Calculate accumulated times from json with bash script - json

Question

I have data in json format that logs timestamps (hh:mm in 24h format) with an event (In/Out). My goal is to add up all the time differences between an "IN" event and the next "OUT" event.
For simplification I assume that there are no inconsistencies (The first element is always an "IN" and each "IN" is followed by an "OUT"). Exception: If the last element is an "IN", the calculation has to be done between the current time and the timestamp from the last "IN" event.
This is my script so far, which calculates all the timespans, also between an OUT and an IN event. But I need only those that are inbetween an IN and OUT event.
Any tips what might be more useful here are welcome !
#!/bin/bash
JSON='{ "times": [ [ "7:43", "IN" ], [ "8:26", "OUT" ], [ "8:27", "IN" ], [ "9:12", "OUT" ], [ "9:14", "IN" ], [ "9:22", "OUT" ], [ "9:23", "IN " ], [ "12:12", "OUT" ], [ "13:12", "IN" ] ]}'
IN_TIMES=$(jq '.times | to_entries | .[] | select(.value[1]| tostring | contains("IN")) | .value[0]' <<< "$JSON")
OUT_TIMES=$(jq '.times | to_entries | .[] | select(.value[1]| tostring | contains("OUT")) | .value[0]' <<< "$JSON")
ALL_TIMES=$(jq -r '.times| to_entries | .[] | .value[0]' <<< "$JSON")
prevtime=0
count=0
for i in $(echo $ALL_TIMES | sed "s/ / /g")
do
if [[ "$count" -eq 0 ]]; then
(( count++ ))
prevtime=$i
continue
else
(( count++ ))
fi
time1=`date +%s -d ${prevtime}`
time2=`date +%s -d ${i}`
diffsec=`expr ${time2} - ${time1}`
echo From $prevtime to $i: `date +%H:%M -ud #${diffsec}`
prevtime=$i
done

Answer 1

Here's an only-jq solution that only calls jq once.
Please note, though, that it may need tweaking to take into account time zone considerations, error-handling, and potentially other complications:
def mins: split(":") | map(tonumber) | .[0] * 60 + .[1];
def diff: (.[1] - .[0]) | if . >= 0 then . else 24*60 + . end;
def now_mins: now | gmtime | .[3] * 60 + .[4];
def pairs:
range(0; length; 2) as $i | [.[$i], .[$i+1] ];
def sigma(s): reduce s as $s (0; . + $s);
.times
| map( .[0] |= mins )
| if .[-1][1] == "IN" then . + [ [now_mins, "OUT"] ] else . end
| sigma(pairs | map(.[0]) | diff)

Answer 2

Since you measure times up to the minute, it is enough to compute minutes without messing up with the command date. I have an awk solution:
awk -F: -vIRS=" " -vfmt="From %5s to %5s: %4u minutes\n" \
'{this=$1*60+$2}a{printf(fmt,at,$0,this-a);a=0;next}{a=this;at=$0}\
END{if(a){$0=strftime("%H:%M");printf(fmt,at,$0,$1*60+$2-a)}}' <<<"$ALL_TIMES"
which works by defining a colon as field separator and a space as record separator. In this way we get a separate record with two fields for each time. Then
{this=$1*60+$2} : We compute how many minutes there are in the current record and put them in the variable this.
a{printf(fmt,at,$0,this-a);a=0;next} : If the (initially empty) variable a is not null nor zero, we are reading an OUT entry, so we print what we want, set a to zero because the next field will be an IN entry, and we continue to the next record.
{a=this;at=$0} : Otherwise, we are reading an IN entry, and set a to its minutes and at to its string representation (needed we will print it, as per previous case).
END{if(a){$0=strftime("%H:%M");printf(fmt,at,$0,$1*60+$2-a)}} : at the end, if we still have some dangling IN data, we set $0 to be the properly formatted current time and print what we want.
All done.

Answer 3

With Xidel and a little XQuery magic this is rather simple:
#!/bin/bash
JSON='{"times": [["7:43", "IN"], ["8:26", "OUT"], ["8:27", "IN"], ["9:12", "OUT"], ["9:14", "IN"], ["9:22", "OUT"], ["9:23", "IN "], ["12:12", "OUT"], ["13:12", "IN"]]}'
xidel -s - --xquery '
let $in:=$json/(times)()[contains(.,"IN")](1) ! time(
substring(
"00:00:00",
1,
8-string-length(.)
)||.
),
$out:=$json/(times)()[contains(.,"OUT")](1) ! time(
substring(
"00:00:00",
1,
8-string-length(.)
)||.
)
for $x at $i in $out return
concat(
"From ",
$in[$i],
" to ",
$x,
": ",
$x - $in[$i] + time("00:00:00")
)
' <<< "$JSON"
$in:
00:07:43
00:08:27
00:09:14
00:09:23
00:13:12
$out:
00:08:26
00:09:12
00:09:22
00:12:12
Output:
From 00:07:43 to 00:08:26: 00:00:43
From 00:08:27 to 00:09:12: 00:00:45
From 00:09:14 to 00:09:22: 00:00:08
From 00:09:23 to 00:12:12: 00:02:49