#!/bin/bash

set -euo pipefail

log() {
    echo "[Env Manager] $*"
}

error() {
    log "ERROR: $*" >&2
    exit 1
}

get_nas_mount() {
    if [[ -f ${DYNAMICALSYSTEM_TEMP_DIR:-/tmp/dynamicalsystem}/nas_mount.env ]]; then
        source ${DYNAMICALSYSTEM_TEMP_DIR:-/tmp/dynamicalsystem}/nas_mount.env
        echo "${NAS_MOUNT_POINT}"
    else
        read -p "Enter NAS mount point: " mount_point
        echo "$mount_point"
    fi
}

prompt_for_env_value() {
    local var_name="$1"
    local prompt="$2"
    local is_secret="${3:-false}"
    
    if [[ "$is_secret" == "true" ]]; then
        read -s -p "$prompt: " value
        echo
    else
        read -p "$prompt: " value
    fi
    
    echo "$value"
}

create_env_template() {
    cat > "$1" << 'EOF'
# Machine Environment Configuration
# Generated on: $(date)

DYNAMICAL_SYSTEM_FOLDER=
ENVIRONMENT=
EOF
}

load_or_create_env() {
    local env_file="$1"
    local env_vars=()
    
    if [[ -f "$env_file" ]]; then
        log "Found existing .env file at $env_file"
        
        while IFS='=' read -r key value; do
            if [[ ! "$key" =~ ^[[:space:]]*# ]] && [[ -n "$key" ]]; then
                key=$(echo "$key" | xargs)
                value=$(echo "$value" | xargs)
                
                if [[ -n "$value" ]]; then
                    export "$key=$value"
                    env_vars+=("$key")
                fi
            fi
        done < "$env_file"
        
        log "Loaded ${#env_vars[@]} environment variables"
    else
        log "No .env file found. Creating new configuration..."
        
        create_env_template "$env_file"
        
        echo
        log "Please provide values for the following environment variables:"
        log "(Press Enter to skip optional variables)"
        echo
        
        # Setup XDG variables for proper expansion
        export XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"
        
        declare -A prompts=(
            ["DYNAMICAL_SYSTEM_FOLDER"]="$XDG_DATA_HOME/dynamicalsystem/"
            ["ENVIRONMENT"]="$(whoami)"
        )
        
        declare -A secrets=(
            ["DYNAMICAL_SYSTEM_FOLDER"]=false
            ["ENVIRONMENT"]=false
        )
        
        > "$env_file"
        echo "# Machine Environment Configuration" >> "$env_file"
        echo "# Generated on: $(date)" >> "$env_file"
        echo >> "$env_file"
        
        for var in ENVIRONMENT DYNAMICAL_SYSTEM_FOLDER; do
            is_secret="${secrets[$var]:-false}"
            default_value="${prompts[$var]}"
            value=$(prompt_for_env_value "$var" "$var [${default_value}]" "$is_secret")
            
            # Use default if empty
            if [[ -z "$value" ]]; then
                value="$default_value"
            fi
            
            if [[ -n "$value" ]]; then
                echo "$var=$value" >> "$env_file"
                export "$var=$value"
                env_vars+=("$var")
            fi
        done
        
        echo >> "$env_file"
        echo "# Custom Configuration" >> "$env_file"
        echo "# Add your custom environment variables below" >> "$env_file"
        
        log "Created .env file with ${#env_vars[@]} variables"
    fi
    
    # Try to set secure permissions, but don't fail if on NFS
    if ! chmod 600 "$env_file" 2>/dev/null; then
        log "Note: Could not change permissions on $env_file (may be on NFS mount)"
    fi
    
    echo "${env_vars[@]}" > ${DYNAMICALSYSTEM_TEMP_DIR:-/tmp/dynamicalsystem}/env_vars.list
}

create_profile_script() {
    local env_file="$1"
    local profile_dir="/etc/profile.d"
    local profile_script="$profile_dir/machine-env.sh"
    
    log "Creating system-wide profile script..."
    
    sudo tee "$profile_script" > /dev/null << 'EOF'
#!/bin/bash
# Machine environment variables loader
# Auto-generated by machine setup

# Determine environment name - default to username
ENVIRONMENT="${ENVIRONMENT:-$(whoami)}"
CONFIG_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/dynamicalsystem/config"
ENV_FILE="$CONFIG_DIR/machine.$ENVIRONMENT.env"

if [[ -f "$ENV_FILE" ]]; then
    set -a
    source "$ENV_FILE"
    set +a
fi
EOF
    
    sudo chmod 644 "$profile_script"
}

main() {
    log "Starting environment variable management..."
    
    # Use the symlink structure instead of raw mount point
    local config_dir="${XDG_DATA_HOME:-$HOME/.local/share}/dynamicalsystem/config"
    
    # Create config directory if it doesn't exist
    if [[ ! -d "$config_dir" ]]; then
        mkdir -p "$config_dir"
    fi
    
    # Determine environment name - default to username
    local environment="${ENVIRONMENT:-$(whoami)}"
    
    # Check for existing env files or prompt for environment
    local existing_files=($(ls "$config_dir"/machine.*.env 2>/dev/null))
    if [[ ${#existing_files[@]} -gt 0 ]] && [[ -z "$ENVIRONMENT" ]]; then
        log "Found existing environment files:"
        for i in "${!existing_files[@]}"; do
            local fname=$(basename "${existing_files[$i]}")
            local env_name=${fname#machine.}
            env_name=${env_name%.env}
            echo "$((i+1))) $env_name"
        done
        echo "$((${#existing_files[@]}+1))) Create new environment"
        
        read -p "Select environment [1]: " selection
        selection="${selection:-1}"
        
        if [[ "$selection" -le "${#existing_files[@]}" ]]; then
            local fname=$(basename "${existing_files[$((selection-1))]}")
            environment=${fname#machine.}
            environment=${environment%.env}
        else
            read -p "Enter new environment name [$(whoami)]: " environment
            environment="${environment:-$(whoami)}"
        fi
    fi
    
    local env_file="$config_dir/machine.$environment.env"
    
    load_or_create_env "$env_file"
    create_profile_script "$env_file"
    
    log "Environment variables configured successfully!"
    log "Variables are stored in: $env_file"
    log "They will be automatically loaded on login via /etc/profile.d/machine-env.sh"
}

main "$@"