#!/usr/bin/env luajit51
local digest = require("openssl.digest")

-- Function to calculate MD5 hash of the input
function md5_hex(input)
    print("Calculating MD5 for:", input) -- Debug print
    local b = digest.new("md5"):final(input)
    local x = ""
    for i = 1, #b do
        x = x .. string.format("%.2x", string.byte(b, i))
    end
    print("MD5 Hash:", x) -- Debug print
    return x
end

-- Called when the filter opens
function filter_open(email, page)
    print("Filter Open. Email:", email) -- Debug print
    buffer = ""
    hexdigest = md5_hex(email:sub(2, -2):lower())
    print("Hex Digest:", hexdigest) -- Debug print
end

-- Called when the filter closes
function filter_close()
    local baseurl = os.getenv("HTTPS") and "https://seccdn.libravatar.org/" or "http://cdn.libravatar.org/"
    print("Base URL:", baseurl) -- Debug print
    print("Hex Digest in filter_close:", hexdigest) -- Debug print
    local avatar_url_small = baseurl .. "avatar/" .. hexdigest .. "?s=13&d=retro"
    local avatar_url_large = baseurl .. "avatar/" .. hexdigest .. "?s=128&d=retro"
    print("Avatar URL Small:", avatar_url_small) -- Debug print
    print("Avatar URL Large:", avatar_url_large) -- Debug print

    html("<span class='libravatar'><img class='inline' src='" .. avatar_url_small .. "' /><img class='onhover' src='" .. avatar_url_large .. "' /></span>" .. buffer)
    return 0
end

-- Called when writing to the filter
function filter_write(str)
    print("Filter Write:", str) -- Debug print
    buffer = buffer .. str
end