#!/usr/bin/env bash
set -euo pipefail

# Script directory and backups directory setup
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
BACKUP_DIR="${SCRIPT_DIR}/backups"
mkdir -p "${BACKUP_DIR}"

# Pre-flight requirements check for core tools
for cmd in zip awk find mktemp; do
    if ! command -v "${cmd}" >/dev/null 2>&1; then
        echo "Error: Required tool '${cmd}' is not installed or not in PATH." >&2
        exit 1
    fi
done

# Determine device hostname using robust fallbacks (no inetutils required)
HOSTNAME_STR=""
if command -v hostname >/dev/null 2>&1; then
    HOSTNAME_STR="$(hostname -s 2>/dev/null || hostname 2>/dev/null || true)"
fi
if [ -z "${HOSTNAME_STR}" ]; then
    HOSTNAME_STR="${HOST:-${HOSTNAME:-}}"
fi
if [ -z "${HOSTNAME_STR}" ] && [ -r /proc/sys/kernel/hostname ]; then
    HOSTNAME_STR="$(cat /proc/sys/kernel/hostname 2>/dev/null || true)"
fi
if [ -z "${HOSTNAME_STR}" ] && [ -r /etc/hostname ]; then
    HOSTNAME_STR="$(cat /etc/hostname 2>/dev/null || true)"
fi
HOSTNAME_STR="$(echo "${HOSTNAME_STR:-}" | xargs)"
[ -z "${HOSTNAME_STR}" ] && HOSTNAME_STR="host"

TIMESTAMP="$(date +"%Y%m%d_%H%M%S")"
DEFAULT_FILENAME="konsole_backup_${HOSTNAME_STR}_${TIMESTAMP}.zip"

# Temporary staging directory
TEMP_DIR="$(mktemp -d)"
trap 'rm -rf "${TEMP_DIR}"' EXIT

echo "=== Starting Konsole Configuration Backup ==="

# Define target paths relative to HOME
CONFIG_PATHS=(
    ".config/konsolerc"
    ".local/share/konsole"
    ".local/share/kxmlgui5/konsole"
    ".config/konsole.notifyrc"
    ".config/konsolesshconfig"
)

COPIED_COUNT=0

for rel_path in "${CONFIG_PATHS[@]}"; do
    src_path="${HOME}/${rel_path}"
    dest_path="${TEMP_DIR}/${rel_path}"

    if [ -e "${src_path}" ]; then
        mkdir -p "$(dirname "${dest_path}")"
        if [ "${rel_path}" = ".config/konsolerc" ]; then
            # Filter out [MainWindow] section to avoid machine-specific geometry/monitor noise
            awk '
                /^\[MainWindow\]/ { skip=1; next }
                /^\[.*\]/ { skip=0 }
                !skip { print }
            ' "${src_path}" > "${dest_path}"
            echo " [+] Staged & Sanitized: ~/${rel_path}"
        else
            cp -a "${src_path}" "${dest_path}"
            echo " [+] Staged: ~/${rel_path}"
        fi
        COPIED_COUNT=$((COPIED_COUNT + 1))
    else
        echo " [-] Skipped (not found): ~/${rel_path}"
    fi
done

if [ "${COPIED_COUNT}" -eq 0 ]; then
    echo "Error: No Konsole configuration files found to backup."
    exit 1
fi

# Determine appropriate interactive input source
get_input() {
    local prompt_msg="$1"
    local var_name="$2"
    local default_val="${3:-}"

    if [ -t 0 ]; then
        read -r -p "${prompt_msg}" "$var_name" || true
    elif [ -c /dev/tty ] && [ -r /dev/tty ] && { : < /dev/tty; } 2>/dev/null; then
        read -r -p "${prompt_msg}" "$var_name" < /dev/tty || true
    else
        read -r -p "${prompt_msg}" "$var_name" || true
    fi

    if [ -z "${!var_name:-}" ] && [ -n "${default_val}" ]; then
        eval "${var_name}=\"${default_val}\""
    fi
}

echo ""
# Prompt user for backup filename (like ssh-keygen)
CHOSEN_NAME=""
get_input "Enter backup filename [default: ${DEFAULT_FILENAME}]: " CHOSEN_NAME "${DEFAULT_FILENAME}"
CHOSEN_NAME="$(echo "${CHOSEN_NAME:-}" | xargs)"

if [ -z "${CHOSEN_NAME}" ]; then
    ZIP_FILENAME="${DEFAULT_FILENAME}"
else
    if [[ "${CHOSEN_NAME}" != *.zip ]]; then
        ZIP_FILENAME="${CHOSEN_NAME}.zip"
    else
        ZIP_FILENAME="${CHOSEN_NAME}"
    fi
fi

ZIP_FILEPATH="${BACKUP_DIR}/${ZIP_FILENAME}"

# Create zip file from staging area
echo "Creating backup archive: ${ZIP_FILENAME}..."
(
    cd "${TEMP_DIR}"
    zip -q -r "${ZIP_FILEPATH}" .
)

echo "Backup successfully saved to: ${ZIP_FILEPATH}"

# Retention Policy: keep at most 10 recent backup zip files
MAX_BACKUPS=10

mapfile -t BACKUP_FILES < <(find "${BACKUP_DIR}" -maxdepth 1 -name "konsole_backup_*.zip" | sort -r)

TOTAL_BACKUPS="${#BACKUP_FILES[@]}"
if [ "${TOTAL_BACKUPS}" -gt "${MAX_BACKUPS}" ]; then
    echo "Cleaning up older backups (keeping top ${MAX_BACKUPS})..."
    for (( i=MAX_BACKUPS; i<TOTAL_BACKUPS; i++ )); do
        file_to_remove="${BACKUP_FILES[$i]}"
        echo " Deleting old backup: $(basename "${file_to_remove}")"
        if git rev-parse --is-inside-work-tree &>/dev/null; then
            git rm -f "${file_to_remove}" 2>/dev/null || rm -f "${file_to_remove}"
        else
            rm -f "${file_to_remove}"
        fi
    done
fi

echo "=== Backup Complete (${TOTAL_BACKUPS} backup(s) currently stored) ==="
echo ""

# Optional Git Commit & Push
if git rev-parse --is-inside-work-tree &>/dev/null; then
    git_choice=""
    get_input "Do you want to commit and push this backup to git? [y/N]: " git_choice "n"
    case "${git_choice,,}" in
        y|yes)
            echo "Staging backup file in git..."
            git add "${ZIP_FILEPATH}"
            COMMIT_MSG="chore(konsole): backup config from ${HOSTNAME_STR} at ${TIMESTAMP}"
            echo "Committing: \"${COMMIT_MSG}\"..."
            git commit -m "${COMMIT_MSG}" || true
            echo "Pushing to remote repository..."
            git push || echo "Warning: git push failed. Please check your git remote configuration."
            ;;
        *)
            echo "Skipping git push."
            ;;
    esac
fi