#!/bin/bash

# Plex Backup Restoration Script
# Usage: ./restore-plex.sh [backup_date] [--dry-run]

set -e

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

# Configuration
SCRIPT_DIR="$(dirname "$(readlink -f "$0")")"
BACKUP_ROOT="/mnt/share/media/backups/plex"
PLEX_DATA_DIR="/var/lib/plexmediaserver/Library/Application Support/Plex Media Server"

# Plex file locations
declare -A RESTORE_LOCATIONS=(
    ["com.plexapp.plugins.library.db"]="$PLEX_DATA_DIR/Plug-in Support/Databases/"
    ["com.plexapp.plugins.library.blobs.db"]="$PLEX_DATA_DIR/Plug-in Support/Databases/"
    ["Preferences.xml"]="$PLEX_DATA_DIR/"
)

log_message() {
    echo -e "$(date '+%H:%M:%S') $1"
}

log_error() {
    log_message "${RED}ERROR: $1${NC}"
}

log_success() {
    log_message "${GREEN}SUCCESS: $1${NC}"
}

log_warning() {
    log_message "${YELLOW}WARNING: $1${NC}"
}

# List available backups
list_backups() {
    log_message "Available backups:"
    find "$BACKUP_ROOT" -maxdepth 1 -type d -name "????????" | sort -r | while read backup_dir; do
        local backup_date=$(basename "$backup_dir")
        local readable_date=$(date -d "${backup_date:0:4}-${backup_date:4:2}-${backup_date:6:2}" '+%B %d, %Y')
        local file_count=$(ls -1 "$backup_dir" 2>/dev/null | wc -l)
        echo "  $backup_date ($readable_date) - $file_count files"
    done
}

# Validate backup integrity
validate_backup() {
    local backup_date="$1"
    local backup_dir="$BACKUP_ROOT/$backup_date"
    
    if [ ! -d "$backup_dir" ]; then
        log_error "Backup directory not found: $backup_dir"
        return 1
    fi
    
    log_message "Validating backup integrity for $backup_date..."
    
    for file in "${!RESTORE_LOCATIONS[@]}"; do
        local backup_file="$backup_dir/$file"
        if [ -f "$backup_file" ]; then
            log_success "Found: $file"
        else
            log_warning "Missing: $file"
        fi
    done
}

# Create backup of current Plex data
backup_current_data() {
    local backup_suffix=$(date '+%Y%m%d_%H%M%S')
    local current_backup_dir="$SCRIPT_DIR/plex_current_backup_$backup_suffix"
    
    log_message "Creating backup of current Plex data..."
    mkdir -p "$current_backup_dir"
    
    for file in "${!RESTORE_LOCATIONS[@]}"; do
        local src="${RESTORE_LOCATIONS[$file]}$file"
        if [ -f "$src" ]; then
            if sudo cp "$src" "$current_backup_dir/"; then
                log_success "Backed up current: $file"
            else
                log_error "Failed to backup current: $file"
                return 1
            fi
        fi
    done
    
    log_success "Current data backed up to: $current_backup_dir"
    echo "$current_backup_dir"
}

# Restore files from backup
restore_files() {
    local backup_date="$1"
    local dry_run="$2"
    local backup_dir="$BACKUP_ROOT/$backup_date"
    
    if [ "$dry_run" = "true" ]; then
        log_message "DRY RUN: Would restore the following files:"
    else
        log_message "Restoring files from backup $backup_date..."
    fi
    
    for file in "${!RESTORE_LOCATIONS[@]}"; do
        local backup_file="$backup_dir/$file"
        local restore_location="${RESTORE_LOCATIONS[$file]}$file"
        
        if [ -f "$backup_file" ]; then
            if [ "$dry_run" = "true" ]; then
                echo "  $backup_file -> $restore_location"
            else
                log_message "Restoring: $file"
                if sudo cp "$backup_file" "$restore_location"; then
                    sudo chown plex:plex "$restore_location"
                    log_success "Restored: $file"
                else
                    log_error "Failed to restore: $file"
                    return 1
                fi
            fi
        else
            log_warning "Backup file not found: $backup_file"
        fi
    done
}

# Manage Plex service
manage_plex_service() {
    local action="$1"
    log_message "$action Plex Media Server..."
    
    case "$action" in
        "stop")
            sudo systemctl stop plexmediaserver.service
            sleep 3
            log_success "Plex stopped"
            ;;
        "start")
            sudo systemctl start plexmediaserver.service
            sleep 3
            log_success "Plex started"
            ;;
    esac
}

# Main function
main() {
    local backup_date="$1"
    local dry_run=false
    
    # Check for dry-run flag
    if [ "$2" = "--dry-run" ] || [ "$1" = "--dry-run" ]; then
        dry_run=true
    fi
    
    # If no backup date provided, list available backups
    if [ -z "$backup_date" ] || [ "$backup_date" = "--dry-run" ]; then
        list_backups
        echo
        echo "Usage: $0 <backup_date> [--dry-run]"
        echo "Example: $0 20250125"
        exit 0
    fi
    
    # Validate backup exists and is complete
    if ! validate_backup "$backup_date"; then
        log_error "Backup validation failed"
        exit 1
    fi
    
    if [ "$dry_run" = "true" ]; then
        restore_files "$backup_date" true
        log_message "Dry run completed. No changes were made."
        exit 0
    fi
    
    # Confirm restoration
    echo
    log_warning "This will restore Plex data from backup $backup_date"
    log_warning "Current Plex data will be backed up before restoration"
    read -p "Continue? (y/N): " -n 1 -r
    echo
    
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        log_message "Restoration cancelled"
        exit 0
    fi
    
    # Stop Plex service
    manage_plex_service stop
    
    # Backup current data
    local current_backup=$(backup_current_data)
    if [ $? -ne 0 ]; then
        log_error "Failed to backup current data"
        manage_plex_service start
        exit 1
    fi
    
    # Restore files
    if restore_files "$backup_date" false; then
        log_success "Restoration completed successfully"
        log_message "Current data backup saved at: $current_backup"
    else
        log_error "Restoration failed"
        manage_plex_service start
        exit 1
    fi
    
    # Start Plex service
    manage_plex_service start
    
    log_success "Plex restoration completed. Please verify your server is working correctly."
}

# Trap to ensure Plex is restarted on script exit
trap 'manage_plex_service start' EXIT

main "$@"