/*
# This file is part of the Astrometry.net suite.
# Licensed under a 3-clause BSD style license - see LICENSE
*/

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <assert.h>

#include "solvedclient.h"
#include "bl.h"

static int serveraddr_initialized = 0;
static struct sockaddr_in serveraddr;
static FILE* fserver = NULL;

int solvedclient_set_server(char* addr) {
	char buf[256];
	char* ind;
	struct hostent* he;
	int len;
	int port;
	if (fserver) {
		if (fflush(fserver) ||
			fclose(fserver)) {
			fprintf(stderr, "Failed to close previous connection to server.\n");
		}
		fserver = NULL;
	}
	if (!addr)
		return -1;
	ind = index(addr, ':');
	if (!ind) {
		fprintf(stderr, "Invalid IP:port address: %s\n", addr);
		return -1;
	}
	len = ind - addr;
	memcpy(buf, addr, len);
	buf[len] = '\0';
	he = gethostbyname(buf);
	if (!he) {
		fprintf(stderr, "Solved server \"%s\" not found: %s.\n", buf, hstrerror(h_errno));
		return -1;
	}
    if (!serveraddr_initialized) {
        memset(&serveraddr, 0, sizeof(serveraddr));
        serveraddr_initialized = 1;
    }
	memcpy(&(serveraddr.sin_addr), he->h_addr, he->h_length);
	port = atoi(ind+1);
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_port = htons(port);

	return 0;
}

static int connect_to_server() {
	int sock;
	if (fserver)
		return 0;
	sock = socket(PF_INET, SOCK_STREAM, 0);
	if (sock == -1) {
		fprintf(stderr, "Couldn't create socket: %s\n", strerror(errno));
		return -1;
	}
	fserver = fdopen(sock, "r+b");
	if (!fserver) {
		fprintf(stderr, "Failed to fdopen socket: %s\n", strerror(errno));
		return -1;
	}
    assert(serveraddr_initialized);
    // gcc with strict-aliasing warns about this cast but it should be okay.
	if (connect(sock, (struct sockaddr*)&serveraddr, sizeof(serveraddr))) {
		fprintf(stderr, "Couldn't connect to server: %s\n", strerror(errno));
		if (fclose(fserver))
			fprintf(stderr, "Failed to close socket: %s\n", strerror(errno));
		fserver = NULL;
		return -1;
	}
	return 0;
}

int solvedclient_get(int filenum, int fieldnum) {
	char buf[256];
	const char* solvedstr = "solved";
	int nchars;
	int solved;

	if (connect_to_server())
		return -1;
	nchars = sprintf(buf, "get %i %i\n", filenum, fieldnum);
	if ((fwrite(buf, 1, nchars, fserver) != nchars) ||
		fflush(fserver)) {
		fprintf(stderr, "Failed to write request to server: %s\n", strerror(errno));
		fclose(fserver);
		fserver = NULL;
		return -1;
	}
	if (!fgets(buf, 256, fserver)) {
		fprintf(stderr, "Couldn't read response: %s\n", strerror(errno));
		fclose(fserver);
		fserver = NULL;
		return -1;
	}
	solved = (strncmp(buf, solvedstr, strlen(solvedstr)) == 0);
	return solved;
}

void solvedclient_set(int filenum, int fieldnum) {
	char buf[256];
	int nchars;
	if (connect_to_server())
		return;
	nchars = sprintf(buf, "set %i %i\n", filenum, fieldnum);
	if ((fwrite(buf, 1, nchars, fserver) != nchars) ||
		fflush(fserver)) {
		fprintf(stderr, "Failed to send command (%s) to solvedserver: %s\n", buf, strerror(errno));
		return;
	}
	// wait for response.
	if (!fgets(buf, 256, fserver)) {
		fprintf(stderr, "Couldn't read response: %s\n", strerror(errno));
		fclose(fserver);
		fserver = NULL;
		return;
	}
}

il* solvedclient_get_fields(int filenum, int firstfield, int lastfield,
							int maxnfields) {
	char* buf;
	int bufsize;
	il* list;
	char* cptr;
	int fld;
	int nchars;

	if (connect_to_server())
		return NULL;
	bufsize = 100 + 10 * (maxnfields ? maxnfields : (1 + lastfield - firstfield));
	buf = malloc(bufsize);
	nchars = sprintf(buf, "getall %i %i %i %i\n", filenum, firstfield,
					 lastfield, maxnfields);
	if ((fwrite(buf, 1, nchars, fserver) != nchars) ||
		fflush(fserver)) {
		fprintf(stderr, "Failed to send command (%s) to solvedserver: %s\n", buf, strerror(errno));
		return NULL;
	}
	// wait for response.
	if (!fgets(buf, bufsize, fserver)) {
		fprintf(stderr, "Couldn't read response: %s\n", strerror(errno));
		fclose(fserver);
		fserver = NULL;
		free(buf);
		return NULL;
	}
	if (sscanf(buf, "unsolved %i%n", &fld, &nchars) != 1) {
		fprintf(stderr, "Couldn't parse response: %s\n", buf);
		free(buf);
		return NULL;
	}
	if (fld != filenum) {
		fprintf(stderr, "Expected file number %i, not %i.\n", filenum, fld);
		free(buf);
		return NULL;
	}
	cptr = buf + nchars;
	list = il_new(256);
	while (*cptr && *cptr != '\n') {
		if (sscanf(cptr, " %i%n", &fld, &nchars) != 1) {
			fprintf(stderr, "Couldn't parse response: %s\n", buf);
			il_free(list);
			free(buf);
			return NULL;
		}
		cptr += nchars;
		il_append(list, fld);
	}
	free(buf);
	return list;
}