#!/usr/bin/env bash
set -eu -o pipefail
SECONDS=${1:-1000000}

# Report system stats to text file each second for reference.
# Ideally want to start the script via terminal so that closing the terminal will stop writing the file!
# Otherwise it'll just keep writing with no limits until RPi is restarted!

#	Example of what gets printed out:
#	2022-03-26 07:18:44; Temp=39.9ºC. RAM 'Used': 399MB (10.5%); RAM 'Free': 2.4GB (64.7%); RAM 'Available': 3.1GB (84.6%); RAM used in Shared & Buffer: 26.0%. Swap used: 0.0%. µSD @/dev/root uses 20,178,276kB.

#	HDPARM added to RPi to check out the speeds of writing.
#	https://www.youtube.com/watch?v=Tgrka088ZFk
#	Shown to run at 40MB/s with RPi and MMC (SSD is upwards of 240MB/s if used...
#	sudo hdparm -t --direct /dev/mmcblk0

## OTHER potential interesting bits:
#actual_cpu_clock_speed() {
#	/opt/vc/bin/vcgencmd measure_clock arm | cut -d"=" -f2 | cut -d"'" -f1
#}
#desired_cpu_clock_speed() {
#	cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
#}

#	All memory (note the 'Gi' may need further cropping.
#	free -h | cut -b 1-6,15-19,27-31,39-43,50-55,58-67,71-79
#	free -h | head -n 2 | cut -b 1-6,15-20,27-33,71-79	# Alternative - Total,Used,Available...
#**	Below cut each of these and assign to the titles given by "free -h" **#
CPU_Temp() {
	/opt/vc/bin/vcgencmd measure_temp | cut -d"t" -f2 | cut -d"'" -f1
}
RAM_Total_Num() {
	free -h | tail -n 2 | head -n 1 | cut -b 15-18
}
RAM_Used_Num() {
	free -h | tail -n 2 | head -n 1 | cut -b 27-30
}
RAM_Free_Num() {
		free -h | tail -n 2 | head -n 1 | cut -b 39-42
}
RAM_Shared_Num() {
		free -h | tail -n 2 | head -n 1 | cut -b 50-55
}
RAM_BufCash_Num() {
		free -h | tail -n 2 | head -n 1 | cut -b 58-67
}
RAM_Available_Num() {
	free -h | tail -n 2 | head -n 1 | cut -b 75-78
}
SWAP_Total_Num() {
	# Swap is HDD memory used as RAM. Used SWAP should be as low as possible.
	free -h | tail -n 1 | cut -b 15-18
}
SWAP_Used_Num() {
	free -h | tail -n 1 | cut -b 27-30
}
SD_Location() {
	df -k | head -n 2 | tail -n 1 | cut -b 1-9
}
SD_Used_NumA() {									# Given in kB, so split so easy to add commas and read in output
	df -k | head -n 2 | tail -n 1 | cut -b 26-27
}
SD_Used_NumB() {
	df -k | head -n 2 | tail -n 1 | cut -b 28-30
}
SD_Used_NumC() {
	df -k | head -n 2 | tail -n 1 | cut -b 31-33
}
# Calculate out percentages here
RAM_Used_Perc() {
	free | grep Mem | awk '{printf ("%4.1f"), $3/$2 * 100.0}'
# https://stackoverflow.com/questions/10585978/how-to-get-the-percentage-of-memory-free-with-a-linux-command
}
RAM_Free_Perc() {
	free | grep Mem | awk '{printf ("%4.1f"), $4/$2 * 100.0}'
}
RAM_Available_Perc() {
	free | grep Mem | awk '{printf ("%4.1f"), $7/$2 * 100.0}'
}
RAM_Others_Perc() {
	free | grep Mem | awk '{printf ("%4.1f"), ($5 + $6)/$2 * 100.0}'
}
SWAP_Used_Perc() {
	free | grep Swap | awk '{printf ("%4.1f"), $3/$2 * 100.0}'
}
# Following variables available from the above coding:
#	CPU_Temp,		RAM_Total_Num,	RAM_Used_Num,	RAM_Free_Num,	RAM_Shared_Num,		RAM_BufCash_Num,	RAM_Available_Num,	SD_Location,	SD_Used_Num(A-C)
#	SWAP_Total_Num,	SWAP_Used_Num,	RAM_Used_Perc,	RAM_Free_Perc,	RAM_Available_Perc,	RAM_Others_Perc,	SWAP_Used_Perc

echo "" >> "/home/astroberry/Astro/SystemLog.txt"
echo "*************************************************************************" >> "/home/astroberry/Astro/SystemLog.txt"
echo "**      New record of system info started at $(date '+%Y-%m-%d, %H:%M:%S')      **" >> "/home/astroberry/Astro/SystemLog.txt"
echo "**   Total RAM available is $(RAM_Total_Num)B and total SWAP available is $(SWAP_Total_Num)B.   **" >> "/home/astroberry/Astro/SystemLog.txt"
echo "*************************************************************************" >> "/home/astroberry/Astro/SystemLog.txt"

for i in `seq 1 $SECONDS`; do
	echo $(date '+%Y-%m-%d %H:%M:%S') "T$(CPU_Temp)ºC. RAM 'Used': $(RAM_Used_Num)B ($(RAM_Used_Perc)%); RAM 'Free': $(RAM_Free_Num)B ($(RAM_Free_Perc)%); RAM 'Available': $(RAM_Available_Num)B ($(RAM_Available_Perc)%); RAM used in Shared & Buffer: $(RAM_Others_Perc)%. Swap used:$(SWAP_Used_Perc)%. µSD @$(SD_Location) uses $(SD_Used_NumA),$(SD_Used_NumB),$(SD_Used_NumC)kB." >> "/home/astroberry/Astro/SystemLog.txt"
	sleep 1
done