#!/bin/bash

# Find currently used resolution
res=$( xrandr | awk '/\sconnected/{i=split(substr($0,0,index($0,"+")-1),a);if($0~/\sprimary\s/){if(p==""){p=a[i]}}else{if(d==""){d=a[i]}}}END{if(p==""){print d}else{print p}}' )

bgpath="/usr/share/mga/backgrounds"
if [ $(readlink "$bgpath/default.jpg") != "$bgpath/Mageia-Default-$res.jpg" ]; then
   # Check if this is a supported resolution, if not, find the background with the same aspect ratio
    if [ ! -e "$bgpath/Mageia-Default-$res.jpg" ]; then
        width=$(echo $res | cut -f1 -d"x")
        height=$(echo $res | cut -f2 -d"x")
        # Bash only does integer arithmetic, we multiply everything by 1000 to workaround this
        ratio=$((1000*$width/$height))

        found=false
        declare -A refRatios=( ["1250"]="1280x1024" ["1333"]="1600x1200" ["1600"]="1920x1200"
                               ["1667"]="1280x768" ["1707"]="1024x600" ["1778"]="1920x1080" )
        for key in "${!refRatios[@]}"; do
            if [ $(($ratio % $key)) -lt 25 -o $(($key % $ratio)) -lt 25 ]; then
                res=${refRatios[$key]}
                ratio=$key
                found=true
                break
            fi
        done

        if ! $found; then
            echo "mga-bg-res: Your aspect ratio does not seem to be supported, keeping default background resolution."
            exit 1
        fi
    fi

    if [ $(readlink "$bgpath/default.jpg") != "$bgpath/Mageia-Default-$res.jpg" ]; then
        echo "mga-bg-res: Changing the background symlink to point to Mageia-Default-$res.jpg (aspect ratio ${ratio:0:1}.${ratio:1:3})"
        /usr/bin/mga-bg-res $res
    else
        echo "mga-bg-res: Nothing to do, the background symlink is already correct."
    fi
else
    echo "mga-bg-res: Nothing to do, the background symlink is already correct."
fi