#!/bin/bash
#
# Database Backup Health Check Script
# Verifies backup status and alerts if backups are stale or missing
#
# Usage:
#   ./database/check_backups.sh           # Check backup health
#   ./database/check_backups.sh --quiet   # Minimal output (for cron)
#

# Directories
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
BACKUP_BASE_DIR="$PROJECT_DIR/backups"
DUMP_DIR="$BACKUP_BASE_DIR/dumps"
BASEBACKUP_DIR="$BACKUP_BASE_DIR/basebackups"

# Colors
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
NC='\033[0m'

# Quiet mode
QUIET=false
if [ "$1" = "--quiet" ]; then
    QUIET=true
fi

# Output function
output() {
    if [ "$QUIET" = false ]; then
        echo -e "$1"
    fi
}

# Check if backups exist
check_daily_backups() {
    output "${GREEN}Daily Backups (pg_dump):${NC}"

    if [ ! -d "$DUMP_DIR" ]; then
        output "${RED}✗ Backup directory not found: $DUMP_DIR${NC}"
        return 1
    fi

    local backup_count=$(ls -1 "$DUMP_DIR"/*.sql.gz 2>/dev/null | wc -l)

    if [ "$backup_count" -eq 0 ]; then
        output "${RED}✗ No daily backups found${NC}"
        return 1
    fi

    output "${GREEN}✓ Found $backup_count daily backup(s)${NC}"

    # Find latest backup
    local latest_backup=$(ls -t "$DUMP_DIR"/*.sql.gz 2>/dev/null | head -1)

    if [ -n "$latest_backup" ]; then
        local backup_age_hours=$(( ($(date +%s) - $(stat -f %m "$latest_backup")) / 3600 ))
        local backup_size=$(du -h "$latest_backup" | cut -f1)
        local backup_name=$(basename "$latest_backup")

        output "  Latest: $backup_name"
        output "  Size: $backup_size"
        output "  Age: ${backup_age_hours} hours ago"

        if [ "$backup_age_hours" -gt 25 ]; then
            output "${YELLOW}  ⚠️  WARNING: Backup is older than 25 hours${NC}"
            return 1
        else
            output "${GREEN}  ✓ Backup is fresh${NC}"
        fi
    fi

    output ""
    return 0
}

check_weekly_backups() {
    output "${GREEN}Weekly Backups (pg_basebackup):${NC}"

    if [ ! -d "$BASEBACKUP_DIR" ]; then
        output "${YELLOW}⚠️  Weekly backup directory not found (optional)${NC}"
        return 0
    fi

    local backup_count=$(ls -1 "$BASEBACKUP_DIR"/*.tar.gz 2>/dev/null | wc -l)

    if [ "$backup_count" -eq 0 ]; then
        output "${YELLOW}⚠️  No weekly backups found (will be created on Sunday)${NC}"
        return 0
    fi

    output "${GREEN}✓ Found $backup_count weekly backup(s)${NC}"

    # Find latest backup
    local latest_backup=$(ls -t "$BASEBACKUP_DIR"/*.tar.gz 2>/dev/null | head -1)

    if [ -n "$latest_backup" ]; then
        local backup_age_days=$(( ($(date +%s) - $(stat -f %m "$latest_backup")) / 86400 ))
        local backup_size=$(du -h "$latest_backup" | cut -f1)
        local backup_name=$(basename "$latest_backup")

        output "  Latest: $backup_name"
        output "  Size: $backup_size"
        output "  Age: ${backup_age_days} days ago"
    fi

    output ""
    return 0
}

# Display disk space
check_disk_space() {
    output "${GREEN}Disk Space Usage:${NC}"

    if [ -d "$BACKUP_BASE_DIR" ]; then
        local total_size=$(du -sh "$BACKUP_BASE_DIR" 2>/dev/null | cut -f1)
        output "  Total backup size: $total_size"
    else
        output "${YELLOW}  Backup directory not yet created${NC}"
    fi

    output ""
}

# List all backups
list_all_backups() {
    output "${GREEN}All Available Backups:${NC}"
    output ""

    if [ -d "$DUMP_DIR" ] && ls "$DUMP_DIR"/*.sql.gz 1> /dev/null 2>&1; then
        output "Daily Backups:"
        ls -lht "$DUMP_DIR"/*.sql.gz | head -10 | awk '{print "  " $9 " - " $5 " - " $6 " " $7 " " $8}'
        output ""
    fi

    if [ -d "$BASEBACKUP_DIR" ] && ls "$BASEBACKUP_DIR"/*.tar.gz 1> /dev/null 2>&1; then
        output "Weekly Backups:"
        ls -lht "$BASEBACKUP_DIR"/*.tar.gz | awk '{print "  " $9 " - " $5 " - " $6 " " $7 " " $8}'
        output ""
    fi
}

# Main
main() {
    if [ "$QUIET" = false ]; then
        echo "========================================="
        echo "Ferrero Database Backup Health Check"
        echo "========================================="
        echo ""
    fi

    local status=0

    # Check daily backups
    if ! check_daily_backups; then
        status=1
    fi

    # Check weekly backups
    check_weekly_backups

    # Check disk space
    check_disk_space

    # List all backups if not quiet
    if [ "$QUIET" = false ]; then
        list_all_backups
    fi

    if [ "$QUIET" = false ]; then
        echo "========================================="
        if [ $status -eq 0 ]; then
            echo -e "${GREEN}✓ Backup system healthy${NC}"
        else
            echo -e "${RED}✗ Backup system needs attention${NC}"
        fi
        echo "========================================="
    fi

    exit $status
}

# Run main
main