#!/bin/bash
# Version: 1.2.0
# Author: Tomi Eckert
# ==============================================================================
# HANA Database Manager Menu (hanamgr.sh)
#
# An interactive command-line menu for managing SAP HANA schemas.
# Provides functionality to Export, Import, Import-Rename, Drop schemas,
# and Rename the B1 company name within a database.
# ==============================================================================

# --- Configuration ---
# Assuming hdbsql is in the environment PATH
HDBSQL_CMD="hdbsql"

# --- Helper Functions ---

# Function to print a separator
print_separator() {
    echo "--------------------------------------------------------"
}

# Function to check if hdbsql is available
check_hdbsql() {
    if ! command -v "$HDBSQL_CMD" &> /dev/null; then
        echo -e "\033[31m[❌] Error: '$HDBSQL_CMD' command not found. Ensure it is in your PATH.\033[0m"
        exit 1
    fi
}

# Function to execute a SQL query and capture the exit code
execute_sql() {
    local key="$1"
    local query="$2"
    local output

    output=$("$HDBSQL_CMD" -U "$key" "$query" 2>&1)
    local exit_code=$?
    
    if [ $exit_code -eq 0 ]; then
        return 0
    else
        echo "$output"
        return $exit_code
    fi
}

# Function to interactively select a schema from the database
# Sets the global variable SELECTED_SCHEMA
select_schema() {
    local user_key="$1"
    SELECTED_SCHEMA=""
    
    echo "[🔎] Fetching available schemas..."
    local query="SELECT SCHEMA_NAME FROM SCHEMAS WHERE SCHEMA_OWNER = 'SYSTEM' AND SCHEMA_NAME NOT IN ('_SYS_SECURITY', 'IFSERV', 'B1if', 'SYSTEM', 'RSP');"
    
    local raw_output
    raw_output=$("$HDBSQL_CMD" -U "$user_key" "$query" 2>/dev/null)
    
    if [ $? -ne 0 ]; then
        echo -e "\033[31m[❌] Error: Failed to fetch schemas. Check your HDBUSERSTORE key.\033[0m"
        # Fallback to manual entry
        read -p "Enter Schema Name manually: " SELECTED_SCHEMA
        return 1
    fi
    
    local schemas=()
    while IFS= read -r line; do
        if [[ -z "$line" || "$line" == SCHEMA_NAME* || "$line" == *"rows selected"* || "$line" == *"row selected"* || "$line" == *"overall time"* || "$line" == -* ]]; then
            continue
        fi
        local clean_name
        clean_name=$(echo "$line" | tr -d '"' | xargs)
        if [[ -n "$clean_name" ]]; then
            schemas+=("$clean_name")
        fi
    done <<< "$raw_output"
    
    if [ ${#schemas[@]} -eq 0 ]; then
        echo -e "\033[33m[⚠️] No eligible schemas found in the database.\033[0m"
        # Fallback to manual
        read -p "Enter Schema Name manually: " SELECTED_SCHEMA
        return 0
    fi
    
    echo -e "\n\033[1mAvailable Schemas:\033[0m"
    for i in "${!schemas[@]}"; do
        echo "$((i+1))) ${schemas[$i]}"
      done
    echo "0) Enter manually"
    echo
    
    local choice
    while true; do
        read -p "Select a schema (0-${#schemas[@]}): " choice
        if [[ "$choice" == "0" ]]; then
            read -p "Enter Schema Name manually: " SELECTED_SCHEMA
            break
        elif [[ "$choice" =~ ^[0-9]+$ ]] && [ "$choice" -ge 1 ] && [ "$choice" -le "${#schemas[@]}" ]; then
            SELECTED_SCHEMA="${schemas[$((choice-1))]}"
            break
        else
            echo -e "\033[31m[❌] Invalid selection. Please try again.\033[0m"
        fi
    done
}

# --- Operation Functions ---

do_export() {
    echo -e "\n\033[1m=== Export Schema ===\033[0m"
    read -p "Enter HDBUSERSTORE Key: " user_key
    select_schema "$user_key"
    local schema_name="$SELECTED_SCHEMA"
    read -p "Enter Target Directory Path: " target_path
    
    local max_threads=$(nproc 2>/dev/null || echo 1)
    local half_threads=$((max_threads / 2))
    [[ $half_threads -lt 1 ]] && half_threads=1
    
    read -p "Number of threads (default: $half_threads, max: $max_threads): " threads
    threads=${threads:-$half_threads}
    
    read -p "Compress output as tar.gz? (y/N): " compress

    if [[ -z "$user_key" || -z "$schema_name" || -z "$target_path" ]]; then
        echo -e "\033[31m[❌] Error: Key, Schema, and Path are required.\033[0m"
        return
    fi

    echo -e "\n[⬇️] Starting export of schema '${schema_name}'..."
    local export_dir="$target_path"

    if [[ "$compress" =~ ^[Yy]$ ]]; then
        export_dir=$(mktemp -d "${target_path}/export_${schema_name}_XXXXXXXX")
        echo "[ℹ️] Using temporary export directory: ${export_dir}"
    else
        mkdir -p "$export_dir"
    fi

    local query="EXPORT \"${schema_name}\".\"*\" AS BINARY INTO '${export_dir}' WITH REPLACE THREADS ${threads} NO DEPENDENCIES;"
    
    if execute_sql "$user_key" "$query"; then
        echo -e "\033[32m[✅] Successfully exported schema '${schema_name}'.\033[0m"
        
        if [[ "$compress" =~ ^[Yy]$ ]]; then
            local archive_file="${target_path}/${schema_name}_export_$(date +%Y%m%d_%H%M%S).tar.gz"
            echo "[📦] Compressing export to ${archive_file}..."
            
            if command -v pigz &> /dev/null; then
                tar -I "pigz -p $threads" -cf "$archive_file" -C "$(dirname "$export_dir")" "$(basename "$export_dir")"
            else
                tar -czf "$archive_file" -C "$(dirname "$export_dir")" "$(basename "$export_dir")"
            fi
            
            if [ $? -eq 0 ]; then
                echo -e "\033[32m[✅] Compression successful.\033[0m"
                rm -rf "$export_dir"
            else
                echo -e "\033[31m[❌] Error: Compression failed.\033[0m"
            fi
        fi
    else
        echo -e "\033[31m[❌] Error: Export failed.\033[0m"
        if [[ "$compress" =~ ^[Yy]$ ]]; then rm -rf "$export_dir"; fi
    fi
}

do_import() {
    local rename_mode="$1"
    
    if [[ "$rename_mode" == "true" ]]; then
        echo -e "\n\033[1m=== Import & Rename Schema ===\033[0m"
    else
        echo -e "\n\033[1m=== Import Schema ===\033[0m"
    fi
    
    read -p "Enter HDBUSERSTORE Key: " user_key
    read -p "Enter Source Schema Name (as it was exported): " schema_name
    
    local new_schema_name=""
    if [[ "$rename_mode" == "true" ]]; then
        read -p "Enter NEW Target Schema Name: " new_schema_name
        if [[ -z "$new_schema_name" ]]; then
            echo -e "\033[31m[❌] Error: New Schema Name is required for renaming.\033[0m"
            return
        fi
    fi
    
    read -p "Enter Source Path (Directory or .tar.gz): " source_path
    
    local max_threads=$(nproc 2>/dev/null || echo 1)
    local half_threads=$((max_threads / 2))
    [[ $half_threads -lt 1 ]] && half_threads=1
    
    read -p "Number of threads (default: $half_threads, max: $max_threads): " threads
    threads=${threads:-$half_threads}
    
    read -p "Replace existing objects? (y/N): " replace_opt

    if [[ -z "$user_key" || -z "$schema_name" || -z "$source_path" ]]; then
        echo -e "\033[31m[❌] Error: Key, Schema, and Path are required.\033[0m"
        return
    fi

    echo -e "\n[⬆️] Starting schema import..."
    local import_dir="$source_path"
    local cleanup_temp=false

    # Handle compressed archives
    if [[ -f "$source_path" && "$source_path" == *.tar.gz ]]; then
        import_dir=$(mktemp -d "/tmp/import_${schema_name}_XXXXXXXX")
        cleanup_temp=true
        echo "[ℹ️] Decompressing archive to ${import_dir}..."
        
        if command -v pigz &> /dev/null; then
            tar -I "pigz -p $threads" -xf "$source_path" -C "$import_dir" --strip-components=1
        else
            tar -xzf "$source_path" -C "$import_dir" --strip-components=1
        fi
        
        if [ $? -ne 0 ]; then
             echo -e "\033[31m[❌] Error: Failed to decompress archive.\033[0m"
             rm -rf "$import_dir"
             return
        fi
    elif [[ ! -d "$import_dir" ]]; then
        echo -e "\033[31m[❌] Error: Path is neither a directory nor a valid .tar.gz archive.\033[0m"
        return
    fi

    local import_options="IGNORE EXISTING"
    if [[ "$replace_opt" =~ ^[Yy]$ ]]; then
        import_options="REPLACE"
    fi

    if [[ "$rename_mode" == "true" ]]; then
        import_options="${import_options} RENAME SCHEMA \"${schema_name}\" TO \"${new_schema_name}\""
    fi

    local query="IMPORT \"${schema_name}\".\"*\" AS BINARY FROM '${import_dir}' WITH ${import_options} THREADS ${threads};"
    
    if execute_sql "$user_key" "$query"; then
        echo -e "\033[32m[✅] Successfully imported schema.\033[0m"
    else
        echo -e "\033[31m[❌] Error: Import failed.\033[0m"
    fi

    if [[ "$cleanup_temp" == "true" ]]; then
        echo "[🧹] Cleaning up temporary files..."
        rm -rf "$import_dir"
    fi
}

do_drop() {
    echo -e "\n\033[1m=== Drop Schema ===\033[0m"
    read -p "Enter HDBUSERSTORE Key: " user_key
    select_schema "$user_key"
    local schema_name="$SELECTED_SCHEMA"

    if [[ -z "$user_key" || -z "$schema_name" ]]; then
        echo -e "\033[31m[❌] Error: Key and Schema Name are required.\033[0m"
        return
    fi

    echo -e "\033[31m[⚠️] WARNING: You are about to completely drop the schema '${schema_name}'.\033[0m"
    read -p "Are you absolutely sure? Type 'YES' to confirm: " confirm

    if [[ "$confirm" == "YES" ]]; then
        echo "[🗑️] Dropping schema '${schema_name}'..."
        local query="DROP SCHEMA \"${schema_name}\" CASCADE"
        if execute_sql "$user_key" "$query"; then
            echo -e "\033[32m[✅] Schema successfully dropped.\033[0m"
        else
            echo -e "\033[31m[❌] Error: Failed to drop schema.\033[0m"
        fi
    else
        echo "[🤷] Operation cancelled."
    fi
}

do_rename_db() {
    echo -e "\n\033[1m=== Rename Database (Company Name) ===\033[0m"
    read -p "Enter HDBUSERSTORE Key: " user_key
    select_schema "$user_key"
    local schema_name="$SELECTED_SCHEMA"
    read -p "Enter NEW Company Name: " new_compny_name

    if [[ -z "$user_key" || -z "$schema_name" || -z "$new_compny_name" ]]; then
        echo -e "\033[31m[❌] Error: Key, Schema Name, and New Company Name are required.\033[0m"
        return
    fi

    echo -e "\n[✍️] Updating company name for '${schema_name}' to '${new_compny_name}'..."
    
    # Update CINF
    echo "   -> Updating CINF table..."
    local q_cinf="UPDATE \"${schema_name}\".CINF SET \"CompnyName\" = '${new_compny_name}';"
    execute_sql "$user_key" "$q_cinf" > /dev/null

    # Update OADM
    echo "   -> Updating OADM table..."
    local q_oadm="UPDATE \"${schema_name}\".OADM SET \"CompnyName\" = '${new_compny_name}', \"PrintHeadr\" = '${new_compny_name}';"
    execute_sql "$user_key" "$q_oadm" > /dev/null

    echo -e "\033[32m[✅] Database renamed successfully.\033[0m"
}

# --- Main Menu Loop ---

check_hdbsql

while true; do
    echo
    echo "========================================================"
    echo "             HANA Database Manager Menu                 "
    echo "========================================================"
    echo "1) Export Schema"
    echo "2) Import Schema"
    echo "3) Import-Rename Schema"
    echo "4) Drop Schema"
    echo "5) Rename Database (Update Company Name)"
    echo "6) Quit"
    echo
    read -p "Please select an option (1-6): " choice
    
    case $choice in
        1)
            do_export
            ;;
        2)
            do_import "false"
            ;;
        3)
            do_import "true"
            ;;
        4)
            do_drop
            ;;
        5)
            do_rename_db
            ;;
        6)
            echo "[👋] Exiting."
            exit 0
            ;;
        *)
            echo -e "\033[31m[⚠️] Invalid option. Please try again.\033[0m"
            ;;
    esac
    
    echo
    read -n 1 -s -r -p "Press any key to continue..."
done