rake_tab_completion_profile_time_analysis

# ----------------------
# Time Analysis
# ----------------------
# Function to measure the runtime of another function in microseconds
measure_runtime() {
    local start_time end_time elapsed_time
    # Start measuring time
    # Note: MacOS date does not measure beyoned seconds, install gdate via coreutils with brew. 
    start_time=$([ "$(uname)" = "Darwin" ] && gdate +%s.%3N || date +%s.%3N)
    # Execute the provided function or command
    "$@"
    
    # Calculate the elapsed time
    end_time=$([ "$(uname)" = "Darwin" ] && gdate +%s.%3N || date +%s.%3N)
    elapsed_time=$(echo "scale=63; $end_time - $start_time" | bc)
    # Print the elapsed time
    printf "\nElapsed time: %.6f seconds, for: %s\n" "$elapsed_time" "$1"
}

# ----------------------
# Rake Tab Completion
# ----------------------

# Validates the user's terminal is capable of running the script.
function validate_terminal_session() {
    # Check if 'rake' command is available
    if ! command -v rake &>/dev/null; then
        echo "Error: 'rake' command not found. Make sure rake is installed and available in the PATH."
        return 1
    fi

    # Check if 'md5sum' command is available
    if ! command -v md5sum &>/dev/null; then
        echo "Error: 'md5sum' command not found. Make sure md5sum is installed and available in the PATH."
        return 1
    fi

    # Check 'date/gdate' command is available
    if "$(uname)" = "Darwin"; then
        if ! command -v gdate &>/dev/null; then
            echo "Error: 'gdate' command not found. Make sure gdate is installed and available in the PATH."
            return 1
        fi
    else
        if ! command -v date &>/dev/null; then
            echo "Error: 'date' command not found. Make sure date is installed and available in the PATH."
            return 1
        fi
    fi
    return 0;
}

# Finds the nearest Rakefile. In or above, not lateral or down.
function _rake_cache_path() {
    local current_dir="$PWD"

     # Search for Rakefile in the current directory and its parent directories.
    while [ "$current_dir" != "/" ]; do
        if [ -e "$current_dir/Rakefile" ]; then
            echo "${current_dir}"
            return 0
        fi
        current_dir="$(dirname "$current_dir")"
    done

    echo "No Rakefile found"
    return 1
}

# Runs a silent rake task list and stores the output in a cache file.
function rake_task_cache_store() {
    rake --tasks --silent > "$(_rake_cache_path)/.rake_t_cache"
}

# Runs a md5sum on the target Gemfile, Rakefile, and any extra rake filees in a rakelib directory. These values are stored adjacent to the rake tasks cache file. 
function rake_md5_cache_store() {
    md5sum $(_rake_cache_path)/{Gemfile,Rakefile} $(find $(_rake_cache_path)/rakelib -type f 2>/dev/null) > "$(_rake_cache_path)/.rake_md5_cache"
}

# Validates md5sums. On failure, regenerate the task and md5 cache files.
function validate_cache() {
    measure_runtime validate_terminal_session
    # Build cache if missing.
    if [ ! -e "$(_rake_cache_path)/.rake_t_cache" ]; then
        measure_runtime rake_task_cache_store
        measure_runtime rake_md5_cache_store
    else
        md5sum --check "$(_rake_cache_path)/.rake_md5_cache" --status 2>/dev/null || rake_task_cache_store && rake_md5_cache_store
    fi
}

# Modify the tab completion behavior.
export COMP_WORDBREAKS=${COMP_WORDBREAKS/\:/}

# Main tab completion modification function.
function _rakecomplete() {
    # Validate/ Build cache files. 
    measure_runtime validate_cache
    
    local tasks=$(awk '{print $2}' "$(_rake_cache_path)/.rake_t_cache")
    COMPREPLY=($(compgen -W "${tasks}" -- "${COMP_WORDS[COMP_CWORD]}"))
    return 0
}

complete -o default -o nospace -F _rakecomplete rake