#!/bin/sh
HUGO_GITHUB="https://github.com/gohugoio/hugo"
HUGO_DIR_PREFIX="${XDG_DATA_HOME:=$HOME/.local/share}"
HUGO_DIR="${HUGO_DIR:=$HUGO_DIR_PREFIX/hugo}"

_prompt() {
    printf "[HUGO MANAGER] \033[34m%s\033[0m \033[1m[y/n]:\033[0m " "$1"
    read -r opt

    case "$opt" in
        [Yy]) return 0;;
        [Nn]) return 1;;
        *)    return 1;;
    esac
}

_msg() {
    printf "[HUGO MANAGER] \033[0m%s\033[0m\n" "$1"
}

_error() {
    printf "[HUGO MANAGER] \033[31merror: %s\033[0m\n" "$1"
}

# Check if $HUGO_DIR exists, if it doesn't, create it.
# If there is an error, return 1.
_hugo_dir_check() {
    if ! [ -d "$HUGO_DIR" ]; then
        return 1
    fi
}

# Cleans $HUGO_DIR
_clean_hugo_versions() {
    if [ -d "$HUGO_DIR" ]; then
        rm -rf "${HUGO_DIR:?}"/*
    fi
}

# Echoes list of hugo versions.
_list_hugo_versions() {
    preferred="$1"

    for v in "$HUGO_DIR"/*; do
        if [ -d "$v" ]; then
            version="${v##*hugo-}"

            if [ "$preferred" = "$version" ]; then
                echo "$version*"
            else
                echo "$version"
            fi
        fi
    done
}

# Echoes latest installed hugo version. e.g. 25.5.31
# If there is an error, return 1.
_latest_local() {
    versions="$(_list_hugo_versions)"
    for v in $versions ; do
        latest_local="$v"
    done

    echo "$latest_local"
}

# Sets the preferred hugo version
# If there is an error, return 1.
_set_preferred_version() {
    version="$1"

    if [ -z "$version" ]; then
        _error "provide a version to set. e.g. 25.5.31"
       return 1
    fi

    echo "$version" > "$HUGO_DIR"/hugo_version
}

# Echoes current set hugo version. e.g. 25.5.31
# If there is an error, return 1.
_current_local() {
    if [ -f "$HUGO_DIR"/hugo_version ]; then
        cat "$HUGO_DIR"/hugo_version
    else
        return 1
    fi
}

# Get the latest installed hugo binary path.
# If there is a problem with the binary, return 1.
_hugo_bin() {
    preferred="$1"

    if [ -z "$preferred" ]; then
        preferred="$(_latest_local)"
    fi

    bin="$HUGO_DIR/hugo-$preferred/hugo"

    if [ -x "$bin" ]; then
        echo "$bin"
    else
        return 1
    fi
}

# Echoes the latest remote available hugo version. e.g. 25.5.31
# If there is an error, return 1.
_latest_remote() {
    # shellcheck disable=SC1083
    release_url="$(curl -Ls -o /dev/null -w %{url_effective} "$HUGO_GITHUB"/releases/latest)"
    if [ "$?" -eq 1 ]; then
        return 1
    fi
    echo "${release_url##*/v}"
}

# Downloads a given hugo version. e.g. _download_hugo 25.5.31
# If there is an error, return 1.
_download_hugo() {
    version="$1"
    if [ -z "$version" ]; then
        _error "provide a version to download. e.g. 25.5.31 or latest"
       return 1
    fi

    case "$version" in
        latest) version="$(_latest_remote)"
                if [ "$?" -eq 1 ]; then
                    _error "failed get latest"
                    return 1
                fi
            ;;
        *) ;;
    esac

    target_dir="$HUGO_DIR/hugo-$version"
    target="$target_dir/hugo-$version.tar.gz"
    download_url="$HUGO_GITHUB/releases/download/v$version/hugo_${version}_linux-amd64.tar.gz"

    mkdir -p "$target_dir"

    curl -sLo "$target" "$download_url"
    if [ "$?" -eq 1 ]; then
        _error "failed to download"
        return 1
    fi

    if ! [ -f "$target" ]; then
        _error "failed to download"
        return 1
    fi

    tar -C "$target_dir" -xf "$target" >/dev/null
    if [ "$?" -eq 1 ]; then
        _error "failed to extract"
        return 1
    fi

    _set_preferred_version "$version"
    rm -f "$target"
}

# Updates to latest remote available version.
# If there is an error, return 1.
_update_hugo() {
    latest_remote="$(_latest_remote)"
    if [ "$?" -eq 1 ]; then
        _error "failed to look up latest version"
        return 1
    fi

    latest_local="$(_latest_local)"
    if [ "$?" -eq 1 ]; then
        _error "failed to look up local version"
        return 1
    fi

    if [ "$latest_local" != "$latest_remote" ]; then
        _msg "updating hugo ${latest_local:-none} -> $latest_remote..."
        _download_hugo "$latest_remote"
        if [ "$?" -eq 1 ]; then
            _error "failed installation"
            return 1
        fi
        _set_preferred_version "$latest_remote"
    else
        _msg "already up-to-date"
    fi
}

if [ -d "$HUGO_DIR" ]; then
    HUGO_BIN="$(_hugo_bin "$(_current_local)")"
    if [ "$?" -eq 1 ] && [ "$1" != "--manager-download" ] ; then
        _prompt "no version of hugo installed, download latest?"

        if [ "$?" -eq 1 ]; then
            _error "no version of hugo installed, download via '--manager-download x.x.x'"
            return 1
        fi

        _download_hugo "latest"
        if [ "$?" -eq 1 ]; then
            _error "error downloading latest version"
            return 1
        fi
    fi

    # shellcheck disable=SC2068
    case "$1" in
        --manager-update)   _update_hugo ;;
        --manager-download) _download_hugo "$2" ;;
	--manager-list)     _list_hugo "$(_current_local)" ;;
        --manager-set)      _set_preferred_version "$2" ;;
        --manager-clean)    _clean_hugo ;;
        *)  $HUGO_BIN $@ ;;
    esac
else
    _hugo_dir_check
    if [ "$?" -eq 1 ]; then
        _prompt "Installation directory '$HUGO_DIR' does not exist, create?"
        if [ "$?" -eq 1 ]; then
            return 1
        fi
        mkdir -p "$HUGO_DIR"
    fi

    _prompt "hugo not installed, download latest?"
    if ! [ "$?" -eq 1 ]; then
        _update_hugo
    fi
fi