#!/bin/bash

# Time sheet creator
# Stores clock in and outs to timesheet named for the ending date of the ts
usage() {
    cat <<EOF
Usage: timetracker [-i|o|t|v|h]

Tracks timesheets automatically

Options:
  -i, --in          clock in
  -o, --out         clock out
  -t, --total       totals the hours worked
  -v, --visualize   prints the timesheet
  -h, --help        display this message
EOF
}

# dir for timesheets
WORKING_DIR="$HOME/.local/share/timetracker"
TIMESHEET_DIR="$WORKING_DIR/timesheets"
ARCHIVE_DIR="$TIMESHEET_DIR/archive"
# existing
TIMESHEET=$(ls "$TIMESHEET_DIR" | grep ".csv")
# generated by clock in
CURRENT_SESSION="$TIMESHEET_DIR/.session"

createTimesheet() {
    payperiods=$((($(date +%s) - $(date -d "Dec-30-22" +%s)) / (14*24*3600)))
    period_end=$(date -d "Dec-30-22 + $((($payperiods + 1) * 14)) days" +%b-%d-%y)
    TIMESHEET=$(printf "%s.csv" "$period_end")
    # create timesheet 
    echo "Date, Time In, Time Out, Total Time (HH:MM)" > "${TIMESHEET_DIR}/${TIMESHEET}"
}

getTimesheet() {
    # get Timesheet to use
    if [[ -z "$TIMESHEET" ]] ; then
        # no timesheet, create one
        createTimesheet
    else
        # timesheet found, check we are still in period
        period_end=$(date -d "$(echo "$TIMESHEET" | awk -F . '{print $1}') + 1 days" +%s) 
        if [[ $(date +%s) -ge $period_end ]] ; then
            # past timesheet, moving to archive and creating new
            mv "${TIMESHEET_DIR}/${TIMESHEET}" "$ARCHIVE_DIR"
            createTimesheet
        fi
    fi
}

clockIn() {
    # clock in by creating env file
    curdate=$(date +%s)
    env_details=$(printf 'DATE=%s\nTIME_IN=%s\n' "$curdate" "$curdate")
    if [[ ! -f "$CURRENT_SESSION" ]] ; then
        # creating session
        echo "$env_details" > "$CURRENT_SESSION"
    else
        echo "Already Clocked In!" >&2
        exit 1
    fi
}

clockOut() {
    # clock out
    if [[ -f "$CURRENT_SESSION" ]] ; then
        # session exists, get info
        source "$CURRENT_SESSION"
        # printing to timesheet
        TIME_OUT=$(date +%s) 
        TOTAL_TIME=$(($TIME_OUT - $TIME_IN + 3600 * 5)) 
        echo "$TOTAL_TIME"
        # printing to timesheet
        printf '%s, %s, %s, %s\n' "$(date -d @$DATE "+%a %b-%d")" "$(date -d @$TIME_IN +%I:%M%P)" "$(date -d @$TIME_OUT +%I:%M%P)" "$(date -d @$TOTAL_TIME +%H:%M)" >> ${TIMESHEET_DIR}/${TIMESHEET}
        # cleaning up session
        rm ${CURRENT_SESSION}
    else
        # no session
        echo "Not clocked in!" >&2
        exit 1
    fi
}

visualize() {
    # visualize the current timesheet
    column -s "," -t < ${TIMESHEET_DIR}/${TIMESHEET}
}

totalHours() {
    # tally up hours for the current timesheet
    while read -r entry; do
        date=$(echo "$entry" | awk -F , '{print $1}' | tr -d ",\n")
        time=$(echo "$entry" | awk -F , '{print $4}' | tr -d " ,\n")
        if [[ "$date" != "Date" ]] ; then
            printf 'On %s worked %s\n' "$date" "$time"
            hours=$(($hours + 10#$(echo "$time" | awk -F : '{print $1}')))
            mins=$(($mins + 10#$(echo "$time" | awk -F : '{print $2}')))
        fi
    done < ${TIMESHEET_DIR}/${TIMESHEET}
    hours=$(($hours + $mins/60)) # overflow
    mins=$(($mins%60))
    printf 'Worked %d hours, %d minutes\n' "$hours" "$mins"
}

# get the timesheet
getTimesheet

# parse args
while [[ $# -gt 0 ]] ; do
    case $1 in
        -h | --help)
            usage
            exit 0
            ;;
        -i | --in)
            clockIn
            ;;
        -o | --out)
            clockOut
            ;;
        -v | --visualize)
            visualize
            ;;
        -t | --total)
            totalHours
            ;;
        *)
            echo "Error: Unrecognized" >&2
            usage
            exit 1
            ;;
    esac
    shift
done