<?php

use PHPUnit\Framework\TestCase;

/**
 * FileAccessTokenTest — characterization tests for the file-access one-time
 * token lifecycle (Database::generateAccessToken / redeemAccessToken).
 *
 * These pin the CURRENT contract so we can migrate the implementation onto
 * the shared OneTimeToken model without changing behavior (behaviour-
 * preserving refactor). Run before and after the migration; results must
 * stay green.
 */
class FileAccessTokenTest extends TestCase
{
    private Database $db;
    private PDO $pdo;

    protected function setUp(): void
    {
        TestDatabase::resetData();
        $this->db = TestDatabase::getInstance();
        $this->pdo = TestDatabase::getPDO();
    }

    /**
     * Seed a thesis + an approved file-access request, returning
     * [thesisId, requestId].
     */
    private function seedApprovedRequest(): array
    {
        [$authorId, $thesisId] = TestDatabase::seedBasicThesis();
        $requestId = $this->db->createFileAccessRequest($thesisId, 'xamxam@erg.be', null);
        // Approve it (status must be 'approved' for redemption to succeed).
        $this->pdo->prepare(
            "UPDATE file_access_requests SET status = 'approved', approved_at = CURRENT_TIMESTAMP WHERE id = ?"
        )->execute([$requestId]);
        return [$thesisId, $requestId];
    }

    // ── generateAccessToken ──────────────────────────────────────────────────

    public function testGenerateAccessTokenReturns256BitHex(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();

        $token = $this->db->generateAccessToken($requestId, 24);

        $this->assertMatchesRegularExpression('/^[0-9a-f]{64}$/', $token);
    }

    public function testGenerateAccessTokenPersistsRowWithExpectedState(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();

        $token = $this->db->generateAccessToken($requestId, 24);

        $stmt = $this->pdo->prepare(
            "SELECT * FROM one_time_tokens WHERE purpose = 'file_access' ORDER BY id DESC LIMIT 1"
        );
        $stmt->execute();
        $row = $stmt->fetch();

        $this->assertNotFalse($row);
        $this->assertSame(hash('sha256', $token), $row['token_hash'], 'Only the hash is stored, never the plaintext');
        $this->assertNotSame($token, $row['token_hash']);
        $this->assertSame(['request_id' => $requestId], json_decode($row['context'], true));
        $this->assertSame(1, (int) $row['is_valid']);
        $this->assertNull($row['used_at']);
        $this->assertNotNull($row['expires_at']);
    }

    // ── redeemAccessToken ────────────────────────────────────────────────────

    public function testRedeemValidTokenReturnsThesisAndRequestIds(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        $token = $this->db->generateAccessToken($requestId, 24);

        $result = $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');

        $this->assertNotNull($result);
        $this->assertSame($thesisId, $result['thesis_id']);
        $this->assertSame($requestId, $result['request_id']);
    }

    public function testRedeemMarksTokenUsed(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        $token = $this->db->generateAccessToken($requestId, 24);

        $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');

        $stmt = $this->pdo->prepare(
            "SELECT used_at, is_valid FROM one_time_tokens WHERE purpose = 'file_access'"
        );
        $stmt->execute();
        $row = $stmt->fetch();

        $this->assertNotNull($row['used_at']);
        $this->assertSame(0, (int) $row['is_valid']);
    }

    public function testRedeemIsOneTimeUse(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        $token = $this->db->generateAccessToken($requestId, 24);

        $first = $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');
        $second = $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');

        $this->assertNotNull($first);
        $this->assertNull($second);
    }

    public function testRedeemUnknownTokenReturnsNull(): void
    {
        $result = $this->db->redeemAccessToken(str_repeat('ab', 32), '1.2.3.4', 'ua');
        $this->assertNull($result);
    }

    public function testRedeemExpiredTokenReturnsNull(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        // Negative hours → already expired
        $token = $this->db->generateAccessToken($requestId, -1);

        $result = $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');
        $this->assertNull($result);
    }

    public function testRedeemLogsAuditOnSuccess(): void
    {
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        $token = $this->db->generateAccessToken($requestId, 24);

        $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');

        $stmt = $this->pdo->prepare(
            "SELECT COUNT(*) FROM file_access_audit WHERE request_id = ? AND event = 'redeemed'"
        );
        $stmt->execute([$requestId]);
        $this->assertSame(1, (int) $stmt->fetchColumn());
    }

    public function testRedeemDoesNotRequireThesisIdArgument(): void
    {
        // The thesis is resolved from the request JOIN, not passed in.
        [$thesisId, $requestId] = $this->seedApprovedRequest();
        $token = $this->db->generateAccessToken($requestId, 24);

        // Approving a different request must not affect this one's scoping —
        // the returned thesis_id is derived from file_access_requests.
        $result = $this->db->redeemAccessToken($token, '1.2.3.4', 'ua');
        $this->assertSame($thesisId, $result['thesis_id']);
    }
}