#!/bin/bash
set -x

# ==========================================================
# CONFIGURATION
# ==========================================================
CONTAINER_NAME="postgresql18"
PG_HOST="localhost"
PG_PORT="5432"
PG_USER="vladimir.buzalka"
export PGPASSWORD="Vlado7309208104++"

UNRAID_NAME="tower"
BASE_PATH="/mnt/user/Backup/Critical/PostgreSQLBackup"

KEEP_DAYS=7
KEEP_COUNT=7   # počet posledních záloh k udržení (mimo time-based)

# ==========================================================
# START
# ==========================================================
echo "Starting PostgreSQL full backup (pg_dumpall)"
START_TS=$(date '+%Y-%m-%d %H:%M:%S')

DATE=$(date +%Y-%m-%d_%H%M)
FINAL_PATH="$BASE_PATH/$UNRAID_NAME/$DATE"
mkdir -p "$FINAL_PATH"

DUMP_FILE="$FINAL_PATH/all_databases.sql.gz"
ERR_FILE="$FINAL_PATH/all_databases.err"

# ==========================================================
# DUMP + GZIP
# pg_dumpall zachovává: všechny DB, role, tablespaces, grants
# Streamuje přes stdout, nepotřebuje volume mount
# ==========================================================
docker exec \
    -e PGPASSWORD="$PGPASSWORD" \
    "$CONTAINER_NAME" \
    pg_dumpall \
        --host="$PG_HOST" \
        --port="$PG_PORT" \
        --username="$PG_USER" \
        --clean \
        --if-exists \
    | gzip > "$DUMP_FILE" 2> "$ERR_FILE"

EXIT_CODE=${PIPESTATUS[0]}

# ==========================================================
# VALIDATION
# ==========================================================
if [ $EXIT_CODE -eq 0 ] && [ -s "$DUMP_FILE" ] && [ ! -s "$ERR_FILE" ]; then
    echo "SUCCESS: Full PostgreSQL backup completed"
    echo "Dump size: $(du -h "$DUMP_FILE" | cut -f1)"
    rm -f "$ERR_FILE"
else
    echo "ERROR: Backup failed"
    echo "Exit code: $EXIT_CODE"
    echo "Dump file:"
    ls -lh "$DUMP_FILE" 2>/dev/null || echo "  (not created)"
    echo "Error output:"
    [ -s "$ERR_FILE" ] && cat "$ERR_FILE" || echo "  (no stderr output)"
fi

# ==========================================================
# CLEANUP OLD BACKUPS
# 1. Smaž zálohy starší než KEEP_DAYS dnů
# 2. Z toho co zbyde, ponech jen posledních KEEP_COUNT
# ==========================================================
echo "Cleaning up old backups..."
find "$BASE_PATH/$UNRAID_NAME" \
    -mindepth 1 -maxdepth 1 -type d -mtime +$KEEP_DAYS \
    -exec rm -rf {} \;

# Nech jen posledních KEEP_COUNT záloh
ls -td "$BASE_PATH/$UNRAID_NAME"/*/ 2>/dev/null \
    | tail -n +$((KEEP_COUNT + 1)) \
    | xargs -r rm -rf

echo "------------------------------------------"
echo "Backup task completed at $(date)"
echo "Started at: $START_TS"
set +x