#!/bin/bash
# ---------------------------------------------------------------------------
# gpull – Pull changes from a remote Git repository
#
# Usage:
#   ./gpull [repo] [remote] [branch]
#
#   repo   – (optional) Directory of repository to pull, default is current
             directory.
#   remote – (optional) Remote name, default is origin.
#   branch – (optional) Branch name, default is current branch.
#
# The script will pull the specific remote branch into the local repository.
# ---------------------------------------------------------------------------

# Function to handle errors gracefully without closing terminal
handle_error() {
    echo "Error: $1"
    return 1
}

# Get command line arguments
repo_dir=${1:-$(pwd)}
remote=${2:-origin}
branch=${3:-}

# Change to the specified directory
if [ ! -d "$repo_dir" ]; then
    handle_error "Directory '$repo_dir' does not exist."
    exit 1
fi

cd "$repo_dir" || { handle_error "Failed to change to directory '$repo_dir'."; exit 1; }

# Check if the current directory is a git repository
if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then
    handle_error "'$repo_dir' is not a git repository."
    exit 1
fi

# If no branch specified, get the current branch
if [ -z "$branch" ]; then
    branch=$(git rev-parse --abbrev-ref HEAD)
    if [ "$branch" = "HEAD" ]; then
        handle_error "Not currently on a branch. Please specify a branch to pull."
        exit 1
    fi
fi

echo "Pulling changes from $remote/$branch into $repo_dir"

# Perform the git pull
git pull "$remote" "$branch"

# Check if the pull was successful
if [ $? -eq 0 ]; then
    echo "Successfully pulled changes from $remote/$branch"
else
    handle_error "Failed to pull changes from $remote/$branch"
    exit 1
fi