use "core"

%hash_to_filename <- {}

lua> ".."
    local Hash = require("openssl.digest");
    local function sha1(x)
        local hash = Hash.new("sha1"):final(x);
        local hex = hash:gsub('.', function(c) return string.format('%02x', string.byte(c)) end)
        return hex
    end
    local lfs = require('lfs');
    local function attrdir(path)
        for filename in lfs.dir(path) do
            if filename ~= "." and filename ~= ".." and filename:sub(1,1) ~= "." then
                local filename = path..'/'..filename
                local attr = lfs.attributes(filename);
                if attr.mode == "directory" then
                    attrdir(filename);
                elseif filename:match(".*%.nom") then
                    local file = io.open(filename);
                    local hash = sha1(file:read("*a"));
                    file:close();
                    \%hash_to_filename[hash] = filename
                end
            end
        end
    end
    attrdir(".");

action [sha1 %]:
    lua> "return sha1(\%);"

action [file with hash %hash]:
    %file <- (%hash in %hash_to_filename)
    assume %file or barf "File with SHA1 hash \%hash not found!"
    return %file

action [hash of file %filename]:
    lua> ".."
        local f = io.open(\%filename);
        local hash = sha1(f:read("*a"));
        f:close();
        return hash;

parse [use file with hash %hash] as: use (file with hash %hash)