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

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
# shellcheck source=./lib.sh
source "$SCRIPT_DIR/lib.sh"

REMOTE_HOST=""
REMOTE_USER=""
REMOTE_PORT="22"
OUT_DIR="$SCRIPT_DIR/output"
AUTO_YES=false
USE_SUDO=true

usage() {
  cat <<USAGE
Usage: $(basename "$0") --host=IP --user=NAME [options]

Collect Nginx config inventory from a remote host for conversion planning.

Options:
  --host=IP            Remote host/IP (required)
  --user=NAME          SSH username (required)
  --port=PORT          SSH port (default: 22)
  --out-dir=PATH       Output directory (default: setup/nginx-to-caddy/output)
  --no-sudo            Use nginx commands without sudo
  --yes, -y            Skip confirmation prompt
  --help, -h           Show help

Outputs:
  nginx-version.txt
  nginx-full.conf            (nginx -T combined output)
  etc-nginx.tar.gz           (/etc/nginx snapshot tarball)
  inventory-summary.txt      (basic discovered domains/proxy targets)
USAGE
}

for arg in "$@"; do
  case "$arg" in
    --host=*) REMOTE_HOST="${arg#*=}" ;;
    --user=*) REMOTE_USER="${arg#*=}" ;;
    --port=*) REMOTE_PORT="${arg#*=}" ;;
    --out-dir=*) OUT_DIR="${arg#*=}" ;;
    --no-sudo) USE_SUDO=false ;;
    --yes|-y) AUTO_YES=true ;;
    --help|-h) usage; exit 0 ;;
    *) log_error "Unknown argument: $arg"; usage; exit 1 ;;
  esac
done

require_cmd ssh tar awk sed grep

if [[ -z "$REMOTE_HOST" || -z "$REMOTE_USER" ]]; then
  log_error "--host and --user are required"
  usage
  exit 1
fi

if ! confirm_action "Collect nginx config from ${REMOTE_USER}@${REMOTE_HOST}?" "$AUTO_YES"; then
  log_info "Cancelled"
  exit 0
fi

mkdir -p "$OUT_DIR"

sudo_prefix=""
if [[ "$USE_SUDO" == "true" ]]; then
  sudo_prefix="sudo "
fi

ssh_target="${REMOTE_USER}@${REMOTE_HOST}"
ssh_opts=( -p "$REMOTE_PORT" -o BatchMode=yes -o StrictHostKeyChecking=accept-new )

log_info "Checking SSH connectivity..."
ssh "${ssh_opts[@]}" "$ssh_target" "echo connected" >/dev/null

log_info "Capturing nginx version and build info..."
ssh "${ssh_opts[@]}" "$ssh_target" "${sudo_prefix}nginx -V 2>&1" > "${OUT_DIR}/nginx-version.txt"

log_info "Capturing full rendered nginx config (nginx -T)..."
ssh "${ssh_opts[@]}" "$ssh_target" "${sudo_prefix}nginx -T 2>&1" > "${OUT_DIR}/nginx-full.conf"

log_info "Capturing /etc/nginx snapshot..."
ssh "${ssh_opts[@]}" "$ssh_target" "${sudo_prefix}tar -C / -czf - etc/nginx" > "${OUT_DIR}/etc-nginx.tar.gz"

log_info "Building inventory summary..."
{
  echo "Inventory generated: $(date -u +%Y-%m-%dT%H:%M:%SZ)"
  echo
  echo "Server names:"
  awk '
    /^[[:space:]]*server_name[[:space:]]+/ {
      line=$0
      sub(/^[[:space:]]*server_name[[:space:]]+/, "", line)
      sub(/[[:space:]]*;[[:space:]]*$/, "", line)
      gsub(/[[:space:]]+/, " ", line)
      print "  - " line
    }
  ' "${OUT_DIR}/nginx-full.conf" | sort -u
  echo
  echo "Proxy targets:"
  awk '
    /^[[:space:]]*proxy_pass[[:space:]]+/ {
      line=$0
      sub(/^[[:space:]]*proxy_pass[[:space:]]+/, "", line)
      sub(/[[:space:]]*;[[:space:]]*$/, "", line)
      print "  - " line
    }
  ' "${OUT_DIR}/nginx-full.conf" | sort -u
} > "${OUT_DIR}/inventory-summary.txt"

log_success "Nginx inventory collected in: ${OUT_DIR}"
log_info "Next: run nginx_to_caddy.sh --input=${OUT_DIR}/nginx-full.conf"