<?php

namespace App\Services;

use App\Models\User;
use App\Models\WalletTransfer;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Hash;

class WalletService
{
    /**
     * Verify and handle Vault PIN
     */
    public function verifyVaultPin(User $user, string $pin): ?\Illuminate\Http\JsonResponse
    {
        // Locked?
        if (!empty($user->vault_pin_locked_until) && now()->lessThan($user->vault_pin_locked_until)) {
            return response()->json([
                'message' => 'Vault PIN locked. Try again later.',
                'locked_until' => optional($user->vault_pin_locked_until)->toIso8601String(),
            ], 423);
        }
        if (empty($user->vault_pin_hash)) {
            return response()->json(['message' => 'Vault PIN not set'], 400);
        }
        if (!Hash::check($pin, $user->vault_pin_hash)) {
            // increment attempts and maybe lock
            $attempts = (int) ($user->vault_pin_attempts ?? 0) + 1;
            $user->vault_pin_attempts = $attempts;
            if ($attempts >= 5) {
                $user->vault_pin_locked_until = now()->addMinutes(15);
                $user->vault_pin_attempts = 0; // reset after lock
            }
            $user->save();
            return response()->json(['message' => 'Invalid PIN'], 423);
        }
        // success → reset attempts
        if (!empty($user->vault_pin_attempts)) {
            $user->vault_pin_attempts = 0;
            $user->save();
        }
        return null;
    }

    /**
     * Get the vault balance for a given currency.
     */
    public function getVaultBalance(User $user, string $currency): float
    {
        if ($currency === 'BTX') {
            return (float) ($user->vault_balance ?? 0);
        }
        $map = $user->vault_balances ?? [];
        return (float) ($map[$currency] ?? 0);
    }

    /**
     * Get the wallet balance for a given currency.
     */
    public function getWalletBalance(User $user, string $currency): float
    {
        if ($currency === 'BTX') {
            return (float) ($user->balance ?? 0);
        }
        // For other currencies, check wallets relationship or JSON field if present
        $map = $user->vault_balances ?? []; // re-use structure — wallet balance not stored here
        // Non-BTX wallet balances are not tracked in the main user table yet
        return 0.0;
    }

    /**
     * Deposit from main balance to vault.
     */
    public function depositToVault(User $user, string $amountStr, ?string $idempotencyKey = null, string $currency = 'BTX'): array
    {
        $amount = (float) $amountStr;
        if ($amount <= 0) {
            abort(422, 'Amount must be greater than zero');
        }

        if ($idempotencyKey) {
            $existing = WalletTransfer::where('user_id', $user->id)
                ->where('idempotency_key', $idempotencyKey)
                ->first();
            if ($existing) {
                return $this->buildBalanceResponse($user, $currency);
            }
        }

        return DB::transaction(function () use ($user, $amount, $idempotencyKey, $currency) {
            $u = User::where('id', $user->id)->lockForUpdate()->first();

            if ($currency === 'BTX') {
                $balanceBefore = (float) $u->balance;
                $vaultBefore   = (float) $u->vault_balance;

                if ($balanceBefore < $amount) abort(400, 'Insufficient balance');

                $u->balance       = $balanceBefore - $amount;
                $u->vault_balance = $vaultBefore + $amount;
                $u->save();

                WalletTransfer::create([
                    'user_id'          => $u->id,
                    'type'             => 'deposit',
                    'amount'           => $amount,
                    'balance_before'   => $balanceBefore,
                    'balance_after'    => (float) $u->balance,
                    'vault_before'     => $vaultBefore,
                    'vault_after'      => (float) $u->vault_balance,
                    'currency'         => $currency,
                    'idempotency_key'  => $idempotencyKey,
                    'meta'             => null,
                ]);
            } else {
                // Non-BTX: use vault_balances JSON map
                $map          = $u->vault_balances ?? [];
                $vaultBefore  = (float) ($map[$currency] ?? 0);
                // Wallet balance for non-BTX is not in DB yet — block if 0
                abort(400, "Deposits for {$currency} are not yet supported.");
            }

            return $this->buildBalanceResponse($u, $currency);
        });
    }

    /**
     * Withdraw from vault to main balance.
     */
    public function withdrawFromVault(User $user, string $amountStr, ?string $idempotencyKey = null, string $currency = 'BTX'): array
    {
        $amount = (float) $amountStr;
        if ($amount <= 0) {
            abort(422, 'Amount must be greater than zero');
        }

        if (!empty($user->withdraw_cooldown_until) && now()->lessThan($user->withdraw_cooldown_until)) {
            abort(429, 'Withdraw cooldown active. Try again at ' . $user->withdraw_cooldown_until->toIso8601String());
        }

        if ($idempotencyKey) {
            $existing = WalletTransfer::where('user_id', $user->id)
                ->where('idempotency_key', $idempotencyKey)
                ->first();
            if ($existing) {
                return $this->buildBalanceResponse($user, $currency);
            }
        }

        return DB::transaction(function () use ($user, $amount, $idempotencyKey, $currency) {
            $u = User::where('id', $user->id)->lockForUpdate()->first();

            if ($currency === 'BTX') {
                $balanceBefore = (float) $u->balance;
                $vaultBefore   = (float) $u->vault_balance;

                if ($vaultBefore < $amount) abort(400, 'Insufficient vault balance');

                $u->vault_balance             = $vaultBefore - $amount;
                $u->balance                   = $balanceBefore + $amount;
                $u->withdraw_cooldown_until   = now()->addMinutes(30);
                $u->save();

                WalletTransfer::create([
                    'user_id'          => $u->id,
                    'type'             => 'withdraw',
                    'amount'           => $amount,
                    'balance_before'   => $balanceBefore,
                    'balance_after'    => (float) $u->balance,
                    'vault_before'     => $vaultBefore,
                    'vault_after'      => (float) $u->vault_balance,
                    'currency'         => $currency,
                    'idempotency_key'  => $idempotencyKey,
                    'meta'             => null,
                ]);
            } else {
                $map         = $u->vault_balances ?? [];
                $vaultBefore = (float) ($map[$currency] ?? 0);

                if ($vaultBefore < $amount) abort(400, 'Insufficient vault balance');

                $map[$currency]      = number_format($vaultBefore - $amount, 8, '.', '');
                $u->vault_balances   = $map;
                $u->withdraw_cooldown_until = now()->addMinutes(30);
                $u->save();

                WalletTransfer::create([
                    'user_id'          => $u->id,
                    'type'             => 'withdraw',
                    'amount'           => $amount,
                    'balance_before'   => 0,
                    'balance_after'    => 0,
                    'vault_before'     => $vaultBefore,
                    'vault_after'      => (float) $map[$currency],
                    'currency'         => $currency,
                    'idempotency_key'  => $idempotencyKey,
                    'meta'             => null,
                ]);
            }

            return $this->buildBalanceResponse($u, $currency);
        });
    }

    /**
     * Build the balance response for a given currency.
     */
    private function buildBalanceResponse(User $user, string $currency): array
    {
        $map = $user->vault_balances ?? [];
        return [
            'balance'       => $currency === 'BTX' ? (string) $user->balance : '0',
            'vault_balance' => $currency === 'BTX'
                ? (string) $user->vault_balance
                : (string) ($map[$currency] ?? '0'),
            'vault_balances' => array_merge(['BTX' => (string) ($user->vault_balance ?? '0')], $map),
        ];
    }
}