#!/bin/bash
# Author: Alexander Epstein https://github.com/alexanderepstein

setglobal currentVersion = '"1.11.1'"
setglobal configuredClient = ''""
## rest of these variables are search flags
setglobal search = '"0'"
setglobal insensitive = ''""
setglobal recursive = ''""
setglobal boundry = ''""

## 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."
    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 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
  }
}

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 usage
{
  echo "Cheat"
  echo "Description: Cheatsheets for quick information about multiple programming languages along with terminal commands"
  echo "Usage: cheat [flags] [command] or cheat [flags] [programming language] [subject]"
  echo "  -s Does a search for last argument rather than looking for exact match"
  echo "  -i Case insensitive search"
  echo "  -b Word boundaries in search"
  echo "  -r Recursive search"
  echo "  -u Update Bash-Snippet Tools"
  echo "  -h Show the help"
  echo "  -v Get the tool version"
  echo "Special Pages:"
  echo "  hello Describes building the hello world program written in the language"
  echo "  list This lists all cheatsheets related to previous arg if none it lists all cheatsheets"
  echo "  learn Shows a learn-x-in-minutes language cheat sheet perfect for getting started with the language"
  echo "  1line A collection of one-liners in this language"
  echo "  weirdness A collection of examples of weird things in this language"
  echo "Examples:"
  echo "  cheat rust hello"
  echo "  cheat -r -b -i go"
  echo "  cheat julia Functions"
  echo "  cheat -i go operators"
}

proc getCheatSheet
{
  if [[ $# == 1 ]] {
    if [[ $search == "1" ]]{
      setglobal link = "cheat.sh/~$1"
    } else {
      setglobal link = "cheat.sh/$1"
    }
  } else {
    setglobal link = "cheat.sh/$1"
  }

  if [[ $# == 2 ]]{
    if [[ $search == "1" ]]{
      setglobal link = "/~$2" ## add this to end of link where ~ indicates search
    } else {
      setglobal link = "/$2" ## add this to end of link
    }
  }

  if [[ $insensitive != "" || $recursive != "" || $boundry != "" ]]{ setglobal link = "/$boundry$insensitive$recursive"; } ## add this to the end of the link as flags

  httpGet $link
}


### This function just wraps some of the special pages provided by cheat.sh
proc checkSpecialPage
{
  setglobal temp = $1
  if [[ $1 == "list" ]]{
    setglobal temp = '":list'"
  } elif [[ $1 == "learn" ]]{
    setglobal temp = '":list'"
  } elif [[ $1 == "styles" ]]{
    setglobal temp = '":styles'"
  }
  if [[ $2 == "1" ]]{
    setglobal arg1 = $temp
  } else {
    setglobal arg2 = $temp
  }
}

getConfiguredClient || exit 1
checkInternet || exit 1

while getopts "ribuvhis" opt {
  match $opt {
    with \?
      echo "Invalid option: -$OPTARG" > !2
      exit 1
    
    with h
      usage
      exit 0
    
    with v
      echo "Version $currentVersion"
      exit 0
    
    with u
      update
      exit 0
    
    with i
      setglobal insensitive = '"i'"
      setglobal search = '"1'"
    
    with b
      setglobal boundry = '"b'"
      setglobal search = '"1'"
    
    with r
      setglobal recursive = '"r'"
      setglobal search = '"1'"
    
    with s
      setglobal search = '"1'"
    
    with :
      echo "Option -$OPTARG requires an argument." > !2
      exit 1
    
  }
}for arg in @Argv {
  if [[ $arg != "-r" && $arg != "-s" && $arg != "-b" && $arg != "-i" ]]{
    if test -z $(arg1+x){
      setglobal arg1 = $arg
    }
    if test ! -z $(arg1+x){
      setglobal arg2 = $arg
    }
  }
}

## check for special pages before moving on
checkSpecialPage $arg1 1
checkSpecialPage $arg2 2

if [[ $# == 0 ]] {
  usage
  exit 0
} elif [[ $1 == "update" ]]{
  update
  exit 0
} elif [[ $1 == "help" || $1 == ":help" ]]{ ## shows the help and prevents the user from seeing cheat.sh/:help
  usage
  exit 0
} else {
  if [[ $arg1 != $arg2 ]]{ ## if they equal each other that means there was no arg 2 supplied
    getCheatSheet $arg1 $arg2
    exit 0
  } else {
    getCheatSheet $arg1
    exit 0
  }
  exit 0

}