<?php
/**
 * Preservation Property Tests - Teacher List Non-Delete Interactions
 *
 * **Validates: Requirements 3.1, 3.2, 3.3, 3.4, 3.5**
 *
 * PURPOSE: Verify that all non-delete interactions in portal/teacher_list.php
 * work correctly on UNFIXED code and continue to work after the fix is applied.
 * This ensures the fix does not introduce regressions.
 *
 * METHODOLOGY: Observation-first approach
 * 1. Run tests on UNFIXED code to observe baseline behavior
 * 2. Document observed behavior patterns
 * 3. After fix is applied, re-run tests to verify behavior is preserved
 *
 * EXPECTED OUTCOME: All tests PASS on unfixed code (confirms baseline behavior).
 * After fix, all tests should still PASS (confirms no regressions).
 *
 * Run via CLI: php portal/tests/test_teacher_deletion_preservation.php
 */

// ── Bootstrap ────────────────────────────────────────────────────────────────
$root = dirname(__DIR__); // portal/
require_once $root . '/includes/dbconnection.php';

// $con is the MySQLi connection provided by dbconnection.php
if (!isset($con) || mysqli_connect_errno()) {
    echo "FATAL: Could not connect to database.\n";
    exit(1);
}

// ── Helpers ──────────────────────────────────────────────────────────────────
$pass = 0;
$fail = 0;
$counterexamples = [];

function assert_test(string $label, bool $condition, string $counterexample = ''): void
{
    global $pass, $fail, $counterexamples;
    if ($condition) {
        echo "[PASS] $label\n";
        $pass++;
    } else {
        echo "[FAIL] $label\n";
        if ($counterexample !== '') {
            echo "       Counterexample: $counterexample\n";
        }
        $fail++;
        $counterexamples[] = $counterexample ?: $label;
    }
}

// ── Setup: Create test teachers ──────────────────────────────────────────────
echo "\n=== Preservation Property Tests - Teacher List ===\n\n";

$testTeachers = [];
for ($i = 1; $i <= 3; $i++) {
    $testUsername = 'test_preserve_' . time() . '_' . $i;
    $testEmail = $testUsername . '@test.com';
    $testName = 'Preserve' . $i;
    $testLastname = 'Teacher';
    $testMobile = '123456789' . $i;
    $testPassword = password_hash('testpass123', PASSWORD_DEFAULT);

    $insertTeacher = $con->prepare(
        "INSERT INTO tblusers (name, lastname, username, email, mobile, password, status, permission, userimage, sex)
         VALUES (?, ?, ?, ?, ?, ?, 2, 'teacher', 'default.jpg', 'Male')"
    );
    if (!$insertTeacher) {
        echo "FATAL: Could not prepare teacher insert: " . $con->error . "\n";
        exit(1);
    }
    $insertTeacher->bind_param('ssssss', $testName, $testLastname, $testUsername, $testEmail, $testMobile, $testPassword);
    $insertTeacher->execute();
    $teacherId = $con->insert_id;
    $insertTeacher->close();

    if (!$teacherId) {
        echo "FATAL: Failed to insert test teacher $i.\n";
        exit(1);
    }

    $testTeachers[] = [
        'id' => $teacherId,
        'username' => $testUsername,
        'name' => $testName,
        'lastname' => $testLastname,
        'email' => $testEmail,
        'mobile' => $testMobile
    ];

    echo "Test teacher $i created: ID=$teacherId, username='$testUsername'\n";
}

echo "\n";

// ── Property 1: Teacher List Display (Requirement 3.3, 3.4) ──────────────────
echo "--- Property 1: Teacher List Display ---\n";
echo "Validates: Requirements 3.3 (status = 2 filter), 3.4 (display fields)\n\n";

// Test that teacher list query returns only active teachers (status = 2)
$query = mysqli_query($con, "SELECT * FROM tblusers WHERE status = 2");
$activeTeachers = [];
while ($row = mysqli_fetch_array($query)) {
    $activeTeachers[] = $row;
}

assert_test(
    "Teacher list query returns only active teachers (status = 2)",
    count($activeTeachers) >= 3,
    "Expected at least 3 active teachers (our test teachers), found " . count($activeTeachers)
);

// Verify our test teachers are in the active list
foreach ($testTeachers as $teacher) {
    $found = false;
    foreach ($activeTeachers as $activeTeacher) {
        if ($activeTeacher['id'] == $teacher['id']) {
            $found = true;
            break;
        }
    }
    assert_test(
        "Test teacher ID {$teacher['id']} appears in active list",
        $found,
        "Teacher ID {$teacher['id']} with status=2 not found in active list query"
    );
}

// Test that soft-deleted teachers (status = 0) do NOT appear in active list
$softDeletedQuery = mysqli_query($con, "SELECT id FROM tblusers WHERE status = 0");
$softDeletedIds = [];
while ($row = mysqli_fetch_array($softDeletedQuery)) {
    $softDeletedIds[] = $row['id'];
}

if (count($softDeletedIds) > 0) {
    $foundInActive = false;
    foreach ($softDeletedIds as $deletedId) {
        foreach ($activeTeachers as $activeTeacher) {
            if ($activeTeacher['id'] == $deletedId) {
                $foundInActive = true;
                break 2;
            }
        }
    }
    assert_test(
        "Soft-deleted teachers (status = 0) do NOT appear in active list",
        !$foundInActive,
        "Found soft-deleted teacher in active list query (status = 2 filter not working)"
    );
} else {
    echo "[INFO] No soft-deleted teachers in database to test exclusion\n";
}

// ── Property 2: Teacher Display Fields (Requirement 3.4) ─────────────────────
echo "\n--- Property 2: Teacher Display Fields ---\n";
echo "Validates: Requirement 3.4 (image, firstname, lastname, username, email, contact)\n\n";

// Verify that each active teacher has the required display fields
foreach ($testTeachers as $teacher) {
    $checkFields = $con->prepare(
        "SELECT id, name, lastname, username, email, mobile, userimage FROM tblusers WHERE id = ?"
    );
    $checkFields->bind_param('i', $teacher['id']);
    $checkFields->execute();
    $result = $checkFields->get_result();
    $row = $result ? $result->fetch_assoc() : null;
    $checkFields->close();

    if ($row) {
        $hasAllFields = !empty($row['name']) && !empty($row['lastname']) &&
                       !empty($row['username']) && !empty($row['email']) &&
                       !empty($row['mobile']) && !empty($row['userimage']);

        assert_test(
            "Teacher ID {$teacher['id']} has all required display fields",
            $hasAllFields,
            "Teacher ID {$teacher['id']} missing required fields: " .
            "name=" . ($row['name'] ?? 'NULL') . ", " .
            "lastname=" . ($row['lastname'] ?? 'NULL') . ", " .
            "username=" . ($row['username'] ?? 'NULL') . ", " .
            "email=" . ($row['email'] ?? 'NULL') . ", " .
            "mobile=" . ($row['mobile'] ?? 'NULL') . ", " .
            "userimage=" . ($row['userimage'] ?? 'NULL')
        );
    } else {
        assert_test(
            "Teacher ID {$teacher['id']} has all required display fields",
            false,
            "Teacher ID {$teacher['id']} not found in database"
        );
    }
}

// ── Property 3: HTML Structure Preservation ──────────────────────────────────
echo "\n--- Property 3: HTML Structure Preservation ---\n";
echo "Validates: Requirements 3.1, 3.2, 3.5 (UI elements present)\n\n";

$teacherListContent = file_get_contents($root . '/teacher_list.php');

// Check for edit button structure
$hasEditButton = strpos($teacherListContent, 'class="btn btn-primary btn-xs edit_data"') !== false ||
                 strpos($teacherListContent, 'btn-primary btn-xs edit_data') !== false;

assert_test(
    "Edit button HTML structure present in teacher_list.php",
    $hasEditButton,
    "Edit button with class 'edit_data' not found in teacher_list.php"
);

// Check for delete button structure (should exist regardless of bug)
$hasDeleteButton = strpos($teacherListContent, 'btn btn-danger btn-xs') !== false ||
                   strpos($teacherListContent, 'fa fa-trash') !== false;

assert_test(
    "Delete button HTML structure present in teacher_list.php",
    $hasDeleteButton,
    "Delete button with trash icon not found in teacher_list.php"
);

// Check for Restore Teacher button
$hasRestoreButton = strpos($teacherListContent, 'restore_teacher.php') !== false;

assert_test(
    "Restore Teacher button link present (Requirement 3.5)",
    $hasRestoreButton,
    "Restore Teacher button link to restore_teacher.php not found"
);

// Check for DataTables initialization (table controls)
$hasDataTable = strpos($teacherListContent, 'id="example1"') !== false;

assert_test(
    "DataTables table structure present (for sorting, searching, pagination)",
    $hasDataTable,
    "DataTables table with id='example1' not found"
);

// Check for edit modal structure
$hasEditModal = strpos($teacherListContent, 'id="editData"') !== false &&
                strpos($teacherListContent, 'class="modal fade"') !== false;

assert_test(
    "Edit modal structure present (Requirement 3.2)",
    $hasEditModal,
    "Edit modal with id='editData' not found in teacher_list.php"
);

// Check for AJAX edit functionality
$hasAjaxEdit = strpos($teacherListContent, "url: \"edit_teacher.php\"") !== false ||
               strpos($teacherListContent, 'url: "edit_teacher.php"') !== false;

assert_test(
    "AJAX edit functionality present (loads teacher details)",
    $hasAjaxEdit,
    "AJAX call to edit_teacher.php not found in teacher_list.php"
);

// ── Property 4: Cancel Behavior Structure (Requirement 3.1) ──────────────────
echo "\n--- Property 4: Cancel Behavior Structure ---\n";
echo "Validates: Requirement 3.1 (Cancel prevents navigation)\n\n";

// Check that delete button has confirmation mechanism
// On unfixed code: inline onClick with confirm()
// On fixed code: event listener with confirm()
$hasConfirmation = strpos($teacherListContent, "confirm('Are you sure you want to delete?')") !== false ||
                   strpos($teacherListContent, 'confirm("Are you sure you want to delete?")') !== false ||
                   strpos($teacherListContent, 'confirm(\'Are you sure you want to delete?\')') !== false;

assert_test(
    "Delete confirmation dialog present (enables Cancel behavior)",
    $hasConfirmation,
    "Confirmation dialog 'Are you sure you want to delete?' not found in teacher_list.php"
);

// Note: We cannot test actual Cancel behavior without browser interaction,
// but we can verify the structure that enables it exists

echo "[INFO] Cancel behavior structure verified. Actual Cancel interaction requires browser testing.\n";
echo "[INFO] Expected behavior: Clicking Cancel in confirmation dialog prevents navigation.\n";

// ── Property 5: Table Controls Structure ─────────────────────────────────────
echo "\n--- Property 5: Table Controls Structure ---\n";
echo "Validates: Requirement 3.3 (table controls work correctly)\n\n";

// Check for DataTables script inclusion (enables sorting, searching, pagination)
$headContent = file_get_contents($root . '/includes/head.php');
$footContent = file_get_contents($root . '/includes/foot.php');

$hasDataTablesJS = strpos($headContent, 'datatables') !== false ||
                   strpos($footContent, 'datatables') !== false ||
                   strpos($teacherListContent, 'datatables') !== false;

assert_test(
    "DataTables JavaScript library included (enables table controls)",
    $hasDataTablesJS,
    "DataTables library not found in includes or teacher_list.php"
);

// Check for table headers (required for sorting)
$hasTableHeaders = strpos($teacherListContent, '<thead>') !== false &&
                   strpos($teacherListContent, '</thead>') !== false;

assert_test(
    "Table headers present (enables sorting)",
    $hasTableHeaders,
    "Table <thead> structure not found in teacher_list.php"
);

// Check for table body (required for data display)
$hasTableBody = strpos($teacherListContent, '<tbody>') !== false &&
                strpos($teacherListContent, '</tbody>') !== false;

assert_test(
    "Table body present (displays teacher data)",
    $hasTableBody,
    "Table <tbody> structure not found in teacher_list.php"
);

echo "[INFO] Table controls structure verified. Actual sorting/searching/pagination requires browser testing.\n";

// ── Property 6: Restore Teacher Navigation (Requirement 3.5) ─────────────────
echo "\n--- Property 6: Restore Teacher Navigation ---\n";
echo "Validates: Requirement 3.5 (Restore Teacher button works)\n\n";

// Check that restore_teacher.php file exists
$restoreTeacherExists = file_exists($root . '/restore_teacher.php');

assert_test(
    "restore_teacher.php file exists (navigation target)",
    $restoreTeacherExists,
    "restore_teacher.php file not found in portal directory"
);

// Check for Restore Teacher button in card-tools section
$hasRestoreButtonInTools = strpos($teacherListContent, '<div class="card-tools">') !== false &&
                           strpos($teacherListContent, 'restore_teacher.php') !== false;

assert_test(
    "Restore Teacher button in card-tools section",
    $hasRestoreButtonInTools,
    "Restore Teacher button not found in card-tools section of teacher_list.php"
);

echo "[INFO] Restore Teacher navigation structure verified. Actual navigation requires browser testing.\n";

// ── Property 7: Non-Delete Interactions Preserve Data ────────────────────────
echo "\n--- Property 7: Non-Delete Interactions Preserve Data ---\n";
echo "Validates: Requirement 3.2 (non-delete interactions don't modify data)\n\n";

// Verify that simply loading the page doesn't modify teacher data
$beforeLoad = [];
foreach ($testTeachers as $teacher) {
    $check = $con->prepare("SELECT id, name, lastname, status FROM tblusers WHERE id = ?");
    $check->bind_param('i', $teacher['id']);
    $check->execute();
    $result = $check->get_result();
    $beforeLoad[$teacher['id']] = $result ? $result->fetch_assoc() : null;
    $check->close();
}

// Simulate page load by reading the file (no actual HTTP request)
$pageContent = file_get_contents($root . '/teacher_list.php');

// Verify data unchanged after "page load"
foreach ($testTeachers as $teacher) {
    $check = $con->prepare("SELECT id, name, lastname, status FROM tblusers WHERE id = ?");
    $check->bind_param('i', $teacher['id']);
    $check->execute();
    $result = $check->get_result();
    $afterLoad = $result ? $result->fetch_assoc() : null;
    $check->close();

    $unchanged = $beforeLoad[$teacher['id']] && $afterLoad &&
                 $beforeLoad[$teacher['id']]['name'] === $afterLoad['name'] &&
                 $beforeLoad[$teacher['id']]['lastname'] === $afterLoad['lastname'] &&
                 $beforeLoad[$teacher['id']]['status'] === $afterLoad['status'];

    assert_test(
        "Teacher ID {$teacher['id']} data unchanged by page load",
        $unchanged,
        "Teacher ID {$teacher['id']} data modified by non-delete interaction"
    );
}

// ── Property 8: Edit Modal AJAX Target Exists ────────────────────────────────
echo "\n--- Property 8: Edit Modal AJAX Target ---\n";
echo "Validates: Requirement 3.2 (edit button opens modal with AJAX-loaded details)\n\n";

$editTeacherExists = file_exists($root . '/edit_teacher.php');

assert_test(
    "edit_teacher.php file exists (AJAX target for edit modal)",
    $editTeacherExists,
    "edit_teacher.php file not found in portal directory"
);

echo "[INFO] Edit modal AJAX target verified. Actual AJAX loading requires browser testing.\n";

// ── Cleanup ───────────────────────────────────────────────────────────────────
echo "\n--- Cleanup ---\n";
foreach ($testTeachers as $teacher) {
    $con->query("DELETE FROM tblusers WHERE id = {$teacher['id']}");
}
echo "Test data cleaned up.\n";

// ── Summary ───────────────────────────────────────────────────────────────────
echo "\n=== Results: $pass passed, $fail failed ===\n";

if ($fail > 0) {
    echo "\n✗ PRESERVATION TESTS FAILED!\n\n";
    echo "Failure(s):\n";
    foreach ($counterexamples as $i => $ce) {
        echo "  " . ($i + 1) . ". $ce\n";
    }
    echo "\nThis indicates:\n";
    echo "  - Baseline behavior is broken or missing\n";
    echo "  - Database structure may be incomplete\n";
    echo "  - HTML structure has been modified unexpectedly\n\n";
    echo "These tests should PASS on unfixed code to establish baseline behavior.\n";
    echo "If they fail on unfixed code, the baseline behavior needs investigation.\n\n";
    exit(1);
} else {
    echo "\n✓ ALL PRESERVATION TESTS PASSED!\n\n";
    echo "Baseline behavior confirmed:\n";
    echo "  ✓ Teacher list displays only active teachers (status = 2)\n";
    echo "  ✓ All required display fields present (image, name, email, etc.)\n";
    echo "  ✓ Edit button and modal structure present\n";
    echo "  ✓ Delete button with confirmation dialog present\n";
    echo "  ✓ Restore Teacher button and navigation present\n";
    echo "  ✓ DataTables structure present (sorting, searching, pagination)\n";
    echo "  ✓ Non-delete interactions preserve teacher data\n";
    echo "  ✓ AJAX targets for edit functionality exist\n\n";
    echo "These behaviors must be preserved after the fix is applied.\n";
    echo "Re-run this test after implementing the fix to verify no regressions.\n\n";
    exit(0);
}
