# More informative error messages for readonly variables
readonly CONFIG_PATH="/etc/app/config"

# Attempting to modify generates clearer error
CONFIG_PATH="/tmp/config"  # bash: CONFIG_PATH: readonly variable

# Better handling of unset variables with set -u
set -u

# Checking before use is now more reliable
if [[ -n "${OPTIONAL_VAR:-}" ]]; then
    echo "Variable is set: ${OPTIONAL_VAR}"
else
    echo "Variable is not set"
fi

# Practical example: Configuration validation
validate_config() {
    local -a required_vars=("DATABASE_URL" "API_KEY" "LOG_DIR")
    local var

    for var in "${required_vars[@]}"; do
        if [[ -z "${!var:-}" ]]; then
            printf 'Error: Required variable %s is not set\n' "${var}" >&2
            return 1
        fi
    done

    echo "All required configuration variables are set"
}

export DATABASE_URL="postgres://localhost/db"
export API_KEY="secret123"
export LOG_DIR="/var/log/app"

validate_config

# Better completion behavior in ~/.inputrc
# Skip completions for invisible characters
set skip-completed-text on

# Enhanced history search
# Cycle through history with prefix matching
bind '"\e[A": history-search-backward'  # Up arrow
bind '"\e[B": history-search-forward'   # Down arrow

# Improved completion coloring
set colored-stats on
set colored-completion-prefix on

# Better handling of long completions
set completion-display-width 0  # Use full terminal width

# Improved array slicing and expansion
array=(10 20 30 40 50 60 70 80 90)

# Slice notation is more reliable
echo "First 3: ${array[@]:0:3}"      # 10 20 30
echo "Last 3: ${array[@]: -3}"       # 70 80 90
echo "Middle: ${array[@]:3:3}"       # 40 50 60

# Practical example: Batch processing
process_batch() {
    local -a items=("$@")
    local batch_size=3
    local i

    for ((i = 0; i < ${#items[@]}; i += batch_size)); do
        local -a batch=("${items[@]:i:batch_size}")
        printf 'Processing batch %d: %s\n' \
            "$((i / batch_size + 1))" \
            "${batch[*]}"

        # Process batch items...
        for item in "${batch[@]}"; do
            echo "  Processing: ${item}"
        done
    done
}

files=(file1 file2 file3 file4 file5 file6 file7)
process_batch "${files[@]}"

# Benchmark example showing improved performance
benchmark_arrays() {
    local -a array
    local i
    local start end

    start="${EPOCHREALTIME}"

    # Large array operations are faster in 5.2
    for ((i = 0; i < 10000; i++)); do
        array+=("item_${i}")
    done

    end="${EPOCHREALTIME}"

    printf 'Array population time: %.4f seconds\n' \
        "$(awk "BEGIN {print ${end} - ${start}}")"

    echo "Array size: ${#array[@]}"
}

benchmark_arrays

# Check for Bash 5.2 features
if [[ "${BASH_VERSINFO[0]}" -eq 5 ]] && [[ "${BASH_VERSINFO[1]}" -ge 2 ]]; then
    echo "Bash 5.2+ features available"
    # Use enhanced features
elif [[ "${BASH_VERSINFO[0]}" -ge 6 ]]; then
    echo "Bash 6.0+ detected"
else
    echo "Bash version too old for 5.2 features"
fi