#!/bin/sh

# Function to process each repo-destination pair
process_repo() {
    FULL_REPO_URL=$1
    DESTINATION=$2

    # Extract the URL without credentials for logging and notifications
    CLEAN_REPO_URL=$(echo "$FULL_REPO_URL" | sed 's/https:\/\/[^@]*@/https:\/\//')

    # Directory to hold the repository locally
    REPO_DIR="/srv/Repo_Cache/$(basename $CLEAN_REPO_URL .git)"

    # Clone the repo if it doesn't exist, or navigate to it if it does
    if [ ! -d "$REPO_DIR" ]; then
        curl -d "Cloning: $CLEAN_REPO_URL" $NTFY_URL
        git clone "$FULL_REPO_URL" "$REPO_DIR" > /dev/null 2>&1
    fi
    cd "$REPO_DIR" || exit

    # Fetch the latest branch information
    git fetch origin > /dev/null 2>&1

    # List the available branches at the remote
    AVAILABLE_BRANCHES=$(git ls-remote --heads origin | awk '{print $2}' | sed 's/refs\/heads\///')

    # Detect the default branch dynamically (check for both 'main' and 'master')
    if echo "$AVAILABLE_BRANCHES" | grep -q "^main$"; then
        DEFAULT_BRANCH="main"
    elif echo "$AVAILABLE_BRANCHES" | grep -q "^master$"; then
        DEFAULT_BRANCH="master"
    else
        echo "Error: Neither 'main' nor 'master' branch exists in $FULL_REPO_URL"
        exit 1
    fi

    # Check if the branch exists locally, and if not, create and set upstream
    if ! git show-ref --verify --quiet refs/heads/$DEFAULT_BRANCH; then
        git checkout -b $DEFAULT_BRANCH origin/$DEFAULT_BRANCH || exit 1
    fi

    # Check if an upstream is configured; if not, set it
    if ! git rev-parse --abbrev-ref --symbolic-full-name @{u} > /dev/null 2>&1; then
        git branch --set-upstream-to=origin/$DEFAULT_BRANCH $DEFAULT_BRANCH || exit 1
    fi

    # Fetch the latest changes from the correct branch
    git fetch origin $DEFAULT_BRANCH > /dev/null 2>&1

    # Check if the local repository is behind the remote
    LOCAL=$(git rev-parse @)
    REMOTE=$(git rev-parse @{u})

    if [ "$LOCAL" != "$REMOTE" ]; then
        curl -d "Updating: $CLEAN_REPO_URL" $NTFY_URL
        git pull origin $DEFAULT_BRANCH > /dev/null 2>&1
        rsync -av --delete --exclude '.git/' ./ "$DESTINATION" > /dev/null 2>&1
    fi
}

# Main loop
while true; do

    # Iterate over each environment variable matching 'REPO_[0-9]+'
    env | grep '^REPO_[0-9]\+=' | while IFS='=' read -r name value; do
        # Split the value by comma and read into separate variables
        OLD_IFS="$IFS"          # Save the original IFS
        IFS=','                 # Set IFS to comma for splitting
        set -- $value           # Set positional parameters ($1, $2, ...)
        REPO_URL="$1"           # Assign first parameter to REPO_URL
        DESTINATION="$2"        # Assign second parameter to DESTINATION
        IFS="$OLD_IFS"          # Restore original IFS

        process_repo "$REPO_URL" "$DESTINATION"
    done

    # Wait for 30 seconds before the next iteration
    sleep 30
done