#!/bin/bash
# Author: Linyos Torovoltos https://github.com/linyostorovovoltos
# Modifications: Alexander Epstein https://github.com/alexanderepstein

if [[ -d $HOME/.cache/ytview ]]{  rm -rf $HOME/.cache/ytview/ ;}

setglobal player = ''""
setglobal configuredClient = ''""
setglobal currentVersion = '"1.11.1'"
setglobal flag = ''""

## This function determines which http get tool the system has installed and returns an error if there isnt one
proc getConfiguredClient
{
  if  command -v curl &>/dev/null  {
    setglobal configuredClient = '"curl'"
  } elif command -v wget &>/dev/null  {
    setglobal configuredClient = '"wget'"
  } elif command -v fetch &>/dev/null  {
    setglobal configuredClient = '"fetch'"
  } else {
    echo "Error: This tool reqires either curl, wget, or fetch to be installed."  > !2
    return 1
  }
}

proc checkInternet
{
  echo -e "GET http://google.com HTTP/1.0\n\n" | nc google.com 80 > /dev/null !2 > !1 # query google with a get request
  if test $Status -eq 0 { #check if the output is 0, if so no errors have occured and we have connected to google successfully
    return 0
  } else {
    echo "Error: no active internet connection" > !2 #sent to stderr
    return 1
  }
}

## Allows to call the users configured client without if statements everywhere
proc httpGet
{
  match $configuredClient {
    with curl curl -A curl -s @Argv
    with wget wget -qO- @Argv
    with fetch fetch -o "..."
  }
}

proc update
{
  # Author: Alexander Epstein https://github.com/alexanderepstein
  # Update utility version 1.2.0
  # To test the tool enter in the defualt values that are in the examples for each variable
  setglobal repositoryName = '"Bash-Snippets'" #Name of repostiory to be updated ex. Sandman-Lite
  setglobal githubUserName = '"alexanderepstein'" #username that hosts the repostiory ex. alexanderepstein
  setglobal nameOfInstallFile = '"install.sh'" # change this if the installer file has a different name be sure to include file extension if there is one
  setglobal latestVersion = $[httpGet https://api.github.com/repos/$githubUserName/$repositoryName/tags | grep -Eo '"name":.*?[^\\]",'| head -1 | grep -Eo "[0-9.]+] #always grabs the tag without the v option

  if [[ $currentVersion == "" || $repositoryName == "" || $githubUserName == "" || $nameOfInstallFile == "" ]]{
    echo "Error: update utility has not been configured correctly." > !2
    exit 1
  } elif [[ $latestVersion == "" ]]{
    echo "Error: no active internet connection" > !2
    exit 1
  } else {
    if [[ "$latestVersion" != "$currentVersion" ]] {
      echo "Version $latestVersion available"
      echo -n "Do you wish to update $repositoryName [Y/n]: "
      read -r answer
      if [[ "$answer" == "Y" || "$answer" == "y" ]] {
        cd  ~ || do { echo 'Update Failed' ; exit 1 ; }
        if [[ -d  ~/$repositoryName ]] { rm -r -f $repositoryName  ||  do { echo "Permissions Error: try running the update as sudo"; exit 1; } ; }
        git clone "https://github.com/$githubUserName/$repositoryName" || do { echo "Couldn't download latest version" ; exit 1; }
        cd $repositoryName ||  do { echo 'Update Failed' ; exit 1 ;}
        git checkout "v$latestVersion" !2 > /dev/null || git checkout $latestVersion !2 > /dev/null || echo "Couldn't git checkout to stable release, updating to latest commit."
        chmod a+x install.sh #this might be necessary in your case but wasnt in mine.
        ./$nameOfInstallFile "update" || exit 1
        cd ..
        rm -r -f $repositoryName ||  do { echo "Permissions Error: update succesfull but cannot delete temp files located at ~/$repositoryName delete this directory with sudo"; exit 1; }
      } else {
        exit 1
      }
    } else {
      echo "$repositoryName is already the latest version"
    }
  }
}

proc getConfiguredPlayer
{
  if [[ "$OSTYPE" == "linux"* ]]{
    if command -v vlc &>/dev/null{
      setglobal player = '"vlc'"
    } elif  command -v mpv &>/dev/null{
      setglobal player = '"mpv'"
    } elif command -v mplayer &>/dev/null{
      setglobal player = '"mplayer'"
    } else {
      echo "Error: no supported video player installed (vlc, mpv or mplayer)"  > !2
      return 1
    }
  } elif [[ "$OSTYPE" == "darwin"* ]] {
    if [[ -f /Applications/VLC.app/Contents/MacOS/VLC ]]{
      setglobal player = '"/Applications/VLC.app/Contents/MacOS/VLC'"
    } else {
      echo "Error: vlc is not installed and it is required to play videos"  > !2
      return 1
    }
  }
}


# Get the video titles
proc channelview
{

  mkdir -p $HOME/.cache/ytview/channels/$channel || return 1
  httpGet https://www.youtube.com/user/$channel/videos | grep "Duration" | awk '{print $10 " " $11 " " $12 " " $13 " " $14 " " $15 " " $16 " " $17 " " $18 " " $19 " " $20 " " $21 " " $22 " " $23 " " $24 " " $25 " " $26 " " $27 " " $29}' | sed 's/aria-describedby="description-id.*//' | sed s/title=// | sed 's/"//' | sed 's/"//' | awk '{printf "%s.\t%s\n",NR,$0}'  | sed  s/'''/"'"/g | sed  s/'&'/'and'/g > $HOME/.cache/ytview/channels/$channel/titles.txt || return 1

  # Get the video urls
  httpGet https://www.youtube.com/user/$channel/Videos | grep "watch?v=" | awk '{print $6}' | sed s/spf-link//  | sed s/href=// | sed 's/"//' | sed 's/"//' | sed '/^\s*$/d' | sed 's/\//https:\/\/www.youtube.com\//' |  awk '{printf "%s.\t%s\n",NR,$0}' > $HOME/.cache/ytview/channels/$channel/urls.txt || return 1


  # Print 20 first video titles for the user to choose from
  head -n 20 $HOME/.cache/ytview/channels/$channel/titles.txt || return 1
  # Prompt the user for video number
  read -p "Choose a video: " titlenumber



  # Play the video with your player
  $player $[sed -n $[echo $titlenumber]p < $HOME/.cache/ytview/channels/$channel/urls.txt | awk '{print $2}] > /dev/null !2 > !1 &
}

proc searchview
{

  setglobal search = $[echo $search | tr " " +]
  mkdir -p $HOME/.cache/ytview/searches/$search

  #Get video titles
httpGet https://www.youtube.com/results'?'search_query'='$search | grep "Duration" | grep "watch?v=" | awk '{print $13 " " $14 " " $15 " " $16 " " $17 " " $18 " " $19 " " $20 " " $21 " " $22 " " $23 " " $23}' | sed 's/aria-describedby="description-id.*//g' | sed s/title=// | sed 's/"//g' | sed  s/spf-link// | sed 's/data-session-link=itct*.//' | sed s/spf-prefetch//g | sed 's/rel=//g' | sed 's/"//' | awk '{printf "%s.\t%s\n",NR,$0}' | sed  s/'&#39;'/"'"/g | sed  s/'&amp;'/'and'/g  > $HOME/.cache/ytview/searches/$search/titles.txt || return 1

  #Get video urls
  httpGet https://www.youtube.com/results'?'search_query'='$search | grep "watch?v=" | awk '{print $5}' | sed s/vve-check// | sed 's/href="/https:\/\/www.youtube.com/' | sed 's/"//' | sed s/class="yt-uix-tile-link"// |sed '/^\s*$/d' | awk '{printf "%s.\t%s\n",NR,$0}'  > $HOME/.cache/ytview/searches/$search/urls.txt || return 1
  #Print 20 first video titles for the user to choose from
  cat $HOME/.cache/ytview/searches/$search/titles.txt || return 1

  #Let the user choose the video number
  read -p "Choose a video: " titlenumber

  #Play the video with your favorite player
  $player $[sed -n $[echo $titlenumber]p < $HOME/.cache/ytview/searches/$search/urls.txt | awk '{print $2}]  > /dev/null !2 > !1 &



}

proc usage
{
  echo "Ytview"
  echo "Description: Search and play youtube videos right from the terminal."
  echo "Usage: ytview [flag] [string] or ytview [videoToSearch]"
  echo "  -s Searches youtube"
  echo "  -c Shows the latest videos of a channel"
	echo "  -u Update Bash-Snippet Tools"
	echo "  -h Show the help"
	echo "  -v Get the tool version"
  echo "Examples:"
  echo "  ytview -s Family Guy Chicken Fight"
  echo "  ytview -c Numberphile"
}

getConfiguredClient || exit 1
getConfiguredPlayer || exit 1
checkInternet || exit 1

while getopts vuc:s:h*: option
{
  match $(option) {
    with s
      if [[ $flag != "channel" ]]{
        setglobal search = $[printf '%s ' @Argv]
        setglobal flag = '"search'"
      } else {
        echo "Error: search and channel options are mutually exclusive" > !2
        exit 1
      }
    
    with c
      if [[ $flag != "search" ]]{
        setglobal channel = $OPTARG
        setglobal flag = '"channel'"
      } else {
        echo "Error: search and channel options are mutually exclusive" > !2
        exit 1
      }
    
    with h usage && exit 0 
    with u update && exit 0 
    with v echo "Version $currentVersion" && exit 0 
    with * usage && exit 0 
  }
}

if [[ $# == "0" ]] {
  usage
  exit 0
} elif [[ $1 == "help" ]]{
  usage
  exit 0
} elif [[ $1 == "update" ]] {
  update
  exit 0
} elif [[ $flag == "search" ]] {
  searchview || exit 1
} elif [[ $flag == "channel" ]] {
  channelview || exit 1
} else {
	setglobal search = $[printf '%s ' @Argv]
  searchview || exit 1
}