/* Copyright (c) 2023 Peter McGoron <code@mcgoron.com>

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "../creole.c"

#if 0
struct seq {
	creole_word max;
	unsigned encode_to;
	unsigned high_bits;

	unsigned char minbuf[7];
	unsigned char maxbuf[7];
};

void bprint(unsigned char c) {
	int i;

	for (i = 0; i < 8; i++) {
		printf("%u", (c >> (7 - i)) & 1);
	}
}

void bprintb(unsigned char *b, int len) {
	while (len-- > 0) {
		bprint(*b++);
		printf(" ");
	}
}

static void encode_byte_seq(struct seq *s) {
	creole_word i = 0;
	int j;
	unsigned char buf[7];

	for (;;) {

		assert(creole_encode(i, s->encode_to, s->high_bits,
		                        buf) == 1);
		if (memcmp(s->minbuf, buf, s->encode_to) != 0) {
			printf("0x%X ", i);
			bprintb(s->minbuf, s->encode_to);
			printf("|");
			bprintb(buf, s->encode_to);
			printf("\n");
			abort();
		}

		if (i == s->max)
			break;
		i++;

		for (j = s->encode_to - 1; j > 0; j--) {
			if (s->minbuf[j] == 0xBF) {
				s->minbuf[j] = 0x80;
			} else {
				s->minbuf[j]++;
				break;
			}
		}

		if (j == 0)
			s->minbuf[0]++;
	}
	assert(memcmp(s->maxbuf, s->minbuf, s->encode_to) == 0);
}

static void encode_1(void) {
	struct seq s;

	s.max = 0x7F;
	s.encode_to = 1;
	s.high_bits = 0;
	s.minbuf[0] = 0x00;
	s.maxbuf[0] = 0x7F;

	encode_byte_seq(&s);
}

static void encode_2(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0x7F;
	s.encode_to = 2;
	s.maxbuf[0] = s.minbuf[0] = 0xC0 | (high_bits << 1);
	s.maxbuf[0] = 0xC1 | (high_bits << 1);
	s.minbuf[1] = 0x80;
	encode_byte_seq(&s);
}

static void encode_3(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0xFFF;
	s.encode_to = 3;
	s.minbuf[0] = 0xE0 | high_bits;
	s.maxbuf[0] = 0xE0 | high_bits;
	s.minbuf[1] = 0x80;
	encode_byte_seq(&s);
}

static void encode_4(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0x1FFFF;
	s.encode_to = 4;
	s.maxbuf[0] = s.minbuf[0] = 0xF0 | (high_bits >> 1);
	s.minbuf[1] = 0x80 | ((high_bits & 0x1) << 5);
	s.maxbuf[1] = 0x9F | ((high_bits & 0x1) << 5);
	encode_byte_seq(&s);
}

static void encode_5(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0x3FFFFF;
	s.encode_to = 5;
	s.maxbuf[0] = s.minbuf[0] = 0xF8 | (high_bits >> 2);
	s.minbuf[1] = 0x80 | ((high_bits & 0x3) << 4);
	s.maxbuf[1] = 0x8F | ((high_bits & 0x3) << 4);
	encode_byte_seq(&s);
}

static void encode_6(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0x7FFFFFF;
	s.encode_to = 6;
	s.maxbuf[0] = s.minbuf[0] = 0xFC | (high_bits >> 3);
	s.minbuf[1] = 0x80 | ((high_bits & 0x7) << 3);
	s.maxbuf[1] = 0x87 | ((high_bits & 0x7) << 3);
	encode_byte_seq(&s);
}

static void encode_7(unsigned high_bits) {
	struct seq s;
	s.high_bits = high_bits;

	memset(s.maxbuf, 0xBF, sizeof(s.maxbuf));
	memset(s.minbuf, 0x80, sizeof(s.minbuf));
	s.max = 0xFFFFFFFF;
	s.encode_to = 7;
	s.maxbuf[0] = s.minbuf[0] = 0xFE;
	s.minbuf[1] = 0x80 | (high_bits << 2);
	s.maxbuf[1] = 0x83 | (high_bits << 2);
	encode_byte_seq(&s);
}

static void test_encode(void) {
	void (*tests[6])(unsigned) = {encode_2, encode_3, encode_4, encode_5, encode_6, encode_7};
	unsigned high_bits;
	unsigned test;
	encode_1();

# pragma omp parallel for collapse(2) num_threads(8)
	for (high_bits = 0; high_bits < 16; high_bits++) {
		for (test = 0; test < 6; test++)
			tests[test](high_bits);
	}
}
#endif

void encode_decode_byte_seq(creole_word max, unsigned encode_to, unsigned high_bits) {
	unsigned char buf[7];
	struct creole_reader r = {0};
	struct word w;
	creole_word i = 0;

	for (;;) {
		r.p = buf;
		r.left = encode_to;
		assert(creole_encode(i, encode_to, high_bits,
		                        buf) == 1);

		assert(decode_seq(&r, &w) == 1);
		assert(w.len == encode_to);
		if (w.high_bits != high_bits) {
			printf("high bits %u != %u\n", w.high_bits, high_bits);
			abort();
		}

		if (w.word != i) {
			printf("word %X != %X\n", w.word, i);
			abort();
		}

		if (i == max)
			break;
		i++;
	}
}

static void test_encode_decode(void) {
	unsigned high_bits = 0;
	int encode_len;
	const creole_word maxima[6] = {0x7F, 0xFFF, 0x1FFFF, 0x3FFFFF, 0x7FFFFFF, 0xFFFFFFFF};

	encode_decode_byte_seq(0x7F, 1, 0);

#pragma omp parallel for collapse(2) num_threads(8)
	for (high_bits = 0; high_bits < 16; high_bits++) {
		for (encode_len = 2; encode_len < 8; encode_len++)
			encode_decode_byte_seq(maxima[encode_len - 2], encode_len, high_bits);
	}
}

int main(void) {
	printf("test encode\n");
	test_encode_decode();

	printf("finished\n");
	return 0;
}