#include "kvstore.h"
#include "kvs_rw_tools.h"
#include "kvs_protocol_resp.h"
#include "dump/kvs_dump.h"
#include "memory/alloc_dispatch.h"
#include "common/config.h"
#include "diskuring/diskuring.h"
#include "replica_shm.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <libxml/parser.h>

extern int slave_bootstrap(const char *listen_ip, int listen_port, const char *master_ip, int master_port);

extern mp_pool_t global_mempool;

AppConfig global_cfg;
iouring_ctx_t global_uring_ctx;
unsigned long long global_seq;

extern int global_oplog_fd;

replica_shm_t g_rep_shm;

__attribute__((noinline))
void __completed_cmd(const uint8_t *cmd, size_t len, unsigned long long seq){
    asm volatile("" ::: "memory");

}

// __attribute__((noinline))
// void __replica_notify(uint64_t seq, uint32_t off, uint32_t len)
// {
//     // 空函数即可，目的是让 uprobe 拿到参数
//     asm volatile("" ::: "memory");
// }

int kvs_protocol(struct conn* conn){
	if (!conn) return -1;
	char *request = conn->rbuffer;
	int request_length = conn->rlength;
	char *response = conn->wbuffer;
	int *response_length = &conn->wlength;

	if (!request || request_length <= 0 || !response || !response_length) return -1;
	
	int consumed = 0;
	int out_len = 0;

	while(consumed < request_length ){
		const uint8_t *p = request+consumed;
		int remain = request_length - consumed;
		
		resp_cmd_t cmd;
		memset(&cmd, 0, sizeof(cmd));

		int len = resp_parse_one_cmd(p, remain, &cmd);
		if(len < 0){
			/* 协议错误：直接返回，已构建的响应仍可写回 */
			*response_length = out_len;
			return -1;
		}
		else if(len == 0){
			// 半包
			break;
		}
		
		resp_value_t val;
		memset(&val, 0, sizeof(val));

		int dr = resp_dispatch(&cmd, &val);

        /*
         * 语义建议：
         * - resp_dispatch() 即使返回 -1（比如 unknown command / wrong argc），
         *   一般也已经把 out_value 设置成了 RESP error，这样客户端能收到错误响应。
         * - 如果 dr < 0 但 val.type 没被正确设置，兜底回一个通用错误。
         */
		if(dr < 0){
			if (val.type != RESP_T_SIMPLE_STR &&
                val.type != RESP_T_ERROR &&
                val.type != RESP_T_INTEGER &&
                val.type != RESP_T_BULK_STR &&
                val.type != RESP_T_NIL) {
                val = resp_error("ERR dispatch failed");
            }
		} else {
			// persist into oplog 
			/* 执行成功：在这里保存到日志中（只记录更新类命令） */
			if (cmd.argc > 0 && cmd.argv[0].ptr) {
				/* 更新类命令：SET/DEL/MOD/RSET/RDEL/RMOD/HSET/HDEL/HMOD/SAVE */
				const resp_slice_t *c0 = &cmd.argv[0];
				int is_update = 0;
				if (c0->ptr && c0->len) {
					if (ascii_casecmp(c0->ptr, c0->len, "SET") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "DEL") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "MOD") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "RSET") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "RDEL") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "RMOD") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "HSET") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "HDEL") == 0 ||
						ascii_casecmp(c0->ptr, c0->len, "HMOD") == 0) {
						is_update = 1;
					}
				}

				if (is_update) {
					if(global_cfg.persistence == PERSIST_INCREMENTAL){			
						kvs_oplog_append(p, len, global_oplog_fd);
					}	

					// __completed_cmd(p, len, global_seq);
					// global_seq ++;
					
					if (global_cfg.replica_mode == REPLICA_ENABLE) {
						uint32_t off = 0;
						int ar = replica_shm_append(&g_rep_shm, global_seq, p, (uint32_t)len, &off);
						if (ar == 0) {
							// __replica_notify(global_seq, off, (uint32_t)len);
							global_seq++;

						} else {
							// shm 满或异常：你可以选择降级（比如直接跳过复制，或阻塞/丢弃）
							// 为了不影响主路径，这里先打印并跳过
							fprintf(stderr, "replica_shm_append failed %d\n", ar);
						}
					}
				}
			}
		}

        /* 构建响应 */
        int cap = KVS_MAX_RESPONSE - out_len;
        if (cap <= 0) {
            *response_length = out_len;
            return consumed;
        }

		int resp_len = resp_build_value(&val, response + out_len, (size_t)cap);
        if (resp_len < 0) {
            *response_length = out_len;
            return consumed;
        }

		out_len += resp_len;
		consumed += len;
	}

    *response_length = out_len;
	return consumed;
}



int init_kvengine(void) {

#if ENABLE_ARRAY
	memset(&global_array, 0, sizeof(kvs_array_t));
	kvs_array_create(&global_array);

	kvs_array_load(&global_array, global_array_file);
#endif

#if ENABLE_RBTREE
	memset(&global_rbtree, 0, sizeof(kvs_rbtree_t));
	kvs_rbtree_create(&global_rbtree);

	kvs_rbtree_load(&global_rbtree, global_rbtree_file);
#endif

#if ENABLE_HASH
	memset(&global_hash, 0, sizeof(kvs_hash_t));
	kvs_hash_create(&global_hash);
	
	kvs_hash_load(&global_hash, global_hash_file);
#endif

	if(global_cfg.persistence == PERSIST_INCREMENTAL){
		init_cmd_log(global_oplog_file, &global_oplog_fd);
		kvs_replay_log(global_oplog_fd);
	}

	printf("kvengine init complete\n");
	return 0;
}

void dest_kvengine(void) {
#if ENABLE_ARRAY
	kvs_array_destroy(&global_array);
#endif
#if ENABLE_RBTREE
	kvs_rbtree_destroy(&global_rbtree);
#endif
#if ENABLE_HASH
	kvs_hash_destroy(&global_hash);
#endif

	destroy_cmd_log(global_oplog_fd);
}

void init_memory_pool(AppConfig *cfg){

	if(cfg->allocator == ALLOC_MYPOOL)
		mp_create(&global_mempool);
		
	kvs_set_memleak_detect(cfg->leak_mode);
	kvs_set_alloc_type(cfg->allocator);

	printf("mempool init complete\n");
}

void dest_memory_pool(void){
	mp_destroy(&global_mempool);
}

static int ensure_dir_exists(const char *dir)
{
    struct stat st;
    if (stat(dir, &st) == 0) {
        return S_ISDIR(st.st_mode) ? 0 : -2; // 存在但不是目录
    }
    if (mkdir(dir, 0755) == 0) return 0;
    if (errno == EEXIST) return 0;
    return -1;
}

static int join_path(char *out, size_t out_sz, const char *dir, const char *file)
{
    if (!out || out_sz == 0 || !dir || !file) return -1;

    size_t dlen = strlen(dir);
    if (dlen == 0) return -1;

    int need_slash = (dir[dlen - 1] != '/');

    int n = snprintf(out, out_sz, need_slash ? "%s/%s" : "%s%s", dir, file);
    if (n < 0 || (size_t)n >= out_sz) return -2; // 截断了
    return 0;
}

void init_data_file(AppConfig *cfg){
	ensure_dir_exists(cfg->persist_dir);
	join_path(global_oplog_file, sizeof(global_oplog_file), cfg->persist_dir, cfg->oplog_file);
	join_path(global_array_file, sizeof(global_array_file), cfg->persist_dir, cfg->array_file);
	join_path(global_rbtree_file, sizeof(global_rbtree_file), cfg->persist_dir, cfg->rbtree_file);
	join_path(global_hash_file, sizeof(global_hash_file), cfg->persist_dir, cfg->hash_file);
}

int init_config(AppConfig *cfg){
	xmlInitParser();
	
	if (config_load("config/config.xml", cfg) != 0) {
        fprintf(stderr, "Failed to load config/config.xml\n");
        xmlCleanupParser();
        return -1;
    }

	printf("=============== Config ===============\n");
    printf("IP          		: %s\n", cfg->ip);
    printf("Port        		: %d\n", cfg->port);

	printf("Replica-Mode		: %s\n", replica_to_string(cfg->replica_mode));
	printf("Mode        		: %s\n", server_mode_to_string(cfg->mode));
	printf("|—— Master IP   	: %s\n", cfg->master_ip);
    printf("|—— Master Port 	: %d\n", cfg->master_port);

	printf("Persistence 		: %s\n", persistence_to_string(cfg->persistence));
    printf("|—— Persist-dir 	: %s\n", cfg->persist_dir);
    printf("|—— Persist-oplog 	: %s\n", cfg->oplog_file);
    printf("|—— Persist-array	: %s\n", cfg->array_file);
    printf("|—— Persist-rbtree	: %s\n", cfg->rbtree_file);
    printf("|—— Persist-hash	: %s\n", cfg->hash_file);

	printf("Log level   		: %s\n", log_level_to_string(cfg->log_level));
	printf("Memory			: \n");
    printf("|——Allocator   		: %s\n", allocator_to_string(cfg->allocator));
	printf("|——MemLeakDetectMode	: %s\n", leakage_to_string(cfg->leak_mode));
	printf("=============== Config ===============\n");
	
	xmlCleanupParser();
	return 0;
}

void init_disk_uring(iouring_ctx_t *uring_ctx){
	// iouring_init(uring_ctx, 4096);
	iouring_init(uring_ctx, (1024*8));
}

void dest_disk_uring(iouring_ctx_t *uring_ctx){
	iouring_shutdown(uring_ctx);
}

int kvs_replica_init(void)
{
	if (global_cfg.replica_mode == REPLICA_ENABLE) {
		int rc = replica_shm_open(&g_rep_shm, REPLICA_SHM_NAME, REPLICA_SHM_SIZE, /*create=*/ 1);
		if (rc != 0) {
			fprintf(stderr, "replica_shm_open failed rc=%d\n", rc);
			return rc;
		}
	}
    return 0;
}


int main(int argc, char *argv[]) {
	if(-1 == init_config(&global_cfg)){
		printf("Init Config error");
		return -1;
	} 
	global_seq = 0;

	kvs_replica_init();
	init_memory_pool(&global_cfg);
	init_data_file(&global_cfg);
	init_disk_uring(&global_uring_ctx);
	
	int port = global_cfg.port;
	
	char *master_ip = NULL;
	int master_port = -1;

	if(global_cfg.mode == MODE_SLAVE){
		master_ip = global_cfg.master_ip;
		master_port = global_cfg.master_port;
		slave_bootstrap(global_cfg.ip, port, master_ip, master_port);
	}else if(global_cfg.mode == MODE_MASTER){
		
	}

	init_kvengine();
	
#if (NETWORK_SELECT == NETWORK_REACTOR)
	reactor_start(port, kvs_protocol);  //
#elif (NETWORK_SELECT == NETWORK_PROACTOR)
	proactor_start(port, kvs_protocol);
#elif (NETWORK_SELECT == NETWORK_NTYCO)
	ntyco_start(port, kvs_protocol);
#endif

	dest_kvengine();
	dest_memory_pool();
}