#!/usr/bin/env bash
# scripts/1_backup.sh — Step 1: Backup before Docker migration
# Run this FIRST before any migration steps.
set -euo pipefail

REPO_DIR="/opt/sandbox-notebookllamalm-nextjs"
BACKUP_BASE="/opt/backups"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
BACKUP_DIR="${BACKUP_BASE}/notebookllama_${TIMESTAMP}"
POSTGRES_CONTAINER="sandbox-nextjs-postgres"
VOLUME_PREFIX="sandbox-notebookllamalm-nextjs_"

# Read postgres credentials from backend .env (keys: pgql_user, pgql_psw, pgql_db)
_read_env() { grep -E "^${1}=" "${REPO_DIR}/backend/.env" 2>/dev/null | head -1 | cut -d= -f2- | tr -d '"'"'" ; }
PG_USER=$(_read_env pgql_user)
PG_PSW=$(_read_env pgql_psw)
PG_DB=$(_read_env pgql_db)

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

# ── Preflight ────────────────────────────────────────────────────────────────
info "Starting backup — ${TIMESTAMP}"

if [[ ! -d "$REPO_DIR" ]]; then
    error "Repo directory not found: $REPO_DIR"
    exit 1
fi

if ! docker info &>/dev/null; then
    error "Docker is not available"
    exit 1
fi

sudo mkdir -p "$BACKUP_DIR"
# Give current user ownership so subsequent writes don't need sudo
sudo chown "$(id -u):$(id -g)" "$BACKUP_DIR"
info "Backup directory: $BACKUP_DIR"

# ── 1. PostgreSQL dump ────────────────────────────────────────────────────────
info "Dumping PostgreSQL..."
if docker ps --format '{{.Names}}' | grep -q "^${POSTGRES_CONTAINER}$"; then
    PGPASSWORD="$PG_PSW" docker exec -e PGPASSWORD="$PG_PSW" "$POSTGRES_CONTAINER" \
        pg_dump -U "$PG_USER" "$PG_DB" \
        > "${BACKUP_DIR}/postgres_dump.sql"
    info "  → postgres_dump.sql ($(du -sh "${BACKUP_DIR}/postgres_dump.sql" | cut -f1))"
else
    warn "Postgres container '${POSTGRES_CONTAINER}' is not running — skipping SQL dump"
fi

# ── 2. Archive application files ─────────────────────────────────────────────
info "Archiving application files..."

# conversation_*.mp3 in backend root
MP3_COUNT=$(find "${REPO_DIR}/backend" -maxdepth 1 -name 'conversation_*.mp3' 2>/dev/null | wc -l | tr -d ' ')
if [[ "$MP3_COUNT" -gt 0 ]]; then
    info "  → Found ${MP3_COUNT} MP3 file(s) in backend/"
    tar -czf "${BACKUP_DIR}/mp3_root.tar.gz" \
        -C "${REPO_DIR}/backend" \
        $(find "${REPO_DIR}/backend" -maxdepth 1 -name 'conversation_*.mp3' -printf '%f\n')
    info "  → mp3_root.tar.gz ($(du -sh "${BACKUP_DIR}/mp3_root.tar.gz" | cut -f1))"
else
    info "  → No MP3 files in backend root (already moved or not yet generated)"
fi

# backend/conversations/ (may already exist)
if [[ -d "${REPO_DIR}/backend/conversations" ]]; then
    tar -czf "${BACKUP_DIR}/conversations.tar.gz" \
        -C "${REPO_DIR}/backend" conversations/
    info "  → conversations.tar.gz ($(du -sh "${BACKUP_DIR}/conversations.tar.gz" | cut -f1))"
else
    info "  → backend/conversations/ not found, skipping"
fi

# backend/failed_uploads/
if [[ -d "${REPO_DIR}/backend/failed_uploads" ]]; then
    tar -czf "${BACKUP_DIR}/failed_uploads.tar.gz" \
        -C "${REPO_DIR}/backend" failed_uploads/
    info "  → failed_uploads.tar.gz ($(du -sh "${BACKUP_DIR}/failed_uploads.tar.gz" | cut -f1))"
else
    info "  → backend/failed_uploads/ not found, skipping"
fi

# .env files
for envfile in \
    "${REPO_DIR}/backend/.env" \
    "${REPO_DIR}/frontend/.env.production" \
    "${REPO_DIR}/.env"; do
    if [[ -f "$envfile" ]]; then
        rel="${envfile#${REPO_DIR}/}"
        dest="${BACKUP_DIR}/$(echo "$rel" | tr '/' '_')"
        cp "$envfile" "$dest"
        info "  → $(basename "$dest") (env file)"
    fi
done

# ── 3. Docker volume backup (pgdata) ─────────────────────────────────────────
PGDATA_VOLUME="${VOLUME_PREFIX}pgdata_nextjs"
info "Backing up Docker volume: ${PGDATA_VOLUME}..."
if docker volume inspect "$PGDATA_VOLUME" &>/dev/null; then
    docker run --rm \
        -v "${PGDATA_VOLUME}:/source:ro" \
        -v "${BACKUP_DIR}:/backup" \
        alpine \
        tar -czf /backup/pgdata_volume.tar.gz -C /source .
    info "  → pgdata_volume.tar.gz ($(du -sh "${BACKUP_DIR}/pgdata_volume.tar.gz" | cut -f1))"
else
    warn "Volume '${PGDATA_VOLUME}' not found — skipping volume backup"
fi

# ── 4. Summary ───────────────────────────────────────────────────────────────
echo ""
info "── Backup complete ──────────────────────────────────────────────"
info "Location : $BACKUP_DIR"
info "Contents :"
ls -lh "$BACKUP_DIR"
echo ""
TOTAL=$(du -sh "$BACKUP_DIR" | cut -f1)
info "Total size: ${TOTAL}"
echo ""
info "To restore PostgreSQL:"
echo "  PGPASSWORD=\$pgql_psw docker exec -i ${POSTGRES_CONTAINER} psql -U \$pgql_user \$pgql_db < ${BACKUP_DIR}/postgres_dump.sql"
echo ""
info "Backup finished successfully at $(date)"