#!/bin/bash

# Author: Julien Gautier <jgautier.webdev@gmail.com>
# Organization: AdAstra
# Project: adastra_scripts
#
################################################################################
# MongoDB Restore Utility Script (Standalone)
# 
# This script restores MongoDB database dumps from backup files.
# It provides interactive navigation through dump directories and restores
# to a configured MongoDB instance.
#
# Usage: ./db-restore.sh
#
# Configuration:
#   Requires .env file with MongoDB connection details:
#   - MONGO_USERNAME
#   - MONGO_PASSWORD
#   - MONGO_HOST
#   - MONGO_PORT
#   - MONGO_DATABASE
#   - MONGO_AUTHSOURCE
#
# Example command (what the script executes):
#   mongorestore --uri "mongodb://user:pass@host:port/db?authSource=admin" /path/to/dumps
#
################################################################################

set -e

# Configuration
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ENV_FILE="${SCRIPT_DIR}/.env"

# Global variables
SELECTED_DUMP_PATH=""

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

# Helper functions
print_info() {
    echo -e "${BLUE}┣━${NC} ${CYAN}${1}${NC}"
}

print_success() {
    echo -e "${GREEN}✓ ${1}${NC}"
}

print_error() {
    echo -e "${RED}✗ ${1}${NC}"
}

print_warning() {
    echo -e "${YELLOW}⚠ ${1}${NC}"
}

print_separator() {
    echo -e "${BLUE}┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
}

print_separator_up() {
    echo -e "${BLUE}┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
}

print_separator_down() {
    echo -e "${BLUE}┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
}

print_section() {
    echo
    print_separator_up
    print_info "$1"
    print_separator_down
    echo
}

check_mongorestore() {
    if ! command -v mongorestore &> /dev/null; then
        print_error "mongorestore is not installed or not in PATH"
        print_info "Install MongoDB Database Tools from: https://www.mongodb.com/try/download/database-tools"
        exit 1
    fi
    print_success "mongorestore found: $(mongorestore --version | head -1)"
}

check_env_file() {
    if [[ ! -f "$ENV_FILE" ]]; then
        print_error "Configuration file not found: $ENV_FILE"
        print_info "Please create .env file with the following variables:"
        print_info "  MONGO_USERNAME=<username>"
        print_info "  MONGO_PASSWORD=<password>"
        print_info "  MONGO_HOST=<host>"
        print_info "  MONGO_PORT=<port>"
        print_info "  MONGO_DATABASE=<database>"
        print_info "  MONGO_AUTHSOURCE=<authSource>"
        print_info "You can copy from .env.example"
        exit 1
    fi
}

load_config() {
    # shellcheck source=/dev/null
    source "$ENV_FILE"
    
    # Validate required variables
    if [[ -z "$MONGO_USERNAME" ]] || [[ -z "$MONGO_PASSWORD" ]] || [[ -z "$MONGO_HOST" ]] || \
       [[ -z "$MONGO_PORT" ]] || [[ -z "$MONGO_DATABASE" ]] || [[ -z "$MONGO_AUTHSOURCE" ]]; then
        print_error "Missing required configuration variables in .env file"
        exit 1
    fi
}

has_bson_files() {
    local dir="$1"
    [[ -n $(find "$dir" -maxdepth 1 -type f -name "*.bson" 2>/dev/null | head -1) ]]
}

has_subdirectories() {
    local dir="$1"
    [[ -n $(find "$dir" -maxdepth 1 -type d ! -name "." ! -name ".." 2>/dev/null | head -1) ]]
}

navigate_to_dump() {
    SELECTED_DUMP_PATH=""
    local current_path="$1"
    
    # Expand ~ in path
    current_path="${current_path/#\~/$HOME}"
    
    # Check if path exists
    if [[ ! -d "$current_path" ]]; then
        print_error "Path does not exist: $current_path"
        return 1
    fi
    
    # If this directory has BSON files, we're at the right level
    if has_bson_files "$current_path"; then
        SELECTED_DUMP_PATH="$current_path"
        return 0
    fi
    
    # If no subdirectories and no BSON files, this isn't a valid dump directory
    if ! has_subdirectories "$current_path"; then
        print_error "No BSON files found and no subdirectories in: $current_path"
        return 1
    fi
    
    # Navigate through subdirectories
    while true; do
        print_separator_up
        print_info "Select Dump Directory"
        print_separator_down
        echo
        print_info "Current location: $current_path"
        echo
        
        # Get list of subdirectories
        local subdirs=()
        local count=0
        
        # Read subdirectories into array (null-terminated, excluding . and ..)
        while IFS= read -r -d '' subdir; do
            subdirs+=("$subdir")
            echo "  $((++count))) $(basename "$subdir")"
        done < <(find "$current_path" -maxdepth 1 -mindepth 1 -type d -print0 | sort -z)
        
        if [[ $count -eq 0 ]]; then
            print_error "No subdirectories found in: $current_path"
            return 1
        fi
        
        echo
        echo -n "Enter your choice (1-$count): "
        read choice
        
        if [[ "$choice" =~ ^[0-9]+$ ]] && [[ $choice -ge 1 ]] && [[ $choice -le $count ]]; then
            current_path="${subdirs[$((choice - 1))]}"
            
            # Check if this directory has BSON files
            if has_bson_files "$current_path"; then
                SELECTED_DUMP_PATH="$current_path"
                return 0
            fi
            
            # If no more subdirectories and no BSON files, error
            if ! has_subdirectories "$current_path"; then
                print_error "No BSON files found in: $current_path"
                return 1
            fi
            # Continue loop to show next level
        else
            print_error "Invalid choice"
        fi
    done
}

get_backup_summary() {
    local dump_path="$1"
    local bson_count=$(find "$dump_path" -name "*.bson" -type f 2>/dev/null | wc -l)
    local total_size=$(du -sh "$dump_path" 2>/dev/null | cut -f1)
    
    echo "Backup files: $bson_count"
    echo "Total size: $total_size"
}

show_summary() {
    local dump_path="$1"
    
    print_section "Restore Summary"
    
    echo "MongoDB Connection:"
    echo "  Host:       $MONGO_HOST"
    echo "  Port:       $MONGO_PORT"
    echo "  Username:   $MONGO_USERNAME"
    echo "  Database:   $MONGO_DATABASE"
    echo "  AuthSource: $MONGO_AUTHSOURCE"
    echo
    echo "Backup Source:"
    echo "  Location: $dump_path"
    echo "  $(get_backup_summary "$dump_path")"
    echo
    echo "Connection string:"
    echo "  mongodb://<username>:<password>@$MONGO_HOST:$MONGO_PORT/$MONGO_DATABASE?authSource=$MONGO_AUTHSOURCE"
    echo
}

confirm_restore() {
    echo -n "Do you want to proceed with the restore? (yes/no): "
    read response
    [[ "$response" == "yes" ]]
}

perform_restore() {
    local dump_path="$1"
    
    print_separator_up
    print_info "Starting MongoDB Restore..."
    print_separator_down
    echo
    
    # Construct connection string
    local connection_uri="mongodb://${MONGO_USERNAME}:${MONGO_PASSWORD}@${MONGO_HOST}:${MONGO_PORT}/${MONGO_DATABASE}?authSource=${MONGO_AUTHSOURCE}"
    
    # Perform restore
    if mongorestore --uri "$connection_uri" "$dump_path" 2>&1; then
        print_success "Restore completed successfully"
        return 0
    else
        print_error "Restore operation failed"
        return 1
    fi
}

main() {
    print_separator_up
    print_info "MongoDB Restore Utility"
    print_separator_down
    
    # Initial checks
    check_mongorestore
    check_env_file
    load_config
    
    print_success "Configuration loaded"
    echo
    
    # Ask for initial dump path
    print_info "Enter the path to the dumps directory"
    echo "   Example: ~/Works/dbdump/dumps"
    echo
    echo -n "Dumps path: "
    read dumps_path
    
    if [[ -z "$dumps_path" ]]; then
        print_error "Dumps path cannot be empty"
        return 1
    fi
    
    # Navigate to the correct dump directory
    print_info "Navigating to backup location..."
    navigate_to_dump "$dumps_path"
    if [[ $? -ne 0 ]]; then
        print_error "Failed to select backup directory"
        return 1
    fi
    
    # Show summary of what will be restored
    show_summary "$SELECTED_DUMP_PATH"
    
    # Ask for confirmation
    if ! confirm_restore; then
        print_info "Restore operation cancelled"
        return 1
    fi
    
    # Perform the restore
    if perform_restore "$SELECTED_DUMP_PATH"; then
        print_success "Restore operation completed"
    else
        print_error "Restore operation failed"
        return 1
    fi
}

main "$@"