no_parity_chunks, chunk:sub(2))
        end
    end
    return no_parity_chunks
end

local function convert_to_hex(chunks)
    local hex_values = {}
    for _, chunk in ipairs(chunks) do
        if #chunk > 0 then
            table.insert(hex_values, string.format("%X", tonumber(chunk, 2)))
        end
    end
    return hex_values
end

local function convert_to_decimal(chunks)
    local decimal_values = {}
    for _, chunk in ipairs(chunks) do
        table.insert(decimal_values, tonumber(chunk, 2))
    end
    return decimal_values
end

local function find_until_before_f(hex_values)
    local result = {}
    for _, value in ipairs(hex_values) do
        if value == 'F' then
            break
        end
        table.insert(result, value)
    end
    return result
end

local function process_block(block)
    local binary_str = hex_to_bin(block)
    binary_str = remove_last_two_bits(binary_str)
    local chunks = split_into_5bit_chunks(binary_str)
    local no_parity_chunks = remove_parity_bit(chunks)
    return no_parity_chunks
end

local function calculate_id_net(blocks)
    local all_hex_values = {}
    for _, block in ipairs(blocks) do
        local hex_values = convert_to_hex(process_block(block))
        for _, hex in ipairs(hex_values) do
            table.insert(all_hex_values, hex)
        end
    end
    local selected_hex_values = find_until_before_f(all_hex_values)
    if #selected_hex_values == 0 then
        error(ac.red..'Error: '..ac.reset..'No valid data found in blocks 4 and 5')
    end
    local combined_hex = table.concat(selected_hex_values)
    if not combined_hex:match("^%x+$") then
        error(ac.red..'Error: '..ac.reset..'Invalid data in blocks 4 and 5')
    end
    local decimal_id = tonumber(combined_hex)
    local stripped_hex_id = string.format("%X", decimal_id)
    local padded_hex_id = string.format("%010X", decimal_id)
    return decimal_id, padded_hex_id
end

local function calculate_id_switch(blocks)
    local all_decimal_values = {}
    for _, block in ipairs(blocks) do
        local decimal_values = convert_to_decimal(process_block(block))
        for _, dec in ipairs(decimal_values) do
            table.insert(all_decimal_values, dec)
        end
    end
    if #all_decimal_values < 15 then
        error(ac.red..' Error:'..ac.reset..' Not enough data after processing blocks 4, 5, 6, and 7')
    end
    local id_positions = {9, 11, 13, 15, 2, 4, 6, 8}
    local id_numbers = {}
    for _, pos in ipairs(id_positions) do
        table.insert(id_numbers, all_decimal_values[pos])
    end
    local decimal_id = tonumber(table.concat(id_numbers))
    local padded_hex_id = string.format("%010X", decimal_id)
    return decimal_id, padded_hex_id
end

local function log_result(blocks, em410_id)
    local dir = os.getenv('HOME')..'/.proxmark3/logs/'
    local log_file_path = dir .. 'Paxton_log.txt'
    local log_file = io.open(log_file_path, "a")
    if log_file then
        log_file:write("Date: ", os.date("%Y-%m-%d %H:%M:%S"), "\n")
        for i = 4, 7 do
            log_file:write(string.format("Block %d: %s\n", i, blocks[i] or "nil"))
        end
        log_file:write(string.format('EM4102 ID: %s\n', em410_id))
        log_file:close()
    else
        print("Failed to open log file for writing.")
    end
end

local function handle_cloning(decimal_id, padded_hex_id, blocks)
    local previous_choice = nil

    while true do
        if not previous_choice then
            io.write('  Create Paxton choose '..ac.cyan..'1'..ac.reset..' or EM4102 choose '..ac.cyan..'2'..ac.reset..' >')
            previous_choice = io.read()
        end

        if previous_choice == "1" then
            io.write('  Place the '..ac.cyan..'Paxton'..ac.reset..' Fob on the coil to write..'..ac.green..' ENTER'..ac.reset..' to continue >')
            io.read()
            print(dash)
            core.console('lf hitag wrbl --ht2 -p 4 -d ' .. blocks[4] .. ' -k BDF5E846')
            core.console('lf hitag wrbl --ht2 -p 5 -d ' .. blocks[5] .. ' -k BDF5E846')
            core.console('lf hitag wrbl --ht2 -p 6 -d ' .. blocks[6] .. ' -k BDF5E846')
            core.console('lf hitag wrbl --ht2 -p 7 -d ' .. blocks[7] .. ' -k BDF5E846')
            break
        elseif previous_choice == "2" then
            io.write('  Place the '..ac.cyan..'T5577'..ac.reset..' tag on the coil and press'..ac.green..' ENTER'..ac.reset..' to continue >')
            io.read()
            print(dash)
            core.console('lf em 410x clone --id ' .. padded_hex_id)
            break
        else
            print(ac.yellow..'  Invalid choice.'..ac.reset..' Please enter'..ac.cyan..' 1'..ac.reset..' or'..ac.cyan..' 2'..ac.reset)
            previous_choice = nil
        end
    end

    while true do
        print(dash)
        io.write('  Make next RFID Fob'..ac.green..' (y/n)'..ac.reset..' >')
        local another = io.read()
        if another:lower() == 'n' then
            print()
            print(ac.yellow..'  Paxton_log.txt file created in directory: '..ac.green..'logs'..ac.reset)
            print(dash)
            print()
            os.exit(1)
        elseif another:lower() == 'y' then
            if previous_choice == "1" then
                io.write('  Place the '..ac.cyan..'Paxton'..ac.reset..' Fob on the coil to write..'..ac.green..' ENTER'..ac.reset..' to continue..')
                io.read()
                print(dash)
                core.console('lf hitag wrbl --ht2 -p 4 -d ' .. blocks[4] .. ' -k BDF5E846')
                core.console('lf hitag wrbl --ht2 -p 5 -d ' .. blocks[5] .. ' -k BDF5E846')
                core.console('lf hitag wrbl --ht2 -p 6 -d ' .. blocks[6] .. ' -k BDF5E846')
                core.console('lf hitag wrbl --ht2 -p 7 -d ' .. blocks[7] .. ' -k BDF5E846')
            elseif previous_choice == "2" then
                io.write('  Place the '..ac.cyan..'T5577'..ac.reset..' tag on the coil and press'..ac.green..' ENTER'..ac.reset..' to continue..')
                io.read()
                print(dash)
                core.console('lf em 410x clone --id ' .. padded_hex_id)
            end
        else
            print(ac.yellow..'  Invalid response.'..ac.reset..' Please enter'..ac.cyan..' y'..ac.reset..' or'..ac.cyan..' n'..ac.reset)
        end
    end
end

local function is_valid_hex(input)
    return #input == 8 and input:match("^[0-9A-Fa-f]+$")
end

local function main()
    while true do
        core.console('clear')
        print()
        print(dash)

        local input_option
        print(ac.green .. '  Select option: ' .. ac.reset)
        print(ac.cyan .. '  1' .. ac.reset .. ' - Read Paxton blocks 4-7 to make a copy')
        print(ac.cyan .. '  2' .. ac.reset .. ' - Manually input data for Paxton blocks 4-7')
        print(dash)
        while true do
            io.write('  Your choice'..ac.cyan..' (1/2) '..ac.reset..'>')
            input_option = io.read()

            if input_option == "1" or input_option == "2" then
                break
            else
                print(ac.yellow .. '  Invalid choice.' .. ac.reset .. ' Please enter ' .. ac.cyan .. '1' .. ac.reset .. ' or ' .. ac.cyan .. '2' .. ac.reset)
            end
        end

        if input_option == "1" then
            local show_place_message = true
            while true do
                if show_place_message then
                    print('  Place the' .. ac.cyan .. ' Paxton' .. ac.reset .. ' Fob on the coil to read..' .. ac.green .. 'ENTER' .. ac.reset .. ' to continue..')
                    print(dash)
                end
                io.read()

                core.console('lf hitag read --ht2 -k BDF5E846')
                core.console('clear')

                local dir = os.getenv('HOME') .. '/.proxmark3/logs/'
                local logfile = (io.popen('dir /a-d /o-d /tw /b/s "' .. dir .. '" 2>nul:'):read("*a"):match("%C+"))
                if not logfile then
                    error("No files in this directory")
                end

                local result = read_log_file(logfile)
                local blocks = parse_blocks(result)

                local empty_block = false
                for i = 4, 7 do
                    if not blocks[i] then
                        empty_block = true
                        break
                    end
                end

                if empty_block then
                    print(dash)
                    print(ac.yellow .. '  Adjust the Fob position on the coil.' .. ac.reset .. ' Press' .. ac.green .. ' ENTER' .. ac.reset .. ' to continue..')
                    print(dash)
                    show_place_message = false
                else
                    print(dash)
                    for i = 4, 7 do
                        if blocks[i] then
                            print(string.format("                        Block %d: %s%s%s", i, ac.yellow, blocks[i], ac.reset))
                        end
                    end

                    local decimal_id, padded_hex_id
                    if blocks[5] and (blocks[5]:sub(4, 4) == 'F' or blocks[5]:sub(4, 4) == 'f') then
                        print(dash)
                        print('  Identified Paxton ' .. ac.cyan .. 'Net2' .. ac.reset)
                        decimal_id, padded_hex_id = calculate_id_net({blocks[4], blocks[5]})
                    else
                        print(dash)
                        print('  Identified Paxton ' .. ac.cyan .. 'Switch2' .. ac.reset)
                        decimal_id, padded_hex_id = calculate_id_switch({blocks[4], blocks[5], blocks[6], blocks[7]})
                    end

                    print(dash)
                    print(string.format("  ID for EM4102 is: %s", ac.green .. padded_hex_id .. ac.reset))
                    print(dash)
                    log_result(blocks, padded_hex_id)
                    handle_cloning(decimal_id, padded_hex_id, blocks)
                    break
                end
            end

        elseif input_option == "2" then
            local blocks = {}
            for i = 4, 7 do
                while true do
                    io.write(ac.reset..'  Enter data for block ' .. i .. ': ' .. ac.yellow)
                    local input = io.read()
					input = input:upper()
                    if is_valid_hex(input) then
                        blocks[i] = input
                        break
                    else
                        print(ac.yellow .. '  Invalid input.' .. ac.reset .. ' Each block must be 4 bytes (8 hex characters).')
                    end
                end
            end

            local decimal_id, padded_hex_id
            if blocks[5] and (blocks[5]:sub(4, 4) == 'F' or blocks[5]:sub(4, 4) == 'f') then
                print(ac.reset.. dash)
                print('  Identified Paxton ' .. ac.cyan .. 'Net2' .. ac.reset)
                decimal_id, padded_hex_id = calculate_id_net({blocks[4], blocks[5]})
            else
                print(ac.reset.. dash)
                print('  Identified Paxton ' .. ac.cyan .. 'Switch2' .. ac.reset)
                decimal_id, padded_hex_id = calculate_id_switch({blocks[4], blocks[5], blocks[6], blocks[7]})
            end

            print(dash)
            print(string.format("  ID for EM4102 is: %s", ac.green .. padded_hex_id .. ac.reset))
            print(dash)
            log_result(blocks, padded_hex_id)
            if not padded_hex_id then
			    print(ac.red..'  ERROR: '..ac.reset.. 'Invalid block data provided')
				os.exit(1)
            end
            handle_cloning(decimal_id, padded_hex_id, blocks)
            break
        end
    end
end

main()