<?php

namespace App\Http\Controllers;

use App\Models\Budget;
use App\Models\GatewayUser;
use Illuminate\Http\Request;
use Illuminate\Support\Str;

class BudgetController extends Controller
{
    /**
     * Display a listing of budgets
     */
    public function index()
    {
        $budgets = Budget::withCount('gatewayUsers')
            ->orderBy('created_at', 'desc')
            ->paginate(20);

        return view('budgets.index', compact('budgets'));
    }

    /**
     * Show the form for creating a new budget
     */
    public function create()
    {
        return view('budgets.create');
    }

    /**
     * Store a newly created budget
     */
    public function store(Request $request)
    {
        $validated = $request->validate([
            'budget_name' => 'required|string|max:255',
            'max_budget' => 'required|numeric|min:0',
            'budget_type' => 'required|in:daily,weekly,monthly,custom,unlimited',
            'custom_duration_days' => 'nullable|integer|min:1|required_if:budget_type,custom',
        ]);

        // Set monthly and daily limits based on budget type
        $monthlyLimit = null;
        $dailyLimit = null;
        
        switch($validated['budget_type']) {
            case 'daily':
                $dailyLimit = $validated['max_budget'];
                break;
            case 'weekly':
                $dailyLimit = $validated['max_budget'] / 7;
                break;
            case 'monthly':
                $monthlyLimit = $validated['max_budget'];
                $dailyLimit = $validated['max_budget'] / 30;
                break;
            case 'custom':
                $days = $validated['custom_duration_days'] ?? 1;
                $dailyLimit = $validated['max_budget'] / $days;
                break;
            case 'unlimited':
                // No limits
                break;
        }

        $budget = Budget::create([
            'budget_id' => 'budget-' . Str::uuid(),
            'name' => $validated['budget_name'],
            'monthly_limit' => $monthlyLimit,
            'daily_limit' => $dailyLimit,
        ]);

        return redirect()
            ->route('budgets.index')
            ->with('success', 'Budget template created successfully!');
    }

    /**
     * Display the specified budget
     */
    public function show(string $id)
    {
        $budget = Budget::with('gatewayUsers')->findOrFail($id);
        
        // Get users without budget for potential assignment
        $availableUsers = GatewayUser::whereNull('budget_id')
            ->orWhere('budget_id', '')
            ->get();

        return view('budgets.show', compact('budget', 'availableUsers'));
    }

    /**
     * Show the form for editing the specified budget
     */
    public function edit(string $id)
    {
        $budget = Budget::findOrFail($id);
        
        // Determine budget type from duration
        $budgetType = 'unlimited';
        if ($budget->budget_duration_sec) {
            $days = $budget->budget_duration_sec / 86400;
            $budgetType = match(true) {
                $days == 1 => 'daily',
                $days == 7 => 'weekly',
                $days == 30 => 'monthly',
                default => 'custom'
            };
        }

        return view('budgets.edit', compact('budget', 'budgetType'));
    }

    /**
     * Update the specified budget
     */
    public function update(Request $request, string $id)
    {
        $budget = Budget::findOrFail($id);

        $validated = $request->validate([
            'budget_name' => 'required|string|max:255',
            'max_budget' => 'required|numeric|min:0',
            'budget_type' => 'required|in:daily,weekly,monthly,custom,unlimited',
            'custom_duration_days' => 'nullable|integer|min:1|required_if:budget_type,custom',
        ]);

        // Set monthly and daily limits based on budget type
        $monthlyLimit = null;
        $dailyLimit = null;
        
        switch($validated['budget_type']) {
            case 'daily':
                $dailyLimit = $validated['max_budget'];
                break;
            case 'weekly':
                $dailyLimit = $validated['max_budget'] / 7;
                break;
            case 'monthly':
                $monthlyLimit = $validated['max_budget'];
                $dailyLimit = $validated['max_budget'] / 30;
                break;
            case 'custom':
                $days = $validated['custom_duration_days'] ?? 1;
                $dailyLimit = $validated['max_budget'] / $days;
                break;
            case 'unlimited':
                // No limits
                break;
        }

        $budget->update([
            'name' => $validated['budget_name'],
            'monthly_limit' => $monthlyLimit,
            'daily_limit' => $dailyLimit,
        ]);

        return redirect()
            ->route('budgets.show', $budget->budget_id)
            ->with('success', 'Budget updated successfully!');
    }

    /**
     * Remove the specified budget
     */
    public function destroy(string $id)
    {
        $budget = Budget::findOrFail($id);
        
        // Check if budget is assigned to users
        if ($budget->gatewayUsers()->count() > 0) {
            return redirect()
                ->route('budgets.index')
                ->with('error', 'Cannot delete budget that is assigned to users. Please reassign users first.');
        }

        $budget->delete();

        return redirect()
            ->route('budgets.index')
            ->with('success', 'Budget deleted successfully!');
    }

    /**
     * Assign budget to users (bulk)
     */
    public function assignUsers(Request $request, string $id)
    {
        $budget = Budget::findOrFail($id);

        $validated = $request->validate([
            'user_ids' => 'required|array',
            'user_ids.*' => 'exists:users,user_id',
        ]);

        GatewayUser::whereIn('user_id', $validated['user_ids'])
            ->update([
                'budget_id' => $budget->budget_id,
                'budget_started_at' => now(),
                'next_budget_reset_at' => $budget->budget_duration_sec 
                    ? now()->addSeconds($budget->budget_duration_sec)
                    : null,
            ]);

        return redirect()
            ->route('budgets.show', $budget->budget_id)
            ->with('success', count($validated['user_ids']) . ' user(s) assigned to budget successfully!');
    }
}