#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "memory.h"
#include "buffer.h"


struct buffer buffer_make(size_t capacity) {
	struct buffer buffer = (struct buffer){malloc(capacity, char), capacity + 1, 0};
	return buffer;
}

void buffer_free(struct buffer buffer) {
	free(buffer.buf);
}

void buffer_append_mem(struct buffer *buffer, const char *str, size_t len) {
	if (buffer->len + len >= buffer->cap) {
		do buffer->cap *= 2; while (buffer->len + len >= buffer->cap);
		buffer->buf = realloc(buffer->buf, buffer->cap, char);
	}
	memcpy(buffer->buf + buffer->len, str, len);
	buffer->len += len;
	buffer->buf[buffer->len] = 0;
}

void buffer_append_str(struct buffer *buffer, const char *str) {
	buffer_append_mem(buffer, str, strlen(str));
}

// returns whether successful
bool buffer_append_file(struct buffer *buffer, const char *path) {
	FILE *f = fopen(path, "rb");
	if (!f) return false;

	char block[4096];
	while (true) {
		size_t nr = fread(block, 1, sizeof block, f);
		if (nr > 0) buffer_append_mem(buffer, block, nr);
		if (nr < sizeof block) break;
	}

	bool has_error = ferror(f);
	fclose(f);
	return !has_error;
}