// Mirrors Hare's hex @test fns (ref/hare/encoding/hex/hex.ha:82,96,194)
// plus a full-byte round-trip. A failing row aborts via the assert/abort
// builtin (task #5 @test conversion).
//
// The streaming decoder (newdecoder) is deferred (#247), so the decode
// side is exercised through decodestr only.

package hex_test;

import bytes;
import errors;
import hex;
import io;
import memio;


fn streq(a: str, b: str) bool = {
	if (a.len != b.len) { return false; };
	let i: i32 = 0;
	for (i < a.len) {
		if (a[i] != b[i]) { return false; };
		i += 1;
	};
	return true;
};

fn cafebabe() [8]u8 = {
	let r: [8]u8;
	r[0] = 0xCAu8; r[1] = 0xFEu8; r[2] = 0xBAu8; r[3] = 0xBEu8;
	r[4] = 0xDEu8; r[5] = 0xADu8; r[6] = 0xF0u8; r[7] = 0x0Du8;
	return r;
};

@test fn encodestr_basic() void = {
	let in: [8]u8 = cafebabe();
	assert(!(!streq(hex.encodestr(in[0:8]), "cafebabedeadf00d")));
};

// 0x00 → "00" guards a sign-extend / signed-shift on the high nibble.
@test fn encodestr_zero() void = {
	let in: [1]u8; in[0] = 0u8;
	assert(!(!streq(hex.encodestr(in[0:1]), "00")));
};

// 0xFF → "ff" guards an off-by-one in the digit lookup.
@test fn encodestr_ff() void = {
	let in: [1]u8; in[0] = 0xFFu8;
	assert(!(!streq(hex.encodestr(in[0:1]), "ff")));
};

@test fn encodestr_empty() void = {
	let in: [1]u8;
	assert(!(hex.encodestr(in[0:0]).len != 0));
};

@test fn encode_stream() void = {
	let in: [8]u8 = cafebabe();
	let out: memio.stream = memio.dynamic();
	match (hex.encode(&out.vt, in[0:8])) {
	case let n: size => { assert(!(n: i32 != 16)); };
	case let e: io.error => abort();
	};
	assert(!(!streq(memio.string(&out), "cafebabedeadf00d")));
};

@test fn decodestr_lower() void = {
	match (hex.decodestr("cafebabedeadf00d")) {
	case let b: []u8 => {
		let want: [8]u8 = cafebabe();
		assert(!(!bytes.equal(b, want[0:8])));
	};
	case let e: errors.invalid => abort();
	};
};

// Mixed/upper case must decode too; the encoder is lowercase-only but
// the decoder accepts both per ref/hare/encoding/hex/README:13.
@test fn decodestr_upper() void = {
	match (hex.decodestr("CAFEBABEDEADF00D")) {
	case let b: []u8 => {
		let want: [8]u8 = cafebabe();
		assert(!(!bytes.equal(b, want[0:8])));
	};
	case let e: errors.invalid => abort();
	};
};

@test fn decodestr_mixed() void = {
	match (hex.decodestr("CaFeBaBeDeAdF00d")) {
	case let b: []u8 => {
		let want: [8]u8 = cafebabe();
		assert(!(!bytes.equal(b, want[0:8])));
	};
	case let e: errors.invalid => abort();
	};
};

@test fn decodestr_empty() void = {
	match (hex.decodestr("")) {
	case let b: []u8 => { assert(!(b.len != 0)); };
	case let e: errors.invalid => abort();
	};
};

// Odd length and non-hex chars both return errors.invalid
// (ref/hare/encoding/hex/hex.ha:154,199).

@test fn decodestr_odd() void = {
	match (hex.decodestr("abc")) {
	case let b: []u8 => abort();
	case let e: errors.invalid => void;
	};
};

@test fn decodestr_bad() void = {
	match (hex.decodestr("zz00")) {	// 'z' isn't hex
	case let b: []u8 => abort();
	case let e: errors.invalid => void;
	};
};

@test fn decodestr_bad_mid() void = {
	match (hex.decodestr("aabbgg")) {	// 'g' isn't hex
	case let b: []u8 => abort();
	case let e: errors.invalid => void;
	};
};

@test fn roundtrip_all_bytes() void = {
	let src: [256]u8;
	let i: i32 = 0;
	for (i < 256) {
		src[i] = i: u8;
		i += 1;
	};
	let s: str = hex.encodestr(src[0:256]);
	assert(!(s.len != 512));
	match (hex.decodestr(s)) {
	case let b: []u8 => {
		assert(!(b.len != 256));
		assert(!(!bytes.equal(b, src[0:256])));
	};
	case let e: errors.invalid => abort();
	};
};