module CryptoFileTests.Main

open System
open System.IO
open CryptoFile

let printUsage () = 
    printfn "%s [ tests | encrypt <in file> <out file> | decrypt <in file> <out dir> ]\n\
             \ttests: Run some tests to valid the 'CryptoFile' assembly\n\
             \tencrypt: Encrypt a file <in> to <out>\n\
             \tdecrypt: Decrypt a file <in> to <out>" System.AppDomain.CurrentDomain.FriendlyName

// Module to store and retreive the keys to and from a file.
// The private keys are stored in plain file! Do not let anyone access these files!
module internal Keys =
    // Try to read the public key and private key from files. If one of a file doesn't exist
    // a new key pair is created, stored then returned.
    let getKey (filenamePub: string) (filenamePriv: string) : Key * Key =
        try
            use srPub = new StreamReader (filenamePub)
            use srPriv = new StreamReader (filenamePriv)
            srPub.ReadToEnd (), srPriv.ReadToEnd ()
        with
        | _ ->
            use swPub = new StreamWriter (filenamePub)
            use swPriv = new StreamWriter (filenamePriv)
            let keyPub, keyPriv = API.generatKeysPair ()
            swPub.Write keyPub
            swPriv.Write keyPriv
            keyPub, keyPriv

    let getSig : Key * Key = getKey "keys-sign.pub" "keys-sign.priv"
    let getCrypt : Key * Key = getKey "keys-crypt.pub" "keys-crypt.priv"

[<EntryPoint>]
let main args = 
    let keySigPub, keySigPriv = Keys.getSig
    let keyCryptPub, keyCryptPriv = Keys.getCrypt

    match args with
    | [| "tests" |] -> Tests.doSomeTests ()
    | [| "encrypt"; input; output |] -> API.encryptFile input output keySigPriv keyCryptPub
    | [| "decrypt"; input; outputDir |] -> API.decryptFile input outputDir keySigPub keyCryptPriv
    | _ -> printUsage ()
    0