from visualdl import LogWriter, LogReader
import random

def write(log_dir):
    log_writer = LogWriter(dir = log_dir, sync_cycle = 5)
    with log_writer.mode("train") as logw:
        # this scalar will record value in mode "train" and has tag "record1"
        scalar_train_1 = logw.scalar("record1")
        # this scalar will record value in mode "train" and has tag "record2"
        scalar_train_2 = logw.scalar("record2")
        
    with log_writer.mode("test") as logw:
        # this scalar will record value in mode "test" and has tag "record1"
        scalar_val_1 = logw.scalar("record1")
        # this scalar will record value in mode "test" and has tag "record2"
        scalar_val_2 = logw.scalar("record2")
        
    for i in range(5):
        # add scalar record with step from 0 to 4
        scalar_train_1.add_record(i, random.random())
        scalar_train_2.add_record(i, random.random())
        scalar_val_1.add_record(i, random.random())
        scalar_val_2.add_record(i, random.random())

def read(log_dir):
    log_reader = LogReader(dir = log_dir)
    
    # get all mode
    modes = log_reader.modes()
    for mode in modes:
        # switch log_reader to appointed mode
        with log_reader.mode(mode) as logr:
            # get all tags, in this case, tag will be record1 or record2
            tags = logr.tags("scalar")
            for tag in tags:
                # each tag consists of many records
                records = logr.scalar(tag = tag).records()
                for step, record in enumerate(records):
                    print("mode %s -- tag %s -- step %d -- val %.2f" % (mode, tag, step, record))
        
if __name__ == "__main__":
    log_dir = "vdl_log"
    write(log_dir)
    read(log_dir)