#!/bin/bash

if [ $# -lt 2 ]
then	printf 'Usage: %s output_file stat_file...\n' "${0%%*/}" >&2
	exit 1
fi

# where to write the output
logfile=$1
# remaining operands are stat files to be read directly by awk...
shift

awk '
BEGIN           {LAB="train statistics|test statistics|validate statistics|ival statistics"
                }

function prec()	{if(! HDDONE)	{printf "filename"
                                 for (i=1; i<=CNT; i++) printf OFS"%s", HD[i]
                                 printf ORS
                                 HDDONE = 1
                                }
                 printf "%s", FN
                 for (i=1; i<=CNT; i++) printf OFS"%s", VAL[HD[i]]
                 printf ORS
                 split ("", VAL)
                }

FNR == 1        {if (NR != 1) prec()
		 FN = FILENAME
		}

$0 ~ LAB        {PH = $1
                 for (i=1; i<=5; i++)   {getline
                                         IX = PH "_" $1
                                         VAL[IX] = $2
                                         if (! HDDONE) HD[++CNT] = IX 
                                        }
                } 

END             {prec()
                }

' OFS="\t" "$@" > "$logfile"

column -t logfile.txt

script_name logfile.txt S-mae_0.3810_V-mae_0.4956_all_B30_E800_EC503_S1v1_30.15.1.txt

column -t logfile.txt

filename                                                       train_r2  train_MeAE  train_MdAE  train_SE  train_n  test_r2  test_MeAE  test_MdAE  test_SE  test_n  validate_r2  validate_MeAE  validate_MdAE  validate_SE  validate_n  ival_r2  ival_MeAE  ival_MdAE  ival_SE  ival_n
S-mae_0.3810_V-mae_0.4956_all_B30_E800_EC503_S1v1_30.15.1.txt  0.8320    0.3215      0.2784      0.3068    400      0.7183   0.3810     0.2922     0.4129   400     0.5309       0.4956         0.4186         0.5013       400         0.0000   0.0000     0.0000     0.0000   0