///////////////// Imports
//

const AES = @import("crypto/aes.zig");
const ED25519 = @import("crypto/ed25519.zig");
const HKDF = @import("crypto/hkdf.zig");
const HMAC = @import("crypto/hmac.zig");
const SHA256 = @import("crypto/sha256.zig");
const SHA512 = @import("crypto/sha512.zig");
const X25519= @import("crypto/x25519.zig");
const RANDOM = @import("crypto/random.zig");


///////////////// Structs
//

pub const PartialEngine = struct {
    aes_cbc256: ? AES.CBC256_Implementation = null,
    ed25519:    ? ED25519.Implementation    = null,
    hkdf:       ? HKDF.Implementation       = null,
    hmac:       ? HMAC.Implementation       = null,
    sha256:     ? SHA256.Implementation     = null,
    sha512:     ? SHA512.Implementation     = null,
    x25519:     ? X25519.Implementation     = null,
    random:     ? RANDOM.Implementation     = null,
};

pub const Engine = struct {
    aes_cbc256: AES.CBC256_Implementation,
    ed25519:    ED25519.Implementation,
    hkdf:       HKDF.Implementation,
    hmac:       HMAC.Implementation,
    sha256:     SHA256.Implementation,
    sha512:     SHA512.Implementation,
    x25519:     X25519.Implementation,
    random:     RANDOM.Implementation,
};


///////////////// Functions
//

// Initializes the cyrpto engine with the functions given inside Provider
// These functions must follow the same structure as the struct returned by this
// function and its sub-structs.
pub fn resolveEngine(comptime provider: PartialEngine) Engine {

    // Used by other engine components
    const randomImpl = provider.random orelse RANDOM.defaultImplementation;

    return .{
        .aes_cbc256 = provider.aes_cbc256 orelse AES.CBC256_DefaultImplementation,
        .ed25519    = provider.ed25519    orelse ED25519.DefaultImplementation(randomImpl),
        .hkdf       = provider.hkdf       orelse HKDF.DefaultImplementation,
        .hmac       = provider.hmac       orelse HMAC.DefaultImplementation,
        .sha256     = provider.sha256     orelse SHA256.DefaultImplementation,
        .sha512     = provider.sha512     orelse SHA512.DefaultImplementation,
        .x25519     = provider.x25519     orelse X25519.DefaultImplementation,
        .random     = randomImpl,
    };
}


///////////////// Tests
//

const std = @import("std");

test "AES encryption defaults" {
    
    const crypto = resolveEngine(.{});

    var data = [_]u8{ 1, 2, 3, 4 };
    const key = [_]u8{ 1, 2, 3, 4 };
    const iv = [_]u8{ 1, 2, 3, 4 };
    crypto.aes_cbc256.encrypt(&data, &key, &iv);
}