require "table2"
local crypto = require "crypto"
local fmt = require "fmt"

$define ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"

local function decode_base58(input)
    local output = table.rep(25, 0)
    for i = 1, #input do
        local c = input[i]
        local p = ALPHABET:find(c, 1, true)
        if !p then return nil end
        p -= 1
        for j = 25, 2, -1 do
            p += 58 * output[j]
            output[j] = p % 256
            p >>= 8
        end
        if p != 0 then return nil end
    end
    return output
end

local function sha256(data, start, len, recursion)
    if recursion == 0 then return data end
    local ds = data:slice(start, start + len - 1)
    local md = crypto.sha256(string.char(ds:unpack()))
    md = md:split(""):chunk(2):map(|x| -> tonumber(x:concat(), 16))
    return sha256(md, 1, 32, recursion - 1)
end

local function validate_address(address)
    local len = #address
    if len < 26 or len > 35 then return false end
    local decoded = decode_base58(address)
    if !decoded then return false end
    local hash = sha256(decoded, 1, 21, 2)
    return table.same(hash:slice(1, 4), decoded:slice(22, 25))
end

local addresses = {
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62j",
    "1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62X",
    "1ANNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i",
    "1A Na15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i",
    "BZbvjr",
    "i55j",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62!",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62iz",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62izz",
    "1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nJ9",
    "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62I"
}

for addresses as address do
    fmt.print("%-36s -> %s", address, validate_address(address) ? "valid" : "invalid")
end