module actions;

import std.stdio : File, stdin, stdout, writeln;
import std.base64 : Base64;
import std.random : Random, uniform;
import std.algorithm : joiner;

import cipher;

public:

enum chunkSize = 4096;
enum base64ChunkSize = 57;

enum string randomDeviceName = "/dev/random";

void encrypt(string keyFileName, Cipher cipher, bool armor)
{
    auto key = loadKey(keyFileName, armor);
    ubyte[8] nonce;
    if (armor)
    {
        ubyte[base64ChunkSize] buf;
        char[Base64.encodeLength(base64ChunkSize)] buf2;
        int counter;
        foreach (b; stdin.byChunk(chunkSize).joiner.cipherFunction(key, nonce, cipher))
        {
            buf[counter] = b;
            ++counter;
            if (counter == 57)
            {
                Base64.encode(buf, buf2[]);
                stdout.writeln(buf2);
                counter = 0;
            }
        }
        if (counter > 0)
        {
            Base64.encode(buf[0..counter], buf2[]);
            stdout.writeln(buf2[0..Base64.encodeLength(counter)]);
        }
    }
    else
    {
        ubyte[chunkSize] buf;
        int counter;
        foreach (b; stdin.byChunk(chunkSize).joiner.cipherFunction(key, nonce, cipher))
        {
            buf[counter] = b;
            ++counter;
            if (counter == chunkSize)
            {
                stdout.rawWrite(buf);
                counter = 0;
            }
        }
        if (counter > 0)
            stdout.rawWrite(buf[0..counter]);
    }
}

void decrypt(string keyFileName, Cipher cipher, bool armor)
{
    import std.range;
    auto key = loadKey(keyFileName, armor);
    ubyte[8] nonce;
    ubyte[chunkSize] buf;
    int counter;
    InputRange!ubyte r;
    if (armor)
        r = Base64.decoder(stdin.byLine).joiner.cipherFunction(key, nonce, cipher).inputRangeObject;
    else
        r = stdin.byChunk(chunkSize).joiner.cipherFunction(key, nonce, cipher).inputRangeObject;

    foreach (b; r)
    {
        buf[counter] = b;
        ++counter;
        if (counter == 4096)
        {
            stdout.rawWrite(buf);
            counter = 0;
        }
    }
    if(counter > 0)
        stdout.rawWrite(buf[0..counter]);
}

void generateKey(bool armor)
{
    auto rng = Random();
    auto randomDevice = File(randomDeviceName, "r");
    scope (exit)
        randomDevice.close();
    uint[1] seed;
    randomDevice.rawRead(seed);
    rng.seed(seed[0]);

    ubyte[32] key;
    foreach (ref b; key)
        b = uniform!ubyte(rng);

    if (armor)
    {
        writeln(Base64.encode(key));
    }
    else
    {
        stdout.rawWrite(key);
    }
}

private:

ubyte[32] loadKey(string filename, bool armor)
{
    auto keyFile = File(filename, "r");
    scope (exit)
        keyFile.close();
    ubyte[32] key;
    ubyte[33] temp;
    if (armor)
    {
        import std.string : chomp;
        key = Base64.decode(keyFile.readln.chomp, temp[]);
    }
    else
    {
        keyFile.rawRead(key);
    }
    return key;
}