#!/usr/bin/env bash
# scripts/3_cleanup.sh — Step 3: Post-migration cleanup
# Run ONLY after verifying that the Docker deployment is working correctly.
# Frees disk space by removing build artifacts and source files now in volumes.
#
# Usage:
#   bash 3_cleanup.sh          # interactive — prompts before each rm
#   bash 3_cleanup.sh --yes    # skip confirmation prompts (use with care)
set -euo pipefail

REPO_DIR="/opt/sandbox-notebookllamalm-nextjs"
VOLUME_PREFIX="sandbox-notebookllamalm-nextjs_"
BACKEND_SVC="notebookllama-backend"
FRONTEND_SVC="notebookllama-frontend"
BACKEND_PORT=9000
FRONTEND_PORT=4000
AUTO_YES=false

# ── Parse args ────────────────────────────────────────────────────────────────
for arg in "$@"; do
    [[ "$arg" == "--yes" ]] && AUTO_YES=true
done

# ── Colors ──────────────────────────────────────────────────────────────────
RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; CYAN='\033[0;36m'; NC='\033[0m'
info()    { echo -e "${GREEN}[INFO]${NC}  $*"; }
warn()    { echo -e "${YELLOW}[WARN]${NC}  $*"; }
error()   { echo -e "${RED}[ERROR]${NC} $*" >&2; }
step()    { echo -e "\n${CYAN}══ $* ${NC}"; }

# ── Confirm helper ────────────────────────────────────────────────────────────
confirm() {
    local prompt="$1"
    if $AUTO_YES; then
        info "${prompt} — auto-confirmed (--yes)"
        return 0
    fi
    echo -en "${YELLOW}${prompt} [y/N]: ${NC}"
    read -r answer
    [[ "$answer" =~ ^[Yy]$ ]]
}

cd "$REPO_DIR"

# ── Step 1: Verify all containers are running ─────────────────────────────────
step "1 / Verify Docker containers"

EXPECTED_SERVICES=(postgres redis backend frontend)
ALL_RUNNING=true

for svc in "${EXPECTED_SERVICES[@]}"; do
    STATUS=$(docker compose ps --format '{{.Service}} {{.State}}' 2>/dev/null \
        | grep "^${svc} " | awk '{print $2}' || echo "missing")
    if [[ "$STATUS" == "running" ]]; then
        info "  ${svc}: running"
    else
        error "  ${svc}: ${STATUS:-not found}"
        ALL_RUNNING=false
    fi
done

if ! $ALL_RUNNING; then
    error "Not all containers are running. Fix the deployment before cleaning up."
    echo "  docker compose ps"
    exit 1
fi

# Double-check via HTTP
check_alive() {
    local name="$1"; local url="$2"
    local code
    code=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 "$url" 2>/dev/null || echo "000")
    if [[ "$code" == "200" ]]; then
        info "  ${name}: HTTP 200 OK"
    else
        warn "  ${name}: HTTP ${code} — proceeding anyway (container is up)"
    fi
}
check_alive "Backend"  "http://localhost:${BACKEND_PORT}/api/health"
check_alive "Frontend" "http://localhost:${FRONTEND_PORT}/notebookllama"

# ── Step 2: Verify data in podcasts_data volume ────────────────────────────────
step "2 / Verify data in Docker volumes"

PODCASTS_VOLUME="${VOLUME_PREFIX}podcasts_data"
UPLOADS_VOLUME="${VOLUME_PREFIX}uploads_data"

VOL_MP3=$(docker run --rm -v "${PODCASTS_VOLUME}:/d:ro" alpine \
    sh -c 'find /d -name "*.mp3" | wc -l' 2>/dev/null || echo "0")
SRC_MP3=$(find backend/conversations -name '*.mp3' 2>/dev/null | wc -l | tr -d ' ')

info "podcasts_data volume: ${VOL_MP3} MP3 file(s)"
info "backend/conversations source: ${SRC_MP3} MP3 file(s)"

if [[ "$VOL_MP3" -lt "$SRC_MP3" ]]; then
    error "Volume has fewer MP3s (${VOL_MP3}) than source (${SRC_MP3}). Copy may be incomplete."
    error "Aborting cleanup. Re-run 2_deploy.sh or copy manually."
    exit 1
fi

if [[ "$SRC_MP3" -gt 0 && "$VOL_MP3" -ge "$SRC_MP3" ]]; then
    info "Volume data matches source — safe to remove source files"
elif [[ "$SRC_MP3" -eq 0 ]]; then
    info "No MP3 files in source directory (already cleaned or never populated)"
fi

# ── Step 3: Remove source MP3s (now in volume) ────────────────────────────────
step "3 / Remove backend/conversations/ (data is in Docker volume)"

if [[ -d "backend/conversations" ]] && [[ -n "$(ls -A backend/conversations 2>/dev/null)" ]]; then
    CONV_SIZE=$(du -sh backend/conversations | cut -f1)
    warn "Will delete: backend/conversations/ (${CONV_SIZE})"
    if confirm "Delete backend/conversations/?"; then
        sudo rm -rf backend/conversations/
        info "Deleted backend/conversations/"
    else
        info "Skipped — keeping backend/conversations/"
    fi
else
    info "backend/conversations/ is empty or does not exist — nothing to remove"
fi

# ── Step 4: Remove build artifacts ────────────────────────────────────────────
step "4 / Remove build artifacts (Docker builds its own)"

remove_dir() {
    local path="$1"
    local label="$2"
    if [[ -d "$path" ]]; then
        local size
        size=$(du -sh "$path" 2>/dev/null | cut -f1)
        warn "Will delete: ${path} (${size}) — ${label}"
        if confirm "Delete ${path}?"; then
            sudo rm -rf "$path"
            info "Deleted ${path}"
        else
            info "Skipped — keeping ${path}"
        fi
    else
        info "${path} does not exist — skipping"
    fi
}

remove_dir "frontend/.next"       "Next.js build cache (Docker builds its own)"
remove_dir "frontend/node_modules" "Node.js deps (Docker installs its own)"
remove_dir "backend/.venv"         "Python virtualenv (Docker uses uv)"

# ── Step 5: Prune dangling Docker images ──────────────────────────────────────
step "5 / Prune dangling Docker images"

if confirm "Run docker image prune -f (remove dangling images)?"; then
    docker image prune -f
    info "Dangling images removed"
else
    info "Skipped image prune"
fi

# ── Step 6: Show freed disk space ────────────────────────────────────────────
step "6 / Disk usage"

df -h /opt
echo ""
info "Docker disk usage:"
docker system df

# ── Step 7: Finalize systemd ──────────────────────────────────────────────────
step "7 / Finalize systemd"

for svc in "$BACKEND_SVC" "$FRONTEND_SVC"; do
    if sudo systemctl is-enabled --quiet "$svc" 2>/dev/null; then
        warn "${svc} is still enabled — disabling now..."
        sudo systemctl disable "$svc"
        info "  → disabled"
    else
        info "${svc}: already disabled"
    fi
done

sudo systemctl daemon-reload
info "systemd daemon reloaded"

# ── Done ──────────────────────────────────────────────────────────────────────
echo ""
info "── Cleanup complete ──────────────────────────────────────────────"
echo ""
info "Docker containers (should all be running):"
docker compose ps
echo ""
info "Docker volumes (should still exist):"
docker volume ls | grep "$VOLUME_PREFIX" || true
echo ""
info "Note: .service files in the repository have NOT been deleted."
echo "      They serve as a reference in case you need to roll back to systemd."
echo ""
info "Docker containers are configured with 'restart: unless-stopped' and will"
info "start automatically when the server reboots — no systemd required."
echo ""
info "Cleanup finished at $(date)"