<?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;

use Modules\ApprovalWorkflow\Services\ApprovalService;
use App\Models\User;

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

    // --- Invoice List ---
    public function index(Request $request)
    {
        $query = FinancialInvoice::with([
            'project' => fn ($query) => $query
                ->withoutGlobalScopes()
                ->select('id', 'ulid', 'name', 'code'),
        ]);

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

        $query->whereIn('project_id', $this->availableProjectIdsQuery());

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

        // Compute summary stats
        $allInvoices = FinancialInvoice::whereIn('project_id', $this->availableProjectIdsQuery());
        $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')
                ->whereIn('project_id', $this->availableProjectIdsQuery())->sum('amount')
                - (float) RetentionEntry::where('type', 'credit')
                ->whereIn('project_id', $this->availableProjectIdsQuery())->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::whereIn('projects.id', $this->availableProjectIdsQuery())
            ->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 $invoice)
    {
        abort_unless($this->canAccessProject(auth()->user(), $invoice->project_id), 403);
        $invoice->load(['project:id,name,code', 'lineItems', 'retentionEntries']);

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

    // --- State Transitions ---
    public function submit(Request $request, FinancialInvoice $invoice)
    {
        abort_unless($this->canAccessProject($request->user(), $invoice->project_id), 403);
        try {
            $invoice->transitionTo(InvoiceStatus::Submitted);

            // Fetch Admins and Super Admins as approvers
            $adminIds = User::where('user_type', 'admin')
                ->orWhereHas('roles', function ($q) {
                    $q->whereIn('name', ['Super Admin', 'admin', 'Project Manager', 'Main Contractor Admin']);
                })
                ->pluck('id')
                ->toArray();

            if (!empty($adminIds)) {
                $this->approvalService->createChain(
                    approvable: $invoice,
                    approverIds: $adminIds,
                    type: 'financial_invoice',
                    initiatedBy: $request->user()->id,
                    notes: "Progress Invoice {$invoice->invoice_number} submitted for approval.",
                );
            }
        } catch (\InvalidArgumentException $e) {
            return back()->with('error', $e->getMessage());
        }

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

    public function approve(FinancialInvoice $invoice)
    {
        $user = auth()->user();
        abort_unless($this->canAccessProject($user, $invoice->project_id), 403);
        $isApprover = $user->user_type === 'admin' || 
                       $user->roles()->whereIn('name', ['Super Admin', 'admin'])->exists();

        if (!$isApprover) {
            return back()->with('error', 'Unauthorized. Only Admin or Super Admin can approve client invoices.');
        }

        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)
    {
        $user = auth()->user();
        abort_unless($this->canAccessProject($user, $invoice->project_id), 403);
        $isApprover = $user->user_type === 'admin' || 
                       $user->roles()->whereIn('name', ['Super Admin', 'admin'])->exists();

        if (!$isApprover) {
            return back()->with('error', 'Unauthorized. Only Admin or Super Admin can reject client invoices.');
        }

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

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

    public function send(FinancialInvoice $invoice)
    {
        abort_unless($this->canAccessProject(auth()->user(), $invoice->project_id), 403);
        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 $invoice)
    {
        abort_unless($this->canAccessProject($request->user(), $invoice->project_id), 403);
        $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)
    {
        $query = RetentionEntry::with([
            'project' => fn ($query) => $query
                ->withoutGlobalScopes()
                ->select('id', 'ulid', 'name', 'code'),
            'invoice:id,invoice_number',
        ]);

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

        $query->whereIn('project_id', $this->availableProjectIdsQuery());

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

        // Compute per-project totals
        $projectTotals = RetentionEntry::whereIn('project_id', $this->availableProjectIdsQuery())
            ->selectRaw('project_id, type, SUM(amount) as total')
            ->groupBy('project_id', 'type')
            ->get()
            ->groupBy('project_id')
            ->map(function ($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']),
        ]);
    }

    // Cash Advances
    public function cashAdvances(Request $request)
    {
        $user = $request->user();
        $isApprover = $this->canApproveCashAdvance($user);
        $query = $isApprover
            ? \Modules\FinancialManagement\Models\CashAdvance::withoutGlobalScopes()
            : \Modules\FinancialManagement\Models\CashAdvance::query();

        $query->with(['project:id,name,code', 'requester:id,name,email', 'approver:id,name,email']);
        $query->whereIn('project_id', $this->availableProjectIdsQuery());

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

        $cashAdvances = $query->latest()->paginate(20)->withQueryString();
        $projects = Project::whereIn('projects.id', $this->availableProjectIdsQuery())
            ->select('id', 'ulid', 'name', 'code')->get();

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

    public function storeCashAdvance(Request $request)
    {
        $validated = $request->validate([
            'project_ulid' => 'required|string',
            'amount' => 'required|numeric|min:1',
            'reason' => 'required|string|max:1000',
        ]);

        $project = Project::where('ulid', $validated['project_ulid'])->firstOrFail();

        $cashAdvance = \Modules\FinancialManagement\Models\CashAdvance::create([
            'project_id' => $project->id,
            'amount' => $validated['amount'],
            'reason' => $validated['reason'],
            'status' => 'pending',
            'requested_by' => auth()->id(),
        ]);

        return back()->with('success', 'Cash advance request submitted successfully.');
    }

    public function approveCashAdvance(string $cashAdvance)
    {
        $user = auth()->user();
        $cashAdvance = \Modules\FinancialManagement\Models\CashAdvance::withoutGlobalScopes()
            ->where('ulid', $cashAdvance)
            ->firstOrFail();

        if ($cashAdvance->requested_by === $user->id && $user->user_type !== 'admin' && !$user->hasRole('Super Admin')) {
            return back()->with('error', 'You cannot approve your own cash advance request.');
        }

        $isApprover = $this->canApproveCashAdvance($user);

        if (! $isApprover) {
            return back()->with('error', 'Unauthorized to approve cash advance requests.');
        }

        if (! $this->isPlatformUser($user)
            && ! $this->availableProjectIdsQuery()->where('projects.id', $cashAdvance->project_id)->exists()) {
            return back()->with('error', 'You cannot approve a cash advance for an unrelated project.');
        }

        $cashAdvance->update([
            'status' => 'approved',
            'approved_by' => auth()->id(),
        ]);

        return back()->with('success', 'Cash advance request approved.');
    }

    private function canApproveCashAdvance(User $user): bool
    {
        return $user->user_type === 'admin'
            || $user->hasAnyRole(['Super Admin', 'admin', 'Project Manager', 'Main Contractor Admin']);
    }

    private function availableProjectIdsQuery()
    {
        return Project::query()->select('projects.id');
    }

    private function isPlatformUser(User $user): bool
    {
        return $user->user_type === 'admin' || $user->hasAnyRole(['Super Admin', 'admin']);
    }

    private function canAccessProject(User $user, ?int $projectId): bool
    {
        return $projectId !== null
            && ($this->isPlatformUser($user)
                || $this->availableProjectIdsQuery()->where('projects.id', $projectId)->exists());
    }
}