#include "kvstore.h"
#include "diskuring/diskuring.h"
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/types.h>

char global_oplog_file[256] 	= "kvs_oplog.default.db";
char global_array_file[256] 	= "kvs_array.default.db";
char global_rbtree_file[256] 	= "kvs_rbtree.default.db";
char global_hash_file[256]		= "kvs_hash.default.db";

int kvs_create_snapshot(iouring_ctx_t *uring, const char* array_file, const char* rbtree_file, const char* hash_file){
	int ret = 0;
	int rc = 0;
	#if ENABLE_ARRAY
	rc = kvs_array_save(uring, &global_array, array_file);
	if(rc < 0){
		printf("kvs_engine_array save error\n");
		ret = -1;
	}
	#endif

	#if ENABLE_RBTREE
	rc = kvs_rbtree_save(uring, &global_rbtree, rbtree_file);
	if(rc < 0){
		printf("kvs_engine_rbtree save error\n");
		ret = -1;
	}
	#endif

	#if ENABLE_HASH
	rc = kvs_hash_save(uring, &global_hash, hash_file);
	if(rc < 0){
		printf("kvs_engine_hash save error\n");
		ret = -1;
	}
	#endif
	return ret;
}

void __complete_snapshot(const char *ip, int port, const char *array_file, const char *rbtree_file, const char *hash_file){
	
}

static int send_file_to_ipport(const char *ip, int port, const char *filename) {
	int sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) { perror("socket"); return -1; }

	struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
	addr.sin_addr.s_addr = inet_addr(ip);

	if (connect(sockfd, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
        perror("connect"); close(sockfd); return -1;
    }

	FILE *fp = fopen(filename, "rb");
    if (!fp) { perror("fopen"); close(sockfd); return -1; }

	char buf[4096];
	size_t n;
	
	while ((n = fread(buf, 1, sizeof(buf), fp)) > 0) {
        ssize_t written = 0;
        while (written < n) {
            ssize_t ret = write(sockfd, buf + written, n - written);
            if (ret < 0) { 
                perror("write"); 
                fclose(fp); 
                close(sockfd); 
                return -1; 
            }
            written += ret;
        }
    }

	if (ferror(fp)) {
        perror("fread");
        fclose(fp);
        close(sockfd);
        return -1;
    }

	fclose(fp);
	shutdown(sockfd, SHUT_WR);
    close(sockfd);
    return 0;
}

int kvs_create_snapshot_async(const char *ip, int port){
	pid_t pid = fork();
	if (pid == -1) { perror("fork"); return -1; }

	if (pid == 0) {
		char tmp_array[128];
        char tmp_rbtree[128];
        char tmp_hash[128];

		snprintf(tmp_array,  sizeof(tmp_array),  "data/snapshot_array_%s.tmp.db", ip);
        snprintf(tmp_rbtree, sizeof(tmp_rbtree), "data/snapshot_rbtree_%s.tmp.db", ip);
        snprintf(tmp_hash,   sizeof(tmp_hash),   "data/snapshot_hash_%s.tmp.db", ip);

		iouring_ctx_t uring;
		iouring_init(&uring, 256);

		int ret = kvs_create_snapshot(&uring, tmp_array, tmp_rbtree, tmp_hash);
		if (ret != 0) {
            fprintf(stderr, "snapshot creation failed\n");
            _exit(1);
        }

		// 发送快照到目标 IP:port
		if (send_file_to_ipport(ip, port, tmp_array) != 0 ||
            send_file_to_ipport(ip, port, tmp_rbtree) != 0 ||
            send_file_to_ipport(ip, port, tmp_hash) != 0) {
            fprintf(stderr, "snapshot send failed\n");
            _exit(1);
        }

		// hook 通知 eBPF
		__complete_snapshot(ip, port, tmp_array, tmp_rbtree, tmp_hash);

		iouring_shutdown(&uring);
		_exit(0);
	} else {

		return 0;
	}
}