#!/usr/bin/env bash
#
# docker-stacks-update - Pull latest images and restart all running
#                        Docker Compose stacks that have updates.
#
# Usage:  docker-stacks-update
#
# Works from any directory; put it anywhere in $PATH.

set -euo pipefail

# ── Terminal colours (disabled when not on a terminal) ──────────────
if [[ -t 1 ]]; then
  GREEN='\033[0;32m'; YELLOW='\033[1;33m'; RED='\033[0;31m'
  CYAN='\033[0;36m';  BOLD='\033[1m';       NC='\033[0m'
else
  GREEN=''; YELLOW=''; RED=''; CYAN=''; BOLD=''; NC=''
fi

# ── State ───────────────────────────────────────────────────────────
updated_names=()     # stack names that were updated
updated_detail=()    # parallel: "stack: service1, service2"
unchanged_names=()   # stack names already up to date
orphaned_names=()    # stacks whose compose files are gone – removed
failed_names=()      # stack names that errored

# ── Helpers ─────────────────────────────────────────────────────────
info()    { echo -e "${CYAN}::${NC} $*"; }
ok()      { echo -e " ${GREEN}✓${NC} $*"; }
warn()    { echo -e " ${YELLOW}~${NC} $*"; }
fail()    { echo -e " ${RED}✗${NC} $*"; }

# ── Pre-flight ──────────────────────────────────────────────────────
if ! command -v docker &>/dev/null; then
  echo -e "${RED}Error: 'docker' not found in PATH.${NC}" >&2
  exit 1
fi

echo -e "${BOLD}Docker Compose Stack Updater${NC}"
echo -e "${BOLD}────────────────────────────${NC}"
echo

# ── Discover stacks ─────────────────────────────────────────────────
info "Scanning for running Docker Compose stacks ..."
echo

stack_json=$(docker compose ls --format json 2>/dev/null || true)

if [[ -z "$stack_json" ]]; then
  warn "No running Docker Compose stacks found."
  exit 0
fi

# Parse JSON with jq (required).
if ! command -v jq &>/dev/null; then
  echo -e "${RED}Error: 'jq' is required.  Install it first.${NC}" >&2
  exit 1
fi

readarray -t names  < <(echo "$stack_json" | jq -r '.[].Name')
readarray -t configs < <(echo "$stack_json" | jq -r '.[].ConfigFiles')

total=${#names[@]}
echo "   Found ${total} running stack(s):"
printf "     • %s\n" "${names[@]}"
echo

# ── Process each stack ──────────────────────────────────────────────
for i in "${!names[@]}"; do
  stack="${names[$i]}"
  cfg_str="${configs[$i]}"

  echo -e "${BOLD}── ${stack}${NC}"

  # Support multi-file projects (ConfigFiles is comma-separated).
  IFS=',' read -ra cfg_files <<< "$cfg_str"
  compose_args=()
  compose_dir=""
  for f in "${cfg_files[@]}"; do
    f_trimmed=$(echo "$f" | xargs)
    compose_args+=(-f "$f_trimmed")
    # Use the directory of the first config file as working directory.
    if [[ -z "$compose_dir" ]]; then
      compose_dir=$(dirname "$f_trimmed")
    fi
  done

  # Check whether the compose files still exist (orphan detection).
  missing_files=()
  for f in "${compose_args[@]}"; do
    [[ "$f" == "-f" ]] && continue
    [[ ! -e "$f" ]] && missing_files+=("$f")
  done

  if [[ ${#missing_files[@]} -gt 0 ]]; then
    warn "Orphaned stack — compose file(s) missing:"
    for m in "${missing_files[@]}"; do
      echo "       ${m}"
    done
    info "Tearing down orphaned stack ..."
    if docker compose -p "$stack" down 2>/dev/null; then
      ok "${stack} — orphaned stack removed"
    else
      # Fall back to direct container / network cleanup by project label.
      info "Fallback: removing containers by project label …"
      containers=$(docker container ls -q --filter label=com.docker.compose.project="$stack") || true
      if [[ -n "$containers" ]]; then
        docker container rm -f $containers 2>/dev/null || true
      fi
      networks=$(docker network ls -q --filter label=com.docker.compose.project="$stack") || true
      if [[ -n "$networks" ]]; then
        docker network rm $networks 2>/dev/null || true
      fi
      ok "${stack} — orphaned containers removed"
    fi
    orphaned_names+=("$stack")
    echo; continue
  fi

  info "Pulling latest images ..."
  pull_out=$(docker compose "${compose_args[@]}" pull 2>&1) || {
    fail "Image pull failed for ${stack}"
    echo "$pull_out" | head -5
    failed_names+=("$stack")
    echo; continue
  }

  # Always run up -d after a successful pull (idempotent when nothing
  # changed).
  info "Recreating containers …"
  docker compose "${compose_args[@]}" up -d 2>&1 || {
    fail "Container recreation failed for ${stack}"
    failed_names+=("$stack"); echo; continue
  }

  # Determine which services (if any) received new images by parsing the
  # pull output.  Only the pull output is authoritative — up -d restarts
  # are idempotent and tell us nothing about whether images changed.
  #
  # Patterns matched (TTY and non-TTY alike):
  #   " ✔ svc Pulled"   /   "svc Pulled"
  #   "Downloaded newer image for svc"
  updated_svc=()

  while IFS= read -r line; do
    # "Downloaded newer image for svc" — unambiguous.
    if [[ "$line" =~ Downloaded\ newer\ image\ for\ ([^:/\"]+) ]]; then
      updated_svc+=("${BASH_REMATCH[1]}"); continue
    fi

    # "Pulled" not "Already up to date"
    [[ "$line" =~ Already\ up\ to\ date ]] && continue
    [[ ! "$line" =~ Pulled ]] && continue

    # Extract the word before "Pulled".  Strip leading " ✔ " if
    # present, then read the first field.
    cleaned="${line#*✔ }"
    read -r svc _ <<< "$cleaned"
    [[ -n "$svc" && "$svc" != "Pulled" ]] && updated_svc+=("$svc")
  done <<< "$pull_out"

  # Deduplicate while preserving order.
  seen=""
  deduped=()
  for svc in "${updated_svc[@]}"; do
    if [[ ! " $seen " =~ [[:space:]]${svc}[[:space:]] ]]; then
      deduped+=("$svc")
      seen+=" $svc "
    fi
  done

  if [[ ${#deduped[@]} -gt 0 ]]; then
    ok "${stack} — updated: ${deduped[*]}"
    updated_names+=("$stack")
    updated_detail+=("${stack}: ${deduped[*]}")
  else
    info "${stack} — already up to date"
    unchanged_names+=("$stack")
  fi

  echo
done

# ── Summary ─────────────────────────────────────────────────────────
echo -e "${BOLD}──────────────────────────────────────────────────────${NC}"
echo -e "${BOLD}  Summary${NC}"
echo -e "${BOLD}──────────────────────────────────────────────────────${NC}"
echo

total_found=$(( ${#updated_names[@]} + ${#unchanged_names[@]} + ${#orphaned_names[@]} + ${#failed_names[@]} ))
echo "   Total stacks found:  ${total_found}"
echo

if [[ ${#updated_names[@]} -gt 0 ]]; then
  echo -e " ${GREEN}✓${NC} ${BOLD}Updated (${#updated_names[@]})${NC}"
  for d in "${updated_detail[@]}"; do
    echo "     ${d}"
  done
  echo
fi

if [[ ${#unchanged_names[@]} -gt 0 ]]; then
  echo -e " ${YELLOW}−${NC} ${BOLD}Unchanged (${#unchanged_names[@]})${NC}"
  printf "     %s\n" "${unchanged_names[@]}"
  echo
fi

if [[ ${#orphaned_names[@]} -gt 0 ]]; then
  echo -e " ${RED}✗${NC} ${BOLD}Removed (orphaned — ${#orphaned_names[@]})${NC}"
  printf "     %s\n" "${orphaned_names[@]}"
  echo
fi

if [[ ${#failed_names[@]} -gt 0 ]]; then
  echo -e " ${RED}✗${NC} ${BOLD}Failed (${#failed_names[@]})${NC}"
  printf "     %s\n" "${failed_names[@]}"
  echo
fi