<?php
// 后台：管理员 / 客服账户管理（增删改角色 + 终极管理员保护）
require __DIR__ . '/../includes/init.php';
requireStaff();
require '_common.php';
$isAdmin = isAdminStaff();
$me = currentStaff();
$db  = db();
$msg = '';
$err = '';

// 客服只读
if (!$isAdmin && $_SERVER['REQUEST_METHOD'] === 'POST') {
    $err = '客服账号仅可查看，如需操作请联系管理员。';
}

// ─── 编辑角色（admin ↔ cs）────
if (isset($_POST['edit_role']) && $isAdmin) {
    verifyCsrf();
    $id   = (int) ($_POST['edit_role'] ?? 0);
    $role = trim($_POST['new_role'] ?? '');
    $role = in_array($role, ['admin', 'cs'], true) ? $role : '';

    if ($id <= 0 || $role === '') {
        $err = '参数不合法。';
    } elseif ($id === (int) $me['id']) {
        $err = '不能修改当前登录账号的角色。';
    } elseif ($id === 1) {
        $err = '不能修改终极管理员（ID=1）的角色。';
    } else {
        $row = $db->prepare('SELECT id, role, is_admin FROM ' . tn('users') . ' WHERE id = ? AND role IN (\'admin\',\'cs\')')->execute([$id])->fetch();
        if (!$row) {
            $err = '账号不存在。';
        } else {
            $newIsAdmin = ($role === 'admin') ? 1 : 0;
            $db->prepare('UPDATE ' . tn('users') . ' SET role = ?, is_admin = ? WHERE id = ?')
               ->execute([$role, $newIsAdmin, $id]);
            $msg = '已将账号 #' . $id . ' 角色改为「' . ($role === 'admin' ? '管理员' : '客服') . '」。';
        }
    }
}

// ─── 删除 ──
if (isset($_POST['delete']) && $isAdmin) {
    verifyCsrf();
    $id = (int) ($_POST['delete'] ?? 0);
    if ($id === (int) $me['id']) {
        $err = '不能删除当前登录的账号。';
    } elseif ($id === 1) {
        $err = '不能删除终极管理员（ID=1），该账号受系统保护。';
    } else {
        $row = $db->prepare('SELECT id, role, is_admin FROM ' . tn('users') . ' WHERE id = ? AND role IN (\'admin\',\'cs\')')->execute([$id])->fetch();
        if (!$row) {
            $err = '账号不存在。';
        } elseif ((int) $row['is_admin'] === 1) {
            // 管理员：确保至少保留一名管理员（含终极管理员）
            $cnt = $db->query('SELECT COUNT(*) FROM ' . tn('users') . ' WHERE role = \'admin\' AND status = 1')->fetchColumn();
            if ((int) $cnt <= 1) {
                $err = '至少要保留一名管理员，不能继续删除。';
            } else {
                $db->prepare('DELETE FROM ' . tn('users') . ' WHERE id = ?')->execute([$id]);
                $msg = '管理员已删除。';
            }
        } else {
            $db->prepare('DELETE FROM ' . tn('users') . ' WHERE id = ?')->execute([$id]);
            $msg = '客服已删除。';
        }
    }
}

// ─── 添加 ──
if (isset($_POST['add']) && $isAdmin) {
    verifyCsrf();
    $u  = trim($_POST['username'] ?? '');
    $em = trim($_POST['email'] ?? '');
    $pw = $_POST['password'] ?? '';
    $role = trim($_POST['role'] ?? 'admin');
    $role = in_array($role, ['admin', 'cs'], true) ? $role : 'admin';
    if (strlen($u) < 3)              $err = '账号至少 3 个字符。';
    elseif (!filter_var($em, FILTER_VALIDATE_EMAIL)) $err = '请填写有效的邮箱。';
    elseif (strlen($pw) < 6)        $err = '密码至少 6 位。';
    else {
        $chk = $db->prepare('SELECT id FROM ' . tn('users') . ' WHERE username = ?');
        $chk->execute([$u]);
        if ($chk->fetch()) {
            $err = '该用户名已存在。';
        } else {
            $hash = password_hash($pw, PASSWORD_DEFAULT);
            $code = genInviteCode();
            $isAdminFlag = $role === 'admin' ? 1 : 0;
            $db->prepare('INSERT INTO ' . tn('users') . ' (username,password,email,invite_code,is_admin,role,created_at) VALUES (?,?,?,?,?,?,NOW())')
               ->execute([$u, $hash, $em, $code, $isAdminFlag, $role]);
            $msg = ($role === 'admin' ? '管理员' : '客服') . '已添加。';
        }
    }
}

$list = $db->query('SELECT id, username, email, status, role, created_at FROM ' . tn('users') . ' WHERE role IN (\'admin\',\'cs\') ORDER BY role DESC, id ASC')->fetchAll();

adminHeader('管理员', 'admins');
?>
<h1 class="page-title"><i class="fas fa-user-shield"></i> 管理员与客服</h1>

<?php if ($msg): ?><p class="banner-ok"><i class="fas fa-check-circle"></i> <?= h($msg) ?></p><?php endif; ?>
<?php if ($err): ?><p class="form-err"><?= h($err) ?></p><?php endif; ?>

<div class="panel">
    <h3>添加账号（管理员 / 客服）</h3>
    <?php if ($isAdmin): ?>
    <p class="muted">管理员拥有全部后台权限；客服可查看所有页面但仅能处理工单相关操作。</p>
    <form method="post" action="" class="grid-form" style="max-width:680px;">
        <?= csrfField() ?>
        <label>账号 *<input type="text" name="username" placeholder="至少 3 个字符" required></label>
        <label>邮箱 *<input type="email" name="email" required></label>
        <label>角色
            <select name="role">
                <option value="admin">管理员（全部权限）</option>
                <option value="cs">客服（查看 + 工单操作）</option>
            </select>
        </label>
        <label class="span2">密码 *<input type="password" name="password" placeholder="至少 6 位密码" required></label>
        <div class="form-actions span2"><button type="submit" name="add" class="btn btn-primary"><i class="fas fa-user-plus"></i> 添加账号</button></div>
    </form>
    <?php else: ?>
        <p class="muted">客服账号无法添加新管理员，如需操作请联系管理员。</p>
    <?php endif; ?>
</div>

<div class="panel">
    <h3>账号列表（共 <?= count($list) ?> 名）</h3>
    <?php if (empty($list)): ?>
        <p class="empty">暂无账号。</p>
    <?php else: ?>
        <table class="data-table">
            <thead><tr><th>ID</th><th>账号</th><th>邮箱</th><th>角色</th><th>状态</th><th>注册时间</th><th>操作</th></tr></thead>
            <tbody>
            <?php foreach ($list as $a): ?>
                <?php
                    $isMe   = (int)$a['id'] === (int)$me['id'];
                    $isSuper = (int)$a['id'] === 1;
                    $isAdm  = ($a['role'] === 'admin');
                ?>
                <tr <?= $isSuper ? 'style="background:color-mix(in srgb,var(--primary) 6%,transparent)"' : '' ?>>
                    <td><?= (int) $a['id'] ?><?= $isSuper ? ' <sup style="color:var(--primary);font-size:.72rem">超级</sup>' : '' ?></td>
                    <td><?= h($a['username']) ?><?= $isMe ? ' <span class="badge-on">我</span>' : '' ?></td>
                    <td><?= h($a['email']) ?></td>
                    <td>
                        <?php if ($isAdmin && !$isMe && !$isSuper): ?>
                            <form method="post" action="" style="display:inline" onsubmit="return confirmRoleChange(<?= (int) $a['id'] ?>, '<?= h($a['username']) ?>');">
                                <?= csrfField() ?>
                                <input type="hidden" name="edit_role" value="<?= (int) $a['id'] ?>">
                                <select name="new_role" onchange="this.form.submit()" style="padding:2px 6px;border:1px solid var(--outline);border-radius:6px;font-size:.82rem;cursor:pointer;background:transparent;color:inherit">
                                    <option value="admin" <?php if ($isAdm): ?>selected<?php endif; ?>>管理员</option>
                                    <option value="cs" <?php if (!$isAdm): ?>selected<?php endif; ?>>客服</option>
                                </select>
                            </form>
                        <?php else: ?>
                            <?php if ($isAdm): ?>
                                <span class="badge-on">管理员</span>
                            <?php else: ?>
                                <span class="badge-on" style="background:var(--primary-container);color:var(--on-primary-container)">客服</span>
                            <?php endif; ?>
                            <?php if ($isSuper): ?><span class="muted" style="font-size:.75rem;margin-left:4px">(受保护)</span><?php endif; ?>
                        <?php endif; ?>
                    </td>
                    <td><?= (int) $a['status'] === 1 ? '<span class="badge-on">正常</span>' : '<span class="badge-off">封禁</span>' ?></td>
                    <td><?= date('Y-m-d', strtotime($a['created_at'])) ?></td>
                    <td class="row-actions">
                        <?php if ($isMe): ?>
                            <span class="muted">当前账号</span>
                        <?php elseif ($isAdmin): ?>
                            <?php if ($isSuper): ?>
                                <span class="muted" title="终极管理员受系统保护，不可删除"><i class="fas fa-shield-halved" style="color:var(--primary)"></i> 受保护</span>
                            <?php else: ?>
                                <form method="post" action="" style="display:inline" onsubmit="return confirm('确定删除该账号？此操作不可恢复。');">
                                    <?= csrfField() ?>
                                    <button type="submit" name="delete" value="<?= (int) $a['id'] ?>" class="mini-btn danger"><i class="fas fa-trash"></i></button>
                                </form>
                            <?php endif; ?>
                        <?php else: ?>
                            <span class="muted">—</span>
                        <?php endif; ?>
                    </td>
                </tr>
            <?php endforeach; ?>
            </tbody>
        </table>
        <?php if ($isAdmin): ?>
        <p class="muted" style="margin-top:10px;font-size:.82rem">
            <i class="fas fa-info-circle"></i> 终极管理员（ID=1）受系统保护，不可被删除或降级。其他管理员可由同级管理员删除或改为客服。
        </p>
        <?php endif; ?>
    <?php endif; ?>
</div>
<script>
function confirmRoleChange(id, name) {
    var sel = event.target.form.elements.new_role;
    var roleLabel = sel.options[sel.selectedIndex].text;
    return confirm('确定将 ' + name + ' 的角色改为「' + roleLabel + '」？');
}
</script>
<?php adminFooter(); ?>