#!/bin/bash
# =============================================================================
# AYON Automated Backup Script
# Author: Daniel van Westen
# Date: 2026-02-04
# License: MIT - Use at your own risk, no warranty!
# =============================================================================
set -euo pipefail

# === Configuration ===
BACKUP_DIR="$HOME/ayon-docker/backups"
LOG_DIR="$HOME/ayon-docker/logs"
AYON_DIR="$HOME/ayon-docker"
LOCKFILE="/tmp/ayon_backup.lock"

DATE=$(date +%Y%m%d)
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
WEEKDAY=$(date +%u)  # 1=Monday, 7=Sunday

# Retention settings
FULL_BACKUP_KEEP=4      # Number of full backups to keep
PROJECT_BACKUP_DAYS=14  # Delete project backups older than X days

# === Create directories ===
mkdir -p "$BACKUP_DIR" "$LOG_DIR"

# === Logging ===
LOGFILE="$LOG_DIR/backup_${DATE}.log"

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a "$LOGFILE"
}

log_error() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: $*" | tee -a "$LOGFILE" >&2
}

# === Lock mechanism ===
exec 200>"$LOCKFILE"
if ! flock -n 200; then
    log_error "Backup already running (lock file: $LOCKFILE)"
    exit 1
fi

# === Cleanup on exit ===
cleanup() {
    local exit_code=$?
    if [ $exit_code -ne 0 ]; then
        log_error "Backup finished with error code $exit_code"
    fi
    # Lock is automatically released
}
trap cleanup EXIT

# === Check if container is running ===
cd "$AYON_DIR"

if ! docker compose ps postgres --format '{{.State}}' 2>/dev/null | grep -q running; then
    log_error "PostgreSQL container is not running!"
    exit 1
fi

log "=== Backup started ==="

# === Backup validation ===
validate_backup() {
    local file="$1"
    local min_size="${2:-1024}"  # At least 1KB

    if [ ! -f "$file" ]; then
        log_error "Backup file does not exist: $file"
        return 1
    fi

    local size
    size=$(stat -c%s "$file")
    if [ "$size" -lt "$min_size" ]; then
        log_error "Backup too small ($size bytes): $file"
        return 1
    fi

    log "  Validated: $file ($size bytes)"
    return 0
}

# ------------------------------------------------------------
# 1) Full backup: only once per week (Sunday)
# ------------------------------------------------------------
if [ "$WEEKDAY" -eq 7 ]; then
    FULL_BACKUP_FILE="$BACKUP_DIR/${DATE}_full_backup.sql.gz"
    log "Creating full backup: $FULL_BACKUP_FILE"

    if docker compose exec -T postgres \
        pg_dump -U ayon --no-owner --no-privileges --format=plain ayon \
        | gzip > "$FULL_BACKUP_FILE"; then

        if validate_backup "$FULL_BACKUP_FILE" 100; then
            log "Full backup successful"
        else
            rm -f "$FULL_BACKUP_FILE"
            log_error "Full backup failed - file deleted"
        fi
    else
        log_error "pg_dump for full backup failed"
        rm -f "$FULL_BACKUP_FILE"
    fi

    # Clean up old full backups
    log "Cleaning up old full backups (keeping $FULL_BACKUP_KEEP)"
    find "$BACKUP_DIR" -name "*_full_backup.sql.gz" -type f | sort -r | tail -n +$((FULL_BACKUP_KEEP + 1)) | xargs -r rm -v -- 2>&1 | while read -r line; do log "  Deleted: $line"; done
fi

# ------------------------------------------------------------
# 2) Get project list from database
# ------------------------------------------------------------
log "Fetching project list from database"
PROJECTS=$(docker compose exec -T postgres psql -U ayon -d ayon -t -c "SELECT name FROM projects;" | tr -d ' ' | grep -v '^$')

if [ -z "$PROJECTS" ]; then
    log "No projects found - skipping project backups"
else
    PROJECT_COUNT=$(echo "$PROJECTS" | wc -l)
    log "Found: $PROJECT_COUNT project(s)"

    # ------------------------------------------------------------
    # 3) Daily backup for each project
    # ------------------------------------------------------------
    for PROJECT in $PROJECTS; do
        log "Backup for project: $PROJECT"

        if make dump projectname="$PROJECT" >> "$LOGFILE" 2>&1; then
            # Find dump file
            DUMP_FILE="dump.${PROJECT}.sql"

            if [ -f "$DUMP_FILE" ]; then
                TARGET_FILE="$BACKUP_DIR/${DATE}_${PROJECT}.sql.gz"

                # Compress and move
                if gzip -c "$DUMP_FILE" > "$TARGET_FILE"; then
                    rm "$DUMP_FILE"

                    if validate_backup "$TARGET_FILE" 100; then
                        log "  -> saved: $TARGET_FILE"
                    else
                        rm -f "$TARGET_FILE"
                    fi
                else
                    log_error "  Compression failed for $PROJECT"
                    rm -f "$DUMP_FILE" "$TARGET_FILE"
                fi
            else
                log_error "  No dump file found: $DUMP_FILE"
            fi
        else
            log_error "  make dump failed for $PROJECT"
        fi
    done

    # ------------------------------------------------------------
    # 4) Clean up old project backups
    # ------------------------------------------------------------
    log "Cleaning up project backups older than $PROJECT_BACKUP_DAYS days"
    find "$BACKUP_DIR" -name "${DATE}_*.sql.gz" -prune -o -name "*_*.sql.gz" ! -name "*_full_backup.sql.gz" -type f -mtime +$PROJECT_BACKUP_DAYS -print | xargs -r rm -v -- 2>&1 | while read -r line; do log "  Deleted: $line"; done
fi

log "=== Backup completed ==="