#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#include "doc.h"
#include "err.h"

void doc_init(struct doc *d) {
	buf_init(&d->txt, sizeof(struct doc_line));
	buf_init(&d->lnk, 1);
	d->txt.sz = sizeof(struct doc_line);
	*(struct doc_line *)d->txt.buf = (struct doc_line) {
		.prev = 0,
		.link = DOC_LINK_NONE,
		.len = 0,
	};
	d->latest = 0;
}

void doc_fini(struct doc *d) {
	buf_free(&d->txt);
	buf_free(&d->lnk);
}

void doc_new_line(struct doc *d) {
	size_t here = d->latest, there = d->txt.sz;
	buf_grow(&d->txt, sizeof(struct doc_line));
	*(struct doc_line *)&d->txt.buf[there] = (struct doc_line) {
		.prev = there - here,
		.link = DOC_LINK_NONE,
		.len = 0
	};
	d->txt.sz += sizeof(struct doc_line);
	d->latest = there;
}

void doc_add_line(struct doc *d, const char *s) {
	doc_add_text(d, s);
	doc_new_line(d);
}

void doc_add_text(struct doc *d, const char *s) {
	doc_add_textn(d, s, strlen(s));
}

void doc_add_textn(struct doc *d, const char *s, size_t n) {
	buf_grow(&d->txt, n);
	memcpy(&d->txt.buf[d->txt.sz], s, n);
	struct doc_line *dl = (struct doc_line *)&d->txt.buf[d->latest];
	d->txt.sz += n;
	dl->len += n;
}