# treehouses/cli/magazines

## About
The `treehouses magazines` module relies on download scripts for each individual RasberryPi magazine.

These download scripts utilize `wget` to fetch the specified magazine in the form of a PDF file for viewing purposes.

These download scripts are named `download-<magtype>.sh` and are located in the `/magazines/` directory.

Look at the pre-existing download scripts in `/magazines/` for examples.

Once magazines are downloaded, they are saved in the `~/Documents/` directory inside the respective `~/Documents/<magtype>/` location.

An empty download script is shown [below](#Template) for magazines that have the prefix URL `https://<magtype>.raspberrypi.org/`

## Adding a new magazine
Using the [template](#Template), fill in the sections as required.

### 1. Check for the latest issue number of your magazine

   > ***GOAL:*** *Retrieve the issue number of the most current version of the magazine*

   One way to do this is to webscrape the homepage URL of your magazine and store this in a variable called `latest`. This will

   be used in the other functions to make downloading magazines easier.

   ------------------------------------------------------------------------

   For magazines that have the prefix URL `https://<magtype>.raspberrypi.org/`
  
   Replace `<line-num>` with the line number in the `issues.txt` file where the latest magazine issue number is found.
   ```
   latest="$(sed -n '<line-num>p' issues.txt)"
   ```

### 2. Create function for fetching all issues of your magazine

   > ***GOAL:*** *Iterate through each available issue of the magazine*

   One way to do this is to take advantage of any patterns in the URL and iterate through the different version numbers available of

   your specific magazine. Don't forget to add confirmation messages to let the user know each magazine was successfully downloaded.

   ------------------------------------------------------------------------

   For magazines that have the prefix URL `https://<magtype>.raspberrypi.org/`

   `<magtype-lowercase>` should be the same string as `<magtype>` (e.g. magpi).

   `<magtype-uppercase>` refers to the formal name of `<magtype>`  (e.g. MagPi).

   Replace `<magtype-uppercase>` with the name of the magazine and how it will be saved as a PDF file.

   Replace `<magtype-lowercase>` with the name of the magazine and how it appears in the URL, also represents the name of the directory.

   ```
   check_latest
   magnum=$latest
   echo "Fetching <magtype-uppercase>$magnum.pdf..."
   wget -q "https://<magtype-lowercase>.raspberrypi.org/issues/$magnum/pdf"
   ...
   ```

### 3. Create function for fetching the latest issue of your magazine

   > ***GOAL:*** *Download only the latest issue of the magazine*

   The easiest way to do this is to call the `check_latest` function and pass the stored string-value directly into the URL via wget.

   Don't forget to add a confirmation message to let the user know the magazine was sucessfully downloaded.

   ------------------------------------------------------------------------

   For magazines that have the prefix URL `https://<magtype>.raspberrypi.org/`

   See the steps above for replacing `<magtype-uppercase>` and `<magtype-lowercase>` where needed.

### 4. Create function for fetching a specific issue of the magazine

   > ***GOAL:*** *Download only the requested issue number of the magazine*

   The easiest way to do this is to pass the issue number directly into the URL via wget. Don't forget to add a confirmation message to 

   let the user know the magazine was sucessfully downloaded.

   ------------------------------------------------------------------------

   For magazines that have the prefix URL `https://<magtype>.raspberrypi.org/`

   See the steps above for replacing `<magtype-uppercase>` and `<magtype-lowercase>` where needed.

### 5. Add info

   > ***GOAL:*** *Provide a brief description about the magazine*

   Simply replace `<description>` with a short description of your magazine, this is probably located somewhere on the homepage.

   ```
   echo "<description>"
   ```

### 6. Add URL

   > ***GOAL:*** *Provide the homepage URL of the magazine*

   Simply replace `<url>` with the homepage URL of your magazine.

   ```
   echo "<url>"
   ```

Save the file as `download-<magtype>.sh` inside the `/magazines/` directory.

## Template
```
function check_latest {
  wget -q "https://<magtype-lowercase>.raspberrypi.org/issues"
  mv ./issues ./issues.txt
  latest="$(sed -n '<line-num>p' issues.txt)"
  rm ./issues.txt
  latest=${latest:25}
  quoteloc="${latest%%\"*}"
  ind=${#quoteloc}
  latest=${latest:0:$ind}
}

function all {
  check_latest
  echo "Fetching all <magtype-uppercase> magazines..."
  for i in $(seq 1 $latest);
  do
    if [ -f "<magtype-uppercase>$i.pdf" ]; then
      echo "<magtype-uppercase>$i.pdf ✓"
      continue
    fi
    wget -q "https://<magtype-lowercase>.raspberrypi.org/issues/$i/pdf"
    mv ./pdf ./pdf.txt
    url="$(sed -n '10p' pdf.txt)"
    rm ./pdf.txt
    url=${url:44}
    quoteloc="${url%%\"*}"
    ind=${#quoteloc}
    url=${url:0:$ind}
    wget -q -O "<magtype-uppercase>$i.pdf" $url
    echo "<magtype-uppercase>$i.pdf ✓"
  done
}

function latest {
  check_latest
  magnum=$latest
  echo "Fetching <magtype-uppercase>$magnum.pdf..."
  wget -q "https://<magtype-lowercase>.raspberrypi.org/issues/$magnum/pdf"
  mv ./pdf ./pdf.txt
  url="$(sed -n '10p' pdf.txt)"
  rm ./pdf.txt
  url=${url:44}
  quoteloc="${url%%\"*}"
  ind=${#quoteloc}
  url=${url:0:$ind}
  wget -q -O "<magtype-uppercase>$magnum.pdf" $url
}

function number {
  check_latest
  magnum=$req
  if [[ $magnum -lt 1 ]] || [[ $magnum -gt $latest ]]; then
    echo "ERROR: Please enter a valid magazine number"
    echo "       This can be any issue ranging from 1 to $latest"
    cd - &>/dev/null || return
    exit 1
  fi
  if [ -f "<magtype-uppercase>$magnum.pdf" ]; then
    echo "<magtype-uppercase>$magnum.pdf already exists, exiting..."
    cd - &>/dev/null || return
    exit 0
  fi
  echo "Fetching <magtype-uppercase>$magnum.pdf..."
  wget -q "https://<magtype-lowercase>.raspberrypi.org/issues/$magnum/pdf"
  mv ./pdf ./pdf.txt
  url="$(sed -n '10p' pdf.txt)"
  rm ./pdf.txt
  url=${url:44}
  quoteloc="${url%%\"*}"
  ind=${#quoteloc}
  url=${url:0:$ind}
  wget -q -O "<magtype-uppercase>$magnum.pdf" $url
}

function info {
  echo "<description>"
}

function url {
  echo "<url>"
}
```