#!/bin/bash

# Get the absolute path to the project directory
PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CHALLENGE_DIR=~/challenge

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

# Error handling
set -o errexit  # Exit on error
set -o nounset  # Exit on undefined variable
set -o pipefail # Exit on pipe failure

# Trap errors and provide error message
trap 'echo -e "${RED}Error: Command failed at line $LINENO${NC}" >&2' ERR

# Function to show spinner while executing command
show_spinner() {
    local pid=$1
    local delay=0.1
    local spinstr='|/-\'
    while [ "$(ps a | awk '{print $1}' | grep $pid)" ]; do
        local temp=${spinstr#?}
        printf " [%c]  " "$spinstr"
        local spinstr=$temp${spinstr%"$temp"}
        sleep $delay
        printf "\b\b\b\b\b\b"
    done
    printf "    \b\b\b\b"
}

# Function to print banner
print_banner() {
    clear
    cat << "EOF"
   ______                                          __   __    _            
  / ____/___  ____ ___  ____ ___  ____ _____  ___/ /  / /   (_)___  ___  
 / /   / __ \/ __ `__ \/ __ `__ \/ __ `/ __ \/ __  /  / /   / / __ \/ _ \ 
/ /___/ /_/ / / / / / / / / / / / /_/ / / / / /_/ /  / /___/ / / / /  __/ 
\____/\____/_/ /_/ /_/_/ /_/ /_/\__,_/_/ /_/\__,_/  /_____/_/_/ /_/\___/ 
                                                                          
     __  ___           __                    ________        ____         
    /  |/  /___ ______/ /____  _______  __  / ____/ /_  ___/ / /__  ____ 
   / /|_/ / __ `/ ___/ __/ _ \/ ___/ / / / / /   / __ \/ __  / / _ \/ __ \
  / /  / / /_/ (__  ) /_/  __/ /  / /_/ / / /___/ / / / /_/ / /  __/ / / /
 /_/  /_/\__,_/____/\__/\___/_/   \__, /  \____/_/ /_/\__,_/_/\___/_/ /_/ 
                                 /____/                                    
EOF
    echo -e "\n${BOLD}Welcome to the Command Line Mastery Challenge!${NC}"
    echo -e "${BLUE}Test your Linux command-line skills with interactive challenges${NC}"
    echo "=============================================================="
}

# Function to check if command exists
check_command() {
    if ! command -v "$1" &>/dev/null; then
        echo -e "${RED}Error: Required command '$1' not found${NC}"
        return 1
    fi
}

# Function to check required commands
check_requirements() {
    local required_commands=("find" "grep" "awk" "sed" "mkdir" "chmod" "touch")
    local missing_commands=()

    for cmd in "${required_commands[@]}"; do
        if ! check_command "$cmd"; then
            missing_commands+=("$cmd")
        fi
    done

    if [[ ${#missing_commands[@]} -gt 0 ]]; then
        echo -e "${RED}Error: Missing required commands: ${missing_commands[*]}${NC}"
        return 1
    fi
    return 0
}

# Function to clean up previous environment
cleanup_environment() {
    echo -e "${BLUE}Cleaning up previous environment...${NC}"
    if [[ -d "$CHALLENGE_DIR" ]]; then
        if ! rm -rf "$CHALLENGE_DIR" 2>/dev/null; then
            echo -e "${RED}Error: Failed to remove directory: $CHALLENGE_DIR${NC}"
            echo -e "${YELLOW}Tip: Check if you have proper permissions${NC}"
            return 1
        fi
        echo -e "${GREEN}Previous environment cleaned up${NC}"
    fi
}

# Function to setup the environment
setup_environment() {
    echo -e "${BLUE}Setting up challenge environment...${NC}"
    
    # Check requirements first
    if ! check_requirements; then
        echo -e "${RED}Error: Setup failed - missing requirements${NC}"
        return 1
    fi
    
    # Clean up first
    cleanup_environment
    
    # Create directory structure with error checking
    local dirs=(
        "$CHALLENGE_DIR"/{files,backup,temp}
        "$CHALLENGE_DIR/.tracking/data"
    )
    
    for dir in "${dirs[@]}"; do
        if ! mkdir -p "$dir"; then
            echo -e "${RED}Error: Failed to create directory: $dir${NC}"
            return 1
        fi
    done
    
    # Create project directories with error checking
    for i in {1..5}; do
        local project_dirs=(
            "$CHALLENGE_DIR/files/project$i"/{src,config,logs,data}
        )
        for dir in "${project_dirs[@]}"; do
            if ! mkdir -p "$dir"; then
                echo -e "${RED}Error: Failed to create project directory: $dir${NC}"
                return 1
            fi
        done
    done
    
    # Copy setup scripts with error checking
    if ! cp "$PROJECT_DIR"/setup/*.sh "$CHALLENGE_DIR/.tracking/" 2>/dev/null; then
        echo -e "${RED}Error: Failed to copy setup scripts${NC}"
        echo -e "${YELLOW}Tip: Check if setup scripts exist in: $PROJECT_DIR/setup/${NC}"
        return 1
    fi
    
    # Set permissions with error checking
    if ! chmod +x "$CHALLENGE_DIR/.tracking/"*.sh 2>/dev/null; then
        echo -e "${RED}Error: Failed to set script permissions${NC}"
        return 1
    fi
    
    # Initialize tracking files with error checking
    local data_dir="$CHALLENGE_DIR/.tracking/data"
    local tracking_files=(progress score challenge commands time hints_used achievements attempts)
    
    for file in "${tracking_files[@]}"; do
        if ! touch "$data_dir/$file.csv" 2>/dev/null; then
            echo -e "${RED}Error: Failed to create tracking file: $file.csv${NC}"
            return 1
        fi
    done
    
    echo -e "${GREEN}Environment setup complete!${NC}"
}

# Function to validate challenge ID
validate_challenge_id() {
    local id=$1
    if [[ ! $id =~ ^[1-9]\.[1-5]$ ]]; then
        echo -e "${RED}Error: Invalid challenge ID format${NC}"
        echo -e "${YELLOW}Tip: Challenge ID should be in format 'level.number' (e.g., 1.1)${NC}"
        return 1
    fi
}

# Function to handle commands with improved feedback
handle_command() {
    local cmd="$1"
    shift  # Remove first argument, leaving remaining args
    
    case "$cmd" in
        "verify"|"verify-challenge"|"v")
            echo -e "${CYAN}Verifying your solution...${NC}"
            "$CHALLENGE_DIR/.tracking/verify-challenge.sh" "$@"
            ;;
        "hint"|"show-hint"|"h")
            echo -e "${CYAN}Getting hint...${NC}"
            "$CHALLENGE_DIR/.tracking/show-hint.sh" "$@"
            ;;
        "status"|"show-status"|"s")
            echo -e "${CYAN}Showing status...${NC}"
            "$CHALLENGE_DIR/.tracking/show-status.sh" "$@"
            ;;
        "progress"|"check-progress"|"p")
            echo -e "${CYAN}Checking progress...${NC}"
            "$CHALLENGE_DIR/.tracking/check-progress.sh" "$@"
            ;;
        "clear"|"cls"|"c")
            clear
            print_challenge_header "$CURRENT_CHALLENGE_ID"
            ;;
        "reset"|"r")
            echo -e "${YELLOW}Resetting current challenge...${NC}"
            setup_challenge_env "$CURRENT_CHALLENGE_ID"
            ;;
        "exit"|"quit"|"q")
            return 1
            ;;
        "help"|"?")
            print_help_menu
            ;;
        "")
            # Empty command, just continue
            ;;
        *)
            echo -e "${RED}Unknown command: $cmd${NC}"
            echo -e "Type ${YELLOW}help${NC} or ${YELLOW}?${NC} for available commands"
            ;;
    esac
    return 0
}

# Function to print help menu
print_help_menu() {
    echo -e "\n${BOLD}Available Commands:${NC}"
    echo -e "  ${YELLOW}verify, v${NC}      - Check your solution"
    echo -e "  ${YELLOW}hint, h${NC}        - Get a hint"
    echo -e "  ${YELLOW}status, s${NC}      - Show challenge status"
    echo -e "  ${YELLOW}progress, p${NC}    - Check overall progress"
    echo -e "  ${YELLOW}clear, c${NC}       - Clear screen"
    echo -e "  ${YELLOW}reset, r${NC}       - Reset current challenge"
    echo -e "  ${YELLOW}help, ?${NC}        - Show this help message"
    echo -e "  ${YELLOW}exit, q${NC}        - Exit the challenge"
    echo -e "\n${BOLD}Tips:${NC}"
    echo -e "- Commands can be abbreviated (e.g., 'v' for verify)"
    echo -e "- Use TAB for command completion"
    echo -e "- Use arrow keys for command history"
}

# Function to get challenge description
get_challenge_description() {
    local challenge_id=$1
    if [[ -n "${CHALLENGES[$challenge_id]:-}" ]]; then
        IFS='|' read -r _ _ _ _ task _ _ _ <<< "${CHALLENGES[$challenge_id]}"
        echo "$task"
    else
        echo "Challenge not found"
    fi
}

# Function to print challenge header
print_challenge_header() {
    local challenge_id=$1
    echo -e "${GREEN}🎮 Challenge $challenge_id${NC}"
    echo -e "${BLUE}$(get_challenge_description "$challenge_id")${NC}"
    echo -e "${YELLOW}Type 'help' or '?' for available commands${NC}"
}

# Function to setup challenge environment
setup_challenge_env() {
    local challenge_id=$1
    echo -e "${BLUE}Setting up challenge files...${NC}"
    
    # Create necessary directories
    mkdir -p "$CHALLENGE_DIR/files"
    
    # Setup files for the challenge
    case "$challenge_id" in
        "1.1")
            # Create some .conf files with different timestamps
            for i in {1..15}; do
                echo "config$i=value$i" > "$CHALLENGE_DIR/files/config$i.conf"
                # Set random timestamps within the last 48 hours
                touch -d "@$(($(date +%s) - RANDOM % 172800))" "$CHALLENGE_DIR/files/config$i.conf"
            done
            ;;
        "1.2")
            # Create various file types
            for ext in txt conf log py js json yml; do
                for i in {1..5}; do
                    echo "content" > "$CHALLENGE_DIR/files/file$i.$ext"
                done
            done
            ;;
        # Add more challenge setups as needed
    esac
    
    echo -e "${GREEN}Challenge environment ready!${NC}"
    return 0
}

# Function to source required scripts
source_required_scripts() {
    local required_scripts=(common.sh challenges.sh)
    for script in "${required_scripts[@]}"; do
        if ! source "$CHALLENGE_DIR/.tracking/$script" 2>/dev/null; then
            echo -e "${RED}Error: Required script not found: $script${NC}"
            echo -e "${YELLOW}Running setup first...${NC}"
            setup_environment
            if ! source "$CHALLENGE_DIR/.tracking/$script" 2>/dev/null; then
                echo -e "${RED}Error: Failed to source $script even after setup${NC}"
                return 1
            fi
        fi
    done
    return 0
}

# Function to start a challenge
start_challenge() {
    local challenge_id=$1
    export CURRENT_CHALLENGE_ID=$challenge_id
    
    # Validate challenge ID
    if ! validate_challenge_id "$challenge_id"; then
        return 1
    fi
    
    # Source required scripts with error checking
    if ! source_required_scripts; then
        return 1
    fi
    
    print_banner
    
    # Setup challenge environment
    echo -e "${BLUE}Setting up challenge environment...${NC}"
    if ! setup_challenge_env "$challenge_id"; then
        return 1
    fi
    
    if ! get_challenge_details "$challenge_id" 2>/dev/null; then
        echo -e "${RED}Error: Challenge $challenge_id not found${NC}"
        echo -e "${YELLOW}Available challenges:${NC}"
        list_challenges
        return 1
    fi
    
    # Record challenge start
    local start_time=$(date +%s)
    echo "$challenge_id,$start_time" > "$CHALLENGE_DIR/.tracking/current_challenge"
    
    print_challenge_header "$challenge_id"
    
    # Enable command history and tab completion
    bind 'set completion-ignore-case on' 2>/dev/null || true
    bind 'set show-all-if-ambiguous on' 2>/dev/null || true
    
    echo -e "\n${YELLOW}Your challenge environment is ready!${NC}"
    echo -e "${BLUE}Current working directory: $CHALLENGE_DIR${NC}"
    echo -e "${BLUE}Challenge: $(get_challenge_description "$challenge_id")${NC}"
    echo -e "\nAvailable commands:"
    print_help_menu
    
    # Start command loop with improved prompt
    local cmd_count=0
    while true; do
        cmd_count=$((cmd_count + 1))
        echo -ne "\n${GREEN}challenge${BLUE}[$challenge_id]${GREEN}>${NC} "
        read -e -r cmd args || true  # Add || true to prevent exit on Ctrl+D
        
        # Handle Ctrl+D (EOF)
        if [ $? -ne 0 ]; then
            echo -e "\n${YELLOW}Use 'exit' or 'q' to quit${NC}"
            continue
        fi
        
        # Add command to history
        history -s "$cmd $args"
        
        # Handle the command
        if ! handle_command "$cmd" $args; then
            break
        fi
    done
    
    # Record challenge end
    local end_time=$(date +%s)
    local duration=$((end_time - start_time))
    echo "$challenge_id,$duration" >> "$CHALLENGE_DIR/.tracking/data/time.csv"
    
    echo -e "\n${GREEN}Challenge session ended!${NC}"
    echo -e "Time spent: $(printf '%dm %ds' $((duration/60)) $((duration%60)))"
    echo -e "Commands used: $cmd_count"
}

# Function to show help
show_help() {
    cat << EOF
Usage: $0 [command] [options]

Commands:
    start <challenge-id>  Start a specific challenge
    list                 List available challenges
    setup                Setup/reset the environment
    clean                Remove all challenge files
    help                 Show this help message

Examples:
    $0 setup            # First time setup
    $0 clean            # Remove all challenge files
    $0 list             # Show available challenges
    $0 start 1.1        # Start challenge 1.1
EOF
}

# Main execution with error handling
main() {
    if [[ $# -eq 0 ]]; then
        show_help
        return 0
    fi

    case "$1" in
        "setup")
            setup_environment
            ;;
        "clean")
            cleanup_environment
            ;;
        "start")
            if [[ -z "${2:-}" ]]; then
                echo -e "${RED}Error: Please specify a challenge ID${NC}"
                echo "Example: $0 start 1.1"
                return 1
            fi
            start_challenge "$2"
            ;;
        "list")
            if [[ ! -f "$CHALLENGE_DIR/.tracking/challenges.sh" ]]; then
                setup_environment
            fi
            if ! source "$CHALLENGE_DIR/.tracking/challenges.sh" 2>/dev/null; then
                echo -e "${RED}Error: Failed to load challenges${NC}"
                return 1
            fi
            list_challenges
            ;;
        "help"|"--help"|"-h")
            show_help
            ;;
        *)
            echo -e "${RED}Unknown command: $1${NC}"
            show_help
            return 1
            ;;
    esac
}

# Run main with error handling
if ! main "${@:-}"; then
    echo -e "${RED}Command failed. See errors above.${NC}"
    exit 1
fi