<?php

namespace Modules\FinancialManagement\Http\Controllers;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Inertia\Inertia;
use Modules\FinancialManagement\Enums\InvoiceStatus;
use Modules\FinancialManagement\Models\FinancialInvoice;
use Modules\FinancialManagement\Models\InvoiceLineItem;
use Modules\FinancialManagement\Models\RetentionEntry;
use Modules\FinancialManagement\Services\ProgressBillingService;
use Modules\ProjectManagement\Models\Project;

class FinanceController extends Controller
{
    public function __construct(
        private ProgressBillingService $billingService,
    ) {}

    // --- Invoice List ---
    public function index(Request $request)
    {
        $query = FinancialInvoice::with('project:id,name,code');

        if ($status = $request->status) {
            $query->where('status', $status);
        }
        if ($projectId = $request->project_id) {
            $query->where('project_id', $projectId);
        }

        $invoices = $query->latest()->paginate(15)->withQueryString();
        $projects = Project::select('id', 'ulid', 'name', 'code')->get();

        // Compute summary stats
        $allInvoices = FinancialInvoice::query();
        $summary = [
            'total_billed' => (float) $allInvoices->sum('total_amount'),
            'total_paid' => (float) $allInvoices->sum('paid_amount'),
            'outstanding' => (float) $allInvoices->whereNotIn('status', ['paid'])->sum(\DB::raw('total_amount - paid_amount')),
            'total_retention' => (float) RetentionEntry::where('type', 'debit')->sum('amount')
                - (float) RetentionEntry::where('type', 'credit')->sum('amount'),
        ];

        return Inertia::render('FinancialManagement::Invoices/Index', [
            'invoices' => $invoices,
            'projects' => $projects,
            'summary' => $summary,
            'filters' => $request->only(['status', 'project_id']),
        ]);
    }

    // --- Create (Progress Billing) ---
    public function create()
    {
        $projects = Project::select('id', 'ulid', 'name', 'code', 'contract_value', 'last_billed_percentage')
            ->where('current_wizard_step', '>=', 7)
            ->whereNotIn('status', ['completed', 'closed'])
            ->get();

        return Inertia::render('FinancialManagement::Invoices/Create', [
            'projects' => $projects,
        ]);
    }

    public function store(Request $request)
    {
        $validated = $request->validate([
            'project_id' => 'required|string',
            'current_percentage' => 'required|numeric|min:0.01|max:100',
            'retention_rate' => 'nullable|numeric|min:0|max:50',
        ]);

        $project = Project::findByUlid($validated['project_id']);

        if (!$project) {
            return back()->with('error', 'Project not found.');
        }

        try {
            $this->billingService->generateInvoice(
                $project,
                $validated['current_percentage'],
                $validated['retention_rate'] ?? 10.00,
            );
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return redirect()->route('finance.index')->with('success', 'Progress invoice generated.');
    }

    // --- Show Invoice ---
    public function show(FinancialInvoice $invoice)
    {
        $invoice->load(['project:id,name,code', 'lineItems', 'retentionEntries']);

        return Inertia::render('FinancialManagement::Invoices/Show', [
            'invoice' => $invoice,
        ]);
    }

    // --- State Transitions ---
    public function submit(FinancialInvoice $invoice)
    {
        try {
            $invoice->transitionTo(InvoiceStatus::Submitted);
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return back()->with('success', 'Invoice submitted for approval.');
    }

    public function approve(FinancialInvoice $invoice)
    {
        try {
            $invoice->transitionTo(InvoiceStatus::Approved);
            $this->billingService->holdRetention($invoice);
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return back()->with('success', 'Invoice approved. Retention held.');
    }

    public function reject(FinancialInvoice $invoice)
    {
        try {
            $invoice->transitionTo(InvoiceStatus::Rejected);
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return back()->with('success', 'Invoice rejected.');
    }

    public function send(FinancialInvoice $invoice)
    {
        try {
            $invoice->transitionTo(InvoiceStatus::Sent);
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return back()->with('success', 'Invoice sent to client.');
    }

    public function recordPayment(Request $request, FinancialInvoice $invoice)
    {
        $validated = $request->validate([
            'amount' => 'required|numeric|min:0.01',
        ]);

        try {
            $this->billingService->recordPayment($invoice, $validated['amount']);
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

        return back()->with('success', 'Payment recorded.');
    }

    // --- Retention Ledger ---
    public function retention(Request $request)
    {
        $query = RetentionEntry::with('project:id,name,code', 'invoice:id,invoice_number');

        if ($projectId = $request->project_id) {
            $query->where('project_id', $projectId);
        }

        $entries = $query->latest()->paginate(20)->withQueryString();
        $projects = Project::select('id', 'ulid', 'name', 'code')->get();

        // Compute per-project totals
        $projectTotals = RetentionEntry::selectRaw('project_id, type, SUM(amount) as total')
            ->groupBy('project_id', 'type')
            ->get()
            ->groupBy('project_id')
            ->map(function ($items) {
                $debits = $items->where('type', 'debit')->sum('total');
                $credits = $items->where('type', 'credit')->sum('total');
                return ['held' => (float) $debits, 'released' => (float) $credits, 'balance' => (float) $debits - (float) $credits];
            });

        return Inertia::render('FinancialManagement::Retention/Index', [
            'entries' => $entries,
            'projects' => $projects,
            'projectTotals' => $projectTotals,
            'filters' => $request->only(['project_id']),
        ]);
    }
}