#!/usr/bin/bash

# a simple parser for the args <commit> and --no-cache
# if no commit is given, the latest commit is used
# if --no-cache is given, the --no-cache flag is passed to the docker build command
# if only --no-cache is given, the latest commit is used

# check if commit is given as argument, if not use the latest commit
# check if an argument is given at all


if [ -n "$1" ]; then
    #check if the first arg is --no-cache
    if [ "$1" == "--no-cache" ]; then
        FORCE_NO_CACHE="--no-cache"
        COMMIT=$(git rev-parse --short HEAD)
    else
        COMMIT=$1
        #check if this is a valid commit
        if ! git cat-file -e $COMMIT^{commit} 2>/dev/null; then
            echo "ERROR: Commit $COMMIT not found in local repository."
            exit 1
        fi
    fi
else #default to last commit
    COMMIT=$(git rev-parse --short HEAD)
fi


# COMMIT is a valid commit at this point. If COMMIT is the last commit and changes are not commited, the user is warned.

#check if the commit is the last commit
if [ "$COMMIT" == "$(git rev-parse --short HEAD)" ]; then
    # check if we have uncommitted changes and if so warn the user.
    if [ -n "$(git status --porcelain)" ]; then
        echo "WARNING: You are building the latest commit ${COMMIT}, but you have uncommitted changes."
        echo "         This means that the image will not be reproducible."
        echo "         If you want to build the latest commit, please commit your changes first."
        read -p "Do you want to continue anyway? [y/N] " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            exit 1
        fi
    fi
fi

check_remote_commit_exists() {
    # Usage: check_remote_commit_exists <repo-url> <commit-sha>
    local url="$1"
    local commit="$2"

    # Create a temporary directory for a shallow fetch
    local tmpdir
    tmpdir="$(mktemp -d)"
    trap 'rm -rf "$tmpdir"' RETURN  # auto-cleanup on function exit

    git -C "$tmpdir" init -q
    git -C "$tmpdir" remote add origin "$url"

    if git -C "$tmpdir" fetch --quiet --depth=1 origin "$commit" 2>/dev/null; then
        echo "✅ Commit $commit exists on remote."
        return 0
    else
        echo "❌ ERROR: Commit $commit not found on remote."
        echo "Refs currently visible on remote:"
        git ls-remote --heads --tags "$url"
        return 1
    fi
}

# check if the commit has been pushed
if ! check_remote_commit_exists https://github.com/jkiesele/minicalosim $COMMIT; then
    echo "ERROR: Commit $COMMIT not found in remote repository."
fi

# check if no-cache is given as second argument
if [ "$2" == "--no-cache" ]; then
    FORCE_NO_CACHE="--no-cache"
fi

#switch to directory this script is located in
cd "$(dirname "$0")"
cd ../../ #switch to the root directory of the project
echo "Building minicalosim:$COMMIT"

#print the current working directory
echo "Current working directory: $(pwd)"

docker build $FORCE_NO_CACHE -t jkiesele/minicalosim:$COMMIT --build-arg USER=$USER --build-arg BUILD_DATE="$(date)" --build-arg COMMIT=$COMMIT -f minicalosim/docker/Dockerfile .

echo "sucessfully built container jkiesele/minicalosim:${COMMIT}"

docker tag jkiesele/minicalosim:$COMMIT jkiesele/minicalosim:latest

echo "also tagged as jkiesele/minicalosim:latest"