#!/bin/bash

# configurable env settings
pipe=${pipe:-/tmp/viewcount-control}
db=${db:-viewer.db}
wndb=${wndb:-wn.db}
table=${table:-viewer}
interval=${interval:-20}
poll_interval=${poll_interval:-60}

# Log a timestamped message to stdout.
# $1 - message
function log() {
    echo `date "+%Y-%m-%dT%H:%M:%S "` $1
}

# Make sure the pipe for sending commands to listen() exists.
function initialize() {
    log "init - $pipe"
    [ -p "$pipe" ] || mkfifo "$pipe"
}

# Run collect.sh and store data in $db.
# $1 - url
function collect() {
    url=$1
    video_id=${1#*=}
    log "collect - begin - $video_id"
    env db="$db" table="$table" interval="$interval" ./collect.sh "$url"        && log "collect - end - $video_id"
}

# Print the latest non-auPAY video_id in schedule table.
function latest_video_id() {
    echo "SELECT video_id FROM schedule WHERE segment_id != 8 AND video_id IS NOT NULL ORDER BY jst DESC LIMIT 1;" | sqlite3 -cmd ".timeout 5000" $wndb # wait for db to unlock: https://stackoverflow.com/a/57453186
}

# Query $wndb for new video_ids periodically and send messages to listen
# when a new video_id is discovered.  Also keep track of video_ids that
# have already been processed in $seen.
function poll_video_ids() {
    # dictionary of seen video_ids
    declare -A seen

    video_id=$(latest_video_id)
    while true ; do
        if [[ "${seen[$video_id]}" -eq 1 ]] ; then
            #log "poll - seen $video_id already"
            true
        else
            url="https://www.youtube.com/watch?v=$video_id"
            log "poll - new stream $url"
            echo "$url" > $pipe
            seen[$video_id]=1
        fi
        sleep $poll_interval
        video_id=$(latest_video_id)
    done
}

# Read commands from $pipe and execute them.
function listen() {
    # monitor pipe for YouTube stream URLs
    while read cmd < $pipe ; do
        if [[ "$cmd" == http* ]] ; then
            collect $cmd &
        elif [[ "$cmd" == test ]] ; then
            log "test - test"
        else
            log "unknown - $cmd"
        fi
    done
}

log "pid - $$"
log "settings - pipe=$pipe"
log "settings - db=$db"
log "settings - wndb=$wndb"
log "settings - table=$table"
log "settings - interval=$interval"
log "settings - poll_interval=$poll_interval"
initialize
(sleep 1; poll_video_ids &)
listen