#!/bin/bash

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
. "${SCRIPT_DIR}/../share/logging.sh"

# Configuration
SCRIPTS=(
    "../metrics/disk-usage.sh"
    "../metrics/power-usage.sh" 
    "../metrics/temperature.sh"
)

CheckScriptExists() {
    local script="$1"
    local script_path="${SCRIPT_DIR}/${script}"
    
    if [[ -f "$script_path" && -x "$script_path" ]]; then
        return 0
    elif [[ -f "$script_path" ]]; then
        LogWarning "Script $script exists but is not executable. Making it executable..."
        chmod +x "$script_path"
        return 0
    else
        return 1
    fi
}

InstallCrontabEntries() {
    local installed_count=0
    local failed_count=0
    
    BackupCrontab
    
    for script in "${SCRIPTS[@]}"; do
        LogInformation "Processing $script..."
        
        if CheckScriptExists "$script"; then
            LogInformation "Script $script found and is executable"
            if ManageCrontabEntry "$script"; then
                ((installed_count++))
            else
                ((failed_count++))
            fi
        else
            LogWarning "Script $script not found or not accessible, skipping..."
            ((failed_count++))
        fi
    done
    
    LogInformation "Installation summary: $installed_count installed, $failed_count failed"
    
    if [[ $failed_count -gt 0 ]]; then
        exit 1
    fi
}

ManageCrontabEntry() {
    local script="$1"
    local script_path="${SCRIPT_DIR}/${script}"
    local cron_pattern="* * * * * ${script_path}"
    
    local current_crontab
    current_crontab=$(crontab -l 2>/dev/null || echo "")
    
    if echo "$current_crontab" | grep -q "$script_path"; then
        LogInformation "Crontab entry for $script already exists"
        
        if echo "$current_crontab" | grep -q "^\* \* \* \* \* ${script_path}"; then
            LogInformation "Entry for $script is already set to run every minute"
            return 0
        else
            LogInformation "Updating $script to run every minute"
            local new_crontab
            new_crontab=$(echo "$current_crontab" | grep -v "$script_path")
            new_crontab="${new_crontab}${new_crontab:+$'\n'}${cron_pattern}"
            if echo "$new_crontab" | crontab -; then
                LogInformation "Updated crontab entry for $script"
                return 0
            else
                LogError "Failed to update crontab entry for $script"
                return 1
            fi
        fi
    else
        LogInformation "Adding new crontab entry for $script"
        local new_crontab="${current_crontab}${current_crontab:+$'\n'}${cron_pattern}"
        if echo "$new_crontab" | crontab -; then
            LogInformation "Added crontab entry for $script"
            return 0
        else
            LogError "Failed to add crontab entry for $script"
            return 1
        fi
    fi
}

ShowStatus() {
    LogInformation "Crontab entries status:"
    LogInformation ""
    
    local found_entries=0
    for script in "${SCRIPTS[@]}"; do
        local script_path="${SCRIPT_DIR}/${script}"
        local script_name=$(basename "$script")
        
        if crontab -l 2>/dev/null | grep -q "$script_path"; then
            LogInformation "✓ $script_name - INSTALLED"
            ((found_entries++))
        elif [[ -f "$script_path" ]]; then
            LogInformation "✗ $script_name - NOT INSTALLED (script available)"
        else
            LogInformation "✗ $script_name - SCRIPT MISSING"
        fi
    done
    
    LogInformation ""
    if [[ $found_entries -gt 0 ]]; then
        LogInformation "Commands:"
        LogInformation "  View crontab: crontab -l"
        LogInformation "  Edit crontab: crontab -e"
        LogInformation "  Check logs: sudo tail -f /var/log/syslog | grep CRON"
    else
        LogWarning "No crontab entries are currently installed"
    fi
}

RemoveCrontabEntries() {
    local removed_count=0
    
    local current_crontab
    current_crontab=$(crontab -l 2>/dev/null || echo "")
    
    if [[ -z "$current_crontab" ]]; then
        LogWarning "No crontab entries found to remove"
        return
    fi
    
    local new_crontab="$current_crontab"
    
    for script in "${SCRIPTS[@]}"; do
        local script_path="${SCRIPT_DIR}/${script}"
        local script_name=$(basename "$script")
        
        if echo "$new_crontab" | grep -q "$script_path"; then
            LogInformation "Removing crontab entry for $script_name..."
            new_crontab=$(echo "$new_crontab" | grep -v "$script_path")
            ((removed_count++))
        else
            LogDebug "No crontab entry found for $script_name"
        fi
    done
    
    if [[ $removed_count -gt 0 ]]; then
        if [[ -z "$new_crontab" ]]; then
            crontab -r 2>/dev/null || true
            LogInformation "Removed all entries, crontab cleared"
        else
            echo "$new_crontab" | crontab -
            LogInformation "Updated crontab with remaining entries"
        fi
        LogInformation "Removed $removed_count crontab entries"
    else
        LogWarning "No matching crontab entries were found to remove"
    fi
}

BackupCrontab() {
    local backup_file="${SCRIPT_DIR}/crontab_backup_$(date +%Y%m%d_%H%M%S)"
    crontab -l > "$backup_file" 2>/dev/null
    if [[ $? -eq 0 ]]; then
        LogInformation "Crontab backed up to: $backup_file"
    else
        LogWarning "No existing crontab to backup or backup failed"
    fi
}

ShowUsage() {
    echo "Usage: $0 [install|remove|status|help]"
    echo ""
    echo "Commands:"
    echo "  install  - Install all crontab entries (default)"
    echo "  remove   - Remove all crontab entries"
    echo "  status   - Show status of crontab entries"
    echo "  help     - Show this help message"
    echo ""
    echo "This script manages crontab entries for monitoring scripts:"
    echo "$(printf '  %s\n' "${SCRIPTS[@]}" | sed 's|../metrics/||')"
    echo ""
    echo "Examples:"
    echo "  $0 install"
    echo "  $0 status"
}

Main() {
    local action="${1:-install}"
    
    case "$action" in
        install)
            LogInformation "Installing crontab entries for server monitoring scripts"
            InstallCrontabEntries
            LogInformation "Crontab setup completed successfully!"
            ;;
        remove)
            LogInformation "Removing crontab entries for server monitoring scripts"
            RemoveCrontabEntries
            ;;
        status)
            ShowStatus
            ;;
        help|--help|-h)
            ShowUsage
            ;;
        *)
            LogError "Unknown action: $action"
            ShowUsage
            exit 1
            ;;
    esac
}

Main "$@"