// endian — byte-order conversions. Mirrors Hare's endian:: surface:
// big-endian (be*), little-endian (le*), and network-order (hton/ntoh)
// helpers. Host order on amd64 is little-endian, so hton/ntoh are
// byte swaps and the le* family is identity.

// ---- network order (host ↔ big-endian, since amd64 is LE) -----------

package endian;

export fn htonu16(in: u16) u16 = {
	return ((in << 8u16) | (in >> 8u16)) & 0xffffu16;
};
export fn ntohu16(in: u16) u16 = { return htonu16(in); };

export fn htonu32(in: u32) u32 = {
	let b0: u32 = (in >> 24u32) & 0xffu32;
	let b1: u32 = (in >> 16u32) & 0xffu32;
	let b2: u32 = (in >> 8u32)  & 0xffu32;
	let b3: u32 =  in           & 0xffu32;
	return (b3 << 24u32) | (b2 << 16u32) | (b1 << 8u32) | b0;
};
export fn ntohu32(in: u32) u32 = { return htonu32(in); };

export fn htonu64(in: u64) u64 = {
	let b0: u64 = (in >> 56u64) & 0xffu64;
	let b1: u64 = (in >> 48u64) & 0xffu64;
	let b2: u64 = (in >> 40u64) & 0xffu64;
	let b3: u64 = (in >> 32u64) & 0xffu64;
	let b4: u64 = (in >> 24u64) & 0xffu64;
	let b5: u64 = (in >> 16u64) & 0xffu64;
	let b6: u64 = (in >> 8u64)  & 0xffu64;
	let b7: u64 =  in           & 0xffu64;
	return (b7 << 56u64) | (b6 << 48u64) | (b5 << 40u64) | (b4 << 32u64)
	     | (b3 << 24u64) | (b2 << 16u64) | (b1 << 8u64)  | b0;
};
export fn ntohu64(in: u64) u64 = { return htonu64(in); };

// ---- big-endian byte get/put on a slice ------------------------------

export fn begetu16(buf: []u8) u16 = {
	let b0: u16 = buf[0]: u16;
	let b1: u16 = buf[1]: u16;
	return (b0 << 8u16) | b1;
};

export fn beputu16(buf: []u8, in: u16) void = {
	buf[0] = ((in >> 8u16) & 0xffu16): u8;
	buf[1] = (in & 0xffu16): u8;
};

export fn begetu32(buf: []u8) u32 = {
	let b0: u32 = buf[0]: u32;
	let b1: u32 = buf[1]: u32;
	let b2: u32 = buf[2]: u32;
	let b3: u32 = buf[3]: u32;
	return (b0 << 24u32) | (b1 << 16u32) | (b2 << 8u32) | b3;
};

export fn beputu32(buf: []u8, in: u32) void = {
	buf[0] = ((in >> 24u32) & 0xffu32): u8;
	buf[1] = ((in >> 16u32) & 0xffu32): u8;
	buf[2] = ((in >> 8u32)  & 0xffu32): u8;
	buf[3] = (in            & 0xffu32): u8;
};

export fn begetu64(buf: []u8) u64 = {
	let b0: u64 = buf[0]: u64;
	let b1: u64 = buf[1]: u64;
	let b2: u64 = buf[2]: u64;
	let b3: u64 = buf[3]: u64;
	let b4: u64 = buf[4]: u64;
	let b5: u64 = buf[5]: u64;
	let b6: u64 = buf[6]: u64;
	let b7: u64 = buf[7]: u64;
	return (b0 << 56u64) | (b1 << 48u64) | (b2 << 40u64) | (b3 << 32u64)
	     | (b4 << 24u64) | (b5 << 16u64) | (b6 << 8u64)  | b7;
};

export fn beputu64(buf: []u8, in: u64) void = {
	buf[0] = ((in >> 56u64) & 0xffu64): u8;
	buf[1] = ((in >> 48u64) & 0xffu64): u8;
	buf[2] = ((in >> 40u64) & 0xffu64): u8;
	buf[3] = ((in >> 32u64) & 0xffu64): u8;
	buf[4] = ((in >> 24u64) & 0xffu64): u8;
	buf[5] = ((in >> 16u64) & 0xffu64): u8;
	buf[6] = ((in >> 8u64)  & 0xffu64): u8;
	buf[7] = (in            & 0xffu64): u8;
};

// ---- little-endian byte get/put on a slice ---------------------------

export fn legetu16(buf: []u8) u16 = {
	let b0: u16 = buf[0]: u16;
	let b1: u16 = buf[1]: u16;
	return (b1 << 8u16) | b0;
};

export fn leputu16(buf: []u8, in: u16) void = {
	buf[0] = (in & 0xffu16): u8;
	buf[1] = ((in >> 8u16) & 0xffu16): u8;
};

export fn legetu32(buf: []u8) u32 = {
	let b0: u32 = buf[0]: u32;
	let b1: u32 = buf[1]: u32;
	let b2: u32 = buf[2]: u32;
	let b3: u32 = buf[3]: u32;
	return (b3 << 24u32) | (b2 << 16u32) | (b1 << 8u32) | b0;
};

export fn leputu32(buf: []u8, in: u32) void = {
	buf[0] = (in            & 0xffu32): u8;
	buf[1] = ((in >> 8u32)  & 0xffu32): u8;
	buf[2] = ((in >> 16u32) & 0xffu32): u8;
	buf[3] = ((in >> 24u32) & 0xffu32): u8;
};

export fn legetu64(buf: []u8) u64 = {
	let b0: u64 = buf[0]: u64;
	let b1: u64 = buf[1]: u64;
	let b2: u64 = buf[2]: u64;
	let b3: u64 = buf[3]: u64;
	let b4: u64 = buf[4]: u64;
	let b5: u64 = buf[5]: u64;
	let b6: u64 = buf[6]: u64;
	let b7: u64 = buf[7]: u64;
	return (b7 << 56u64) | (b6 << 48u64) | (b5 << 40u64) | (b4 << 32u64)
	     | (b3 << 24u64) | (b2 << 16u64) | (b1 << 8u64)  | b0;
};

export fn leputu64(buf: []u8, in: u64) void = {
	buf[0] = (in            & 0xffu64): u8;
	buf[1] = ((in >> 8u64)  & 0xffu64): u8;
	buf[2] = ((in >> 16u64) & 0xffu64): u8;
	buf[3] = ((in >> 24u64) & 0xffu64): u8;
	buf[4] = ((in >> 32u64) & 0xffu64): u8;
	buf[5] = ((in >> 40u64) & 0xffu64): u8;
	buf[6] = ((in >> 48u64) & 0xffu64): u8;
	buf[7] = ((in >> 56u64) & 0xffu64): u8;
};