#!/bin/bash

set -euo pipefail

PROJECT_ID="pve-guests-state"
ORG_ID="xdev"
INSTALL_DIR="/usr/local/lib/${ORG_ID}/${PROJECT_ID}"
DOC_DIR="/usr/local/share/doc/${ORG_ID}/${PROJECT_ID}"
STATE_DIR="/var/lib/${ORG_ID}/${PROJECT_ID}"
COMMAND_PATH="/usr/local/sbin/pgs"
UNINSTALL_PATH="${INSTALL_DIR}/uninstall.sh"
UNINSTALL_WRAPPER="/usr/local/sbin/${ORG_ID}-${PROJECT_ID}-uninstall"

SOURCE_DIR=""

usage() {
    cat <<EOF
Usage: $0 [--source-dir <path>]

Install ${PROJECT_ID} on the current host.
EOF
}

require_root() {
    if [[ "${EUID}" -ne 0 ]]; then
        echo "ERROR: this script must be run as root" >&2
        exit 1
    fi
}

resolve_source_dir() {
    if [[ -n "${SOURCE_DIR}" ]]; then
        SOURCE_DIR="$(cd "${SOURCE_DIR}" && pwd)"
    else
        SOURCE_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
    fi
}

validate_source_tree() {
    local required_files=(
        "${SOURCE_DIR}/bin/pgs"
        "${SOURCE_DIR}/scripts/uninstall.sh"
        "${SOURCE_DIR}/README.md"
        "${SOURCE_DIR}/INSTALL.md"
        "${SOURCE_DIR}/CHANGELOG.md"
        "${SOURCE_DIR}/LICENSE"
        "${SOURCE_DIR}/docs/DECISIONS.md"
        "${SOURCE_DIR}/docs/TECHNICAL.md"
    )
    local file=""
    for file in "${required_files[@]}"; do
        if [[ ! -f "${file}" ]]; then
            echo "ERROR: missing required source file: ${file}" >&2
            exit 1
        fi
    done
}

cleanup_legacy_artifacts() {
    rm -f /usr/local/sbin/pve-reboot-manager.sh
    rm -f /usr/local/sbin/pve-guest-state.sh
    rm -f /root/bin/pgs
    rm -f /root/bin/pve-reboot-manager.sh
    rm -f /root/bin/pve-guest-state.sh

    systemctl disable pve-suspend-vms.service pve-resume-vms.service >/dev/null 2>&1 || true
    systemctl stop pve-suspend-vms.service pve-resume-vms.service >/dev/null 2>&1 || true
    rm -f /etc/systemd/system/pve-suspend-vms.service
    rm -f /etc/systemd/system/pve-resume-vms.service
    systemctl daemon-reload
    systemctl reset-failed pve-suspend-vms.service pve-resume-vms.service >/dev/null 2>&1 || true
}

run_existing_uninstall() {
    if [[ -x "${UNINSTALL_PATH}" ]]; then
        echo "Existing installation detected. Running canonical uninstall first..."
        "${UNINSTALL_PATH}" --force || true
    else
        bash "${SOURCE_DIR}/scripts/uninstall.sh" --force || true
    fi
}

install_docs() {
    mkdir -p "${DOC_DIR}/docs"
    cp "${SOURCE_DIR}/README.md" "${DOC_DIR}/"
    cp "${SOURCE_DIR}/INSTALL.md" "${DOC_DIR}/"
    cp "${SOURCE_DIR}/CHANGELOG.md" "${DOC_DIR}/"
    cp "${SOURCE_DIR}/LICENSE" "${DOC_DIR}/"
    cp "${SOURCE_DIR}/docs/DECISIONS.md" "${DOC_DIR}/docs/"
    cp "${SOURCE_DIR}/docs/TECHNICAL.md" "${DOC_DIR}/docs/"
}

main() {
    while [[ $# -gt 0 ]]; do
        case "$1" in
            --source-dir)
                SOURCE_DIR="$2"
                shift 2
                ;;
            -h|--help)
                usage
                exit 0
                ;;
            *)
                echo "ERROR: unknown option: $1" >&2
                usage
                exit 1
                ;;
        esac
    done

    require_root
    resolve_source_dir
    validate_source_tree

    echo "=== Installing ${PROJECT_ID} ==="
    run_existing_uninstall

    mkdir -p "${INSTALL_DIR}" "${DOC_DIR}" "${STATE_DIR}" /usr/local/sbin

    cleanup_legacy_artifacts

    install -m 0755 "${SOURCE_DIR}/bin/pgs" "${COMMAND_PATH}"
    install -m 0755 "${SOURCE_DIR}/scripts/uninstall.sh" "${UNINSTALL_PATH}"
    ln -sfn "${UNINSTALL_PATH}" "${UNINSTALL_WRAPPER}"

    install_docs

    echo "Installed paths:"
    echo "  command: ${COMMAND_PATH}"
    echo "  uninstall: ${UNINSTALL_PATH}"
    echo "  docs: ${DOC_DIR}"
    echo "  state: ${STATE_DIR}"
    echo ""
    echo "Running dry-run verification..."
    "${COMMAND_PATH}" suspend --dry-run -v 2>&1 | tail -3 || true
    echo ""
    echo "Installation completed."
}

main "$@"