#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <err.h>
#include "dpi.h"
#include "io.h"

int dpi_check_auth(int fd) {
	char buf[30];
	unsigned key[4], local_key[4];
	char keys[128];
	char *home;
	ssize_t sz;
	int rc;
	rc = read_all(fd, (unsigned char *)buf, 28);
	if (rc < 0) return -1;
	buf[29] = '\0';
	// first byte was read already
	rc = sscanf(buf, "cmd='auth' msg='%4x' '>", key);
	if (rc < 1) { errno = EPROTO; return -1; }
	home = getenv("HOME");
	if (!home) home = ".";
	sz = read_file(keys, sizeof(keys), "%s/.dillo/dpid_comm_keys", home);
	if (sz < 0) { errno = ENOKEY; return -1; }
	rc = sscanf(keys, "%*d %4x", local_key);
	if (rc < 1) { errno = ENOKEY; return -1; }
	if (memcmp(key, local_key, 4)) { errno = EKEYREJECTED; return -1; }
	return 0;
}

int dpi_read_request(int fd, char *url_buf, size_t url_len) {
	char buf[21];
	size_t len;
	int rc;
	size_t i;

	rc = read_all(fd, (unsigned char *)buf, sizeof(buf));
	if (rc < 0 && errno == EPIPE && !strncmp(buf, "<cmd='DpiBye' '>", 16)) {
		errno = ESHUTDOWN;
		return -1;
	}
	if (rc < 0) return -1;
	if (strncmp(buf, "<cmd='open_url' url='", 21)) {
		errno = EPROTO;
		return -1;
	}
	len = url_len;
	rc = read_some(fd, (unsigned char *)url_buf, &len);
	if (rc < 0) return -1;

	for (i = 0; i < len-1; i++) {
		if (url_buf[i] == '\'' && url_buf[i+1] == ' ') break;
	}
	if (i > len-3 || strncmp(url_buf + i, "' '>", 4)) {
		errno = EPROTO;
		return -1;
	}
	url_buf[i] = '\0';
	return 0;
}

int dpi_send_status(int fd, const char *status) {
	return dprintf(fd, "<cmd='send_status_message' msg='%s' '>", status);
}

int dpi_send_header(int fd, const char *content_type) {
	return dprintf(fd, "<cmd='start_send_page' url='' '>"
	              "Content-Type: %s\n\n", content_type);
}

int dpi_reload(int fd) {
	return dprintf(fd, "<cmd='reload_request' url='' '>");
}