#!/bin/bash

# BiliBili Anaylzer: Analzye the relationship between bilibili users

# Start from
START_UID=4851356
# Extention of temp files
TEMP_EXT=.tmp
# Extention of the crawlwd mark
CRAWLED_EXT=.crawled
# Save relation to
OUTPUT_FILE=bilibili.prolog
# Start from page
PAGE=1

function crawl {
        while true
        do
                [[ ! -z $1 ]] && CURRENT_UID=$1 || CURRENT_UID=$START_UID # If parameter is given, use it as start UID
                echo "[$(date)] Crwaling $CURRENT_UID..." # Print status
                curl http://space.bilibili.com/$CURRENT_UID/fans.html?page=$PAGE 2> /dev/null > $CURRENT_UID$TEMP_EXT # Get the page of follwers of current page
                DATAS=$(cat $CURRENT_UID.tmp | grep http://space.bilibili.com/  | awk -F\" '{print $6}' | grep html | awk -F/ '{print $4}') # Parser the page and get the UID of the followers

                [[ $DATAS == "" ]] && return 0 # No followers? Possiblly the last page. Or... we meet a poor guy

                for DATA in $DATAS
                do
                        [[ ! -z $(cat $CURRENT_UID$CRAWLED_EXT 2> /dev/null | grep $DATA) ]] && return 0 # Already crawled? Okay, let's get away.
                        echo "follow($DATA,$CURRENT_UID)." >> $OUTPUT_FILE # Write the follower data to output
                        echo $DATA >> $CURRENT_UID$CRAWLED_EXT # Mark as crawled.
                        crawl $DATA # Crawl this follower
                done

                nextpage # Done? Go next page.
        done
}


function nextpage {
        echo $PAGE+1 | bc
}

rm *$CRAWLED_EXT 2> /dev/null
rm *$TEMP_EXT

$*