#!/usr/bin/env bash
# =============================================================
#  update-check.sh
#  Reads Watchtower's recent logs to find outdated images,
#  maps them to containers, and fetches GitHub release notes.
#
#  Usage:
#    bash /opt/stacks/scripts/update-check.sh
# =============================================================

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/image-sources.conf"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
GRAY='\033[0;90m'
BOLD='\033[1m'
NC='\033[0m'

SEP="${GRAY}$(printf '─%.0s' $(seq 1 60))${NC}"

# ── Check Watchtower is running ───────────────────────────────
if ! docker inspect watchtower &>/dev/null; then
  echo -e "${RED}✗ Watchtower is not running.${NC}"
  echo -e "  Start it: cd /opt/stacks/watchtower && docker compose up -d"
  exit 1
fi

# ── Parse Watchtower logs for outdated images (last 36h) ─────
echo -e "${BOLD}Checking Watchtower logs for updates...${NC}"
echo ""

OUTDATED_IMAGES=()
while IFS= read -r line; do
  # Extract image name from: "Found new some/image:tag image (sha256:...)"
  img=$(echo "$line" | grep -oP '(?<=Found new )\S+(?= image)')
  [ -n "$img" ] && OUTDATED_IMAGES+=("$img")
done < <(docker logs watchtower --since 36h 2>&1 | grep "Found new")

if [ ${#OUTDATED_IMAGES[@]} -eq 0 ]; then
  echo -e "${GREEN}✓ All images are up to date${NC} ${GRAY}(per last Watchtower scan)${NC}"
  echo ""
  LAST=$(docker logs watchtower --since 72h 2>&1 | grep "Session done" | tail -1 | grep -oP '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}')
  [ -n "$LAST" ] && echo -e "${GRAY}  Last scan: ${LAST}${NC}"
  exit 0
fi

echo -e "${YELLOW}${BOLD}${#OUTDATED_IMAGES[@]} image update(s) available:${NC}"
echo ""

# ── For each outdated image: find container + fetch notes ─────
gh_release_notes() {
  local repo=$1
  local result
  result=$(curl -sf "https://api.github.com/repos/${repo}/releases/latest" 2>/dev/null) || true
  if [ -n "$result" ]; then
    TAG=$(echo "$result" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('tag_name','?'))" 2>/dev/null)
    BODY=$(echo "$result" | python3 -c "
import sys,json,re
d=json.load(sys.stdin)
body=d.get('body','No release notes available.')
# Strip markdown links/badges, collapse whitespace
body=re.sub(r'!\[.*?\]\(.*?\)','',body)
body=re.sub(r'\[([^\]]+)\]\([^\)]+\)',r'\1',body)
body=re.sub(r'<!--.*?-->','',body,flags=re.DOTALL)
lines=[l.strip() for l in body.split('\n') if l.strip()]
print('\n'.join(lines[:6]))
" 2>/dev/null || echo "No release notes available.")
    echo "$TAG|$BODY"
  fi
}

for image in "${OUTDATED_IMAGES[@]}"; do
  # Find container(s) using this image
  CONTAINERS=$(docker ps -a --format '{{.Names}}|{{.Image}}' | awk -F'|' -v img="$image" '$2==img {print $1}' | tr '\n' ' ')
  [ -z "$CONTAINERS" ] && CONTAINERS="${GRAY}(no running containers)${NC}"

  echo -e "$SEP"
  echo -e "  ${CYAN}${BOLD}${image}${NC}"
  echo -e "  ${GRAY}containers:${NC} ${CONTAINERS}"

  # Strip tag for image name lookup
  base_image=$(echo "$image" | sed 's/:.*//')

  if [ -n "${IMAGE_REPOS[$base_image]+_}" ]; then
    REPO="${IMAGE_REPOS[$base_image]}"
    RELEASE=$(gh_release_notes "$REPO")
    if [ -n "$RELEASE" ]; then
      TAG=$(echo "$RELEASE" | cut -d'|' -f1)
      NOTES=$(echo "$RELEASE" | cut -d'|' -f2-)
      echo -e "  ${GRAY}latest tag:${NC}  ${GREEN}${TAG}${NC}"
      echo -e "  ${GRAY}notes:${NC}"
      while IFS= read -r line; do
        echo -e "    ${GRAY}${line}${NC}"
      done <<< "$NOTES"
      echo -e "  ${GRAY}full notes:${NC} https://github.com/${REPO}/releases/latest"
    else
      echo -e "  ${GRAY}→ https://hub.docker.com/r/${base_image}/tags${NC}"
    fi
  else
    echo -e "  ${GRAY}no GitHub mapping — add to scripts/image-sources.conf${NC}"
    echo -e "  ${GRAY}→ https://hub.docker.com/r/${base_image}/tags${NC}"
  fi
  echo ""
done

echo -e "$SEP"
echo ""
echo -e "  Ready to update? Run: ${CYAN}bash /opt/stacks/scripts/do-update.sh${NC}"
echo ""