#include "zvfs.h"

struct spdk_thread *global_thread = NULL;

// mount
void zvfs_do_mount(void *arg);
void zvfs_spdk_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *event_ctx);
void zvfs_spdk_bs_init_cb(void *arg, struct spdk_blob_store *bs, int bserrno);

// create
void zvfs_do_create(void *arg);
void zvfs_spdk_bs_create_blob_cb(void *arg, spdk_blob_id blobid, int bserrno);
void zvfs_spdk_bs_open_blob_cb(void *arg, struct spdk_blob *blb, int bserrno);
void zvfs_spdk_blob_resize_cb(void *arg, int bserrno);
void zvfs_spdk_blob_sync_cb(void *arg, int bserrno);
// open
void zvfs_do_open(void *arg);
void zvfs_spdk_bs_open_blob_cb2(void *arg, struct spdk_blob *blb, int bserrno);

// read
void zvfs_do_read(void *arg);
void zvfs_spdk_blob_read_cb(void *arg, int bserrno);

// write
void zvfs_do_write(void *arg);
void zvfs_do_write_io(zvfs_file_t *file);
void zvfs_spdk_blob_write_resize_cb(void *arg, int bserrno);
void zvfs_spdk_blob_write_sync_cb(void *arg, int bserrno);
void zvfs_spdk_blob_write_cb(void *arg, int bserrno);

// close
void zvfs_do_close(void *arg);
void zvfs_spdk_blob_close_cb(void *arg, int bserrno);

// delete
void zvfs_do_delete(void *arg);
void zvfs_spdk_blob_delete_cb(void *arg, int bserrno);

// setup
void zvfs_json_load_fn(void *arg);
void json_app_load_done(int rc, void *ctx);


// unmount
void zvfs_do_umount(void *arg);
void zvfs_spdk_bs_unload_cb(void *arg, int bserrno);

/* ========== helpers ========== */

static uint64_t zvfs_need_clusters(zvfs_t *fs, uint64_t end_byte) {
	uint64_t cluster_size = spdk_bs_get_cluster_size(fs->bs);
	return (end_byte + cluster_size - 1) / cluster_size;
}

// mount
void zvfs_do_mount(void *arg) {

	zvfs_t *fs = (zvfs_t*)arg;
	
	struct spdk_bs_dev *bs_dev = NULL;

	int rc = spdk_bdev_create_bs_dev_ext("Malloc0", zvfs_spdk_bdev_event_cb, NULL, &bs_dev);
	if (rc != 0) {
		spdk_app_stop(0);
	}

	spdk_bs_init(bs_dev, NULL, zvfs_spdk_bs_init_cb, fs);

	SPDK_NOTICELOG("zvfs_entry\n");

}

void zvfs_spdk_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
				     void *event_ctx) {
	SPDK_NOTICELOG("zvfs_spdk_bdev_event_cb\n");
}

void zvfs_spdk_bs_init_cb(void *arg, struct spdk_blob_store *bs, int bserrno) {
	zvfs_t *fs = (zvfs_t*)arg;

	uint64_t io_unit_size = spdk_bs_get_io_unit_size(bs);
	SPDK_NOTICELOG("io_unit_size : %"PRIu64"\n", io_unit_size);

	fs->io_unit_size = io_unit_size;
	fs->bs = bs;

	fs->channel = spdk_bs_alloc_io_channel(fs->bs);
	if (fs->channel == NULL) {
		return ;
	}

	fs->finished = true;

	SPDK_NOTICELOG("mount finished\n");
}

// create
void zvfs_do_create(void *arg) {
	zvfs_file_t *file = (zvfs_file_t *)arg;
	
	spdk_bs_create_blob(file->fs->bs, zvfs_spdk_bs_create_blob_cb, file);

}

void zvfs_spdk_bs_create_blob_cb(void *arg, spdk_blob_id blobid, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	file->blob_id = blobid;
	SPDK_NOTICELOG("blobid : %"PRIu64"\n", blobid);

	spdk_bs_open_blob(file->fs->bs, blobid, zvfs_spdk_bs_open_blob_cb, file);
}

void zvfs_spdk_bs_open_blob_cb(void *arg, struct spdk_blob *blb, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;
    if (bserrno) {
        SPDK_ERRLOG("load blob error: %d\n", bserrno);
        file->finished = true;
        return;
    }

	file->blob = blb;

	uint64_t free_cluster = spdk_bs_free_cluster_count(file->fs->bs);  //
	SPDK_NOTICELOG("free_cluster : %"PRIu64"\n", free_cluster);

	spdk_blob_resize(blb, free_cluster, zvfs_spdk_blob_resize_cb, file);
}

void zvfs_spdk_blob_resize_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;
	
	uint64_t total = spdk_blob_get_num_clusters(file->blob);
	SPDK_NOTICELOG("resize blob :%"PRIu64"\n", total);

	if (file->dirent) {
		file->dirent->allocated_clusters = total;
	}

	spdk_blob_sync_md(file->blob, zvfs_spdk_blob_sync_cb, file);
}

void zvfs_spdk_blob_sync_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	file->dma_buf = spdk_malloc(BUFFER_SIZE, 0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
	if (file->dma_buf == NULL) {
		SPDK_ERRLOG("spdk_malloc failed\n");
		file->finished = true;
		return ;
	}

	file->dma_buf_size = BUFFER_SIZE;
	SPDK_NOTICELOG("open complete\n");
	file->finished = true;
}

// open
void zvfs_do_open(void *arg) {
    zvfs_file_t *file = (zvfs_file_t *)arg;
    spdk_bs_open_blob(file->fs->bs, file->blob_id, zvfs_spdk_bs_open_blob_cb2, file);
}

void zvfs_spdk_bs_open_blob_cb2(void *arg, struct spdk_blob *blb, int bserrno) {
    zvfs_file_t *file = (zvfs_file_t *)arg;

    if (bserrno) {
        SPDK_ERRLOG("load blob error: %d\n", bserrno);
        file->finished = true;
        return;
    }

    file->blob = blb;

    file->dma_buf = spdk_malloc(BUFFER_SIZE, 0x1000, NULL,
                                SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
    if (!file->dma_buf) {
        SPDK_ERRLOG("spdk_malloc failed\n");
        file->finished = true;
        return;
    }

    file->dma_buf_size = BUFFER_SIZE;
    file->finished = true;
}

// read
void zvfs_do_read(void *arg) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	uint64_t io_unit_size = file->fs->io_unit_size;
	uint64_t offset = file->current_offset;
	uint64_t file_size = file->dirent ? file->dirent->file_size : 0;

	if (offset >= file_size) {
		SPDK_NOTICELOG("read: EOF\n");
		file->io_count = 0;
		file->finished = true;
		return;
	}

	if (offset + file->io_count > file_size) {
		file->io_count = file_size - offset;
	}

	uint64_t lba      = offset / io_unit_size;
	uint64_t page_off = offset % io_unit_size;
	uint64_t lba_count = (page_off + file->io_count + io_unit_size - 1) / io_unit_size;

	spdk_blob_io_read(file->blob, file->fs->channel, 
		file->dma_buf, 
		lba, lba_count,
		zvfs_spdk_blob_read_cb, file);
}

void zvfs_spdk_blob_read_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	if (bserrno) {
		SPDK_ERRLOG("blob_read error: %d\n", bserrno);
		file->io_count = 0;
		file->finished = true;
		return;
	}

	file->current_offset += file->io_count;
	SPDK_NOTICELOG("read complete, new offset=%" PRIu64 "\n", file->current_offset);
	file->finished = true;
}


// write
/*
 * callback 链：
 *
 *   zvfs_do_write
 *       ├─(需要扩容)─→ spdk_blob_resize → zvfs_spdk_blob_write_resize_cb
 *       │                                      → spdk_blob_sync_md → zvfs_spdk_blob_write_sync_cb
 *       │                                                                 → zvfs_do_write_io
 *       │                                                                       → zvfs_spdk_blob_write_cb
 *       └─(不需扩容)─→ zvfs_do_write_io
 *                             → zvfs_spdk_blob_write_cb
 */
void zvfs_do_write_io(zvfs_file_t *file) {
	uint64_t io_unit_size = file->fs->io_unit_size;
	uint64_t lba       = file->current_offset / io_unit_size;
	uint64_t page_off  = file->current_offset % io_unit_size;
	uint64_t lba_count = (page_off + file->io_count + io_unit_size - 1) / io_unit_size;

	spdk_blob_io_write(file->blob, file->fs->channel,
			   file->dma_buf,
			   lba, lba_count,
			   zvfs_spdk_blob_write_cb, file);
}

void zvfs_spdk_blob_write_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	if (bserrno) {
		SPDK_ERRLOG("blob_write error: %d\n", bserrno);
		file->finished = true;
		return;
	}

	uint64_t new_end = file->current_offset + file->io_count;
	if (file->dirent && new_end > file->dirent->file_size) {
		file->dirent->file_size = new_end;
	}
	file->current_offset = new_end;

	SPDK_NOTICELOG("write complete, new offset=%" PRIu64 "\n", file->current_offset);
	file->finished = true;
}

void zvfs_spdk_blob_write_sync_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	if (bserrno) {
		SPDK_ERRLOG("write sync error: %d\n", bserrno);
		file->finished = true;
		return;
	}

	if (file->dirent) {
		file->dirent->allocated_clusters =
			(uint32_t)spdk_blob_get_num_clusters(file->blob);
	}

	zvfs_do_write_io(file);
}

void zvfs_spdk_blob_write_resize_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	if (bserrno) {
		SPDK_ERRLOG("write resize error: %d\n", bserrno);
		file->finished = true;
		return;
	}

	spdk_blob_sync_md(file->blob, zvfs_spdk_blob_write_sync_cb, file);
}

void zvfs_do_write(void *arg) {
	zvfs_file_t *file = (zvfs_file_t *)arg;

	uint64_t end_byte      = file->current_offset + file->io_count;
	uint64_t need_clusters = zvfs_need_clusters(file->fs, end_byte);
	uint64_t cur_clusters  = file->dirent ? file->dirent->allocated_clusters
					      : spdk_blob_get_num_clusters(file->blob);

	SPDK_NOTICELOG("endbyte:%ld, needcluster:%ld, curcluster:%ld\n", end_byte, need_clusters, cur_clusters);
	if (need_clusters > cur_clusters) {
		uint64_t free_clusters = spdk_bs_free_cluster_count(file->fs->bs);
		SPDK_NOTICELOG("free_cluster : %"PRIu64"\n", free_clusters);
		if (need_clusters - cur_clusters > free_clusters) {
			SPDK_ERRLOG("no free clusters\n");
			file->finished = true;
			return;
		}
		spdk_blob_resize(file->blob, need_clusters,
				 zvfs_spdk_blob_write_resize_cb, file);
	} else {
		zvfs_do_write_io(file);
	}
}

// close 
void zvfs_do_close(void *arg) {
	zvfs_file_t *file = (zvfs_file_t *)arg;
	spdk_blob_close(file->blob, zvfs_spdk_blob_close_cb, file);
}

void zvfs_spdk_blob_close_cb(void *arg, int bserrno) {
	zvfs_file_t *file = (zvfs_file_t *)arg;
	
	if (bserrno) {
        SPDK_ERRLOG("blob_close error: %d\n", bserrno);
    }
	spdk_free(file->dma_buf);
	file->dma_buf = NULL;
	file->current_offset = 0;

	SPDK_NOTICELOG("close complete\n");
	file->finished = true;
}

// delete
void zvfs_do_delete(void *arg) {
    zvfs_file_t *file = (zvfs_file_t *)arg;
    spdk_bs_delete_blob(file->fs->bs, file->blob_id, zvfs_spdk_blob_delete_cb, file);
}

void zvfs_spdk_blob_delete_cb(void *arg, int bserrno) {
    zvfs_file_t *file = (zvfs_file_t *)arg;

    if (bserrno) {
        SPDK_ERRLOG("blob_delete error: %d\n", bserrno);
    }

    SPDK_NOTICELOG("delete complete\n");
    file->finished = true;
}

// unmount
void zvfs_do_umount(void *arg) {

	zvfs_t *fs = (zvfs_t *)arg;

	if (fs->bs) {
		if (fs->channel) {
			spdk_bs_free_io_channel(fs->channel);
		}
		spdk_bs_unload(fs->bs, zvfs_spdk_bs_unload_cb, fs);
	}
	
}

void zvfs_spdk_bs_unload_cb(void *arg, int bserrno) {

	zvfs_t *fs = (zvfs_t *)arg;
	fs->finished = true;
}

// waiter 
bool waiter(struct spdk_thread *thread, spdk_msg_fn start_fn, void *ctx, bool *finished) {

	spdk_thread_send_msg(thread, start_fn, ctx);

	int waiter_count = 0;

	do {
		spdk_thread_poll(thread, 0, 0);
		waiter_count ++; 
	} while(!(*finished) && waiter_count < WAITER_MAX_TIME);

	while (spdk_thread_poll(thread, 0, 0) > 0) {}

	if (!(*finished) && waiter_count >= WAITER_MAX_TIME) {
		return false; // timeout
	}

	return true;
}

// setup
// zvfs.json

int zvfs_env_setup(void) {
	struct spdk_env_opts opts;
	spdk_env_opts_init(&opts);

	if (0 != spdk_env_init(&opts)) {
		return -1;
	}

	spdk_log_set_print_level(SPDK_LOG_NOTICE);
	spdk_log_set_level(SPDK_LOG_NOTICE);
	spdk_log_open(NULL);

	spdk_thread_lib_init(NULL, 0);
	global_thread = spdk_thread_create("global", NULL);
	spdk_set_thread(global_thread);

	bool done = false;

	waiter(global_thread, zvfs_json_load_fn, &done, &done);
	SPDK_NOTICELOG("json_app_load_done complete\n");

	return 0;
}

void zvfs_json_load_fn(void *arg) {
	spdk_subsystem_init_from_json_config(json_file, SPDK_DEFAULT_RPC_ADDR, json_app_load_done,
		arg, true);
	
}

void json_app_load_done(int rc, void *ctx) {
	bool *done = ctx;
	*done = true;

	SPDK_NOTICELOG("json_app_load_done\n");
}





// filesystem
// load
int zvfs_mount(struct zvfs_s *fs) {
	fs->finished = false;
	return waiter(global_thread, zvfs_do_mount, fs, &fs->finished);
} 
// unload
int zvfs_umount(struct zvfs_s *fs) {
	fs->finished = false;
	return waiter(global_thread, zvfs_do_umount, fs, &fs->finished);
}
// file
// create
int zvfs_create(struct zvfs_file_s *file) {
	file->finished = false;
	return waiter(global_thread, zvfs_do_create, file, &file->finished);
}
// open
int zvfs_open(struct zvfs_file_s *file) {
    file->finished = false;
    return waiter(global_thread, zvfs_do_open, file, &file->finished);
}
// read
int zvfs_read(struct zvfs_file_s *file, uint8_t *buffer, size_t count) {
	file->io_count = count;
	file->finished = false;

	bool ok = waiter(global_thread, zvfs_do_read, file, &file->finished);
	uint64_t page_off = (file->current_offset - file->io_count) % file->fs->io_unit_size;
	memcpy(buffer, (uint8_t *)file->dma_buf + page_off, file->io_count);
	
	return ok ? (int)file->io_count : -1;
}
// write
int zvfs_write(struct zvfs_file_s *file, const uint8_t *buffer, size_t count) {
	file->io_count = count;
	file->finished = false;

	memcpy(file->dma_buf, buffer, count);  
	bool ok = waiter(global_thread, zvfs_do_write, file, &file->finished);
	return ok ? (int)count : -1;
}
// close
int zvfs_close(struct zvfs_file_s *file) {
	file->finished = false;
	return waiter(global_thread, zvfs_do_close, file, &file->finished);
}
// delete 
int zvfs_delete(struct zvfs_file_s *file) {
    file->finished = false;
    return waiter(global_thread, zvfs_do_delete, file, &file->finished);
}

int main(int argc, char *argv[]) {

	if (zvfs_env_setup()) {
		return -1;
	}

	SPDK_NOTICELOG("zvfs_env_setup success\n");

	SPDK_NOTICELOG("\n\n zvfs mount start \n\n");
	zvfs_t *fs = calloc(1, sizeof(zvfs_t));
	zvfs_mount(fs);


	SPDK_NOTICELOG("\n\n zvfs open start \n\n");
	zvfs_file_t *file = calloc(1, sizeof(zvfs_file_t));
	file->fs = fs;
	zvfs_dirent_t *dirent = calloc(1, sizeof(zvfs_dirent_t));
	file->dirent = dirent;
	zvfs_create(file);

	SPDK_NOTICELOG("\n\n zvfs write start \n\n");
	char *buffer = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	zvfs_write(file, buffer, strlen(buffer));
	char *buffer2 = "abcdefghijklmnopqrstuvwxyz";
	zvfs_write(file, buffer, strlen(buffer2));


	SPDK_NOTICELOG("\n\n zvfs read start \n\n");
	file->current_offset = 0;
	char rbuffer[BUFFER_SIZE] = {0};
	int n = zvfs_read(file, rbuffer, BUFFER_SIZE);
	SPDK_NOTICELOG("READ BUFFER:%d, %s\n", n, rbuffer);

	SPDK_NOTICELOG("\n\n zvfs close start \n\n");
	zvfs_close(file);

	SPDK_NOTICELOG("\n\n zvfs delete start \n\n");
	zvfs_delete(file);

	free(dirent);
	free(file);

	SPDK_NOTICELOG("\n\n zvfs umount start \n\n");
	zvfs_umount(fs);
	free(fs);
	
}